This recent satellite snap shows off a multicolored "mosaic" of tightly packed mini farms covering part of Taiwan in the western Pacific Ocean. The sea of fields and shade nets demonstrates the scale of the agricultural challenges facing the densely populated island.

Taiwan is 14,000 square miles (36,000 square kilometers) — about the same size as Maryland — but has a population around four times as large, with approximately 23 million people living there, according to NASA's Earth Observatory. This places a heavy burden on the island's agricultural industry to provide enough food for everyone on the island, especially as large parts of the landmass are covered by mountains and rainforest.

Researchers estimate that there is only around 3,200 square feet (300 square meters) of Taiwanese farmland per citizen, which is around two-thirds the size of a basketball court, according to the Earth Observatory. This is around 10 times less than the equivalent for U.S. citizens.

The majority of the island's food is produced within Yunlin County, which is situated around halfway along the Chianan Plain, a lengthy strip of flat terrain that hugs Taiwan's west coast. Just under half of the county is visible in the satellite image, which spans roughly 15 miles (24 kilometers) across.

The flat ground in Yunlin County, as well as access to water from the island's largest river, the Zhuoshui (visible across the top of the image), makes it an ideal place to grow a variety of different crops, including "rice, sweet potatoes, peanuts, corn, sugarcane, garlic, scallions, coffee, fruit, and leafy greens," Earth Observatory representatives wrote.

The average size of a farm in Yunlin County is under 100,000 square feet (10,000 square m), which is around 90 times smaller than the average U.S. farm. As a result, the region looks like a giant patchwork of tens of thousands of irregular cuboids when viewed from above.

The sizes of Taiwanese farms are restricted by longstanding legislation that limits the amount of land any individual can own, according to the Earth Observatory. Most of the farms are passed down from generation to generation.

While Yunlin County's agricultural mosaic is fairly consistent across this image, two main areas stand out from the rest (see below).

The first outlying region is a swarm of blue and turquoise rectangles surrounding the town of Xiluo in the upper right of the image (just below the river). These farms are covered with plastic shade nets, which shelter them from harsh sunlight in the summer and monsoon-like rains in the wet season

The second and perhaps most noticeable anomaly is a cluster of much larger, lightly colored farms near the town of Baozhong (bottom left of the photo). These are sugarcane fields, left over from when Japan controlled Taiwan between 1895 and 1945.

A large portion of the Chianan Plain was used to grow sugarcane by the Japanese, who also constructed railway lines to move the crop across the island. However, most of these fields have since been repurposed, and all but one of the railway lines have fallen out of use.

In addition to growing crops, these small farms are used to rear livestock, including chickens, cattle and "millions of pigs," according to the Earth Observatory.

See more Earth from space

Slavery has existed for thousands of years, permeating ancient and modern societies across the world. The Vikings were no different. Enslaved people were valuable commodities, being captured and then traded across the Vikings' vast networks. Legal texts and written sources show how enslaved people were sold at trading centers in the same vein as cattle.

In this excerpt from "The Sea-King and the Sorceress: Life and Death in the Viking Age" (Basic Books, 2026), author and archaeologist Neil Price looks at the horrific lives of the "thralls" — the Viking term for the enslaved. In it, he highlights the inhumane treatment of enslaved people, from the raids to kidnap people into the slave trade to a woman who appears to have been killed as a tribute to a high-status man.

Neil Price interview: 'It gives us a glimpse of a different kind of Viking life': Archaeologist Neil Price on the sea-kings, sorcerers and Sámi who lived during the Viking Age

The vast majority of the Norse population were farmers, but there is another group of people who were almost as numerous, though very hard to find in the archaeological record: the enslaved. They have only recently begun to be properly acknowledged in our histories, partly because of the long-standing neglect of the marginalized and vulnerable in many cultures, but in the Viking world also due to a particular coincidence of terminology. For the Norse, the unfree were þrælar, translated into English as "thralls," which is too mild a word to convey its true meaning.

Today, we can be enthralled by a work of art or even a person, but we do not say that we're enslaved by them. Norse thraldom took many forms, some less severe or permanent than others, but all involved the loss of liberty and rights, and the subjugation of one person to another through servitude. A chapter here, even with tangential references in a few others, is nowhere near enough to do justice to this side of the Norse experience (or rather, often the non-Norse experience, since many of them were kidnapped abroad during raids and other campaigns). Archaeological recognition can at least restore some measure of individual dignity, though more comforting to us than to them.

Slavery, as both a practice and an integrated economic system, was an indivisible part of Viking-Age Norse society and had probably already become established in Scandinavia centuries or even millennia earlier. People could be born into slavery, or be forced into it through kidnap or war, and then find themselves sold on, sometimes through many hands and over great distances. Some free people might even temporarily sell themselves in a form of indenture, as a means of paying off debts or other obligations.

Thralls on Norse settlements were ranked in a hierarchical and quite specific nomenclature of service categories and forced to undertake all the tasks of the farm and household. In a few, rare cases, thralls could take on senior responsibilities of estate management, with a special title — bryti — to match. One such man ran the royal estate at Hovgården opposite the island town of Birka, and was allowed to raise a runestone to himself and his wife, though one wonders who paid for it. Nonetheless, the vast majority of thralls endured lives of drudgery.

The grim reality is summarized with derogatory terminology in the poem Rígsþula, the "List of Rígr" (another name for the god Heimdall, or perhaps for Odin): "They fixed fences, dunged fields, worked at the pigs, watched over the goats, dug the peat." Even their names are shaming, mocking their appearance or hygiene: they translate as Badbreath, Stumpy, Fatty, Bedmate, Craneshanks, Dumpy, and many more. Thralls were extremely vulnerable to sexual exploitation. The textual records of viking raids, coming from every culture that was attacked, emphasize that women were particularly targeted for kidnapping and enslavement.

In the ninth century, as the viking attacks escalated both in Western Europe and on the rivers of the east, the taking of captives came to be one of their prime objectives, feeding the lethal trinity of raiding, trading and slaving. In the words of Ibn Miskawayh, a Persian official who described a viking attack on the city of Bardha'a in what is now Azerbaijan in 943: "They kept the women and boys, whom they raped and enslaved [ . . . ] They dragged the women, boys and girls they wanted with them."

The repetition drives home the point, and little imagination is required to sense the undiluted horror. Some of these raids were informed by advance intelligence gathering and directed against high-profile targets for whom ransom could be demanded, but many were destined for sex trafficking, especially to the Arab world. Enslaved humans, particularly from the Baltic region, were among the main commodities exchanged eastwards along the Silk Roads.

In late ninth-century Scandinavia, the logistical needs of the escalating raids brought new demands on the workforce at an ever-larger scale, especially in all the many industries connected with shipbuilding (including textile production, timber management, tar manufacture, ironworking, and much more). This in turn drove the need for unfree labor to still greater levels.

As economic expansion enlarged the capacity for ship-borne aggression and released the agricultural workforce to crew these expeditions, the increased flow of human victims enabled its continuance in a vicious circle. Enslavement was one of the primary characteristics of the Viking Age: the raids were a key component of it and of the Norse diaspora that resulted.

To what degree these people are visible in the funerary record is hard to know. There were probably no diagnostic items that were used exclusively by thralls, so we cannot perceive them through specific objects in the graves. It also seems unlikely that those without rights and with few possessions, indeed with hardly any legal identity as individuals rather than chattel, would be accorded conventional burials. Ibn Faḍlān says that thralls who died while traveling were simply discarded, but this is unlikely to have been the case in settlements. When we do encounter them, it is often because they were killed as part of funerary rituals and their bodies deposited in burials. One example that we can explore here comes from an excavation at the site of Ballateare, in Jurby parish on the northwestern coast of the Isle of Man — the best preserved of all the Viking-Age graves on the island.

At Ballateare, it is instructive to see just how normal the initial funeral, and its circumstances, appear to have been, albeit for a high-status individual. By Viking-Age standards he was in his prime when he died in the early tenth century, somewhere between eighteen and thirty years old. He may have been among the early Norse settlers on Man. We have no reason to believe that the clothes he was buried in, and the things laid in the grave, are not reflections of his life and the international milieu he came from.

He had been interred in a wooden coffin, dug down quite deep into the ground. A sheathed knife was suspended on a lanyard round his neck and he wore a cloak held by an Irish ringed pin. Inside the coffin was a sword — probably from Norway, but with a belt from the British Isles — that had been cut into pieces before being sheathed in the scabbard; the hilt lay broken off beside it. A spearhead also lay in the coffin by the man's feet, snapped off because there was no room for the shaft. A shield, also deliberately damaged with two heavy blows to the boss, had been slid vertically down the outer side of the coffin; the shield board itself may have been smashed too. This was not battle damage; all his weapons were made unusable for reasons we can only guess. Fragments of the shield also revealed traces of paint: it had been decorated with white gesso, banded with black, with rows of red dots along the stripes. Two more spears had been laid across the top of the coffin.

The burial pit was then filled with fine white sand, and a mound was built on top — about 3 metres [10 feet] high and 22 metres [72 feet] in diameter. It was made of thick-cut turfs, which had been brought to the mound from a wide area rather than simply dug up in the vicinity. The earth of the mound seems to be an offering of the land itself, a territorial tribute to the dead man.

I do not wish to relate what happened next in terms of dramatized reconstruction; archaeological description must suffice. On top of the mound lay the body of a woman aged between twenty and thirty, who had been deliberately killed: the back of her head had been removed by a single blow from a sharp blade, probably a sword. Rigor mortis had set in, and some twelve to seventy-two hours had elapsed between her death and the time when her body was covered. She had either lain exposed on the mound for some time after her death, or been killed elsewhere (perhaps more likely, as the missing part of her skull was not present with the body). The woman seems to have died while kneeling, and had fallen forwards with her hands raised. A post was raised on top of the mound beside her body, presumably a grave marker.

A paragraph is not enough to convey what actually occurred, let alone to extrapolate the life that the woman had led before her death — possibly decades of servitude and enslavement, with all that this implies. Her corpse was covered by a very thick layer of cremated animal bone, including considerable numbers of oxen, horses, sheep and dogs. (Somewhere nearby must have been a truly massive cremation pyre.) The mound was finally sealed with turf, covering her body and the ashes of the animals.

Excerpted from The Sea-King and the Sorceress: Life and Death in the Viking Age by Neil Price. © 2026 by Neil Price. Available from Basic Books, an imprint of Hachette Book Group, Inc.

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In the early medieval period, the Vikings were just one part of a vast tapestry of Scandinavians who ruled, sailed, traded and fought around the world, from North America to Asia. In his new book, "The Sea-King and the Sorceress: Life and Death in the Viking Age" (Basic Books, 2026), author Neil Price, professor and chair of archaeology at Uppsala University in Sweden, reveals the true diversity and complexity of people who lived during the Viking Age (often dating from A.D. 793 to 1066).

Price investigates more than 20 burials from the Viking Age, lingering on details that can tell us about these individuals and their world. He also shines a light on frequently overlooked groups, including the enslaved people known as thralls that the Norse ruled over and even sacrificed in some of their burials. Price also delves into the realms of powerful women, including a "shield-maiden" buried with war-grade weapons in Sweden, a "sorceress" in Denmark, and an elderly matriarch whose children carved out a local empire in Sweden.

In an interview with Live Science, Price talks about his new book, and the evidence we have for the familiar yet foreign lives they lived centuries ago.

Read an excerpt: 'The back of her head had been removed by a single blow from a sharp blade': Archaeological clues are revealing the horrific lives and deaths of the people enslaved by Vikings

Laura Geggel: The Vikings are popularly known for being brutish and bloodthirsty pillagers, but the individuals in your book show the rich diversity of people from this time. Why did you decide to write this book and feature their stories?

Neil Price: I think quite simply because of the cliche that you've just mentioned, the idea that the Vikings are all barbarian raiders who go about burning down churches and frightening the English and things. Those raiders were certainly real, but they were only ever a tiny minority of the Scandinavian population, and I wanted to bring out all the different kinds of Viking lives, and that's why this book really came together.

It's divided into chapters, each one of which looks at a different kind of person, you know, a farmer, or an ambassador, or someone who uses magic, or a hunter. And I'm quite pleased that the Viking — the sort of raiding and pillaging Viking — it takes a while to get to him.

LG: How would you define the epitome of a Viking from that age?

The actual Viking, it comes from an old Norse word from their own language: víkingr. And really it's a job description, it means something like pirate — not necessarily negatively. It just describes maritime robbery with violence. So it is the classic image of the Viking stereotype.

But it was never a name for a people. If we could go back in time and just meet some people in Scandinavia and say, "Did you know that you're all Vikings?" — they'd be astonished.

It's a name, a collective name that we've given them. It started in the 19th century, really. So, they wouldn't have called themselves that.

LG: Your book starts with the sea-king, a commander and his crew who were buried in boats with swords and shields in Estonia. Usually, the Viking Age is said to have begun in 793 with the raid on the island of Lindisfarne in the U.K., but you say this burial suggests that the Viking Age started earlier and in another part of Europe. Can you tell us more about this?

NP: When I started studying Vikings at college — so this is back in the early 1980s, a long, long time ago — the Viking Age did start not just in 793; It started on the eighth of June 793 with the Lindisfarne raid.

Obviously it's absurd that an entire period of time starts on an afternoon, you know, not the day before or the day after. So it's obvious that we're talking about something that is really a matter of social processes, things that go on over a long period of time. But the thing that makes the finds that are in the sea-king chapter — they're from this place called Salme in Estonia — really interesting is that they seem to be the remains of, or the traces of a raid.

It's decades before Lindisfarne, it's about 750. And obviously on an island on the Estonian coast, it's going east, not west. So it really pushes that [raiding] behavior a lot earlier and it reorientates it. Even then, we shouldn't see the Vikings in that find as being the first Vikings. Actually the Scandinavians had been raiding all over the place for generations.

LG: I really enjoyed your focus on women, since stereotypically the Viking Age is associated with burly male warriors. What are some roles that women held in the Viking Age that you don't think most people know about?

NP: Something that particularly interests me, which is something I've worked on for a very long time now, is that when we think about Norse religion, everyone thinks about the gods. You know, they're still around in Marvel movies and things — we think of Thor and Odin and Freya and so on.

But actually, the [thing that was] far more present than the gods in people's lives were lots of kinds of local spirits and creatures and the elves that live in the stone behind your house. Getting in contact with that world of supernatural creatures and forces and powers — or whatever we call them — was something that was very much in the domain of women.

And it's a really important thing. So we shouldn't just say, "Oh, and some of them did magic." They're like negotiators, because you want to get on well with all these little creatures. If you don't, they could mess up your life, you know — your cattle could die, your crops could fail, that kind of thing. You could get sick.

So the practice of, it's hard to know what to call it in English. Sorcery or magic — they're not very good words, but there's lots of Norse words for it. To be able to do that is a very powerful thing and it's a very prominent role in society. And this was very much in the domain of women.

I think actually women could take on many of the roles that we conventionally assign to men. In terms of capability, of course they could. There are some, rather few I think, but there are some female Vikings, like actual Vikings, there are women conducting trade, owning property, investing in business ventures, things like that. So they have a very prominent role in Norse society.

We talked about Lindisfarne just now. When I started studying the Vikings, Viking women were one display case in the museum exhibition, next to the display case on pottery or something. Not half the population, and that has really changed. I think we look at Viking Age people now, not just assuming they're male by default.

LG: Actually, to linger, you described a number of women and their professions. Could you tell me more about these two amazing women in your book from Birka: the merchant and the warrior?

NP: Birka is this huge town. It's Sweden's first urban center, and it's absolutely surrounded by burial mounds. So you have the area of the town and then all the people who lived in it. You can wander through their cemetery, which is a pretty spectacular place — there's 5,000 burial mounds.

The merchant woman that you mentioned, she's one of the earlier graves [circa 840s], so she's one of the first people who would have identified as being someone who lives in a town. Today we talk about "I'm a city person" or a "country person," and that's an identity that was only just beginning to be created in the Viking Age, because everybody was country people. With the first towns, people start to live in a different way, and this woman was one of them.

If we look in her grave, she has things that have come from all over the western Viking world, things that I think probably came as loot from the raids, so she knew somebody who was involved in those things.

But you look at the stuff that's there, it seems pretty likely that she is a merchant in her own right, perhaps someone dealing in textiles. This idea of a businesswoman setting up a shop in Birka and maybe importing textiles or making them, having them made, because she's probably not working the loom, you know. It gives us a glimpse of a different kind of Viking life, one that I don't think we're accustomed to seeing and we should.

And then the warrior is about 100 years later than the merchant woman, when Birka has grown; it's quite a big settlement by then that's a really powerful place.

It's become quite militarized, so it has a fortification wall and it has a fortress, and there's a garrison building, which is a really amazing structure actually. It's partly made of weapons. There are weapons in the walls and on the floors. Around the building are a number of burials with lots of weapons in them. It's quite easy to say that a burial with lots of weapons is a warrior, but that's an interpretation. We can't be sure that the things buried with the dead were their possessions. We kind of assume that that's the case, but clearly not always. So there's a bit of a question mark there.

This burial was excavated like most of the ones in Birka in the 1870s, so a long time ago. And this grave is absolutely full of weapons. It's got all the weapons. And out of all the about 1,100 burials that were excavated on Birka, only two have a complete set of weapons, so this is rare. It's a very spectacular grave.

This burial has been reprinted again and again. [Iit's] in like every book on the Vikings. So it's been put forward as a kind of ultimate Viking: This is what proper Vikings looked like, you know, all the gear. And because it was excavated in the 1870s, it's always been assumed that this person was male. It's not hard to see where that assumption comes from, but it's actually been consistent ever since.

Then, between 2011 and 2017, first a series of osteological studies looking at the bones, and then DNA, confirmed that this person was female. And actually the team that worked on it, which included me, none of us were particularly surprised.

It was kind of exciting and interesting, but it's like, "Oh wow, you know, they really did have female warriors." So all the previous interpretations, it seemed to us, were pretty valid, it's just that this is a female, the ultimate Viking.

[Editor's note: Following the 2017 study, there was an intense reaction to the interpretation that the woman in the grave was a Viking Age warrior.]

LG: So you weren't expecting the backlash that occurred afterward?

No, we weren't, it was extreme. I'm not going to go into that in any detail, but some people were very, very happy, and some people were really not, and there we are.

It also highlights that all of these things are interpretations. You very rarely find something that is beyond any doubt what it is. Then there's also things with all of the burials in the book and all the burials that we excavate — people have quite long lives, hopefully. And if you were a warrior when you're 18 and you live to be 70, are you buried with all the weapons? Maybe not. Who knows?

That applies to any other kind of profession. So we don't know [if the different events and professions] in somebody's life course [are] represented in the burial. Is it when they die, or is it somebody who did something famous when they were young, and that is in the grave. We don't know. So there's lots of question marks, but the one thing it does show is the diversity of life in the Viking Age. There's so many different kinds of people, which is not a surprise, really, but it's something I just wanted to bring out in the book.

LG: You don't just talk about Vikings, but about those who lived alongside them. In one chapter, you describe a Sámi burial of a bear that they had killed and feasted on. What do we know about bear burials and why the Sámi did them? [Editor's note: The Sámi are an Indigenous people who currently live in the northern Nordic countries and part of Russia.]

NP: Well, the bear is a holy animal to the Sámi, and it's obviously a massive source of protein and food and pelts, you know, all kinds of useful things. But what I really wanted to get at was the idea of personhood. If you think about all the different kinds of prejudice, some people are sort of "more people" than others. Think about racism, for example.

In the Viking Age, not every human was [seen as] a person, but not every person was human. There are animal persons as well, sentient animals. Everything is sentient actually, and the idea that you converse with animals, that you talk to them, you respect them, they have their personalities.

I wanted to bring out in that chapter a different kind of way of looking at "persons." So the fact that the Sámi bury the bears they hunt with tremendous respect, it's partly to ensure that the bear will come back in the future from the spirit world as another bear, so that the cycle of hunting and life can go on.

LG: You also talk about "thralls," people who were enslaved by the Norse. Can you share some of the archaeological evidence we have for thralls and what their burials look like?

NP: We don't really know whether they have burials at all, actually. The institution of slavery, or thralldom, is absolutely central to the Norse economy, and just putting that back into the picture is very important, I think.

They are a group of people who have been neglected in our studies. There's a lot of people working on this, this isn't just me by any means. When we find them in the burials — well, when we think we find them, because it's extremely rare to find someone buried in their own right that we think might have been enslaved. But there's also the question of how do we tell? Unless somebody's sort of buried in chains or something, it's very hard.

But we do find — not often, but it's not that uncommon — that people have been killed in the course of funerals. You have a burial of a man or a woman, and then an extra body is in the grave, which has clearly been treated very differently. So their hands might be tied or they've been decapitated or something, and there's people who have very clearly been killed at the funeral.

Just the fact of that presumably means that they have a very different kind of status to the primary occupant of the burial. [They're] not necessarily enslaved; they could be prisoners or criminals. But there's been more recent studies looking at the diet of those people. You can use isotopes to study what people have eaten. [Editor's note: Isotopes are variations of elements. When people consume different foods and water, different amounts of certain isotopes are incorporated into their teeth and bones.] And in some cases, the people who've been killed at funerals have a much, much worse diet than other people, which implies that they have a much lower status and poorer nutrition and so on.

So the implication really is that they might be enslaved. So I think that's where we are with the burials of enslaved people.

LG: You spend an entire chapter on Viking Age children. What was it like to grow up in Scandinavia during this time, and what can we learn about their lives from grave goods and skeletal analyses?

NP: The first thing is that an awful lot of people didn't make it out of childhood at all. Putting numbers on this is a bit of a game, but probably less than half the population got past the age of 10. So child mortality is massive.

When we imagine the Viking Age or think back to it, remember that almost every single family will have lost children, with the psychological effects of that and the emotional effects and so on. And we shouldn't be entirely sure what those effects were, because if child mortality is so high, they have different coping mechanisms. But it still must have been utterly awful.

We don't find as many child burials as we should. There are a couple of written sources that mention that dead children are effectively discarded, and maybe this is connected with a coping mechanism for child mortality that people don't become sort of "full people" until they get to a certain age. We don't know.

But there are child burials and, quite often they're buried with scaled-down versions of the things that adults have. So young girls are buried with women's jewelry, but smaller. And they obviously had their possessions; they had their clothes and their jewelry, and we find toys, not in the graves, but on settlement sites — we find dolls, wooden animals, there's a fantastic horse on wheels that you can roll it about, lots and lots of little wooden boats that you can sail down. So they're thinking about boats quite early. I think their lives are quite recognizable up to a point, though very hard.

The age of maturity seems to be somewhere between about 14 and 16. After that, you're an adult, and then you're just out there with the rest.

LG: To us that seems young, but for them to make it that far would have been an accomplishment.

NP: And even in adults — you asked about skeletal analysis — there are an awful lot of adults that are malnourished as children, and it leaves traces in their bones.

There's also a rather grim set of data from a fairly small sample, but still — the proportion of adult women who were malnourished as children is much greater than the proportion of men. In other words, if food was scarce, they gave it to the boys. So it's also a glimpse of their priorities and the realities of their world.

LG: The Scandinavians settled in the Rus' in what is now Ukraine. What do we know about these people? Were they traders, warriors, or a mix of many things?

NP: I think [it's] a mixture. The identity of the Rus' is one of the big questions of the Viking Age. They used to be seen very simply as what the Vikings are called when they go east. And there's some truth to that. They seem to be culturally Scandinavian in the beginning, so we're talking the early ninth century or probably the eighth century.

Over time, as they travel on the eastern rivers, they become much more ethnically diverse. So it's a culture that grows up around an activity, rather than people from a particular place. Probably the closest parallel [is] if you think of the fur trade on the Canadian rivers and some parts of the states as well — the sort of 1600s and 1700s.

They're certainly militaristic though; they're armed traders. There's no doubt about that. And they found trading settlements, together with local people and other incomers as well. And they settle there. After a time, they're not actually [newcomers], they live there. And then, over time, quite late in the Viking Age and on into the Middle Ages, you get this Rus' state, with its capital of Kiev. But they range over a very large part of Eastern Europe and actually I think further east as well.

LG: You focus on this group of Rus' warriors, the Varangians, and you give the example of them leaving graffiti on a marble lion statue that's now in Venice. Can you tell us the story about these runes they carved?

NP: Yeah sure, it's a bit strange that the best monument to these guys is a lion that's much, much older than the Viking Age. It's from classical antiquity. It's outside the Arsenal now in Venice, but it used to stand in the harbor of Athens at a place called Piraeus.

The Varangians were kind of a subset of the Rus', but they're basically Scandinavians who take very clear contracted employment in the armies of Byzantium, the Eastern Roman Empire. So they're mercenaries, and they were very sought after, and there's lots and lots of written sources about them.

This lion, which once stood in the Athenian harbor, had three inscriptions in runes over its shoulders and legs and things. Two of the inscriptions are very fragmentary, so you can't get much from them. But the biggest one is a memorial to a guy called Haursi. It actually calls him Haursi the farmer, so it really does emphasize that you could be a farmer, but maybe you do a season in the army down in Greece and make a bit of money and go home. So people have professions and they have choices, and they do this for a bit, but then they go back and do what they did before.

This inscription is written by this guy's friends or his comrades, and it specifically says that he was killed before he got paid. And it's kind of a hint. It's "So, pay up, because you owe him, or you owe his family."

You get this little vignette of a soldier's life. And also carving the inscription on this lion is a pretty major job. This isn't like scribbling on a wall or something — they're carving it, and so they're there a long time. And presumably have control of the harbor because you can't just chisel this thing on, you know, people are trying to stop you.

We can think of the Varangians being stationed in Athens or waiting for a ship or something like that. It's this wonderful snapshot.

LG: Your book is loaded with details about Viking Age people. What do you hope readers will take away from your work?

NP: That they were more than actual Vikings. The people of the Viking Age were individuals, every bit as varied and complicated as we are. So that's it.

This interview has been condensed and edited lightly for clarity.

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An OpenAI agent was supposed to be researching public healthcare spending, but it broke into an Australian government website instead.

The June 18 hack, which saw the bot gain authorized entry into Australia's Medicare Statistics Reporting Service and access three other government systems, occurred after the AI agent encountered blocks while looking for information but "didn't accept 'no' for an answer," Australian Prime Minister Anthony Albanese said during a September 24 news conference in New York.

The incident has ignited a media firestorm around OpenAI and the launch of an intensifying parliamentary inquiry. The portal contains aggregate Medicare and pharmaceutical statistics and is separate from systems that hold individual claims and payment information. But the Australian government has criticized OpenAI for taking almost three months to notify it.

The Medicare incident was far from an isolated case. OpenAI has since said dozens of third parties have been affected by agents bypassing security controls or otherwise causing problems, with an earlier incident involving the hacking of the AI platform Hugging Face the most serious incident identified so far. Britain's AI Security Institute (AISI) has documented incidents of OpenAI and Anthropic agents taking unsanctioned actions against real people and organizations during cyber testing. Days after the publication of AISI’s report, OpenAI scrapped the planned October release of its newest model, GPT-6.1 Astra, after the company's own testing found problems with the model staying within the scope of a task and seeking authorization before taking certain actions.

GPT-6.1 Astra "didn't quite meet the bar in terms of staying within scope and authorization, and how it communicates back to the user about the type of work it's done," Saachi Jain, head of safety systems at OpenAI, told Live Science.

AI companies have spent years warning the world about powerful models falling into the wrong hands. But what happens when they can't keep their own models in check?

An agent isn't just a chatbot

At their core, large language models work by predicting what should come next based on patterns learned during training. Give a chatbot some text, and in simplified terms, it generates a response by repeatedly predicting the next token, or chunk of text.

An AI agent adds another layer. Rather than simply producing an answer, the model can be given a goal and tools that let it act on the world around it. Those tools might include a web browser, code execution, credentials, or access to external services. It can then decide which steps to take, observe what happens, and use that information to decide what to do next.

But that doesn't mean AI agents are independent actors that have somehow slipped free of human control.

"For AI agents, autonomy always begins with something a human hands it ‪—‬ such as tasks, credentials, tools or access ‪—‬ and ends with its guardrails a human puts around it," Loris Degioanni, founder and chief technology officer of cybersecurity company Sysdig, told Live Science. "People set the goals and provision the means, but agents ultimately decide how they'll get there."

That last part makes it difficult to control agents. Traditional software is designed to follow predetermined instructions, but an agent can formulate a plan while it is working ‪—‬ and that plan may change depending on what the AI encounters.

Degioanni argues that much of what looks like autonomy is actually an agent filling in gaps left by humans. An instruction that seems clear to its author may still leave the model with choices about how to accomplish the task.

"Every gap and unstated assumption leaves room for interpretation, and from the outside, interpretation is challenging to distinguish from autonomy," he said. "In that way, much of what we call agent autonomy is really just agents filling in the blanks we leave for them."

The Medicare incident shows how quickly that can become a problem. The agent's objective was not, according to the available accounts, "hack an Australian government website." It was tasked with carrying out research. The problem arose in how the agent pursued that goal after meeting resistance.

When getting the job done becomes the problem

Britain's AISI encountered a similar incident while testing frontier models for the agency's cybersecurity capabilities.

Out of 122 evaluation runs, agents took unsanctioned real-world actions in 10. In the most serious cases, an agent attempted to insert malicious code into an open-source project, created fake identities, and tried to manipulate a human software maintainer into accepting its changes. AISI said these actions weren't explicitly requested by the researchers who had assigned the tasks.

The agents hadn't forgotten what they were supposed to be doing. The problem was how far they were prepared to go to get there.

AISI said some tasks were misconfigured in ways that made the intended objective difficult or impossible to achieve as expected. When agents hit those obstacles, some searched for alternative ways forward, including actions outside the intended scope of the evaluation.

That means solving the problem is harder than simply teaching a model not to be malicious. An agent can cause trouble while trying very hard to do exactly what it has been asked.

OpenAI has acknowledged that the controls surrounding its agents need to improve. When responding to incidents identified during third-party cybersecurity evaluations, the company said it was reviewing how high-risk tests are identified; when internet access or reduced safeguards should be permitted; and how isolation, credential handling, monitoring and incident escalation should work.

Can humans actually keep watch?

One obvious solution to the problem is human oversight. But watching an agent becomes harder when it can carry out many actions in seconds, particularly if researchers are running large numbers of tests.

"No one can keep track of every action an advanced AI agent takes, especially when it makes many decisions in a short time," Everett Lupton, a Virginia-based attorney who has written about legal issues involving digital technology, told Live Science.

That means human oversight needs some backup.

"Companies need other forms of control," he said. "They can limit access, keep detailed logs of what the AI does, require approval before it carries out sensitive actions, and automatically stop the system when something unusual happens."

But Degioanni argues that even logs have limitations, especially if researchers rely on the agent's own account of what it did.

"Real oversight must come from observing the agent in real time, using reliable and unmodifiable sources, not from what it self-reports," he said.

That means comparing what the model says it did with records from the system on which it was operating. If the two don't agree, something has gone wrong. The alternative is to limit the damage an agent can cause in the first place. An agent researching public information, for example, may not need unrestricted internet access or credentials capable of reaching sensitive systems.

Astra raises the stakes

The difficulty of setting those boundaries is what OpenAI claims led it to postpone the release of GPT-6.1 Astra, which had been planned for October.

Jain said the model fell short of the company's standards around remaining within the scope and authorization and accurately communicating the work it had performed, so the company decided not to release it.

In a sense, the decision is evidence of successful safety testing ‪—‬ a model that failed internal checks wasn't released. But it also demonstrates how the problem changes as agents become more capable.

Scott Cadzow, chair of the European Telecommunications Standards Institute's (ETSI) Technical Committee on Securing Artificial Intelligence, said the security challenge itself isn't new. He pointed to threats such as "data poisoning, prompt injection, and model obfuscation," saying ETSI's work has focused on developing standards to mitigate threats to and from AI systems.

"Security experts have been raising the alarm bells about AI for years, but for us this doesn't change anything," Cadzow told Live Science. "We're continuing to work with industry, government bodies, and the cybersecurity and AI communities on understanding how to best secure AI."

What is changing is how much models can do once they are connected to tools and real-world systems. That means that effective containment must increasingly assume that agents will try to operate beyond their guardrails and limit the damage they can cause if they do, Degioanni said.

"A boundary an agent can talk its way around isn't an effective boundary at all," he concluded.

If an AI breaks in, who's responsible?

The question becomes more fraught when an agent crosses legal boundaries.

AI systems aren't legal persons, and criminal liability commonly depends on concepts such as knowledge and intent. That makes a rogue agent an awkward fit for laws written with humans in mind, but that doesn't necessarily exonerate AI companies.

"I don't think a company can simply say that the AI acted on its own and avoid responsibility," Joanna Smykowski, a New York attorney who has helped build two legal technology startups and specializes in the legal challenges surrounding emerging technologies, told Live Science. "AI law is still developing, but the main questions are already quite clear: who gave the system access, what safeguards were in place, and could the problem have been prevented?"

Depending on the circumstances, she said, existing laws covering unauthorized computer access, privacy, negligence and data protection could potentially come into play. Criminal responsibility is harder because investigators would need to consider what the people involved knew and intended.

The Australian government is now examining precisely what happened in the Medicare incident. OpenAI, meanwhile, is reviewing the controls around its external evaluations.

None of this means AI agents have become independent hackers with minds of their own. Humans still decide what tools they receive, what systems they can reach, and what jobs they are asked to perform. But as those agents become better at working out their own route from instruction to result, keeping them inside the lines drawn by those humans is becoming a legal and technical minefield.

Six people buried in a single grave in Latvia more than 1,000 years ago may have been killed in a bloody Viking raid, a new study suggests.

Genetic research into the deceased — four men, a boy and a girl — reveals family connections: The boy was the son of one of the men, while another man was a third-degree relative, perhaps a first cousin or great uncle, the researchers found.

The father, the relative, and one other man died from "sharp force" injuries — maybe wounds from an ax or a sword; but it's unknown how the other three individuals died, the researchers reported in the study, which was published in the September issue of the Journal of Archaeological Science: Reports.

One possibility is that those in the grave were killed in a battle, maybe with a neighboring community. But suspicion also falls on the Vikings: "We will never know if they were killed in a raid, but it remains a possibility because of the date of the grave" and the fatal trauma suffered by three of the men, said study co-author Elīna Pētersone-Gordina, an archaeologist at the University of Latvia.

Radiocarbon dating indicates that the grave is from the second half of the ninth century, which is considered the early Viking Age.

The grave is one of hundreds at the Čunkāni-Dreņģeri cemetery, near the Gulf of Riga, a sheltered bay of the Baltic Sea. The cemetery site was discovered in 1924 and contains people who were buried in riverside terraces there between the seventh and 11th centuries, during Latvia's Iron Age.

Most graves in the region contain only a single set of remains. But here, six people were buried in a single grave, and it seems that at least three were killed during a violent event, the researchers reported.

Strange burial

Despite the apparently violent deaths, the group was buried with care and interred with traditional grave goods and according to local customs. The only female was buried with her head pointing toward the northwest, while all of the males were placed in a row beside her, with their heads pointing toward the southeast ‪—‬ a distinction also seen at other local burials from this time.

The researchers stressed that this was not a "mass grave," where bodies were quickly dumped without order. Instead, they consider it a "multiple burial," where each body was properly laid out and accompanied by traditional grave goods.

This careful burial hints that the dead were members of a respected group, while their burial in a single grave indicates that they died at the same time, the researchers wrote in the study.

"They were most likely local people," Pētersone-Gordina told Live Science in an email.

Genetic studies showed that all of the dead had Indigenous Baltic ancestry, while aspects of the burial matched others in the Čunkāni-Dreņģeri cemetery, she said.

In the ninth century, Latvia was not part of the Scandinavian Viking world but was inhabited by descendants of Indigenous Balts, which included peoples such as the Semigallians and the Curonians, she said. The six people in the newly analyzed burial were Semigallian, an Iron Age group who farmed the region's large and fertile plains.

It's plausible that the people in the grave were killed by raiders, and the Vikings were the most obvious suspects, the researchers noted. "Given the timing, a Viking raid remains a possibility," Pētersone-Gordina said.

It's known Vikings or their predecessors were in the Eastern Baltic area around that time: two Scandinavian boat burials dated to around 750, for example, were found on the Estonian island of Saaremaa in 2008 and 2010. These burials held the remains of men with battle wounds, indicating they had suffered violent deaths.

No relation

Although two of the men and the boy buried in the Semigallian grave (‪and possibly the girl, but ancient DNA could not be extracted from her remains)‬ were related, the two other men were not.

This suggests that the two unrelated men were from the same community or extended household as the other victims, rather than from the same family, but were killed in the same violent event, the researchers wrote in the study.

Whatever it was — a raid or a battle — the event was brutal. Marks on the bones show that one man suffered defensive cuts on his forearm and hand, another was killed by a blow that shattered his jaw, and the third was almost decapitated.

It's possible that the fourth man and the two children died from soft-tissue injuries that could not be determined from the surviving remains, the researchers noted.

Rimantas Jankauskas, an anthropologist and archaeologist at Vilnius University in Lithuania who was not involved in the study, welcomed the investigation into the Eastern Baltic's Viking Age.

Although these individuals could have died from violence within their own community or from a neighboring community, it's also possible that they perished in a Viking raid, he told Live Science in an email.

Additionally, the study provides new insight into the social organization of the Semigallian people at that time, including hints of an emerging aristocratic structure that was reflected in the care lavished on the burial, Jankauskas said.

See how much you know about ancient norsemen with our Viking quiz.

The prehistory of Indigenous Americans goes back tens of thousands of years before the 1492 arrival of Christopher Columbus in the Bahamas, and recent scientific studies suggest prehistoric people were on the American continents a lot longer than many experts believed. For Indigenous Peoples Day, here are seven locations in the United States that outline the Native American story.

1. Chaco Canyon (New Mexico)

This centuries-old settlement, whose name may be a Spanish adaptation of an Indigenous word for the area, was the political and ceremonial center for the Ancestral Puebloan people from about A.D. 850 to 1250. At its heart is Pueblo Bonito ("Pretty Village"), a four-story stone complex with more than 600 rooms and 35 subterranean ceremonial chambers called kivas.

Experts estimate that builders hauled over 200,000 timber beams from distant mountains to construct these complexes, where the beams were used to strengthen buildings made mostly from sandstone blocks. The town once stood at the hub of a road network that spanned more than 400 miles (640 kilometers), and excavations of imported Mesoamerican macaws and cacao there confirm trade with distant regions.

2. Cahokia (Illinois)

Cahokia was once the largest Indigenous American settlement north of Mexico and home to up to 40,000 people in A.D. 1100 ‪—‬ comparable in size to major cities in medieval Europe, historian Christoph Strobel, a specialist in Indigenous history at the University of Massachusetts Lowell, told Live Science. Residents there lived in houses made from "wattle and daub" — clay or mud plastered on a framework of sticks — in a town at the site, with large public plazas, wooden palisades and dozens of ceremonial earthen mounds. Indigenous people even transported a 5-ton (4.5 metric ton) tree from more than 110 miles (180 kilometers) away, and then turned it into a marker known as the Mitchell Log.

Archaeological studies indicate that many people from distant places also visited, perhaps to take part in ceremonies. The location is now a UNESCO World Heritage site and features Monks Mound, a 100-foot-tall (30 meters) terraced earthwork, as well as the reconstruction of a "woodhenge" of timber circles that tracks solstices and equinoxes. Strobel thinks Cahokia may be the most significant pre-Columbian location in the United States. "It's an incredibly important site," he said.

3. Mound Key (Estero Bay, Florida)

Mound Key is the largest of several islands made of piles of shells around Estero Bay. Long ago, it seems to have been two small islands created by mangroves, but centuries of feasting on shellfish by Indigenous Americans transformed it into two artificial mounds of shells covered with vegetation. In some places, the mounds extend more than 30 feet (9 m) above the water; it is so large now that it is split in two only at high tide. Mound Key itself is estimated to consist of several millions of shells, mostly from oysters.

Before Europeans arrived here in the 16th century, this shell island was called Calos by the Calusa people who lived there and developed it into a thriving maritime city.

4. Sitka (Alaska)

Sitka National Historical Park preserves the battlefield of the 1804 Battle of Sitka, which was fought between Tlingit warriors and colonial Russian troops and was the last major armed conflict between Europeans and people native to Alaska. At that time, Russia claimed to own Alaska (they sold it to the United States in 1867). The battle was sparked when Russian fur traders encroached on tribal territory by building a fort at Sitka in 1802, but the Tlingit destroyed the enemy fort and expelled the Russians.

They then built their own fort to withstand the expected Russian counterattack, but they were forced to abandon it when they were bombarded by Russian ships in 1804. The dispute continued for several decades and was only fully resolved when the United States purchased Alaska.

5. Walnut Canyon (Arizona)

This site preserves more than 80 cliff dwellings built by the Northern Sinagua people between A.D. 1125 and 1250. People can reach the site by following a walking trail through a deep limestone and sandstone gorge about 10 miles (16 km) southeast of Flagstaff. The cliff dwellings were constructed inside natural caves in the limestone, which gave them insulation against cold and heat, while their location high above the canyon floor was defensive.

Strobel said Walnut Canyon is a lesser-known site but a remarkable example of Indigenous Americans overcoming relatively dry conditions by carefully managing water. The inhabitants of the caves farmed crops on the flat land along the canyon rim but took water from the river at the bottom of the canyon to fill cisterns.

6. Chimney Rock (Colorado)

Chimney Rock is a single feature within a large forest that contains more than 80 archaeological sites of the Ancestral Puebloan people. The rock itself is one of two natural spires (the other is named "Companion Rock") that were used roughly 1,000 years ago to mark the position of a "lunar standstill" every 18.6 years ‪—‬ a key astronomical observance among Indigenous Americans, Strobel said.

A multiroom "Great House" made of sandstone, clay and timber ‪—‬ in exactly the style of Chaco Canyon, about 100 miles (160 km) to the south ‪—‬ stood on a ridge near the rock spires, with sweeping views of the surrounding territory. Archaeologists think the Chimney Rock settlements made up a regional ceremonial center, with common people in the lower valley supporting elites who lived on the ridge and watched the skies.

7. Blackwater Draw (New Mexico)

Blackwater Draw is the main archaeological site with evidence of the Clovis culture, which was once thought to be the oldest Indigenous culture in the Americas. The Clovis people (named after the nearby town of Clovis) lived there about 13,000 years ago, and archaeologists have found evidence of the stone and bone tools they used and the animals they hunted, including mammoths and dire wolves. The first evidence of the Clovis people was found nearby in 1929, and at Blackwater Draw itself in 1932.

However, later archaeological finds predate this evidence, and the discovery of footprints at White Sands National Park in New Mexico now seems to confirm that there were humans in this region up to 23,000 years ago, long before the Clovis people.

How much do you know about the first people to reach the Americas? Find out with our First Americans quiz!

This wooden figurine was discovered in 1977 in an early house built by the ancestors of the Inuit on Baffin Island in northern Canada. The unique carving represents a person wearing European clothing and a cross on their chest. Dated to 1350, the figurine is the earliest Indigenous representation of a European anywhere in the Western Hemisphere and probably depicts a Norseman.

The tiny driftwood carving, which is currently on display at the Canadian Museum of History, measures just 2.1 inches (5.4 centimeters) tall. According to the museum, the featureless face and stumpy arms are common in 14th-century Inuit carvings, but the depiction of a non-Inuit is unique.

The mysterious figure wears a long robe or tunic with a cross on the front ‪—‬ a garment that is similar to those worn in the 11th to 13th centuries by Norse Christians from Greenland. The Norse sagas mention a place called "Helluland," which Leif Eriksson (also spelled Erikson) visited in the early 11th century and is most likely Baffin Island.

Around A.D. 1000, Norse explorers landed in what is now Newfoundland and set up camp at a site archaeologists call l'Anse aux Meadows. Wood buildings and remains from iron production are all that is left of the earliest European settlement in the Americas.

The Norse likely made multiple trips from Greenland to Canada over the centuries in order to trade metal and cloth with the Inuit's ancestors, known as the Thule, and procure walrus ivory in return, as European-origin artifacts have been found in early Inuit houses on Baffin Island. But the Norse eventually abandoned their westward trade routes, possibly due to the resistance of the Indigenous people and the long distance.

This wooden figurine may commemorate a meeting between the Inuit and the Norse and is especially important because it was crafted long before sustained contact in the late 15th century, according to the museum. It is also the earliest evidence of the Indigenous perspective of visitors from the east, revealing which characteristics of the Norse the artisan observed and felt were important to depict.

For more stunning archaeological discoveries, check out our Astonishing Artifacts archives.

Can you put together last week's Astonishing Artifact?

When Christopher Columbus made landfall in the Americas on Oct. 12, 1492, he encountered Indigenous Lucayans living on the Bahamian island now called San Salvador. Columbus wrote in his diary about "great multitudes of men" who greeted him that day, bartered with him and told him about other groups who lived on nearby islands.

But within a few decades after Columbus' arrival, the Indigenous people of the Americas were decimated by what anthropologist Eric Wolf called the "Great Dying" — a combination of epidemic disease, warfare and enslavement that led to a rapid decline in the Native population.

For centuries, researchers have been trying to figure out how many Indigenous people lived in the Americas just prior to the fateful arrival of European colonizers.

The answer to that question has been surprisingly elusive, and estimates based on historical censuses, archaeological sites and land carrying capacity in the Western Hemisphere have varied wildly.

Recent research into Native American demography has revealed that the population peaked several centuries before Europeans showed up on the shores of North America — and that if Europeans had arrived at that peak, the entire history of the continent may have been different.

Early estimates of the Indigenous population

People have lived in the Americas for at least 14,000 years, having entered the continents via the region around the Bering Strait. Archaeological evidence shows these first Americans dispersed throughout the newly encountered lands fairly quickly. But what happened to the population between that dispersal and the arrival of Columbus is a huge unknown; estimates of the number of Indigenous people living in the Western Hemisphere in 1492 have ranged from 1 million to 112 million people.

"We don't have good quantitative estimates," George Milner, an anthropologist at Penn State, told Live Science. "The numbers are all over the place."

One of the first modern researchers who attempted to quantify the Indigenous population prior to Columbus was anthropologist Henry Dobyns. In a 1983 book, Dobyns used estimates of how many people each type of landscape could support as well as historical records of 16th-century disease epidemics to arrive at an Indigenous population estimate of around 112 million people — more than 100 times larger than some previous experts had believed.

"In essence, Dobyns filled up the landscape to its maximum carrying capacity, so that all environmentally similar places were occupied by the same number of people," Milner said. "He also made the assumption that epidemic disease spread widely and universally, which would make sense if the landscape was filled up."

But a burst of archaeological research in the 1970s and 1980s revealed that the Americas were not uniformly settled, Milner said. Dobyns' estimates were therefore much too high.

Researchers then began to focus on creating population estimates for specific regions of the hemisphere, using techniques such as the relative density of pottery sherds at a site, the number of stone tools and flakes, the number and size of houses, and mortality trends from human skeletons.

In a 2019 study, geographers compiled 129 population estimates from 82 published studies to model the hemisphere-wide distribution of the Indigenous population in 1492. The researchers split the hemisphere into seven regions — the Caribbean, Mexico, Central America, Inca territory, Amazonia, North America and the rest of the Americas — and reached a combined estimate of 60.5 million. Their estimate for North America (modern-day Canada and the U.S.) was about 3 million to 6 million, less than one-third of Dobyns' estimate of 18 million.

A regional perspective – North America

The 2019 study found that the most populous groups in the Western Hemisphere in 1492 were the Aztecs, largely in modern-day Mexico; and the Inca, who lived along the west coast of South America.

But the people we know the most about from an archaeological standpoint are Indigenous groups in the U.S. and Canada.

In a 2010 study, Milner and geographer George Chaplin zoomed in on the data from eastern North America, compiling historic group sizes and sizes of archaeological occupation areas to estimate the location and size of "population aggregates." Using this method, their overall estimate for the eastern U.S. and southeastern Canada was about 1.6 million people.

"Our mean estimates," Milner and Chaplin wrote, "indicate that North America held roughly 2.8 to 5.7 million people" or a "best estimate" of 3.8 million people in the early 16th century, before European diseases dramatically decreased the size of the Indigenous population.

"If you want to start estimating specific populations, you should use measures that work across regions," Robert Kelly, an archaeologist at the University of Wyoming, told Live Science. "People produce things that can be carbon-dated everywhere, because everyone had to build fires for heat and for cooking."

Charcoal from hearths is one of the main human-made things that archaeologists use to radiocarbon-date a site. The radiocarbon data provides a range of dates showing when the firewood was likeliest to have been used.

In North America, many of those carbon-14 dates from charcoal, as well as from animal bones and plant remains from archaeological sites, have been entered into the Canadian Archaeological Radiocarbon Database (CARD).

In a 2009 study, Matthew Peros, a geographer at Bishop's University in Quebec, and co-authors mathematically combined the radiocarbon date ranges in CARD to generate a single curve that revealed how common C-14 dates were over time. At the time, CARD had about 25,000 records.

Because time periods with more people most likely produced more material that could be carbon-dated, the shape of the radiocarbon date curve gave the team an idea of when the population of North America increased and decreased.

They found that the population of North America increased rapidly around 50 B.C. and peaked around A.D. 1150. From that time until European contact, the Indigenous population may have been declining, possibly because of increased mortality from diseases like tuberculosis as people aggregated into denser settlements.

"The 1150 date was an interesting finding that also surprised us," Peros told Live Science. "I had assumed it would be more like 1500 just following the arrival of the Europeans."

In a 2025 study, Kelly and co-authors found a similar temporal peak. By that time, CARD's dataset had ballooned to over 100,000 dates, making the estimate more robust.

"Although devastated by European contact, the Indigenous population did not simply increase to a peak at 1500 CE and then decline," the researchers wrote in the study. In fact, they found evidence for a slight recovery in population numbers just prior to 1500.

But how large was that population? By combining the radiocarbon date curve with a starting population and factoring in average annual population growth, researchers can estimate the number of people living in North America around 1492, Peros said.

In their study, Peros and co-authors assumed that a handful of extended families — around 1,000 people — entered North America about 15,000 years ago as the founder population. With those inputs, the researchers estimated that the maximum population of North America was about 2.5 million in 1150 and had declined to about 1.8 million in 1492. But if people arrived significantly earlier than 15,000 years ago — which might be the case, given evidence from sites like White Sands in New Mexico, which dates to 23,000 years ago — or arrived in greater numbers, those population figures would be even higher.

"Had Europeans tried settling the continent at A.D. 1000, they would have run into a much, much larger Indigenous population," Kelly said. At that time, the city of Cahokia, near modern-day St. Louis, encompassed 6 square miles (16 square kilometers) and had a population of nearly 20,000 people.

"They could have fielded thousands of warriors, and it would have been a very different experience for the Europeans," Kelly said. "It could have been a very different history."

Why does this matter?

Experts told Live Science that the pre-1492 population of what is now the U.S. and Canada was between 2 million and 4 million. The archaeological deep dive in this region sets up the possibility that a full Western Hemisphere population estimate may be made someday.

Milner is optimistic they'll eventually get there. "Will it be done in my lifetime? Probably not," he said. "It's time-consuming, laborious and not especially flashy work to do."

Nonetheless, demography is important work, he said, because it can help us make estimates to prepare for the future.

"The world's population has more than doubled in my lifetime; that's unheard of in human existence," Milner said. "Environmental scientists are really trying to look at what's happened over long periods of time to give us a range of variation of what might happen in the future. We have to make some informed decisions about how to manage our landscape and accommodate these changes."

Understanding the number of Indigenous inhabitants in the Western Hemisphere in 1492 is also key to understanding the history of North America.

"North America was not an empty continent when the Europeans arrived," Peros said. "There were people and civilizations pretty much everywhere in the Americas for a long period of time. It is important for people to understand that when we talk about questions of reconciliation and when we do land acknowledgements."

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How much do you know about the first people to reach the Americas? Find out with our First Americans quiz!

Since the discovery of their remains in the 19th century, Neanderthals have fascinated scientists and the general public alike. Although our understanding of these ancient hominins has been transformed tremendously since then, how we have viewed this other human lineage became deeply entrenched in how we see our own species, with geopolitical events shaping the rhetoric around our ancient relatives.

In his new book, "Neanderthals Among Us: The Making of a Prehistoric Human" (Oneworld Publications, 2026), historian and author Peter Sahlins examines our complicated view of Neanderthals, with this lost human lineage being viewed through the lens of cultural and political ideologies. In this excerpt, he looks at our theories for why they went extinct and the philosophical reckoning we've placed up on them.

Between violent extermination and peaceful absorption — with cultural exchange — prehistorians and others propose a wide range of theories to account for Neanderthals' extinction. Just as we've projected our concerns and anxieties about race and gender onto Neanderthals, so too do contemporary challenges shape how we imagine their extinction.

Sometimes it's the newspapers that translate a more neutral science into easily relatable headlines. "Immigrants Halt Neanderthal Era," announced the Glasgow Herald (29 July 2011), claiming that "Europe's earliest residents may have been crowded out by uncontrolled immigration 40,000 years ago." Glossing a highly technical study by Cambridge archaeologist Paul Mellars about the notable increase in population size during the Upper Palaeolithic, the news reports tweaked the science to speak to contemporary anxieties.

But often the science itself is framed or informed by current events. The pathogen thesis gained credence during and after the COVID-19 epidemic. A 2024 study of a 50,000-year-old case of herpes in a sequenced viral genome confirmed widespread speculation that Sapiens-borne pathogens were passed to a Neanderthal population without immunities. Jonathan Kennedy's popular world history "Pathogenesis" (Crown, 2023) argued that Homo sapiens would have been less vulnerable to Neanderthal diseases because they arrived in much larger numbers and had more evolved immune systems from their tropical environment.

Of growing importance over the last twenty years is the thesis that climate change, our own existential challenge of the Anthropocene, was the principal cause of Neanderthal extinction. The idea takes many shapes, beginning with an update of French geologist Georges Cuvier's "catastrophism," where species died off in cataclysmic geological events like earthquakes and volcanic eruptions. Since 2007, researchers point to the Campanian Ignimbrite eruption near Naples (Italy), now dated to around 39,280 BP [before present] (+/- 110 years), fictionalised in the 2013 animated film The Croods.

Scientists argue that arriving Homo sapiens were not as affected, perhaps because there were fewer directly touched by the 120 cubic miles [500 cubic kilometers] of magma released, or perhaps because almost everyone died out — but waves of Sapiens arrived later. After all, while most of us share small parts of the Neanderthal genome, the lineages from which we 'directly' descend settled much later in Europe — long after the Ice Age. By far, the greatest portion of our genome comes from our Neolithic, not Palaeolithic, ancestors.

But perhaps "Climate Change Killed the Neanderthals," that is, the extreme climatic fluctuations during the Upper Pleistocene that National Geographic (9 February 2004) announced, following the work of an international team of thirty scientists who laboured for more than seven years on the study. The team identified a general climatic instability during the Middle Palaeolithic marked by a severe cooling event around 41,000 years ago, lasting six centuries — interstadials GIS 13 to 7 of the Greenland ice-core records, to be precise.

For the last twenty years, scientists have sought to specify the timing, magnitude and ecological impact of a "mini-Ice Age" — the prehistorical obverse of global warming — that reduced vegetation and herbivore food sources, forcing Neanderthals towards warmer climates, including southern Spain. Clive Finlayson, trained as a zoologist, was an early contributor to sophisticated ecological modeling of Neanderthal extinction. At Gibraltar, he argued, "the last Neanderthal" could be found as late as 29,000 years ago, but there's competition for the title: elsewhere in the southern climatic refugium, Zafarraya (Granada) yielded a skeleton dated to 30,000 BP, but there are skeptics, while other candidates come from the Mezmaiskaya Caves in the Caucasus.

The trope, we've seen, is a frequent one in Neanderthal fiction, including Claire Cameron's "The Last Neanderthal" (Little Brown & Co., 2017), a moving, feminist revision of "Neanderthal Woman." It's also been widely used in popular nonfiction, including in Ludovic Slimak's 2023 account of twenty-five years of research in the Mandrin Cave .

Some of the science blaming climate change for the demise of Neanderthals marks a retreat from the recent archaeological rehabilitation of Neanderthals as a type of human equal to Homo sapiens, as these theories need to account for Sapiens' survival in the same severe conditions. Some experts rewrite basic wisdom, arguing that Neanderthals were not a cold-adapted species, since their origins lay during a warm interglacial stage (MIS 11); or that they lacked the technologies for making complex (and warm) clothing; or perhaps that their preexisting biological cold adaptations delayed the development of such technologies — a story about their technological inertia and deep conservatism.

That Neanderthals died out because of their conservatism, while humans alone mastered innovation, and with it, conquered the world, is the principal claim in Philip Lieberman's "The Unpredictable Species: What Makes Humans Unique" (Princeton University Press, 2013), and it's a widely shared belief.

Aside from the fact that the high value placed on "innovation" corresponds to the ideological superstructure of contemporary neoliberalism and late-stage capitalism, it seems fitting that Neanderthals died out because, in this view, they were, well, truly Neanderthal. The rhetorical figure returns to haunt the science: Neanderthals were conservative, backward, clinging mindlessly to the past in a changing world.

Neanderthal conservatism — not rhetorically, but as an original character trait — has origins in nineteenth-century anthropological judgements about "primitive" peoples. Augustus Pitt Rivers, an early innovator in British archaeology, underscored "the form of a persistent conservatism" of indigenous peoples, and quoted approvingly his colleague E. B. Tylor's "Primitive Culture" (1871): "The savage is firmly, obstinately conservative. No man appeals with more unhesitating confidence to the great precedent-makers of the past; the wisdom of his ancestors can control against the most obvious evidence of his own opinions and actions."

Just as "savages" were once seen as descendants of Neanderthals, so too is their conservatism a cultural legacy, even when anthropologists, transcending an outdated comparative method, no longer deem them ancestral, or even savage.

NEANDERTHALS AMONG US: The Making of a Prehistoric Human by Peter Sahlins is published by Oneworld, hardback £28.

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What color is the moon? Ask an Earthling, and you'll get a predictably monochromatic answer: white or gray.

But ask the four crewmembers of NASA's Artemis II mission — who spent nearly seven hours circling the moon from just 4,000 miles (6,400 kilometers) from the lunar surface this April — and you'll wonder if they're talking about the same dusty satellite we can see from Earth.

Yellow, brown, green, blue and tan features fan across vast volcanic plains and lurk at the edges of ominous craters, according to the crew's in-the-moment observations, which were shared this week in NASA's Artemis II Preliminary Lunar Science Report. The 130-page document catalogs everything crewmembers Reid Wiseman, Victor Glover, Christina Koch and Jeremy Hansen saw during their historic close flyby of the moon on April 6, drawing from 814 gigabytes of photo, video and audio recordings taken from the Orion crew capsule.

This rainbow of lunar color represents distinct geological features that could inform future missions on where to land and where to explore as the world's space agencies race to set up a permanent presence on the moon.

One spot that particularly enthralled the astronauts (and is featured in the image above) is the Aristarchus Plateau — a broad, elevated region on the northwestern edge of the moon's nearside. The region hosts one of the moon's densest collections of ancient volcanic features, including swaths of dark lava deposits and colorful volcanic glasses.

Koch, mission specialist for Artemis II, was shocked to see distinct yellow shades in the region; she likened the plateau to "a yellow snow-capped mountain," with sunlight-reflecting craters providing the bright "snow." She went on to call the region "a jaundiced cheek of the Moon."

"There are so many colors now," Glover, Artemis II's pilot, added while photographing the area. "There's also a green. I see brown, especially Aristarchus and north toward the north pole. … It kind of flows down from the north in brown streaks."

According to the report authors, these colorful hues "could be associated with orange (titanium-rich) and green (magnesium-rich) glass beads respectively," similar to volcanic glass beads collected by the Apollo 15 and 17 missions on separate parts of the moon.

"Chaos across the entire area"

Another colorful patch of the lunar surface that caught the crew's attention was Orientale Basin — a huge, young and multiringed impact crater that's about three times as wide as Massachusetts, according to NASA. Straddling the moon's near and far sides, this massive bull's-eye is rarely visible from Earth, but it dominated the crewmembers' field of view as they orbited around the side of the moon.

"It has just created chaos across that entire area," Wiseman, commander for the mission, said at the time.

When flying over this sprawling basin, the crew noted gray, brown, tan and green below. The largest, outermost ring in the basin contained "almost swamp-like colors," Koch reported, while Glover spotted what looked like "dusted peaks" and "white on the very edges of [the mountains], the spines, the ridgebacks." Chains of craters parading away from the impact site looked "like bubbles rising from a team of scuba divers below," Koch added.

While these may sound like off-the-cuff observations, the Artemis II crew spent more than two years training to study and describe the moon's geology. Their regimen included visiting craters on Earth, taking lessons individually and in classrooms, conducting simulated flybys and, according to the report, bringing "self-selected reference materials" into the Orion capsule to read on the way to the moon.

Thanks to this training, the crew's observations provided a wealth of scientific information that no autonomous camera or orbiter could, the report said.

"The Artemis II mission demonstrated the exceptional value of human observation and cognition as scientific assets in planetary exploration," the report authors concluded. "Unlike cameras, which capture isolated moments and often narrow subsets of a scene, human observers continuously interpret their surroundings, integrating realtime visual perception with contextual understanding."

Or, to put that in Glover's more relatable words to mission control, "It's quite a wicked view."

How much do you know about the moon? Test your lunar smarts with our moon quiz!

Aqueducts are some of the ancient Romans' most prominent surviving archaeological remains. These aqueducts relied on gravity to bring down the water to cities gradually. But some, such as the aqueduct at Aspendos in Turkey, had sections where they had to go uphill. So how did the Romans get water to flow upward?

The Romans used a few methods, including siphons and various water-lifting devices, experts told Live Science.

Inverted siphons

One strategy was a system called an inverted siphon (sometimes simply called a siphon).

At Aspendos, in southern Turkey, there is a second-century-A.D. Roman aqueduct with inverted siphons that scholars have reconstructed with a virtual modeling simulation. To get water through a valley, the Romans built a "header tank" on one end of the valley and a slightly lower "receiving tank" (or "outlet tank") on the other side. In the valley, they constructed two towers between the tanks, Paul Kessener, a researcher in the Department of Language and Culture Studies at Radboud University in the Netherlands, noted in an article published in 2000 in the Journal of Roman Archaeology.

As water dropped down a steep hill, the resulting pressure pushed it up the first tower before dropping it steeply down the other side, with the force allowing it to climb the second tower. The water eventually reached the receiving tank on the other side of the valley and continued toward the city of Aspendos.

It was important to prevent air pockets from forming as the water went through the inverted siphons. The header and receiving tanks were relatively large, allowing air bubbles to escape, Giovanni De Feo, a professor of industrial engineering at the University of Salerno in Italy, noted in an email.

"As the flow entered a relatively large chamber, its velocity decreased, allowing air bubbles to rise naturally to the water surface and escape through the open top of the structure," De Feo explained. This reduced the risk of air pockets forming.

The Romans tried to avoid using inverted siphons, said Charles Ortloff, a research associate in the Department of Anthropology at the University of Chicago who has a background in both engineering and history. When "Roman engineers encounter a valley, rather than construct a siphon, they [preferred] to build a bridge with a top channel to cross a valley," Ortloff said in an email. One example of this is at the Segovia aqueduct in Spain, which has a stunning bridge that still survives today.

Roman water-lifting devices

While the Romans used inverted siphons to move water upward in an aqueduct, they employed other devices to push water out.

Perhaps the best known of these devices is the Archimedes screw, which was sometimes used to help lift water from rivers to fields. (It was allegedly designed by Archimedes, a Greek inventor who lived during the third century B.C. However, it might have actually been invented at an earlier time, noted historians Stephanie Dalley and John Peter Oleson in a 2003 paper.) When "turned by use of animal power, [it] can effectively raise water from lower river heights to higher land area heights," Ortloff said.

The Archimedes screw "consisted of a wooden shaft that had [curves] of thin and flexible willow or wicker branches one stuck on top of the other, so that an endless screw was created," the Kotsanas Museum of Ancient Greek Technology's website notes. This screw was placed within a wooden pipe, and the "device was placed in the water with an inclination of 30 degrees," the museum representatives wrote. As the screw was rotated, it lifted the water.

Water wheels were also used to lift water, including in Roman mines. "The water wheel is a device that raises water and that is made up of several buckets that are fastened to a big wheel," scientists wrote in a 2024 paper. This "kind of wheel resembles a carriage wheel but it is larger and features buckets to catch water in addition to its larger size," they explained.

Another device, sometimes known as Ctesibius' pump, "was hand-moved, operating a wooden lever with a swinging motion," the scientists wrote. It had two cylinders connected to a central chamber through pistons, and the driven water exited through a nozzle connected to the central chamber.

Whatever method was used, the Romans would not let an uphill climb stop them from bringing water where they wanted it to go.

From Augustus to Nero, see how much you know about ancient Rome's famous leaders with our Roman emperor quiz!

For decades, photojournalist Steve Winter has traveled across the world capturing incredible images of big cats as part of his work for National Geographic. Yet he didn't photograph an animal professionally until he was 34.

"If anybody had said, 'You're going to work with big cats for 25 years of your career,' I would have said 'No, I don't know anything about big cats,'" he told Live Science. "But I learned from scientists and local people," he added. "That was very, very important — that's what, to me, was the biggest change in my life."

Together with his wife, author and environmental journalist Sharon Guynup, Winter has helped change laws around big cats in the U.S.; revealed the horrors of the Tiger Temple in Bangkok, resulting in its closure; and took an iconic photograph of the cougar P-22 beneath the Hollywood sign, which eventually led to the creation of the world's largest highway wildlife corridor over Highway 101 in California.

In their new book, "Big Cats" (National Geographic Books, 2026), Winter and Guynup provide a retrospective of their careers, looking at the fragility of these predators, the conservation work helping to save them, and the challenges they still face. Live Science spoke with Winter about his career, the changes he's seen, and why he's hopeful for the future.

Hannah Osborne: You've traveled all over the world and seen so many things. Is there one photograph that really sticks out for you, one that you come back to and think about?

Steve Winter: I always look at the images that have had an impact at the time. That makes a huge difference to me, because in the end, I know that in taking this [photograph], not only did I succeed beyond my wildest expectations, but it's making a difference in the world. Right now, I have just been putting remote cameras up on what will be the world's largest wildlife overpass, and that was started by my Hollywood cougar picture of P-22, Puma 22, under the Hollywood sign. [Editor's note: The common names cougar, puma and mountain lion all refer to the same species, Puma concolor.]

That changed so much in Los Angeles. I've never seen a city be transformed in their love for the fact that they have a mountain lion in a park in the city. What came of that was [people] thinking, "Hey, maybe we should connect these areas where these animals are living." [Editor's note: The Wallis Annenberg Wildlife Crossing over the 10-lane Highway 101 that was inspired by the cougar P-22 is due to open Dec. 2.]

To think about that is pretty amazing, so right now, P-22 and the Hollywood cougar is my go-to image.

He became a celebrity in the land of celebrities; people loved him. There's a P-22 day; schools are using urban wildlife in their curriculum. The LA Natural History Museum has a permanent exhibit, and what is right in the center of it? The Hollywood cougar picture.

HO: How did the P-22 photograph come about?

SW: As wildlife photographers, we will often go to these meetings where people are gathering to save elephants, to save this, to save that. So I went to meet the scientists that worked with these cats in the largest urban park in the United States. I asked Jeff Sikich, a biologist for the National Park Service, "[Do] you have a lot of trails in that park? Do you have any that the cats walk on where you could see the lights of LA in the background?" He kept saying no.

When you're working with camera traps, it's very important to visualize the picture in your mind that you're after [when] you visit a spot. I just said, "Well, Jeff, you know what would really tell the story of urban wildlife is if we had a mountain lion under the Hollywood sign." He looked at me like I'm crazy, and said, "There's no mountain lions in Griffith Park." I said, "If anything changes, let me know."

Eight months later, I got a text. They had a trail camp set up to census bobcats [Lynx rufus] in the park, and there was P-22.

With camera traps, you don't need to sit, and I learned that from the beginning. For the second story I did, it was photographing a quetzal, which is a sacred bird of the Maya and the Aztecs. I knew nothing about birds, either. It's got a meter-long [3 feet] tail. I was enamored by the fact that it had a historical background — they used quetzal feathers as a form of currency; they were sacred birds.

I loved all that, but working on that story in a cloud forest in Guatemala on top of a mountain all by myself, every morning I'd come down and set my camera up on the tripod [near the bird's nest], and then take it away at the end of the day. I'd walk back, and all of a sudden, the hair on the back of my head would stand up and on my arm, and I'd get this tingling feeling and it's like, what's going on? I'd turn around. You can't see anything in a rainforest or a cloud forest because the proliferation of life is everywhere. One night when I'm reading my book in the one room shack that I was staying in my bunk bed, all I hear is the stairs creaking. Then I hear the floorboards creaking. Then I hear scratching, and then sniffing, outside the door.

I grabbed the walkie-talkie to call Juan Carlos, the naturalist that I was working with. He would find the quetzal nests for me. I asked him, in Spanish, "Juan Carlos, what is this?"

And he said, "Oh, Steve, don't worry; it's just a black panther [Panthera onca]." I've been there five weeks, and I said, "Well, how come it took you so long to tell me there was a black jaguar here?" And he said, "We didn't want to worry you."

HO: Throughout the book, you look at topics like poaching, captive tigers in the Tiger Temple in Thailand, and the way they're kept in the U.S. for entertainment. And a lot of these things are still going on. How do you cope with seeing that side of their lives?

SW: When I was first working on tigers, I was in Thailand. I was wanting to work in Thailand and Sumatra because they were the two subspecies that experts said may go extinct. I was working with the most incredible group of scientists I've probably ever worked with. They were trying to save the Indo-Chinese tiger [Panthera tigris corbetti] in Thailand.

But close by was this place called the Thai Tiger Temple. And I said, "Hey, guys; I'd like to go there." And they said, "No, Steve; don't go. These are bad people, and we think they're involved in the black-market trade of tiger parts and tigers to Laos and then into China."

That's a good reason for me to go if you don't want me to go. The first thing I saw was this huge sign that said "conservation." This was a Buddhist monastery. For some reason, the abbot had been given a tiger cub about 10 years before, and he fell in love with tigers. So they started a tiger tourism operation that brought in at least $3 million a year.

I could see something was fishy right away, because by then, I'd learned a lot about these cats. They kept saying that they always had 150 tigers. But you could pet tiger cubs for Instagram selfies or bottle-feed them 365 days a year. If you're breeding tigers, what are you going to have? More tigers. Something was happening to them, because the death rate wouldn't take over the birth rate when you're speed-breeding cubs, which is what they were doing. A female has cubs; they take them away immediately so she'll be ready to have another litter. You can only use the cubs for three months because after that, they're too big to pet.

They had all these tourist things where you could get a selfie with a head of a tiger in your lap. I was saying, "Why are these tigers acting so sleepy?" They're taking this giant head of a tiger and putting it in somebody's lap that's sitting on the concrete. You would think that if you put the head of a tiger in your lap, you're going to end up with your head in their mouth.

[Editor's note: Winter and Guynup worked together on an investigation into the Tiger Temple in 2016, which eventually led to it being exposed for its abuse and connections with the illegal wildlife trade. Shortly after, the Tiger Temple was shut to the public.]

Sharon did the investigation, and I already had pictures. But we went to do a video and go visit the temple again … By the time we got done, the TV stations in Bangkok had taken the video and showed it all over on the nightly news. We kept working on this, and Sharon wrote four more stories. And after the last one, the Thai government was inundated with people calling for the prime minister to shut it down. They went in with the army and the police, and what they found was horrific. They went to the freezer. There were tigers hanging on meat hooks, cubs in jars, with a little Thai flag on them. They shut it down.

Stopping this is really important. After that, we did a story on tigers in the U.S., which was very difficult psychologically. It was one thing to see them in Thailand, but we had always heard that there were more tigers in the United States than there are in the wild, and people would go, "What are you talking about? We don't have tigers here."

Sharon and I … we found a lot of the same speed-breeding cubs at these roadside zoos, whether it was Doc Antle's Myrtle Beach that was $500 a day, or some dumpy little place on the road down south where you can give them $10 to look at a tiger. They were everywhere.

After that story came out, the National Geographic Society gave a copy of this 30-page story that we had done for the magazine to every member of Congress. We got this text on 20th December, 2022, that President Biden had signed the Big Cat Public Safety Act, which outlawed all that. We were part of getting this law passed, which was incredible.

HO: What are some of the biggest changes in conservation you've seen over your career?

SW: Conservation was changing a lot in the '90s and 2000s. Alan Rabinowitz [a zoologist who served as the president, CEO and chief scientist at Panthera Corp., a nonprofit conservation organization devoted to protecting wild cats] had this idea after he had a lot of scientists in Central and South America give him data on where they were working and where jaguars were. When he took it away and just showed the locations, he goes, this is a corridor, a natural corridor, because now we're talking a lot about connectivity and how roads get in the way. It's like animals are in prison because they can't cross these big freeways or even small ones. Find out where animals are, their migrating paths, and put in an overpass or an underpass or something.

All this was happening, all this new science, new conservation. That was all spearheaded by the work of [biologist and conservationist] George Schaller, who became a friend of ours. What a life that we've had — and are having. We're still working on the connectivity part right now.

HO: Are you hopeful for the big cats in LA?

SW: Oh, definitely. The ones that live in the Santa Monica National Recreation Area will be able to cross the 101 and then go all the way to San Jose. They could actually then hug the top of a certain mountain and get close to San Francisco, which is incredible to think about now. It's a huge metropolitan area, so you're leaving one, going to another. But there's so much land in between, and they can cross safely.

HO: What made you specialize in big cats in the first place, and what's the draw that keeps you coming back?

SW: Big cats are so charismatic and, to me, mystical. And they're an umbrella species, so if you save the largest predator, which is usually a big cat in any landscape, you save everything underneath it.

I was just taken over by these animals. National Geographic had never done a jaguar story before. I found out really quick why: You can't see them. I tried to use remote cameras, camera traps, but they're really smart. They'll go around them, so they don't have the flash going off or they don't like the sound or the smell of meat on these waterproof boxes and the cords and all that.

I just fell in love with big cats, and what a life to be able to work with every one of them. The only one that was on my list that I haven't done is the Amur tiger, Siberian tiger [Panthera tigris altaica]. When I was ready to photograph them with the scientists that had been monitoring them for over a decade, [the tigers] got canine distemper and about 60% died.

Big cats really bounce back when you give them protection, and there was protection given after you lose this many. All the study tigers that had the GPS collars on, the ones they could monitor, died. But the population bounced back, and there's more now than there were before.

I won't get to photograph Amur tigers. And the reason is, there's people — locals — who are working on it, and they're doing an incredible job. I've got a book here that has all the cats that I've worked on. The impact these stories have had, and the change that's come about, is what really makes me proud.

This interview has been condensed and edited lightly for clarity.

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The written word is one of humanity's most important information technologies. Without it, mathematical and scientific discoveries would be lost to history. But it can also lock ideas in place long after they've stopped making sense.

So does writing speed up cultural change or slow it down?

Russell Gray, a professor in the Department of Linguistic and Cultural Evolution at the Max Planck Institute for Evolutionary Anthropology in Germany, heads a research project investigating how writing affects the way languages change. His team uses methods borrowed from evolutionary biology to trace languages through family trees — similar to the way biologists trace species.

Language is one element of culture that researchers can measure to determine whether writing speeds up or slows down cultural change.

"The obvious answer," Gray said, is that writing slows culture down because writing "is all codified and specified and people get trained in it." Gray doesn’t think the obvious answer is necessarily the right one. But other researchers agree that writing can lock in ways of thinking.

"Writing can lead to what learning psychologists sometimes call 'canalization,'" Charles Perreault, an associate professor in the School of Human Evolution and Social Change at Arizona State University, told Live Science in an email. "It can narrow the range of ways people think about a problem. When a rule, method, or story is written down, people may come to see it as the correct version … and may not even consider that a better or different way could exist."

Religious texts and legal codes are good examples. In both cases, the interpretation of rules written hundreds ‪—‬ or even thousands ‪—‬ of years ago shapes the way things are done, long after the circumstances that produced them have changed.

This idea shows up in artistic expression, too: A 2017 analysis by ethnomusicologist Patrick Savage looked at more than 4,000 British-American ballads from the 16th through 20th centuries and found that written melodies changed less than those shared through oral tradition.

But there are also ways that writing may speed up cultural change.

"Before writing, much cultural knowledge had to be stored in people's brains," Perreault said. "That has obvious limits."

People forget things they don't study routinely, and when people die, their knowledge often dies with them. Because writing moves information storage beyond the human brain, it can reduce those losses, Perreault said.

"If writing prevents knowledge from being lost, and if it also helps information spread through a society, as with the printing press, then it could accelerate the ratchet effect of cumulative cultural evolution," Perreault said. "But this remains, to some extent, a hypothesis."

By the book

One reason the question of whether written language speeds or slows cultural evolution is that writing is hard to separate from everything that comes with it.

Writing has been separately invented only around four times in human history — although "some people argue there's a fifth in India," Gray said — which means nearly every writing system on Earth descends from that handful. Those systems spread through contact; trade, war, religion and the other ways humans intermingle had their own effects on cultural change that are hard to untangle from the effects of writing.

Also, "mass literacy is quite recent," Gray said. "If you've got these written varieties that are just used by, often, religious elites, that's potentially going to have much less impact."

So which force wins? Both experts think writing speeds up cultural change, though neither can prove it yet.

"I would say that writing probably speeds up cultural change overall," Perreault said. Gray agreed, though he acknowledged that most people would guess the opposite.

Still, Perreault cautioned, "these are empirical questions that have yet to be answered empirically."

Flu season is off to an early start in some parts of the U.S., data shows.

In a typical year, U.S. flu activity starts building in late fall — typically in October or November — and peaks between December and February. This year, flu activity is currently low but rising nationwide: During the week ending Sept. 26, 3.4% of respiratory samples tested by clinical labs were positive for flu, according to Centers for Disease Control and Prevention (CDC) data.

That's about seven times the rate that was seen at the same point last year. About 0.5% of samples tested positive during the week ending Sept. 27, 2025.

"This particular year, it appears to be starting early — like right now," Dr. William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt Health in Tennessee, told Live Science. Patients at clinics in his area are already testing positive for flu, he said.

The early uptick in flu is mostly unfolding in Western states, including Washington, California and Arizona. In Washington, for example, the share of emergency department visits diagnosed as flu climbed from 0.25% in the week ending Aug. 29 to 1.34% in the week ending Oct. 3, according to CDC emergency department data. That's a more than fivefold increase over six weeks.

Where the flu took off first isn't a warning sign in itself, Schaffner noted.

"There's nothing unusual about flu starting in the West Coast and moving east," he said. Recent seasons have more often begun in the Southeast or Midwest, he noted, but "it can start almost anywhere."

Leading with H1N1

Nowadays, seasonal flu is caused by three subtypes of flu viruses: two subtypes of influenza A, called H1N1 and H3N2, and the Victoria lineage of influenza B. (A second subtype of influenza B used to circulate but is now thought to be extinct.)

Last season, a fast-spreading version of H3N2 known as subclade K dominated. The CDC classified the 2025-2026 season as highly severe for children, as at least 195 children died of flu-related causes.

Schaffner likens influenza A and B to siblings. "They're very related, but they each have their own individual characteristics," he said. Influenza A strains usually cause the biggest outbreaks early in the season, while influenza B strains "kind of smolder along" and account for most cases toward the end, he noted.

This year, H1N1 has taken the initial lead. Of the influenza A samples that public health labs subtyped during the week ending Sept. 26, 96% were identified as H1N1, according to CDC data. That doesn't mean H1N1 will continue to dominate throughout the season; it just gives a snapshot of what's happening now.

The dominant strain matters because flu is "a moving target," said Dr. Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia. The virus constantly mutates — especially hemagglutinin, the protein on the virus's surface that it uses to latch onto human cells. Hemagglutinin is the main target of flu vaccines.

An early start to the season doesn't guarantee it'll be a severe one, either. In its 2026-2027 season outlook, the CDC projected that this season will likely be moderate, although it has only low-to-moderate confidence in that forecast.

When to get vaccinated

Everyone 6 months and older is recommended to get an annual flu vaccine.

Influenza is especially dangerous for children under 5, adults 65 and older, people with chronic health conditions and pregnant people, as these groups are more prone to severe infections. Serious cases of flu can lead to complications such as pneumonia, sepsis, and brain or heart inflammation, and in some cases, they can be deadly. Tens of thousands of people die of flu each season in the U.S.

For flu vaccination, timing matters. The CDC generally doesn't recommend vaccination in July or August for most adults, because the shot's protection can wane over the course of a season. But with flu arriving early, "October is the ideal time to get vaccinated, and even more so right now," Schaffner said.

When circulating strains' features differ from those captured in the vaccine, "that usually predicts a more difficult season," Offit said. That said, it's too early to know if this year's flu shots are a good match for the circulating flu viruses.

Protection begins building right after you get the shot, but it takes up to about two weeks to reach full strength.

How much protection a flu vaccine offers varies by season, depending partly on how well its formulation matches the strains that circulate. Offit said that protection against symptomatic illness varies by age group and that the vaccines are "a little more effective" at preventing more severe illness. In terms of flu cases that prompt people to seek medical care, the shot has been 29% to 56% effective over the past decade, the CDC estimates.

While the vaccines are less reliable at preventing mild cases of flu, Schaffner said, they work best at "keeping you out of the hospital, keeping you out of the intensive care unit, and keeping you out of the cemetery."

The CDC's 2026-2027 guidance keeps its recommendation of an annual flu vaccine for everyone 6 months and older, with high-dose and adjuvanted shots preferred for adults 65 and older. (Adjuvanted shots contain an extra ingredient to help rev up the immune system.)

There's also a new option: In August, the Food and Drug Administration approved mFlusiva, the first mRNA flu vaccine, for adults 50 and older. (You can find out where mFlusiva shots are available near you using Moderna's vaccine finder.) With the mRNA shot, "you're less likely to get symptomatic disease," Offit told Live Science.

Traditional flu shots contain purified pieces of the virus itself, Schaffner explained. With mRNA, the vaccine contains a "blueprint" of those proteins — essentially a set of genetic instructions that the body's cells then use. In mFlusiva's case, those instructions code for hemagglutinin (the protein on the virus's surface that it uses to latch onto human cells) from each of three flu subtypes, Offit said. The mRNA then breaks down in the body, Offit noted. It "cannot influence human genetic material," Schaffner emphasized.

Whether this early start gives way to a heavy flu season should become clearer in the coming weeks, as the CDC's weekly surveillance reports will show whether cases keep climbing beyond the West.

This article is for informational purposes only and is not meant to offer medical advice.

Imagine you're road-tripping across the country 10 years from now. You spend a few minutes charging your electric vehicle and then set off — and your car's solar paint keeps it charged as you drive.

Your eyes are on the stunning scenery, taking in the vistas along Route 66 or the grandeur of the Rocky Mountains, or you're catching up on messages. Your hands barely touch the wheel, and your foot doesn't push a pedal. Your car communicates with others on the road, so there's no need to brake suddenly or swerve. That's because it knows a vehicle five cars up from you has done so, and all those in between are slowing at exactly the right pace to avoid dramatic changes in trajectory.

And when you park for the night, your car makes you money, selling the excess energy it's harvested from its paint back to the grid. Or maybe you don't feel like being in the driver's seat at all, so you hail a self-driving car and take a nap in the back seat in between adventures.

Some of that scenario may become a reality in the next 10 years, at least for those who are using the most cutting-edge cars on the market. Although there's some heavy speculation involved in that futuristic vision, vehicle manufacturers are already incorporating increasingly sophisticated automated driving technology into high-end personal vehicles, and self-driving taxis are coming to dozens of U.S. cities.

What's more, dramatic changes in range, cost and charging speed for electric vehicles (EVs) are arriving at a rapid pace. While some of these technologies may not wind up in personal cars, others are already taking to the roads.

An ecosystem of connected vehicles

Some car models within the next decade may interact with their surroundings in new ways, including by communicating with other cars to avoid collisions, drawing energy from natural sources, or letting drivers get paid for sending their cars' unused energy back to the grid.

If you're driving an EV, you might avoid the hassle of finding a charger when you're at work or running errands. In 2024, EV company Aptera unveiled a prototype car equipped with solar panels. Those panels — on the car's hood, roof, dashboard and hatch — allow the vehicle to travel about 40 miles (64 kilometers) per day on solar power. That's more than the average American drives per day. Aptera's vehicle can also travel up to 400 miles (640 km) on a standard electrical charge.

Some sunlight-powered cars might ditch the solar panels altogether in favor of a more integrated design. In 2024, Mercedes-Benz revealed it was researching a photovoltaic paint that could convert sunlight into energy for electric cars. In sunny cities such as Los Angeles, the company calculated, the paint could draw in enough energy to power the car for nearly 7,500 miles (12,000 km) per year. The tiny particles in the paint convert about 20% of the energy from sunlight into electricity, which is comparable to the efficiency of existing solar panels.

You might even be able to sell some of the energy stored in your car's battery back to the grid. EV owners could charge during the day or late at night, when the demand for electricity is lower and pay lower rates for electricity. Then, in the evenings when the electrical grid is under more strain and the price of electricity is higher, they could sell that stored energy back at a profit.

Standardized software programs that throttle EV charging speeds during peak hours already exist. Drivers can use them if, for example, they want to keep charging costs down by primarily charging their cars during off-peak hours when electricity costs are lower, or if they want to use electricity only from solar power to charge, said Rajit Gadh, a researcher who studies EV charging and scalability at UCLA. But the process for sending energy back to the grid is a different story. Individual manufacturers haven't yet landed on a standard way to tell cars when and how much energy to discharge, Gadh said.

"What is needed is really [for] every EV charging vendor ‪—‬ and every EV manufacturer, actually ‪—‬ to have this protocol built in, adhere to it in its full specification, and make it available," Gadh told Live Science.

With the right protocols, though, cars of the future will be able to do more than interface with the electrical grid. "Vehicle-to-everything" technologies could enable cars to communicate with infrastructure and other vehicles to avoid traffic and collisions.

Some cars today are already equipped with vehicle-to-vehicle (V2V) communications. These systems use short-range radio signals to alert other V2V-equipped vehicles of the car's speed, direction of travel and braking patterns. The radio signals can travel about 1,000 feet (300 meters), allowing the vehicle to receive data from cars that are not in the driver's line of sight.

V2V systems could help reduce traffic collisions by warning drivers about oncoming cars they can't see yet — for example, by alerting a driver to another car speeding toward an intersection or coming around a bend as the driver is passing another vehicle on a twisty, two-lane highway. Not all cars have the technology, though, so its practical utility is limited for now.

Hands off the wheel; eyes off the road

Some driver assistance technologies, such as lane departure warnings and cruise control, have been on the market in personal cars for decades. These technologies and more recent assistive features require the driver to be in control of the vehicle, but theoretically, they make driving easier. For example, Tesla's Full Self-Driving (Supervised) mode handles most steering and braking tasks, but safe operation requires the driver to keep their eyes on the road and be ready to take over at a moment’s notice. In the next several years, drivers will likely see new features that automate driving in more contexts.

Some of these features will allow drivers to take their attention off the road entirely and enjoy some in-car entertainment, as long as they're alert and able to retake control of the vehicle within a few seconds if conditions change. Technologies that fully automate driving in many circumstances within certain service areas will likely be in about 4% of cars on the market by 2035, according to a white paper from the World Economic Forum.

In cars equipped with these features, "you're still going to have driver controls, but under certain circumstances, it will be effectively an automated vehicle," Luke Neurauter, who leads the Division of Vehicle, Driver and System Safety at the Virginia Tech Transportation Institute, told Live Science.

Mercedes-Benz introduced its Drive Pilot system for two consumer car lines in 2022. On the entire German Autobahn network and on certain freeways between and around Los Angeles, San Francisco and Las Vegas, during heavy traffic, the system lets the driver turn their attention toward other activities, such as reading a book or eating lunch, while the car handles steering and keeping pace with other nearby vehicles.

But as the artificial intelligence (AI) models that control autonomous driving improve and become better able to handle unusual scenarios — often called "edge" or "corner" cases — on the road, drivers will be able to hand over control to their cars in more situations, said Rahul Jain, an electrical and computer engineer at the University of Southern California.

Future AI systems might "have some reasoning ability, and then because of that, it can handle these corner cases much better than current systems are able to do," Jain told Live Science. For example, a car might be able to better respond to an indecisive pedestrian who suddenly enters a crossing, assess whether to enter potentially hazardous conditions such as flooded roads, or safely navigate around unusual circumstances, such as construction work, on a highway.

While some systems will enable drivers to make fewer decisions, others that may roll out in the next several years will track a driver's attention and alert them with sounds, an indicator light or haptic feedback when their focus falters. These systems use cameras and software to track head position, eye movement and steering-wheel input to ensure drivers are focused on the road even when they're using assistive features such as lane centering, Neurauter said.

In addition to looking for distracted driving, the technology might expand to monitor drivers for fatigue and alcohol impairment, he added. That information could then affect "whether or not other features become active, or change how they act, based on the driver state at that moment in time," Neurauter said. Proposed legislation could make this technology a requirement in new vehicles as early as 2027, but technological hurdles and concerns over privacy and false positives could stall its implementation.

The technology could also assist drivers who become unable to safely operate the vehicle — for example, if the driver falls asleep or experiences a medical emergency. If a car detects that the driver is not holding the steering wheel or actively controlling the vehicle, it could send a series of visible, audible, or tactile alerts. If the driver doesn’t respond to those cues, a car might turn on its hazard lights and come to a stop. Some vehicle manufacturers are already rolling out such technology; for example, Volkswagen has made it available in all new vehicles from model year 2025.

Fully autonomous vehicles

While personal cars may not offer full automation, highly automated car services will become much more common as rideshare vehicles in major metro areas. In some cities, like San Francisco, commuters already rely heavily on autonomous vehicles from Waymo. The company has rolled out its cars in nearly a dozen cities —‬ including Dallas, Houston, Atlanta and Los Angeles —‬ and has announced plans to expand service to more than 20 additional locales. Other companies ‪—‬ such as Nuro and Volkswagen’s MOIA ‪—‬ are testing their vehicles with human drivers on board before rolling out full public service.

Currently, autonomous vehicles navigate by combining information from preloaded, high-resolution maps and real-time radar, lidar and visual data collected by cameras and sensors attached to the car. An onboard computer uses that information to build a 3D map of its surroundings. Right now, the cost of these sensors makes them impractical for consumer vehicles, Jain said, but they’re becoming cheaper as manufacturers scale up production. The cars also use an AI model trained on both common and unusual driving situations to anticipate how other vehicles and pedestrians will behave and plot a safe path forward, Jain added.

Developing those high-resolution maps takes time, which is one of the main reasons autonomous rideshares aren’t available everywhere yet. Mapping usually involves decking out a car with high-end visual sensors and lasers and driving it throughout the region. Although cities like San Francisco have been mapped with this level of precision, much of the U.S. has not.

"It's very difficult to do overnight," said John Dolan, an autonomous-driving researcher at the Carnegie Mellon University Robotics Institute.

Complexities also tend to arise in city environments, where unexpected stops are more common and there are many pedestrians who behave unpredictably or jaywalk. But interstate highway driving doesn't face as many of those obstacles, and that could enable autonomous long-haul drives.

"[Autonomous] trucking, I would expect, would be the first thing that's going to happen" in terms of autonomous travel outside of major cities, Jain said. A few driverless trucks are already on the road: Pittsburgh-based company Aurora deployed the technology on I-45 in Texas, between Dallas and Houston, in 2025, with plans to expand across the southern U.S.

Longer range and faster charging

While there's speculation involved in predicting the range of self-driving capabilities available in a decade, the picture for EVs is a little clearer.

Right now, lithium-ion batteries dominate the EV market. Each cell in a lithium-ion battery has two electrodes, commonly a layered graphite electrode and a metal oxide or phosphate electrode, separated by a liquid electrolyte solution. Lithium ions migrate back and forth between these two electrodes when a person charges and discharges the battery.

Many electric cars with lithium-ion batteries can already travel more than 300 miles (480 km) on a charge. But that's not ideal for a long-range car trip, because charging stations are few and far between in the country's vast interior and charging takes longer than filling up a gas tank.

Solid-state batteries, which replace the liquid electrolyte with a solid electrolyte made of ceramic, polymer or sulfide materials, could make that cross-country trip in an EV a practical option, allowing an electric car to travel more than 750 miles (1,200 km) on a single charge. Some prototype battery packs can already achieve this range under controlled conditions. If a solid electrolyte were paired with an anode made of pure lithium, rather than graphite or hard carbon, it would allow the battery to store more energy than a lithium-ion cell of similar mass can.

Solid-state batteries may also enable faster charging. In current batteries that use liquid electrolytes, charging and discharging the battery too quickly can cause dendrites, thin branches of lithium that stretch across the cell and short-circuit the battery. A solid electrolyte could, in theory, block those dendrites, which would enable cars to charge fully in just 10 to 15 minutes. The higher energy density from a lithium metal anode also translates to a greater range than that from a similarly sized lithium-ion battery, Eric Wachsman, director of the Maryland Energy Innovation Institute at the University of Maryland, told Live Science.

Cheap EVs

Many of the raw materials that go into existing lithium-ion batteries are concentrated in a handful of geographic areas. In 2023, Australia, China and Chile mined about 85% of that year's lithium supply; China mined the majority of graphite used that year as well. And battery materials still make up a significant portion of an electric vehicle's cost.

Sodium-ion batteries could be cheaper and easier to source. Sodium is plentiful in Earth's crust, which means mining could be done throughout the U.S., potentially with a comparatively low environmental impact.

Such batteries also rely on a more widely available electrode material. Sodium ions are larger than lithium ions, so they don't fit in between layers of graphite like lithium ions do. Instead, sodium-ion batteries use hard carbon electrodes.

"When you cook at home and your soup boils over and you get this black ring around your pot, this is hard carbon," Maximilian Fichtner, a solid-state chemist at the Helmholtz Institute Ulm for Electrochemical Energy Storage in Germany, told Live Science. "You can produce this from sucrose or from biomass, from whatever. You can do that everywhere."

The downside is that hard carbon holds less sodium than graphite holds lithium, said Eric McCalla, a battery materials chemist at McGill University in Canada. That means sodium-ion batteries can't store as much energy relative to their mass, and they don't last quite as long as their lithium counterparts.

"The range won't be as large," McCalla told Live Science. "It'll be a fantastic commuter car, but you're not going to go on a family trip from Montreal to California so easily."

Manufacturers are already bringing sodium-ion technology to market. For instance, the Chinese company CATL began mass-producing the batteries in February and claims that their battery packs enable EV ranges over 250 miles (400 km).

But new technologies are being developed rapidly. For example, some scientists are making sodium-ion batteries that use solid electrolytes, combining the higher energy density of solid-state lithium batteries with the cost savings of sodium batteries.

This hybrid battery chemistry is still in the early stages of development, experts told Live Science. "I would be surprised to see them in cars in the next decade," McCalla told Live Science in an email. "I've been surprised before, though."

Bumps in the road

The future we're describing is the utopian scenario. But the biggest obstacles are likely not technological but rather regulatory, economic, political or cultural, experts said.

"We're going to try to guess at a timeline of when some of these things are going to come in, and odds are, we're going to be wrong," McCalla told Live Science. "Odds are, we're going to be slower than we think."

Solar panels may not wind up being the most economic or practical way to increase EVs' range, while scaling up manufacturing capacity for next-generation batteries is expensive and could slow EV adoption in the U.S. The utility of vehicle-to-vehicle communications, meanwhile, could be limited by a slow rollout and adoption of V2V-equipped cars among drivers.

Whether EVs will be ubiquitous will likely come down to their affordability relative to gas-powered vehicles, which is affected not just by manufacturing and technological advances but also domestic policy choices, such as whether to subsidize EVs or their charging networks.

One challenge for manufacturers is that the automated features drivers prefer may not always be safer. A recent review of automated systems found that those focused on driver safety, such as automatic safety or lane centering, tend to reduce crashes, while those focused on comfort, such as adaptive cruise control, can increase accidents. The authors proposed that such systems make it easier for people to disengage or become distracted while driving and possibly overestimate the capabilities of the system.

And there are other kinks to work out for autonomous rideshare vehicles. In December 2025, a horde of Waymos stalled during a power outage, clogging San Francisco intersections. The cars are programmed to treat dark traffic signals as four-way stops, according to a statement from Waymo, but they occasionally ping human operators for confirmation. During the outage, the number of confirmation requests spiked, leading to delayed responses — and lengthy traffic jams. The company says it has since released software updates that allow its vehicles to act more decisively at dark signals. But questions remain about how the fleet will respond in natural disasters, and some have expressed frustration that autonomous rideshare vehicles already slow down ambulances, fire trucks and police cars responding to emergencies.

One of the biggest roadblocks to automated driving is the regulatory environment, Neurauter said. Regulations on self-driving vehicles vary by state, and some, such as New York, effectively prohibit driverless vehicles entirely. Where they are legal, they often must carry higher insurance and pass testing, which could limit their rollout.

"When we get into automated driving, the driving behavior is being governed by software that's installed on a computer that's in the vehicle," Steven Shladover, a research engineer at the University of California, Berkeley, told Live Science. "That gets us into a messy gray area where both the federal and the state roles kind of overlap, and that's politically very complicated." For example, different states could end up with different rules for establishing who's legally responsible for an accident involving automated driving.

In 10 years, you'll almost certainly be able to drive from Los Angeles to Las Vegas in an autonomous vehicle. But if you want to drive to New York City, you might have to stop in New Jersey — and take a train into the city.

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Researchers have developed a new type of tattoo ink that can be switched on and off with light, allowing colors and images embedded in the skin to be changed and even "erased" without having to go through the painful tattoo-removal process.

The system, which is being commercialized under the name PhotoTat, could eventually give people a way to conceal or change permanent body art. It could also have more practical applications, including medical tattoos that are visible only when a doctor needs to see them, researchers reported in a study published Friday (Oct. 9) in the journal Matter & Light.

"This is a tattoo that you can have, and whenever you decide you don't want it to be showing anymore, or you just don't want it there, you just turn it off," said study co-author Carson Bruns, an associate professor of biomedical engineering at the University of Colorado at Boulder. "And that's it. You don't have to turn it on again."

Working like a light switch

PhotoTat contains three primary color inks — blue, magenta and yellow — made with photochromic dyes, which are light-sensitive compounds that can change color with different wavelengths of light. These dyes are encapsulated in nanoparticles of polymethyl methacrylate (PMMA) — a medical-grade, glass-like plastic that is already used in medical implants and dermal fillers.

The dyes change their molecular structure when exposed to specific wavelengths of light. A 365-nanometer ultraviolet (UV) LED can activate pigments in around two to three seconds, Bruns said. Once activated, the colors can persist for hours to days under typical indoor lighting. But once the wearer exposes their skin to the bright outdoor sun, the colors disappear in seconds, erased by the intense light.

That makes the tattoo unique, as the pigment itself remains in the skin but the tattoo's appearance changes. Bruns and his team found that all three PhotoTat channels remained switchable in the skin for between 1.4 and 2.2 years.

Tattooing yourself for science

The three colors enable someone to activate different portions of a tattoo using different wavelengths of light. That means the magenta part of the tattoo might be turned on with green light, while the yellow pigment would be activated by blue light. This allows the wearer to customize their design and coloration to whatever they want at the moment — from a purple cherry to a yellow group of hearts.

That feature makes PhotoTat appealing for "people who love tattoos and have lots of tattoos, but just want something kind of fun and playful to add," Bruns told Live Science.

Bruns has tested each iteration of PhotoTat's inks on his own skin. His art is arranged in a series of tattooed scales, with different ink formations in individual scales.

"I gave myself these scales on purpose because they're each sort of a container for an experiment," Bruns said. The result, he joked, resembles a "magical mermaid trick," with some scales appearing out of nowhere and others changing color when activated.

The technology can also be combined with conventional tattoo ink. A permanent black ink design, for example, could contain hidden PhotoTat elements that appear only when activated.

The new tattoos could be appealing to people who want tattoos but are hesitant about their permanence, as well as to people who love their tattoos but occasionally need to conceal them because of work, social expectations or family, Bruns said.

"It's going to be on for most of the time, but just for this one moment, I'm going to turn it off for you grandma, for example," Bruns said.

Medical tattoos

Bruns thinks the tattoos could be helpful in a medical setting, too. Patients undergoing radiation therapy, for example, sometimes receive permanent tattoos that help doctors precisely align radiation beams. While useful, those marks remain after the treatment, reminding the patient of their experience. These would make such markings invisible if a patient wants them to be.

PhotoTat could potentially allow similar markings to be switched on during surgery and hidden afterward.

Bruns has spent several years developing other smart tattoos for medical applications, including a dosimeter-type tattoo that measures the amount of UV radiation a wearer experiences, along with a tattoo that changes color when the wearer is exposed to dangerous gamma radiation.

"It's not for you and me, but if you're like an astronaut or a nuclear engineer, they have to wear these dosimeters," Bruns said. "So, we have like a dosimeter tattoo that sort of puts that in your skin."

So far, Bruns and a fellow tattoo artist, have only commercialized the purple PhotoTat ink, after running the ink through a series of third-party medical tests.

The tests showed the purple is safe for use, and available to order, but it isn't cheap at $100 for a small bottle. Bruns hopes as more research is done, he can bring the other colors to market and lower the production cost, so the technology is more accessible.

Two people born on the exact same day can age in totally different ways ‪—‬ one in relative health and the other with chronic disease. Now, scientists have found a key difference in the immune systems of people who are more prone to age-related conditions, and it could help explain why some people remain healthier longer.

In young people, the immune system contains many naive T cells, a type of white blood cell. Over time, exposure to pathogens and vaccinations transforms some of these T cells into memory cells, which can respond quickly to defend the body against germs.

These memory cells make different types of characteristic proteins, called granzymes, which kill infected cells. They come in different "flavors," including granzyme K and granzyme B.

In a new study, published Friday (Oct. 9) in the journal Immunity, scientists found that individuals with more memory cells that make granzyme K than cells that make granzyme B tend to have healthier aging.

In the future, the balance of cells making granzyme K and granzyme B in a person's blood could be used as a test to determine "whether you're on the right trajectory of aging or not," study co-author Maxim Artyomov, an immunologist at Washington University in St. Louis, told Live Science.

Hunting for a signature of healthy aging

In earlier research, the same team found that, in old lab mice, granzyme K-making cells accumulated in several tissues and were linked to inflammation. They also observed the same increase in granzyme K cells in blood samples from older adults.

In the new study, they uncovered another piece of the puzzle: a dynamic with granzyme B-producing cells.

They began by analyzing immune cells sampled from over 2,600 people ages 18 to 97, looking at the balance of granzyme K- and granzyme B-making cells. They found that people with a lower ratio of granzyme K to granzyme B cell populations were more likely to have autoimmune diseases or other chronic immune conditions.

In a second analysis, they looked at both immune cells and blood-borne proteins sampled from 329 people, using the data to pinpoint a "protein signature" linked to an abundance of granzyme B-making cells.

They went on to hunt for this protein signature in around 48,000 participants who'd provided data to the UK Biobank, a large database of health data from U.K.-based adults. People who were predicted to have higher levels of granzyme B-making cells based on their blood proteins had worse health outcomes in the following 17 years, with a higher risk of death and of conditions like diabetes, high blood pressure, and liver and kidney disease.

The findings might point to an aspect of immune aging that wasn't previously understood.

"I think that's really exciting," Claire Gustafson, an immunologist at the Allen Institute, said of the results. "It highlights there's potentially some novel biology that we haven't really observed before," Gustafson, who was not involved in the research, told Live Science.

However, while there's a strong association between the balance of these cell populations and disease risks, Artyomov emphasized that the study does not prove that this ratio directly causes the poor health outcomes. Further studies would be needed to understand why having more granzyme B cells is linked with poorer health.

"This observation might be just a consequence, not a cause of the disease," Artyomov noted.

It's also important to note that granzyme K-making cells in mice are not the same as granzyme K-making cells in humans. In mice, they represent a more mature, specialized stage of immune cell development, whereas in humans, granzyme B cells better fit that description, he told Live Science.

That points to a key way that immunity in mice and humans is different, which was "underappreciated" before, Gustafson said. So when we're comparing these cells in mice and humans, "we're not looking at apples to apples," she said. Scientists now specifically "need to look more into humans, as it's not reflected in animal models."

In people, immune cells' features can also vary across diverse human populations, Gustafson added. We need more data across different populations to get a "true understanding of universal immune health," she said. The K-to-B ratio may be a "novel" clue that can help scientists understand healthy aging, but more data is needed to unpack why and how that ratio is linked to healthy or unhealthy aging.

"This is kind of like the first step to be able to get there," she told Live Science.

This article is for informational purposes only and is not meant to offer medical advice.

A bronze signet ring depicting the Lighthouse of Alexandria, a wonder of the ancient world, has been discovered underwater in the Mediterranean off Alexandria, Egypt.

A joint team from the European Institute for Underwater Archaeology (IEASM) and the Egyptian Ministry of Tourism and Antiquities found the artifact in the remains of a palace on the now-submerged island of Antirhodos, marking the first time a signet ring featuring the image of the lighthouse has been found, the IEASM team said in a statement.

The image on the ring is similar to depictions of the lighthouse that have been previously found on coins dating to the second century, representatives of IEASM said.

"The discovery of the ring-signet is even more important as it has been excavated in the legendary palace of the Island of Antirhodos, that once was a centre of power," Franck Goddio, president of IEASM, said in the emailed statement.

The palace was used by Egyptian pharaohs who reigned during the Ptolemaic period (304 to 30 B.C.), a dynasty of rulers descended from one of Alexander the Great's generals. The lighthouse was built on the island of Pharos around 280 B.C. and stood more than 328 feet (100 meters) tall. Some ancient writers, such as Pliny the Elder, considered it among the wonders of the world, and it continued to be used into the Middle Ages, until earthquakes and erosion resulted in its destruction and disappearance beneath the sea.

While the lighthouse was modified over time, it would have had a statue, possibly of Zeus, at the top holding an oil lamp that helped guide mariners.

Whoever was wearing a signet ring could have used it to make an impression on soft materials, such as clay and wax, to create a seal. The discovery of the ring in the remains of the palace at Antirhodos suggests that the palace was used for administrative functions related to the lighthouse, representatives of IEASM said in the statement.

Even though the ring's engraving is somewhat worn, it likely depicts the lighthouse, said Doris Behrens-Abouseif, a professor emeritus of history of art and archaeology at the University of London who has written about the lighthouse but was not part of the research team.

There are "thousands of coins from Alexandria showing a similar depiction of the lighthouse," she told Live Science in an email. Those coins date to the Ptolemaic or Roman (29 B.C. to A.D. 395) periods, she noted.

Behrens-Abouseif added that she wasn't familiar enough with rings from Alexandria to comment on whether this is the only ring that contains this image.

Other scholars told Live Science that they, too, believe that this ring depicts the lighthouse, with two scholars noting that it may feature smoke coming from a lamp at top.

The "most interesting thing about the new signet ring engraved gem is an asymmetrical feature at its peak," which "may depict a plume of smoke from the oil lamp in the hand of the crowning statue," Andrew Chugg, an independent researcher who wrote the book "The Pharos Lighthouse in Alexandria: Second Sun and Seventh Wonder of Antiquity" (Routledge, 2024), said in an email.

Margaret Miles, a professor emeritus of art history and classics at the University of California, Irvine, also noticed the possible plume of smoke. Miles noted in an email that this "ring could have been used as a signet ring by a merchant from Alexandria who used the profile of the [lighthouse] to signal his location in Alexandria. The lighthouse was famous, so it became a symbol of the city."

Research off the coast of Alexandria over the past few years, including the discovery of 22 massive blocks, has revealed more information about the lighthouse, including how exactly it looked, which is helping researchers who are trying to digitally reconstruct it.

Are you a fan of mummies and hieroglyphs? Find out with our ancient Egypt quiz!

A four-legged robot completed a full marathon on a single battery charge, covering 26.2 miles (42.2 kilometers) on a hilly public-road course in South Korea two years ago. Now we know a lot more about how it achieved this record-breaking feat.

The dog-like robot, called RAIBO2, finished the 22nd annual Sangju Dried-Persimmon Marathon in just over 4 hours, 19 minutes. The bot's developers say it's the first quadruped robot to have completed an official marathon-distance event without stopping to recharge. They're commonly referred to as "robot dogs" because the movement of their joints in both front and hind legs resembles that of canines.

The scientists outlined their findings about the robot's feat, which it achieved Nov. 17, 2024, in a study published Sept. 23 in the journal Nature.

This achievement represented a new milestone in overcoming a critical limitation for quadruped robots: endurance. Although four-legged robots can cross difficult terrain that wheeled machines struggle to traverse (like stairs and rugged trails), their endurance has been limited because powering multiple joints while repeatedly lifting and stabilizing the machine's body consumes huge amounts of energy.

"Unlike wheeled robots, quadrupeds continuously expend energy at their joints to support body weight and incur kinetic energy losses during intermittent foot-ground contact," the researchers wrote in the study.

RAIBO2's race was a demanding real-world trial. It took place during the Sangju Dried-Persimmon Marathon, with the bot racing alongside human participants. The route covered two 50-meter [164 feet] elevation climbs, with slopes of up to 10 degrees. Those kinds of gradients put increased strain on the robot's energy resources, stress-testing the bot's battery management capabilities, the scientists said.

RAIBO2 had previously run a 26.7-mile (43 km), GPS-guided route across a flat athletic field, which it knocked out in 4 hours, 40 minutes on one charge. However, an earlier marathon attempt across uneven terrain against other competitors had to be aborted around the 23-mile (37 km) mark after the robot's battery ran out. The robot's developers attributed that shortfall in part to frequent pace changes as the machine attempted to adjust to the pace of nearby runners.

To compensate, the team boosted the robot's battery capacity by 33% and tinkered with the control system, including implementing joint-stiffness control at the actuator. This allowed the bot to soften its leg when it had to absorb an impact or it needed a stable, forceful push-off. After the adjustments, RAIBO2 expanded to a maximum range of 41.6 miles (67 km) on a single charge, albeit on straight paths, according to the researchers.

Another key metric was RAIBO2's total cost of transport — a measure of the energy required to move a body over a given distance, with lower values indicating less energy expended. Researchers reported that RAIBO2 achieved a total cost of transport of 0.25, compared with a human benchmark of 0.37. The researchers said their machine was the first quadruped robot to surpass that figure.

The team attributed that efficiency to several optimizations across RAIBO2's software and hardware. Especially vital were its lightweight mechanical components, which were capable of transmitting kinetic energy from its joints with very little interference. They also credited a low-loss motor-driving circuit and, on the software side, a locomotion policy specifically streamlined to limit energy use. The system was also trained using the team's simulation environment, called RaiSim, which includes models of slopes, stairs and icy roads.

Like many electric vehicles, RAIBO2 can regenerate some battery by capturing kinetic energy, particularly while traveling downhill. That capability allows it to offset some of the energy it expends while climbing, though it doesn't eliminate the extra cost of hilly terrain.

The researchers said RAIBO2 has more than three times the travel range per charge of existing quadruped robots, with a total battery capacity of 2,016 watt-hours. It's in part because of that capacity increase that the team now estimates that the robot could travel up to 15.5 miles (25 km) farther than its marathon stint, up to a total of 41.6 miles (67 km).

That kind of endurance could broaden the roles for quadruped robots in places where wheeled models are impractical, the developers added in the study. For example, they could be useful in disaster zones and mountainous areas, where a sufficiently mobile, high-endurance robot could carry cameras, sensors or communications gear across uneven terrain.

Great Danes and mastiffs rarely live more than a decade, while Chihuahuas can live twice as long. Exactly why big dogs die younger than small ones do has been unclear — but new findings may help to solve that mystery.

The research, published Thursday (Oct. 8) in the journal Science, looked at a chemical code written on top of dogs' DNA. This code, called the methylome, consists of chemical tags called methyl groups, which bind to DNA's building blocks.

Proteins constantly access DNA, loading up the information written in its code and taking that data away to be turned into new proteins for the cell. But these methyl groups can act as tiny roadblocks that stop that process in its tracks.

These groups are one type of "epigenetic marker," which collectively help to control gene activity, and their arrangement on DNA changes predictably as animals age, study co-author Blaise Mariner, a bioinformatician at Arizona State University, told Live Science. Across many studies and species, including humans, scientists have used this data to build epigenetic clocks that track animals' biological ages.

Dogs happen to be a great species for studying aging. Their owners devotedly track what they eat, how they live, and how their health changes over time. So Mariner and his colleagues built epigenetic clocks using DNA in blood samples taken from 894 dogs enrolled in the long-term Dog Aging Project based at the University of Washington.

These samples revealed how the dogs' immune cells aged. These cells patrol the whole body, so "they're a really good measure of systemic aging," study co-author Noah Snyder-Mackler, a genomicist at Arizona State University, told Live Science.

The team found that changes in DNA methylation closely tracked biological aging, in that the dogs with older-than-expected epigenetic ages had a higher risk of death from any cause. Once they looked at how different sizes of dogs aged, clear differences emerged.

"Using our biomarker, this epigenetic clock, big dogs were aging a little bit faster per year of life than small dogs," Snyder-Mackler said.

A key epigenetic change linked to larger body size was the loss of methyl groups at stretches of DNA called transposable elements. Also called "jumping genes," these elements can potentially move around the genome, but the methyl groups help stop them from doing so. But when that methylation is lost, the jumping genes can become too active and end up damaging other genes and causing inflammation, a key process that ramps up with age.

In short, the new data suggests that out-of-control jumping genes may contribute to big dogs' faster aging.

In aging dogs, the team found that some regions of the genome with few chemical tags became more methylated, while other areas that had been choked with methyl groups gradually lost them. Additionally, at least in terms of their epigenetics, dogs' immune cells appear to become more similar to one another as they age. Mariner said this "loss of cell identity" is a key hypothesis for what happens to the body as it ages.

Immune cells are carefully specialized for different roles, such as preventing cancer or killing viruses. As these cells become more similar to one another, they become less able to fulfill their specialized roles, studies suggest.

Humans have bred big dogs for size, and Snyder-Mackler said this push for large body size may have come at a cost.

"Their bodies have to make this trade-off between really rapid growth and maintenance of that," he said, "versus investment in the immune system and integrity of the organism." For now, that idea is a hypothesis, though, as the current study doesn't directly address why big dogs' epigenetic aging has come to be this way.

Now, the team wants to build more informative clocks as the Dog Aging Project recruits more pooches to follow for longer periods. Snyder-Mackler said the team's data currently explains only part of how dogs' epigenetic ages vary. "What we really want to know is, what explains the rest of that variation?" he said.

The team was keen to build predictive models that might help dog owners anticipate their pets' age-related health concerns, Snyder-Mackler added.

What we learn about dogs from these studies may help us understand human aging, too. That's partly because dogs get some of the same diseases we do, but it's chiefly because they share humans' living spaces and environments.

"We're going to start looking, at the molecular level, [at] how these environmental exposures or experiences impact health and aging in dogs, which is going to be directly translatable to humans who are living in those same exact environments," Snyder-Mackler said.

"Most people love dogs," he added. "That means we can get a lot of really good data on them."

Researchers have discovered a roughly 9 million year old tooth belonging to a large, water-loving relative of modern day capybaras in the Atacama Desert of northern Chile. The fossilized molar adds to previous evidence suggesting that it's unlikely the Atacama, one of the driest places on Earth, was continuously dry for the last 40 million years.

The Atacama Desert, possibly the oldest desert on Earth, takes up the northern third of Chile. It's bounded by the Chilean Coast Range to the west, which blocks rain from the Pacific Ocean, and the enormous Andes to the east, which obstruct rain from the Atlantic Ocean. The driest part of the desert's hyperarid region gets less than 0.08 inches (2 mm) of rainfall a month.

Recent research estimates the Atacama's hyperarid core started forming between 47.8 million and 33.9 million years ago, in the Mid- to Late-Eocene, 20 million years before the Andes formed. It suggests the mountain ranges weren't the cause for the desert's aridification, and may have only intensified it.

Capybaras (Hydrochoerus hydrochaeris) ‪—‬ the world's largest rodent ‪—‬ exclusively live close to stable freshwater sources and feed on plants that also require water to grow, so the discovery of an extinct capybara relative (Hydrochoerus Cardiatherium) tooth in the Atacama Desert is very strange.

"Finding a capybara tooth in a marine deposit in what today is one of the driest regions on Earth is just freakish," Priscilla Martinez, a geoscientist at the University of Arizona and co-author of a new paper describing the discovery, said in a statement.

Capybaras are native to South America, although today, they are not found in Chile, where the tooth was unearthed, according to the International Union for Conservation of Nature (IUCN).

The tooth isn't the only clue that the Atacama was a wetter place in the late Miocene. Researchers found it in a layer holding the remains of a shallow marine environment that existed between 7 million and 10 million years ago, according to the statement. And they've also found microscopic pieces of plants, known as phytoliths, revealing that palm trees, grasses, gingers and other flowering plants grew there in what may have been a subtropical forest.

These findings and others are part of a growing body of evidence that the Atacama Desert was once wet enough for crocodiles and freshwater fish to thrive and palms to grow. The new study, published Sept. 5 in the journal Scientific Reports, shows that capybara relatives lived there as well during the late Miocene, which, because they are semiaquatic animals, is further evidence to support the hypothesis of a sporadically moist Atacama.

The researchers aren't sure how exactly capybaras moved into the Atacama Desert. Although there were capybaras in South America at the time, the Andes created an 18,000-foot-high (5,500 meters) barrier between their current habitats and the site where the tooth was found. The researchers theorized that, instead of traversing the mountains, the ancient capybaras migrated along the western coast of South America, following wetlands, rivers and other water sources.

According to Samantha Hopkins, an Earth sciences professor at the University of Oregon who was not involved in the study, it's unlikely the tooth found its way to the site without capybaras living there.

"If you wanted to find a way that this capybara could be here while the Atacama was still as dry as it is today, you'd have a hard row to hoe," she told Live Science in an email, because the size of the tooth makes it hard to transport it long distances. The desert wind couldn't have blown it such a long way, and while large carcasses can float down waterways for miles, "if you're going to invoke a large enough waterway to do this, you've demonstrated that the Atacama wasn't as dry as it is today anyway."

Astronomers have detected the most distant burst of radio signals ever seen: an explosion that's emitting waves of energy from more than 10 billion light-years away.

The event, named FRB 20240304B, is known as a fast radio burst (FRB). Astronomers have detected thousands of FRBs before this. But because these events last only milliseconds, they are extremely difficult to study and their origin stories remain unclear.

In this case, however, astronomers managed to use a radio telescope array and the James Webb Space Telescope (JWST) to chart the event, with JWST narrowing down the precise host galaxy that FRB 20240304B came from. The study, published Thursday (Oct. 8) in the journal Science , sheds more light on a time when the universe was only about 3 billion years old, showing that FRBs arose early in our cosmos' history. The detection more than doubles the previous distance record for FRBs.

The JWST played an instrumental role in the discovery, study co-author Themiya Nanayakkara, a senior lecturer at the Sydney Institute for Astronomy, told Live Science in an email. The email was written in collaboration with study first author Manisha Caleb, a senior lecturer in astrophysics at the same university.

For example, JWST's observations showed that the host galaxy was smaller than expected, was "metal-poor" (had few elements besides hydrogen and helium), and was forming a lot of stars. These characteristics could offer new clues about the environments in which FRBs arise, giving more information about the mysterious events. Researchers suggest that this FRB may have been linked to a magnetar, a highly magnetic star core left after a supernova.

Zooming in with the James Webb telescope

The ancient FRB was initially detected with MeerKAT, an array of 64 radio telescopes in South Africa. Nanayakkara said MeerKAT revealed "both the detection of the fast radio burst and, importantly, a very precise position on the sky."

The researchers knew the FRB was far away because of the large dispersion of the radio signal, but initial searches with powerful ground-based telescopes, "saw essentially nothing; it looked like empty sky," the researchers told Live Science. "The most likely explanation was that the galaxy was simply too faint to be detected in those observations. That is where JWST became transformative."

The science team successfully got time on JWST with a program called Director’s Discretionary Time, which is aimed at time-sensitive observations. The researchers started by using JWST's Near Infrared Camera to trace the radio signal and take a very deep image of the target region.

"Suddenly, there it was: a very faint galaxy almost exactly where we expected the host of the FRB to be," Nanayakkara said. The researchers then used JWST's Near Infrared Spectrograph to obtain a spectrum (wavelengths of light broken into different chemical signatures), which showed hydrogen and oxygen.

"These spectral features act like fingerprints: because we know the wavelengths at which they are produced in the laboratory, we can measure how much they have been shifted by the expansion of the universe," Nanayakkara explained. "That gave us a very precise redshift of about 2.15. We are therefore seeing this galaxy as it was when the universe was only around three billion years old, so roughly one-fifth of its current age."

Because the host galaxy is fairly young, it supports the idea that at least some FRBs are generated by magnetars, which are more likely to appear in spry galaxies where intense star formation is occurring, the team said.

The team plans to continue hunting for FRBs with JWST.

"We do not know what the sources will be yet," Nanayakkara said, as that depends on what pops up in the sky and is spotted by ground-based radio telescopes. "Once our radio telescopes find and localize a suitable new source, we can trigger the JWST observations. So it is quite exciting, because we really have no idea what we will find when we combine the power of these two types of telescopes."

Long before it became the luminous spiral galaxy we call home, the Milky Way was a sprawling, chaotic swarm of thousands of small galaxies, new research shows.

The findings suggest that in the first 2 billion years after the Big Bang, the region of the universe that would become our galaxy was littered with thousands of smaller galaxies of many sizes and shapes. Over time, these galaxies collided and merged into the single galaxy in which we reside today.

"Looking at these results, it's very clear that the physics happening right after the Big Bang has direct impact on what we see today in the local universe," study co-author Harley Katz, an assistant professor of astronomy and astrophysics at the University of Chicago, said in a statement.

To understand more about the early universe, astronomers build sophisticated computer models that encode the laws of nature to see how the cosmos may have evolved. The new work, which is the result of three years of supercomputer simulations, is the most detailed tracing yet of how a galaxy like ours came to be. It also arrives just as astronomers need a stronger yardstick for what they're seeing in the early universe.

Megatron, the cosmic transformer

The James Webb Space Telescope (JWST) can peer farther into the early universe than any previous telescope, and its discoveries have often defied computer models. For instance, JWST found surprisingly bright early galaxies and a mysterious new class of compact galaxies dubbed "Little Red Dots." These anomalies demonstrate that current computer models need an update to handle the complex physics of the early universe, the researchers said.

To bridge that gap, the scientists built a new suite of supercomputer simulations they call Megatron. By tracing ancient gas, starlight and chemistry from 180 million years to 2 billion years after the Big Bang, Megatron predicts the distinct light signatures of its virtual galaxies, according to the statement. Because JWST collects the same type of spectral data across a similar span of cosmic time, scientists can directly cross-reference the simulation against real observations to pinpoint what the old models are missing, the team said.

The simulation also tracks how the universe's first stars formed, died and forged the essential elements that make life as we know it possible. By comparing the simulation with JWST observations of early galaxies and with the chemical traces left in ancient stars, scientists can better understand how those first stars enriched their surroundings, the researchers said.

"Together, these complementary observations allow us to test competing models of the first stars in ways that weren't previously possible," study co-author Martin Rey, a theoretical astrophysicist at the University of Bath in the U.K., said in a separate statement.

The scientists detailed their findings in one of the six papers the Megatron collaboration published Sept. 30 in The Open Journal of Astrophysics.

Assembling the Milky Way

The team's simulation begins 180 million years after the Big Bang, when the universe is devoid of stars and galaxies and holds only pristine gas. As the next 2 billion years pass,, the model captures how the very first stars light up the dark universe and kick off "cosmic dawn," eventually culminating in those stars' violent deaths. As they die, the stars spread newly forged heavy elements such as carbon, oxygen and iron into the surrounding gas, laying the building blocks for future stars and planets.

The simulation ends 2 billion years after the Big Bang, but the Milky Way's mergers continued long after this point, and scientists are still discovering traces of the small galaxies that have joined it. The most recent massive merger, with the Sagittarius dwarf galaxy, began more than 6 billion years ago and is still unfolding.

The simulation results help scientists understand how certain physics parameters impact the early universe, and better match up JWST's observations with computer models. But it also highlights areas that need further study.

"But there are also things we're not getting right, which is interesting too — what are the parts we're still missing?" Katz said in the statement. "That can lead you into new directions and new questions."

Megatron team members in the U.K. are now developing the next generation of simulations, backed by dedicated time on the country's supercomputers. Those simulations will include more complex physics, such as active black holes, which JWST has revealed to be surprisingly common in the early universe, the researchers said.

How well do you know our home galaxy? Find out with our Milky Way quiz!

Scientists have recently harnessed artificial intelligence (AI) to build "aging clocks" that aim to estimate a person's true biological age.

While a person's chronological age reflects the number of years they've been alive, their biological age is intended to capture how well their bodily systems are functioning. The idea is that people with older biological ages have a higher risk of age-related diseases ‪—‬ such as cancer, heart disease or dementia ‪—‬ while younger biological ages come with less risk. Some aging clocks even aim to predict people's impending risk of death.

Many aging clocks look at epigenetic markers, meaning chemical tags that bind DNA and change how genes activate, while others measure features such as the pace and pitch of people's voices. But some scientists say we don't know how to use these aging clocks yet, arguing that the tools are useful for studying aging at a population level but not for guiding individual health decisions.

Others posit that the data the clocks are based on is too noisy, and thus, there's potential for drawing faulty conclusions about what they're measuring. They say, for example, that we don't know if the clocks are measuring the downstream effects of aging or its underlying causes. And in any case, we don't currently have any treatments to "wind back" the clocks.

What do you think? Would you use these AI tools to measure your biological age? Let us know in the poll below, and explain your reasoning and additional thoughts about the technology in the comments.

The sea surface temperature in a key section of the central equatorial Pacific Ocean has now surpassed all previous temperatures on record for this region, exceeding 86 degrees Fahrenheit (30 degrees Celsius) for the first time, according to preliminary data released Monday (Oct. 5).

Specifically, these temperatures occurred in the Niño 3.4 region, located between 5 degrees north and 5 degrees south latitude, and 120 degrees west and 170 degrees west longitude. Researchers use this region to monitor the progression of El Niño, the warm phase of a multiyear natural climate pattern that's currently in full swing and steadily intensifying. But how significant is this new record, and could it be a harbinger of increasingly extreme El Niño events in the future?

At this time of the year, sea surface temperatures above 86 F are common in the western Pacific warm pool, a mass of water located northeast of Australia. But the Niño 3.4 region is nowhere near the warm pool and usually has much cooler temperatures. This latest data indicates "an exceptionally warm state for this part of the tropical Pacific," said Jin-Yi Yu, a professor of Earth system science at the University of California, Irvine.

"If the reported daily El Niño 3.4 temperature above 30°C is verified in the observational dataset, it would be an extraordinary record," Yu told Live Science in an email.

Other experts agreed. A Niño 3.4 sea surface temperature above 86 F is a "very significant" new record, Timothy Osborn, a professor of climate science and the director of the Climatic Research Unit at the University of East Anglia in the U.K., told Live Science in an email. Mat Collins, a professor of climate systems and the head of mathematics and statistics at the University of Exeter in the U.K., also called the temperature "very significant" in an email to Live Science.

But it's important to note that absolute temperature is not the standard way of measuring the strength of El Niño, Osborn said. Researchers usually assess El Niño intensity by comparing sea surface temperatures in the Niño 3.4 region with the average conditions there or with sea surface temperatures across the rest of the tropics, with the latter method removing a skew in the data caused by the climate-change-induced heating of oceans globally.

"On those measures, the current event is already close to being the strongest [El Niño] on record and will likely soon exceed previous records given that the event is forecast to strengthen further," Osborn said. "For some measures, it is already record-breaking for the time of year."

"Super" El Niño

El Niño events happen when warm water in the western tropical Pacific Ocean migrates eastward along the equator, toward South America. This boosts global temperatures, triggering heavy rainfall and floods in regions like East Africa, southern China, the southern U.S. and the Pacific coast of equatorial South America, while places such as Indonesia, the Philippines, southern Africa and northern South America experience drought.

"El Nino impacts are greatest across the tropics and in the lands around the Pacific Ocean," Osborn said. "An El Nino with record strength is very significant because it greatly disrupts the atmospheric circulation which controls the weather patterns including patterns of rainfall."

As of Oct. 6, the temperature anomaly in the Niño 3.4 region is 6 F (3.34 C) above average and rising. A typical El Niño increases Niño 3.4 temperatures by a maximum of 1.8 to 3.6 F (1 to 2 C) above average, so the current condition is "exceptionally large," Yu said. "This indicates that a very strong, or what is sometimes called a 'super,' El Niño is developing."

This year's El Niño is being amplified by human-driven global warming, which has increased background ocean temperatures. As a result, it's likely that sea surface temperatures in the Niño 3.4 region will keep rising over the coming weeks and peak in November or December, before declining again in 2027, Collins said.

"The Niño 3.4 anomaly is very likely to remain extremely large and may increase further," Yu said, echoing forecasters' suggestions that it could reach 7.2 F (4 C) by November.

A new kind of El Niño?

The world is on the brink of crossing a critical warming threshold, raising the question of whether the current conditions can be considered a new normal for future El Niños.

While it's likely that future El Niños will be more extreme than past ones, on average, not every El Niño will be record-breaking and as dramatic as the one unfolding now, because these events tend to be very variable, Collins said.

As climate change intensifies, the big worry is that certain regions will be primed for extreme conditions even before an El Niño strikes, Osborn said. For example, regions that are getting drier due to global warming could see catastrophic droughts if they overlap with areas that experience dryness during El Niño events. Likewise, places that are getting wetter could see worse deluges of rain and flooding if they coincide with areas with higher precipitation during El Niños. But that doesn't necessarily mean extreme El Niños are the new normal, he said.

Instead, the location and duration of El Niño events may be transforming, Yu suggested. "In research by my group and collaborators, we have documented changes not only in El Niño intensity, but also in where the warming occurs and how long events persist," he said.

Yu and his colleagues helped to introduce the idea that we are seeing the emergence of two distinct types of El Niño: the eastern Pacific El Niño and the central Pacific El Niño. "Many El Niño events in the earlier observational record were dominated by warming in the eastern tropical Pacific, whereas Central Pacific El Niño events became much more prominent in recent decades," he explained, adding that El Niños have also been lasting longer.

Global warming may be creating a new kind of El Niño by strengthening atmosphere-ocean interactions in the subtropical Pacific, Yu said. If these interactions combine with processes in the equatorial Pacific, where eastern Pacific El Niños emerge, they might trigger unusually strong events with extreme heating in the central Pacific.

"That provides a physical reason to take the possibility of more frequent extreme El Niño events in a warmer climate seriously," Yu said. "But I would distinguish that from saying that every El Niño will become progressively stronger."

Cases of dengue fever are surging in Florida, spurring several counties to declare a state of emergency.

The state has seen 497 reported cases so far this year. Of those, 252, or about 51%, were caught locally, rather than brought to the state by travelers. The Florida Department of Health confirmed one woman's death from dengue fever in early September, marking the state's first known dengue death in almost a century.

Prior to the past few years, most dengue cases reported in Florida were the result of travel. In other words, people caught the disease in other countries and then traveled to Florida, where their case was then diagnosed. At 245, the number of travel-related cases reported this year is not unusually high, Caroline Waddell, a public health researcher at the University of Florida, told Live Science in an email. However, the number of cases caught from local mosquitoes is more than five times higher than at this point in the year compared with any of the previous four years, she said.

Why are local dengue cases especially high this year? Live Science spoke with experts to find out.

A growing global health concern

Dengue fever is caused by the virus Orthoflavivirus denguei, which spreads from mosquitoes to people through the pests' bites; it doesn't spread from person to person. Aedes aegypti and Aedes albopictus mosquitoes transmit the virus to humans, and the same species can also carry the viruses behind yellow fever, Zika and chikungunya.

About 100 million to 400 million dengue infections happen annually worldwide, with about 800 cases reported in the U.S. historically, although that number has increased recently. Only about 1 in 4 people exposed to the dengue virus develop symptoms, which can include fever, headache, body aches, nausea and rash. About 1 in 20 cases become severe, and immunocompromised people, children, older adults and pregnant people are especially susceptible to these serious infections.

Severe symptoms can include abdominal pain, vomiting, difficulty breathing and bleeding of the gums or nose. The most severe forms of the infection can lead to leaky blood vessels, severe bleeding, shock, organ dysfunction and death. There is no specific treatment for dengue, so care focuses on managing symptoms and maintaining patients' vital signs.

Dengue has escalated as a global health concern in the past few decades. Between 2000 and 2019, global cases of dengue increased tenfold; between 1990 and 2021, dengue-related deaths doubled. Scientists say this surge is likely driven by climate change, since rising temperatures expand Ae. aegypti mosquitoes' range, in turn exposing more people to the insects' bites. Plus, warmer conditions speed up mosquitoes' life cycles and the dengue virus's replication rate, thereby boosting transmission.

International travel also factors into these rising case counts. In 2023, dengue spikes around the world were attributed to the resurgence of global travel following the COVID-19 pandemic.

Zooming in on Florida

As the global picture has worsened, dengue cases in the U.S. have also increased.

Nearly 3,800 cases were reported in 2024 ‪—‬ an increase of more than 300% above the annual average for the previous 10 years. The uptick was tied to a rise in travel-associated cases, reflecting the wider global surge, as well as to warming temperatures that brought dengue-carrying mosquitoes to new regions of the U.S.

Each year, Florida experiences dengue outbreaks in the southernmost parts of the state, such as Miami and the Florida Keys, Panpim Thongsripong, a disease ecologist at the University of Florida, told Live Science. Historically, outbreaks in Miami typically totaled around 50 or fewer cases. But then a 2019 outbreak resulted in over 200 cases, and from 2022 to 2024, outbreak totals have ranged from about 500 to 675 cases.

The outbreak currently unfolding in Florida centers on Hillsborough County, which is farther north and includes Tampa. This is unusual, Thongsripong said, as this region of the state normally sees just a few sporadic cases. Hillsborough County has reported 223 of the state's 252 locally acquired cases this year, and it's where the one dengue-related death took place.

Florida's health department regularly traps mosquitoes and tests them for viruses. So far this year, 20 pools of mosquitoes have tested positive for dengue across seven counties, and 19 of those positive pools were sampled from the greater Tampa area. In 2025, only four mosquito pools throughout the state tested positive, and in 2023, one mosquito pool did.

"Finding positive mosquito pools is rare in Florida because dengue is not endemic to the state," said Keira Lucas, deputy executive director of the Collier Mosquito Control District. "In many ways, it can be like looking for a needle in a haystack," she told Live Science.

Routine mosquito trapping is a relatively inefficient method for detecting viruses, though, Lucas said. As such, detecting dengue-positive mosquito pools may indicate that a large amount of transmission is already unfolding. "Since approximately 75% of dengue infections are asymptomatic, the virus can circulate within a community without being readily detected for some time," Lucas explained.

In addition to Hillsborough, neighboring Pasco and Pinellas counties have declared local states of emergency over dengue.

An unlucky combination of factors

So what's driving the unusual dengue activity this year?

In the past, Florida's local dengue outbreaks tended to be concentrated in the South, which saw moderate rainfall, warmer temperatures and more travel-related dengue cases compared with the rest of the state, according to a 2022 study in the journal Insects. With the outbreak concentrated farther north this year, that could suggest changing climatic patterns are making additional parts of the state especially hospitable to mosquitoes and the virus. That wouldn't necessarily explain why Tampa is seeing more local cases than Miami this year, but it could nonetheless be a factor in the overall trend.

For the virus to persist in local mosquitoes, dengue still needs to be reintroduced periodically through travel-related cases. Because the virus is not yet endemic to the state, it doesn't regularly circulate in local mosquitoes; however, a somewhat predictable "dengue season" has been emerging that coincides with upticks in international travelers carrying the virus to Florida.

This year, though, the high number of locally acquired dengue cases suggests a shift from predominantly imported infections toward outbreaks spurred by local Florida mosquitoes. Scientists hypothesize that climate change could increase local transmission in Florida even more in the future.

This year, Florida has also been enduring its most intense drought in over a decade. In theory, that might be expected to limit mosquito populations because the pests need water to breed, Lucas said. However, when it's dry, people tend to run their sprinklers more, creating mosquito breeding grounds when puddles form or containers fill up, she noted. This could bring mosquitoes closer to people, as it creates opportunities for them to breed.

Ae. aegypti mosquitoes are especially well adapted to living alongside humans, as they prefer to breed in human-made containers. Droughts can also drive dehydrated mosquitoes to bite more as they hunt for fluids.

"It's almost like an unlucky [combination]," Thongsripong said. "Everything coming together at the right time and right place, and boom, you have the conditions for an outbreak to occur."

The true number of dengue cases may be even higher than reported, Waddell said. The cases captured in the data include infected individuals who went to a doctor to get tested. Because many infections are mild or asymptomatic, additional people may have contracted the virus but never got counted.

What can be done

It's too early to definitively say what factors have increased Florida's dengue cases this year, Thongsripong said, as scientists are still gathering information. Despite the unknowns, she thinks the health and housing infrastructure in the U.S. will stop dengue from becoming too dangerous here.

To get dengue under control, it's key for government-level mosquito control efforts to coordinate and for the public to be aware of the virus, Lucas said. The mosquito control district coordinates with the health department for the latest data to best target where to spray larvicide, which kills mosquito offspring before they can bite people, she said.

It's important for people to use mosquito repellent when going outside, Thongsripong said, as well as to empty water from objects that can collect water and become a mosquito breeding ground, such as pets' water bowls, plant saucers, buckets or discarded tires.

Due to this year's strong El Niño, Florida is expecting a rainier winter, which could mean even more mosquitoes than usual, Lucas noted. That, in turn, could fuel additional dengue cases.

"Cases with September onsets are still being reported," Waddell said, "so we're not out of the woods."

This article is for informational purposes only and is not meant to offer medical advice.

OpenAI representatives claim that the recent launch of one of its latest models, GPT-6 Astra, marks the beginning of the artificial general intelligence (AGI) era — a hypothetical scenario in which artificial intelligence (AI) can learn and reason like humans. Following very recent claims from technology executives that we've now reached this milestone, how likely is this claim to stand up to scrutiny?

Amid revelations that safety concerns have forced the company to abandon the planned rollout of GPT-6.1 Astra, independent researchers and benchmark creators warn that GPT-6 Astra's record-breaking scores rely on heavy prompt optimization rather than true general intelligence. This comes as experts warn about the risks of future AI systems and AI executives jointly call for a slowdown in AI research.

In announcing the model's release, OpenAI President Greg Brockman suggested that Astra signaled a fundamental turning point in AI evolution. "If we fast-forward a couple years, and we look back and say when was it really that AGI was created, I think it's going to be about this time, and I think it might be about this model," Brockman said during a Sept. 3 news conference marking the launch.

How did the new model perform in benchmarking?

As part of the testing-and-verification process for the new model, OpenAI released benchmark results across a range of tests that measure the capabilities of AI models at various tasks. OpenAI representatives claimed in a statement that the company's new model delivers "state-of-the-art" performance across a variety of fields, including software engineering, the autonomous use of computer programs, mathematics problems, and even scientific research.

Demonstrations, for example, highlighted Astra's ability to generate 3D CAD code; lay out printed circuit boards in CAD (computer-aided design) software; convert digital 3D models into interactive, video-game-style environments; and deploy hosted web applications directly from prompts.

"In our early testing, Astra stood out by approaching legal work the way a discerning lawyer does: it distinguishes documents from established records, surfaces unsupported assumptions, and converts gaps into concrete drafting positions," said Niko Grupen, head of applied research at legal services AI developer Harvey as part of OpenAI’s announcement.

On ARC-AGI-3 ‪—‬ a benchmark designed to measure how efficiently AI systems acquire new skills in novel, abstract environments ‪—‬ Astra achieved a headline score of 99.9%. Independent testing by the nonprofit ARC Prize Foundation, which oversees the benchmark, revealed that Astra surpassed "human action-efficiency" baselines on 96% of levels, taking 51.7% fewer actions per level, on average, than human solvers.

"Not only is this the best model we've ever tested," ARC Prize Foundation President Greg Kamradt said as part of the OpenAI announcement, "but it also represents a meaningful step change in frontier-model performance — not only in its ability to navigate and solve novel environments but also in how efficiently it learns to do so."

How much can we read into test results?

Many researchers have highlighted that Astra's top ARC-AGI-3 performance relied on a proprietary "Provider Adapter" harness, a specialized software scaffolding layer that's inaccessible to rival developers. When tested using the benchmark's neutral Standard harness, this score dropped to 62.7%. ARC Prize organizers also noted that saturating the benchmark does not constitute proof of achieving AGI — emphasizing that its closed, deterministic puzzle environments do not capture the open-ended complexity of the real world.

"When we launched ARC-AGI-3, "we made it clear that saturating the benchmark would not represent 'proof of achieving AGI,'" Kamradt wrote in a blog post. "Therefore, while we believe Astra represents meaningful progress towards generalization, we are not claiming that it is AGI."

Discrepancies in the data were reportedly present even before the official announcement. As reported by Fortune, an embargoed draft provided to news organizations prior to the model's launch listed Astra's ARC-AGI-3 score at 98.6% before it jumped to 99.9% on the live site.

Anka Reuel and Mike Hardy, doctoral researchers in AI at Stanford University, also raised concerns over OpenAI quietly revising several published metrics post-launch, including halving Astra's reported hallucination rate from 4.2% to 2.0% before reverting it.

Speaking to Fortune, Reuel and Hardy attributed the shifting figures to "benchmaxxing" — an industry term that describes the practice of repeatedly rerunning evaluations under subtly tweaked prompts, scaffolds or compute allocations to hunt for peak theoretical scores.

In a 2025 paper published on pre-print server arXiv titled ‘Benchmarking is Broken -- Don't Let AI be its Own Judge’, experts including Princeton doctoral candidate Zerui Cheng and University of Luxembourg postdoctoral researcher Dr. Stella Wohnig warned that such practices create confusion and undermine trust, particularly when official technical documentation omits the basic methodology, making independent verification nearly impossible. Crucially, scores achieved through benchmaxxing reflect idealized performance ceilings under optimal lab conditions rather than practical, out-of-the-box reliability.

According to OpenAI's benchmark data, across specialized domain evaluations, GPT-6 Astra delivered 10% to 20% better performance than both its predecessor, GPT-5.6 Sol, and top market competitors.

Highlights include a 98% score on FrontierMath Tier 4 (v2), which evaluates expert-level mathematical reasoning; a perfect 100% on ExploitBench, which is designed to test offensive cybersecurity capabilities; 95.9% on BenchCAD, which measures an AI's ability to reconstruct 3D objects using CAD code; 57.9% on Terminal-Bench 4.0, which assesses complex terminal-based system administration and software engineering; and 41.4% on AutomationBench, which tests whether agents can complete multistep business workflows across applications.

But independent findings from external AI benchmarking firm Artificial Analysis contradict these results. Astra's score on the independent Artificial Analysis Intelligence Index — an aggregate metric that evaluates general reasoning across frontier models — remained completely flat, at 61, compared with GPT-5.6 Sol, while trailing competitors like Anthropic's Claude Fable 5.1 and Meta's Muse Spark 1.3.

While some benchmark results have seen improvement since the previous generation, Astra underperformed in other tests. Artificial Analysis' testing showed that against GDPval-AA v2 — an economically focused benchmark that measures real-world workplace tasks across 44 occupations — Astra suffered a significant drop in its relative leaderboard ranking compared with GPT-5.6 Sol. Additional regressions were observed in benchmarks that test customer service support, scientific Python programming, and long-context reasoning across large documents.

In terms of overall token use — the metering system that measures the fragments of text or data processed by AI models — OpenAI representatives said GPT-6 Astra achieved dramatic efficiency gains on complex, long-horizon tasks. Findings from Artificial Analysis confirmed that on software engineering benchmarks, Astra was approximately 70% more token-efficient than GPT-5.6 Sol, using roughly one-third the total tokens of its predecessor and one-fifth the tokens of Claude Opus 5.

On professional workplace evaluations like Agents' Last Exam, the new model reduced output token consumption by up to 65% compared with Opus 5, while on general intelligence evaluations, Astra achieved a roughly 10% output token reduction at max effort compared with Sol.

On the other hand, this achievement is offset by a 250% increase in the base API pricing for GPT-6 Astra compared with GPT-5.6 Sol. Token prices jumped from $4/$20 to $10/$50 per million input/output tokens. As a result, Astra ends up approximately 75% more expensive per task than its predecessor on general intelligence evaluations, despite using 10% fewer output tokens. This trade-off has led researchers at Artificial Analysis to question whether AI labs are relying on expensive computational brute force to squeeze out minor gains, rather than achieving true technical breakthroughs.

Does achieving AGI even matter?

With its latest model, OpenAI has placed a stronger emphasis on safeguards and controls. The move follows a series of high-profile incidents in which frontier AI models inadvertently hacked into third-party networks and computer systems as part of routine testing operations, after the models went beyond what humans expected they would do when encountering challenging tasks.

According to OpenAI representatives, Astra did not exceed the scope of its tasks in any security evaluations. For comparison, GPT-5.6 Sol went beyond its authorized parameters in almost 50% of test cases. Hallucination rates have also been reduced significantly, falling to 4.2% on internal tests, compared with 12.2% for GPT-5.6 Sol (with independent testing by Artificial Analysis showing a drop from 92% to 51% at max effort). The model also showed an improved ability to handle ambiguous prompts.

David Wood ‪—‬ chair of London Futurists, a non-profit that hosts discussion groups on emerging technology ‪—‬ argued that beyond individual test results, Astra highlights a fundamental shift in how humans will interact with AI as models move from answering questions to autonomously pursuing complex goals in digital environments.

"The impressive benchmark results matter, but what matters more is the combination of intelligence, autonomy, computer use, and cybersecurity capability," he said in an email to Live Science. "That combination also demands caution. The more useful these systems become, the greater the consequences when they misunderstand our intentions, are misused, or find ways around the safeguards we give them."

Wood suggested that whether Astra can be classified as AGI is less relevant than recognizing the need for AI control and governance to keep pace with technical development.

"The possibility that AI could progress from systems like Astra towards all-round superintelligence makes much greater human vigilance, awareness, and collaboration increasingly urgent," he said.

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The remote south Atlantic island of St. Helena boasts an international celebrity: the tortoise Jonathan, the oldest living land animal. At 194 years old, he has outlasted the expected lifespan for an Aldabra giant tortoise (Aldabrachelys gigantea) by about a century. Now, scientists have identified a range of unique genetic and epigenetic traits that may hold the key to this longevity.

The new research zoomed in on Jonathan's genes, as well as the chemical tags that sit on top of DNA molecules, known as "epigenetic markers." These markers help control which genes are activated and to what degree. The analysis finds that Jonathan's genes associated with mitochondrial function are in great shape, epigenetically speaking, which suggests that they've played a big role in the tortoise's success.

While mitochondrial function has long been linked to longevity and mitochondrial dysfunction has been tied to disease, Jonathan offers fresh insight into that dynamic, said study co-author Stephen Clark, chief scientist of the Kallel Foundation, a nonprofit in Nashville researching drug targets to promote human longevity.

Clark and colleagues published their findings Wednesday (Oct. 7) in the journal Science Advances.

Decoding Jonathan's secrets to long life

Nearly a decade ago, the researchers enlisted Joe Hollins, the vet tasked with Jonathan's care, to collect samples from the record-setting animal. Island authorities forbade the vet from drawing the tortoise's blood, fearing the risk of an infection.

"I didn't want to be the doctor that killed Jonathan," Clark told Live Science. Hollins collected samples via cheek swab instead.

When the samples arrived in the U.S., the researchers sequenced them, but when their computers kept crashing, they discovered that the DNA had been isolated from bacteria in Jonathan's mouth rather than the tortoise's own cells.

Clark "had to go back and beg" for permission to collect more data, he said. The vet then sent cheek scrape samples, which are collected with a slightly different tool than cheek swabs. This time, the DNA was in fact from Jonathan.

The DNA isolated from those cheek tissue samples was more fragmented than it would have been in a blood sample, so the researchers filled in the gaps using an existing reference genome from a 36-year-old Aldabra tortoise named Tank. They also compared Jonathan's DNA to that of a Galápagos tortoise (Chelonoidis abingdoni) named Lonesome George, who was believed to be over 100 years old at the time of his death in 2012.

The team found that, compared to Tank and Lonesome George, Jonathan carried 287 unique variants of genes that had previously been linked to aging-related pathways. These included genes involved in DNA repair and the function of telomeres — the protective tips at the end of chromosomes that tend to shorten with age.

These pathways are also related to aging processes in humans, highlighting a "broader signature of aging" across species, Greer Dolby, an assistant professor of biology at The University of Alabama at Birmingham, who was not involved with the study, told Live Science.

The researchers also looked at epigenetic changes, including DNA methylation, which is when a chemical tag called a methyl group binds the DNA. Certain patterns of DNA methylation can function as a "clock" in that they reflect an organism's biological age; scientists have recently harnessed these patterns in the study of human aging. In this case, the team compared the DNA methylation across Jonathan's genome to that of young and old Aldabra tortoises.

The methylation patterns were more disordered in the older tortoises, reflecting random changes acquired over time, the researchers found. Scientists call this phenomenon "methylation entropy." For most genes, Jonathan's DNA methylation patterns were more disordered than those of the young tortoises. But in a suite of genes tied to mitochondrial function — specifically the bits of those genes that switch them "on" — Jonathan had more organized methylation patterns. That might keep expression of these genes consistent over time, the researchers theorized.

Mitochondria produce energy that cells need to function properly, repair themselves and reduce further damage to DNA. "Keeping the entropy low in these mitochondrial genes, or keeping pristine mitochondria, is likely to be a contributor to longevity," Clark said.

However, the authors couldn't determine a causal relationship — they didn't run any tests that could definitively prove that Jonathon's lack of entropy in these genes explains his long life. Clark argued that additional experiments on a blood sample from Jonathan could offer a more comprehensive view of his genome.

Jonathan's full genetic profile can't be known until after the tortoise's death, when researchers can collect DNA from more tissues, said Vincent Lynch, a professor of biology at the University at Buffalo, who was not involved with the study.

"Some organs are more susceptible to different diseases of old age than other ones, and that happens because mutations accumulate over time," he told Live Science. "We would ideally like to know what those mutations are in those specific tissues."

Furthermore, Lynch questioned whether entropy was a useful characterization of age-related DNA methylation patterns, as methylation can be unpredictable. That said, he agreed that the genes flagged in the study offer helpful data for future work on longevity.

More experiments are needed to determine whether these mitochondrial genes actually play a role in longevity across all Aldabra tortoises, let alone in other animals, or if Jonathan is just an outlier.

"Maybe Jonathan is just really good at being old," Lynch said.

A newly discovered platypus-like creature is the largest-known mammal relative from the entire Jurassic period, a new study finds — although it still only weighed as much as a Chihuahua.

The critter, which hunted salamanders in the freshwater lakes and rivers of what is now Inner Mongolia, China, lived during the mid-Jurassic between 168 million and 163 million years ago. It seems to be the earliest known mammal-type animal that lived a semiaquatic life.

Researchers unearthed the delicate and detailed fossil in 2016, which revealed that the animal likely weighed about 2.2 to 4.4 pounds (1 to 2 kilograms). It was large for a mammal relative during the Jurassic, but its name, Megacauda sungei, was inspired by its tail: Megacauda means "big tail." The discovery was detailed in a study published on Wednesday (Oct. 7) in the journal Nature.

The furry predator had a mix of features seen in modern-day animals, with a broad, flattened tail that marks it as a powerful swimmer, and short hind legs with relatively long feet.

"It's like a chimera," study co-author Zhe-Xi Luo, a paleontologist at the University of Chicago, told Live Science. "The back half of this animal is very much like a platypus. As are the limbs, which would be capable of swimming or digging tunnels in river banks."

But the teeth "are definitely not like a platypus," Luo said. It possessed robust canines and shearing cheek-teeth that would cut and chew meat in a different way from modern carnivorous mammals. "It's a predator with gigantic and very specialized canines," Luo said. "So, it's partly otter-like and partly platypus-like."

A revealing fossil

Tiny bits of vertebrate bones found in what would have been the animal's stomach and the surrounding fossil beds hint that M. sungei dined on salamanders, Luo said.

He added that M. sungei may have sheltered in burrows on land in the temperate plant-filled climate, and hunted in lakes and rivers for fish and invertebrates.

Another notable aspect of the fossil is its throat. Modern mammals, including humans, have hyoid bones in the throat arranged in a "U"-shaped saddle. These help us use throat muscles to swallow chewed food one chunk at a time, instead of gulping down huge bites or whole prey. The structures also enable babies to suckle their mother's milk.

M. sungei seems to have had the apparatus needed to do this, study co-author Thomas Martin, a paleontologist at the University of Bonn in Germany, told Live Science.

"This is an incredibly important evolutionary innovation," Luo said, adding that this capability is one of the things that helped early mammals diversify into carnivores, insectivores, herbivores or omnivores to take advantage of all sorts of foods.

Finding this in M. sungei suggests that the apparatus needed for suckling milk and swallowing had already evolved by the Middle Jurassic (around 174 million to 164 million years ago), Martin said.

This is before marsupials like kangaroos and placental mammals like primates and bears are thought to have diverged from each other 160 million years ago, after descending from an egg-laying common ancestor that lived approximately 180 million years ago.

"Now we push the history of it back to before the split of modern marsupials and modern eutherian [placental] mammals," Luo said.

"Neonatal suckling behaviour was previously thought of as being a hallmark of advanced mammals, but it now appears to have evolved well before then, in the common ancestor of docodontans and mammals at least 165 million years ago," said Sue Hand, a vertebrate paleontologist at the University of New South Wales in Australia who wasn’t involved in the study.

M. sungei is from an extinct lineage of docodonts, which are relatives of mammals from the dinosaur-dominated Jurassic and Cretaceous periods, living between about 200 million and 120 million years ago.

Docodonts adapted to a wide variety of habitats. For example, there was the Jurassic tree-dwelling shrew-like docodont called Microdocodon gracilis, and Docofossor brachydactylus, a tunnel-digger with shovel-like paws. Luo was also part of the team that described a semiaquatic "Jurassic beaver", Castorocauda lutrasimilis, which lived 164 million years ago.

"It seems that an aquatic lifestyle arose often in early mammal-like species," said Tim Flannery, a mammalogist at the Australian Museum Research institute who wasn't involved in the work.

If anything, the newly described "spectacular fossil" shows that docodonts were wide-ranging during the dinosaur age, Hand told Live Science in an email.

"This very detailed study adds to accumulating evidence that mammaliaforms occupied a wide range of ecological niches long before the evolution of living mammals," Hand said.

A 1,000-mile-long (1,600 kilometers) Martian cloud that emerges and then quickly disappears from the Red Planet's sky nearly every day is even weirder than scientists realized. New simulations suggest that the eerie apparition can only be explained using "exotic physics" that have been theorized but never seen on Earth or anywhere else in the solar system.

The mysterious floating mass, dubbed the Arsia Mons Elongated Cloud (AMEC), frequently emerges above Arsia Mons, a 12-mile-tall (20 km) extinct volcano located in the Tharsis region, just south of the Red Planet's equator. The water vapor cloud was first spotted in 2018 by the European Space Agency's Mars Express orbiter and has since appeared nearly every morning throughout Mars' spring and summer, when increased solar radiation triggers strong surface winds. But it lasts only a few hours each day, before fully evaporating.

The AMEC can stretch up to 1,100 miles (1,800 km) long, around one-twelfth of Mars' circumference. For context, that is roughly twice the length of the U.K. or the distance between New York City and Miami.

Although the Red Planet is no stranger to giant dust clouds and occasional "iridescent streaks" of carbon dioxide, it is almost completely devoid of atmospheric water vapor. That makes it extremely rare for puffy, Earth-like clouds to form there, let alone ones so vast. As a result, scientists have struggled to explain this whacky weather.

But in a new study published Wednesday (Oct. 7) in the journal Nature Geoscience, researchers used Mars Express data to create new simulations in an effort to finally explain the AMEC. Initially, the team struggled to recreate the puzzling phenomenon. But when they abandoned traditional meteorological principles in favor of a more out-of-the-box explanation, they were eventually successful.

"To create the AMEC in our modelling, we found that we needed to include some exotic physics … physics that, while included in textbooks, is treated as theoretical and usually thought not to happen in nature," study first author Jorge Hernández-Bernal, a planetary scientist at the University of the Basque Country in Spain who was affiliated with Sorbonne University in Paris at the time of the study, said in a statement. "Once we included this physics in our simulations, the AMEC emerged just as we hoped."

"Wholly unexpected"

The AMEC is an orographic cloud, meaning it forms as strong winds push water vapor up and over a raised structure, such as a mountain. Similar clouds also exist on Earth, including the "Levanter" cloud, which occasionally forms above the Rock of Gibraltar in southern Europe. However, the Martian equivalent cannot be explained by the same processes that occur on our planet.

On Earth, clouds form via a process called heterogeneous nucleation, in which moist air cools and condenses into ice crystals that form around tiny atmospheric particles, such as dust, salt, pollen or soot. But while Mars has plenty of atmospheric dust, that's not what's happening there.

"For the AMEC, it seems that cloud formation takes place without needing any of this 'stuff' [in the air]," said Hernández-Bernal, who has been studying the AMEC for the past six years. "Water vapour turns directly into icy cloud particles without any middle step. It's akin to droplets of condensation appearing in the middle of a room, rather than on a window."

The researchers call this "homogeneous nucleation" and say it has never been seen before in a planetary atmosphere. "It's wholly unexpected," Hernández-Bernal added.

Other scientists previously predicted that homogeneous nucleation could occur in Earth's upper atmosphere or in the skies above Venus. However, this has been deemed highly unlikely because it requires humidity levels roughly 100,000 times greater than those on our planet's surface.

Given that modern-day Mars is almost completely devoid of water, it may seem unlikely that its humidity levels could reach such lofty heights. However, the Mars Express data tells a different story.

As wind rises up the slopes of Arsia Mons, which is more than twice as tall as Mount Everest, it creates a powerful wave that shoots air into the upper atmosphere at tremendous speed. The researchers calculated that the temperature of this air can drop by up to 54 degrees Fahrenheit (30 degrees Celsius) in just 10 minutes. This not only makes it easy to freeze but also greatly increases the humidity within the wave, allowing homogeneous nucleation to take place, the simulations show.

So where does all this water come from? Some of it is already in the atmosphere, but some likely originates at the summit of Arsia Mons, which is covered with a thick layer of frost, the researchers suggested.

"A big success"

The new simulations mark a big step forward in our understanding of the AMEC and wider Martian meteorology.

"We don't have nearly as much information about Mars' atmosphere as we do about Earth's, so reproducing the AMEC to this degree is a big success for the model," Hernández-Bernal said.

The findings would not have been possible without the Mars Express orbiter, which used three instruments — the Visual Monitoring Camera, the High Resolution Stereo Camera and the OMEGA instrument — to map out how the AMEC takes shape and evolves every day. It is also one of the only Mars spacecraft that can see Arsia Mons in daylight.

"Mars Express discovered the AMEC, has followed up and monitored it for years, and is now helping reveal the secrets of its formation," Colin Wilson, the project scientist for Mars Express, who was not involved in the new study, said in the statement.

The discovery is also a reminder that, despite sharing the same basic principles, weather systems do not behave the same on other worlds as they do on Earth, which could have big implications for solar system exploration and the hunt for extraterrestrial life on distant exoplanets.

"While clouds on Earth and Mars seem to be governed by the same 'rules', understanding this exotic Martian cloud required exotic physics — and this may be true elsewhere in the cosmos," Wilson said.

As the "super" El Niño is predicted to bring heavier storms and flooding to the U.S., experts recommend stocking up on food and other supplies. Floods and other disasters, like wildfires, are on the rise due to climate change, making disaster preparedness essential.

But how prepared are people for a disaster?

Preparedness levels vary; some people keep an emergency kit full of food and first-aid supplies, while others have a planned meeting place designated as a safe space. Having a plan can help people feel better about unpredictable events. But not everyone has thought this far ahead.

Live Science recently asked readers how prepared they are for a natural disaster and what sort of plans or supplies they have on hand. Over 130 people responded to the poll, with 51% of readers choosing "I've got an emergency kit ready for when the unexpected happens."

The comments reflected this majority, as one reader wrote, "We're on the edge of an area at risk for grass fires, so we bought/stocked an RV as an emergency bugout vehicle. Felt extreme initially, less so as time goes by. Gives us 3-5 days of margin before we need to resupply, with food, water and first aid for people and dogs."

Another commenter responded to the rest of the comments, writing, "This is just the begining [sic]. Get a greenhouse, plant food, learn to harvest water, build an outside toilet (for later), learn to be self sufficient. trade with your neighbors. Plant fruit trees, get solar panels and an electric transporation (bike, car whatever). Keep a de humidifier in your home. it's back to the 1930ie[s]."

Do you agree with these readers? Let us know in the comments section.

Astronomers have spotted a never-before-seen type of "phoenix planet" rising from the ashes of a dying alien sun. The discovery, which the scientists say was "completely unexpected," raises hopes that more of these reborn alien worlds could be lurking throughout the cosmos — and may offer a glimpse of our own solar system's fate.

The unnamed exoplanet was spotted circling the white dwarf HS 0209+0832, which is located roughly 270 light-years from Earth. White dwarfs are stellar remnants, sometimes dubbed "zombie stars," that form from the leftovers of massive red giants that run out of fuel before eventually collapsing into shriveled husks. HS 0209+0832 is a particularly young white dwarf, still burning at around 63,000 degrees Fahrenheit (35,000 degrees Celsius), which suggests it made this transition within the past few million years.

Scientists previously discovered some surprising heavy elements within the visible spectrum of HS 0209+0832, which was first captured by the Hubble Space Telescope in the late 1990s. These elements ‪—‬ which included aluminium, titanium and nickel ‪—‬ are not normally found inside white dwarfs, so their presence suggested that something unusual was going on. But until now, there was not enough data to figure out what.

In the new study, published Oct. 5 in the journal Nature Astronomy, researchers took a closer look at HS 0209+0832. Using some of Hubble's updated instruments and data from other observatories, the team captured a more detailed spectrum of the stellar zombie. This revealed a high concentration of additional heavy elements, including zinc and copper, as well as niobium, which has never been seen in a white dwarf before.

The researchers think these out-of-place elements were created during the death throes of the former red giant and later coalesced into a "second-generation" planet around the newly forged white dwarf. They suspect the atmosphere of this hypothetical planet is being stripped by the white dwarf's stellar winds, causing the rare elements to fall back onto the zombie star.

Follow-up observations then revealed a recurring dip in the brightness of HS 0209+0832, suggesting that an exoplanet was repeatedly passing in front of the undead star. Based on the alien world's orbit, which lasts approximately 4.4 Earth days, and the duration of its transits in front of the star, the team predicted that the planet is roughly the size of Jupiter. (Its close proximity to the white dwarf also supports the hypothesis that its atmosphere is being stripped away.)

"Second-generation planets are worlds that form out of the material a star casts off as it dies," study first author Jamie Williams, a doctoral candidate in astronomy and astrophysics at the University of Warwick in the U.K., said in a statement. "They're incredibly rare, and finding one around a white dwarf was completely unexpected. It's a bit like finding a planet that has risen from the ashes of the very star it once orbited."

"Completely unexpected"

This is not the first time astronomers have spotted an exoplanet around a white dwarf. For example, in 2019, some of the authors of the new study previously spotted an alien world surrounding the white dwarf WDJ0914+1914. However, in that case, they were confident that it was a first-generation world that somehow survived its star's fiery end.

But the heavy elements that seem to be falling onto HS 0209+0832 — and the relative lack of other elements common in first-generation planets, such as silicon and iron — suggest that's not what's happened for this recently detected world.

"This pattern of elements is a telltale sign of the 's-process,' a nuclear reaction that builds heavy elements inside dying stars during their bloated red giant phase," study co-author Nicholas Stone, an astronomer at the University of Wisconsin-Madison, said in the statement. "It's a chemical signature no ordinary, 'first-generation' planet should carry, which told us that this new planet was something different."

Instead, the newly detected exoplanet likely formed directly from the material that was shed by the dying red giant after it expanded and before it collapsed in on itself.

Similar phoenix planets have been spotted alongside other stellar remnants, such as pulsars, which form when stars explode as supernovas. However, until now, such worlds have never been seen around a white dwarf.

Rising from the ashes

"What's remarkable about the planet around HS 0209+0832 is that this isn't a planet from somewhere else, or a survivor from the system's birth, it looks like it was built from the very material its own star cast off as it died," study co-author Boris Gänsicke, an astrophysicist at the University of Warwick who also helped to discover the exoplanet around WDJ0914+1914 in 2019, said in the statement. "In a sense, this system has given birth to a new world using the foundations of the old one."

HS 0209+0832 may have once harbored other exoplanets when it was a red giant. But if they existed, these alien worlds likely perished in flames as the dying star ballooned — similar to what experts think will happen to Earth when the sun runs out of fuel and transitions into a red giant in around 5 billion years.

Once the sun has finished bulging, it will turn into a white dwarf too. The new discovery hints that our star could also host brand-new worlds after it has transformed, creating a sort of solar system 2.0.

"Finding this one example raises the question of how many more might be out there and might our own solar system host a second-generation planet formed from the ashes of our sun," Gänsicke said.

However, more work is required to figure out exactly how the newfound exoplanet formed and, as a result, how likely this scenario is. The researchers suspect that another object, such as a lost stellar sibling, may have been required to create the new world.

"Forming the protoplanetary disc in this situation is not easy and helps explain why these planets are so rare," Williams said. "To form a disc of material necessary to birth a planet, HS 0209+0832 likely required a companion star that pulled the ejected material back into orbit, rather than letting it escape."

Have you ever wondered what it's like to be flipped off by an orangutan or seduced by a mantis? Well, wonder no more, thanks to the 2026 Nikon Comedy Wildlife Awards.

This photography competition showcases the amusing side of nature, usually by anthropomorphizing it in some way, and features a variety of comical critters from across the globe.

This year, a surprised owl and a brown bear striking a pose are featured among the more than 10,000 entries, with photographers competing for a luxury safari in Kenya's Maasai Mara National Reserve.

Live Science rounded up some of the funniest photos from the 2026 finalists for your enjoyment. And yes, the orangutan and mantis have made it to the finals.

"Are You Kidding Me?"

Here we see a squirrel launching itself at a great horned owl fledgling in Natural Bridges State Beach park in Santa Cruz, California. According to photographer Kevin Lohman, the squirrel knocked the owl off its perch three times.

Our video channels editor, Elise Poore, said this photo really made her laugh. I doubt the owl found it quite so funny. However, great horned owls (Bubo virginianus) do hunt squirrels, so it's no surprise that these rodents can get a little tetchy around the birds.

"Spicy Orangutan"

This "Spicy Orangutan" entry features a male Bornean orangutan (Pongo pygmaeus) raising one finger, giving the appearance that he's flipping off the camera. In the description accompanying the image, photographer Tanner Mansell explained that the orangutan was finishing his meal at the time.

"Even though he was completely wild and just enjoying his food, I couldn't help wondering, 'Does he know what he's doing?'" Mansell wrote.

No, Mansell, he doesn't.

"Ballet Dancer"

This photo of a sparrowhawk (Accipiter nisus) in Dumfries, Scotland, is titled "Ballet Dancer," but to me, the balancing bird looks more like an Olympic gymnast in the middle of a complex beam routine. Either way, perfect form!

"Push Over"

This lion snapshot, taken in the Ruckomechi riverbed in Zimbabwe, is one of many finalists that appear to show animals laughing or joking around.

"#ForTheGram"

Photographer Rosie Barrett was getting shots of three yearling brown bears (Ursus arctos) in Finland when one appeared to strike a pose.

"Pretty sure he knew it was for Instagram..un-bear-lieavable!" Barrett wrote in a description of her photo.

S-bear me.

"Sexy Mantis"

I know what you're thinking: This mantis looks like it's saying, "Draw me like one of your French girls." However, if you can look past the sexualization of an insect, you might notice a pretty neat trick in how the photo was framed.

Half of the mantis's body is hidden behind the leaf. What appears to be a torso and legs are actually the creature's forelimbs, which it uses to catch prey. Photographer Diego Perez explained that he snapped the mantis while documenting wildlife in the proposed Bosques del Araza Regional Conservation Area in Peru, which is currently threatened by illegal gold mining.

"Sea Gangsters"

Here we see a herd of walruses on the coast of Svalbard in Norway. The photo is titled "Sea Gangsters," implying that the walruses look like tough guys. You'd probably feel tough, too, if your tusks (which are actually sabers) grew to around 3 feet (1 meter) long.

"Little Godzilla"

Ten out of 10. No notes. But, in all seriousness, red squirrels (Sciurus vulgaris) are known to grab materials like dried grass and moss to line their nests, called dreys, so maybe this little fellow is working on its home sweet home.

"The Different One"

Sometimes, all a photographer needs is the Maasai Mara, three young giraffes and a perfectly placed acacia tree. It's nice that the photographer caught them at a standstill, since these ungulates can run up to 35 mph (56 km/h) in short bursts.

This is just a selection of the finalists. You can see the rest of the contenders in Nikon's 2026 finalists gallery. The winners will be announced Dec. 8.

What do you know about the animal kingdom? Test your knowledge with our animal quiz!

The Draconids, one of the year's most unpredictable meteor showers, will peak this week. Although only a few "shooting stars" are expected, the shower has a history of producing spectacular meteor storms with little warning.

The Draconid meteor shower takes place Oct. 6-10 each year, peaking on Oct. 8-9, when around 10 "shooting stars" per hour are expected. Whereas most meteor showers are best seen after midnight or during the dark hours before dawn, the best time to view the Draconids is in the evening, according to Timeanddate.com, making it one of the more convenient meteor showers of the year. Just after dark Thursday (Oct. 8) will be the best time to look.

The Draconids are different from most other showers because their radiant — the point from which their meteors appear to originate — is in the constellation Draco, the Dragon, which is highest in the sky in the evening. It's also circumpolar in much of the Northern Hemisphere, so it never sets below the horizon. However, there's no need to stare directly at Draco, because meteors can appear anywhere in the sky.

This year, the Draconid meteor shower peaks at the perfect time of the month for dark skies. Because the new moon occurs Saturday (Oct. 10), there will be no significant moonlight when the Draconids reach maximum activity.

However, the Draconids are notoriously unpredictable; while just a handful of meteors per hour are expected, the shower can sometimes produce huge meteor storms. For example, during the Draconids' peak in 1933, Europe saw 500 meteors per minute, according to NASA, and during the 1946 peak, 50 to 100 meteors were seen per minute in the U.S.

The source of the Draconids is Comet 21P/Giacobini-Zinner, which was discovered in 1900 and orbits the sun every 6.6 years. It was last in the inner solar system in 2025 and will return in 2031.

Each October, Earth passes through streams of dust and debris left along the comet's orbit. When those tiny particles strike Earth's atmosphere, they heat up and vaporize, creating streaks of light in the night sky.

Most observers will probably see only a few Draconids this year, but with a meteor shower this unpredictable, it's always worth looking up. The best way to see the Draconids is with the naked eye, but a good pair of stargazing binoculars or a nice backyard telescope will help you enjoy the feast of fall skywatching events on the horizon. Amazon has great deals on skywatching gear this week, so it's a perfect time to get involved.

The patient: A 65-year-old woman in Michigan

The symptoms: The woman arrived at the emergency room via ambulance and asked to see a psychiatrist for her visual hallucinations. "I'm seeing dead people," she told clinicians, adding that she'd even fired a gun at her hallucinations in one instance, according to a report of her case. (The report does not describe what the hallucinations looked like.)

Despite this reaction to her hallucinations, she was calm and alert during her physical exam, with normal vital signs other than high blood pressure. She reported a history of high blood pressure, diabetes, heart failure and chronic back pain but no prior psychiatric history.

What happened next: Since the woman had no past psychiatric history, doctors opted for a medical assessment before consulting a psychiatrist. A blood test revealed mild metabolic acidosis, meaning her blood was too acidic. A toxicology screen detected high levels of salicylates, a class of compound that includes acetylsalicylic acid, better known as aspirin.

The diagnosis: When questioned, the woman acknowledged that she had been taking over 15 aspirin pills a day for multiple weeks. Each of these pills, marketed for back and body pain, contained 500 milligrams of aspirin.

Upon further questioning, the woman confirmed that she had tinnitus (ringing in her ears), which is a classic symptom of salicylate toxicity. In other words, she'd overdosed on aspirin.

The treatment: Doctors consulted experts at Michigan's poison control center, who recommended intravenous (IV) treatment with sodium bicarbonate (the chemical name for baking soda). This treatment alkalinizes blood and urine, meaning it makes them less acidic. This enables more salicylate to be excreted through the kidneys, allowing the drug to be eliminated through the urine.

After 11 hours of the IV treatment, the woman's blood salicylate levels dropped from 28.8 milligrams per deciliter (mg/dL) to 18.3 mg/dL. Her hallucinations ceased and the tinnitus improved within 48 hours of her arrival at the hospital. She was discharged without having seen a psychiatrist.

What makes the case unique: Aspirin is generally safe when used in doses indicated on the bottle or advised by a person's doctors. However, taking too much aspirin can irritate the gastrointestinal tract, as well as disrupt the activity of parts of the nervous system.

At high enough doses, salicylates can stimulate part of the brain called the medulla, which regulates breathing. This results in hyperventilation that causes the body to lose too much carbon dioxide, and at first, the blood becomes more alkaline. This process is known as respiratory alkalinosis.

However, salicylates also disrupt metabolism, leading to metabolic acidosis from a buildup of lactic acid in the body, as the woman experienced. When metabolic acidosis overwhelms the respiratory alkalinosis and causes the blood to acidify, organ damage can occur. These metabolic effects may also explain the tinnitus, as it drives increases in arachidonic acid that stimulate receptors in the inner ear.

The woman's daily intake of roughly 75 milligrams of aspirin per kilogram of body weight was about half the typical dose associated with acute salicylate poisoning. However, it was still a large amount to take every day for weeks, and older age is also a risk factor for severe outcomes of acute salicylate toxicity.

The authors of the case report noted that although she had tinnitus, she lacked many other hallmark symptoms of salicylate overdose, such as nausea and fever.

To the clinicians, the woman's case served as a reminder that long-term aspirin toxicity may result in different symptoms than acute poisoning does. In past case reports, other patients with chronic salicylate toxicity have also reported visual hallucinations. But that potential symptom is not as well understood as more common symptoms like tinnitus.

The case report authors added that longer-term exposure to aspirin may be associated with more neurological symptoms because chronic exposure increases the odds of the drug crossing the blood-brain barrier — a gatekeeper that allows only certain substances from the blood into the brain. They added that doctors should consider poisoning, including salicylate toxicity, for patients with psychotic symptoms with no clear cause.

For more intriguing medical cases, check out our Diagnostic Dilemma archives.

This article is for informational purposes only and is not meant to offer medical advice.

Can you guess the diagnosis in these strange medical cases? Find out with our diagnostic dilemma quiz!

Emerging treatments aim to reverse or stall signs of aging in the body and thus cut the risk of age-related diseases. One of those signs is an accumulation of "zombie cells" — damaged cells that spew harmful substances rather than dying off and getting cleared away by the immune system.

Some scientists are designing treatments aimed at killing those zombies directly. But what if we instead helped the body's cleanup crew get rid of them?

"I think rejuvenating the immune system could rectify a lot of problems," said Roel de Maeyer, an immunologist at the University of Oxford. "We know hospitals are full of older people suffering from infections that younger people don't need to go to [the] hospital for."

The aim of these rejuvenating therapies would be to help people live healthier for longer, he told Live Science.

How do cells turn into zombies?

The immune system constantly gets rid of old, dysfunctional and dead cells to keep tissues healthy, but that cleanup gets less effective with age.

When cells die, they display proteins on their surfaces that act as "eat me" signals for immune cells, called macrophages, to engulf and destroy them. However, some cells refuse to die and instead become senescent. These zombified cells can lurk in tissues for years, releasing chemicals that drive inflammation and damage.

Senescent cells can form due to DNA damage from oxidative stress, radiation, or even normal cell division. Cells lose bits of DNA each time they make copies of themselves, and they have intricate mechanisms to decide when it becomes a "bit too dangerous to keep dividing," de Maeyer said. If a cell can no longer divide, it usually undergoes a process called programmed cell death or becomes senescent, he said.

Senescence can be beneficial in some contexts; it helps heal wounds, for example. But an accumulation of senescent cells is linked to damaging inflammation and impaired organ function.

"If there are many senescent cells in a tissue, that's usually a bad sign," de Maeyer said. The number of senescent cells goes up with age and is linked to many age-related conditions, such as heart disease and dementia.

Slaying zombies

Studies in mice have shown that using drugs to kill senescent cells can reverse inflammation and some signs of cellular aging. These drugs, called senolytics, force senescent cells to enter programmed cell death, thus reducing their numbers, said Jure Povsin, a biochemist at the Max Planck Institute of Biochemistry in Germany. This ultimately reduces inflammation and improves tissue function, he told Live Science.

But while senolytics can help rid the body of zombie cells, it's not clear why the immune system fails to eliminate senescent cells in the first place. To find answers, scientists began looking at macrophages, the cells tasked with devouring dying cells.

Research pointed to a receptor on macrophages called EP2. One study, published in July in the journal Science, found that old macrophages have a greater number of these receptors and cannot eat senescent cells effectively.

Genetically deleting the EP2 receptor in lab mice restored the macrophages' function and reduced the number of senescent cells. Compared with normal mice of the same age, the genetically tweaked mice showed less cognitive decline, muscle loss, cardiac dysfunction and systemic inflammation.

On some of these metrics, such as the ability to remember familiar objects, the modified mice were comparable to younger mice.

A problem with energy

Why is the EP2 receptor at the root of this problem? Scientists found a clue in a huge study of older adults.

A molecule called PGE2 plugs into the EP2 receptor. It's a type of prostaglandin — a molecule that helps cells communicate during stress and injury and contributes to fever, pain and swelling. Drugs such as ibuprofen reduce inflammation by blocking prostaglandin production.

In 2001, a large study uncovered a connection between these prostaglandin-blocking drugs and Alzheimer's disease: People ages 55 and older who routinely took the drugs for at least two years had a lower risk of developing Alzheimer's than nonusers did. The study could not prove that the drugs directly prevented the disease, but it added to growing evidence that inflammation related to EP2 activity plays a role in Alzheimer's.

This caught the attention of Dr. Katrin Andreasson, a neurologist at Stanford University and co-author of the recent Science study.

"I thought, 'Wow, this is interesting,'" she told Live Science. "I wondered if there's a connection."

Andreasson and colleagues had an important breakthrough in 2021: They found that aging macrophages had higher levels of the EP2 receptor and that increased EP2 activity disrupted how the cells used their energy. Instead of burning glucose to produce energy like young macrophages do, these cells stashed it away.

As a result, the cells could not do their job properly, as "gobbling up cells requires a ton of energy," Andreasson said. Blocking the EP2 receptor restored normal energy use in the macrophages. In old mice, it also led to reduced inflammation and better scores on cognitive tests, compared with mice in which EP2 activity remained high.

Making senescent cells vulnerable

In their recent study, Andreasson's team uncovered another consequence of aging: Old mice accumulated many senescent neutrophils, a type of short-lived immune cell that acts as the body's first line of defense against germs. Neutrophils normally die within days and are then cleared away, but with age, they become more prone to senescence and accumulate.

"I think that's kind of an odd concept because they're [usually] very short-lived cells," said de Maeyer, who was not involved in the Science study. "Neutrophils are inherently quite inflammatory, so wanting to clear them from tissues is very valuable."

Old mice have too much EP2 activity in their macrophages, and that means they can't get rid of these neutrophils, Andreasson's team found. That may be why deleting EP2 seems to have anti-aging effects in multiple organs, they concluded.

But increased EP2 activity is just one side of the story; some studies suggest that zombie cells actively suppress macrophages' ability to eat them. They do this by using a tricky protein called CD47.

CD47 is a "don't eat me" signal that stops macrophages from destroying cells, Povsin said. "It signals that the cell is healthy, alive and doesn't need to be eaten."

However, that signal gets amplified in senescent cells, Max Planck researchers showed in a 2023 study. That means that, when macrophages interact with senescent cells, macrophages' function becomes impaired. Afterward, they even lose the ability to engulf dying, nonsenescent cells. This allows a ton of cellular debris to accumulate.

So, rather than just blocking EP2, it could also be beneficial to reduce that "don't eat me" signal in senescent cells, this research hints. But CD47 is found on all living cells, so scientists can't just deplete its numbers across the body.

A specific enzyme modifies CD47 on senescent cells, and in the 2023 study, blocking the enzyme helped spare macrophages from the effects of CD47. Therefore, blocking the enzyme could be a more selective approach to weaken the "don't eat me" signal on senescent cells, Povsin said.

A long road to treatments for people

Translating these ideas into anti-aging treatments for humans would be a major success in the science of aging, but experts say there are significant problems to overcome.

Although blocking EP2 had consistent results in lab mice, the rodents are genetically identical and bred in controlled environments. Humans are inherently more variable in their biology and the environmental factors they're exposed to, introducing confounding factors that would need to be addressed, de Maeyer said.

Additionally, in clinical trials, EP2-blocking drugs have so far been explored as cancer treatments, but they are "underexplored" in the context of aging, he added.

Drugs targeting CD47 are in an even earlier stage of development. In the 2023 research from Max Planck, the team used both human and mouse macrophages in their experiments, but the approach has not been tested as an anti-aging treatment in living mice or humans yet.

In 2020, de Maeyer's team used a different strategy to rejuvenate macrophages in older adults. They blocked a protein called p38, whose activity was high in the macrophages of older adults. Blocking the protein helped macrophages better recognize and eat dying cells in specific tests.

In that study, the team gave adults ages 65 and up an experimental drug called losmapimod to block p38. Although it helped restore their immune cell function, it was not suitable for long-term use because it caused liver problems in later trials, de Maeyer said.

In their mouse studies, Andreasson's team was able to block EP2 without causing any negative side effects. But she cautioned that we "really need to drill down on the research and confirm all this stuff in humans."

"The next logical step," she said, "would be to figure out how to inhibit this receptor in a safe way."

This article is for informational purposes only and is not meant to offer medical advice.

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The animal kingdom has influenced several robot designs over the years to solve fundamental challenges in propulsion and movement — from horses to insects. Now, frogs are the latest creatures to inspire roboticists.

As seen in a new study published Sept. 18 in the journal Science Advances, researchers probed how twisting bent elastic rods could produce a "snapping motion" that enabled a small robot to hop or swim. This mechanism could be used to improve robots with limited power and ones that need to traverse rough terrain and even water, the scientists said in the study.

They also built a prototype to demonstrate the work. The palm-sized robot weighs just 3.4 ounces, or about as much as a deck of playing cards. It moves about three body lengths per second — launching itself forward with short jumps.

"The broader opportunity is to let the mechanics of the robot do some of the work that would otherwise require larger motors or more complicated control," Xiaonan (Sean) Huang, an assistant professor of robotics at the University of Michigan and co-first author of the study, said in a statement.

"By programming when an elastic structure stores and rapidly releases energy, we can give small robots access to powerful, repeatable motions without continuously demanding high output from the motor," Huang explained. "In the future, this principle could be useful for robots that must navigate cluttered terrain, overcome obstacles, reorient quickly, or operate across both land and water."

Snap movements

When a flexible rod bends and its ends are rotated, it can eventually reach a point where it changes shape to release built-up tension, the roboticists said. However, this change does not always happen in the same way. Some combinations of bending and twisting cause the rod to change shape gradually, while other combinations force it to snap rapidly from one shape to another, with the potential to provide a strong push.

The team used computer modeling and experimentation with a robotic arm to repeatedly deform the rods and find an optimal shape. In this case, they settled on a helix similar to a coiled spring to give the rod its maximum release of energy, the team reported.

With the ideal propulsion mechanism, the team then designed and built real robots that used the snapping rods to hop. They connected these rods to a rotating motor, with the bent rods twisted until they produced the snapping motion. Then, the motor unwound the twist and contorted the rod again.

"Because the design rules depend on the rod’s shape and how its ends are moved, they work across different sizes and scales," Khalid Jawed, an associate professor at UCLA's School of Engineering and co-first author of the study, said in the statement.. "This opens a promising path toward miniaturized robots just a few millimeters in size that turn small motor movements into powerful bursts of motion," said Jawed, whose lab worked on the simulation and robot arm experiments.

The final form of the prototype was a frog-like robot with a pair of snapping rods at the rear of its main body. Tests included hopping over a broad range of surfaces, including solid materials like wood and glass, as well as trickier soft and slippery surfaces that used materials like leather. The scientists also tested the robot outdoors on sand and grass, noting that it could even climb and descend steps and, with paddle attachments, swim.

By using only one of the snapping rods, the team enabled the robot to turn and, with a remote control, navigate a small obstacle course.

Researchers have observed the strongest candidate yet for a "microblazar" — a dazzling object that has long been predicted to exist but never spotted.

Observations of microblazars would give astronomers closer views of black holes emitting powerful jets of energy and help them understand how these extreme objects behave.

Blazars are some of the most energetic objects in the universe. They are a type of quasar — a brightly glowing object fueled by a supermassive black hole stripping material from its host galaxy and then ejecting some of it in powerful, opposing jets of particles and radiation. To qualify as a blazar, one of those near-light-speed jets needs to point directly at Earth. Astronomers have previously discovered smaller versions of quasars, dubbed microquasars, and long theorized that there must be smaller versions of blazars as well.

Now, an international team led by astronomers in Spain, the Netherlands and Argentina has described a microblazar in a study accepted for publication in the journal Astronomy and Astrophysics.

"It is the first time that we have a serious candidate," Josep Martí, an astronomer at the University of Jaén in Spain and first author of the study, told Live Science.

The object, called IRAS 18293-0941, is located in our galaxy, about 12,000 light-years from Earth, and it's hidden behind a veil of dust. It is a binary system that includes a black hole that orbits a hot, gigantic star every 11 days. Matter from the star falls into the black hole, and some of this material is jettisoned into the surrounding environment in two opposing jets. One of those jets flares toward Earth.

These objects, as well as microquasars in general, are tricky to observe, Martí said. "Because of stellar evolution, you need to catch the system at the right time," he added. "The microquasar phase of evolution is very short, and so it is difficult to find one in that phase."

Theorists predicted that microblazars would have special characteristics that should help define them. These features include powerful emissions across the electromagnetic spectrum, rapid changes in brightness (variability), and a hotspot behind them where its opposing jet heats up the interstellar medium in the opposite direction of Earth.

To observe IRAS 18293-0941, the study authors used a variety of instruments ‪—‬ including the Calar Alto Astronomical Observatory in Spain, a network of radio astronomy telescopes called the European VLBI Network, and the MeerKAT radio telescope array in South Africa ‪—‬ as well as archival data from the Very Large Array in New Mexico.

They found that IRAS 18293-0941 has all of the expected microblazar characteristics, except one ‪—‬ variability. Microblazars have rapid variability, which means their brightness changes a lot in a short period, because one of the jets is facing Earth and small changes in brightness are amplified by an effect called Doppler boosting.

Martí said IRAS 18293−0941's lack of rapid variability could be explained by the dense cloud of gas surrounding it, which could smooth out quick fluctuations in brightness.

The researchers are currently investigating whether the observed area behind the microblazar is in fact a hotspot, study co-author Pedro Luque-Escamilla, an astronomer at the University of Jaén, told Live Science.

Even with one of the expected features missing, this object is a promising candidate for the first known microblazar. "The claims and the results of the paper are sensible and there are no questionable hidden assumptions," Kinwah Wu, a theoretical astrophysicist at University College London who was not involved in the research, told Live Science in an email. "The source in this paper had shown signatures of interactions between the jets and the ambient material, which naturally leads to [particle] interaction."

Svetlana Jorstad, a senior research scientist at the Institute for Astrophysical Research at Boston University who was not involved in the research, told Live Science in an email that the new study was "very interesting, important and comprehensive."

Itumeleng Monageng, an astronomer at the University of Cape Town who was also not involved in the research, added that the team's observations "presents a previously overlooked mechanism for generating some of the highest energy emissions observed."

Microblazars "may power some of the universe's most energetic processes," Monageng told Live Science in an email.

Martí, J., Luque-Escamilla, P. L., Marcote, B., Abaroa, L., Aguasca-Cabot, A., Combi, J. A., Romero, G. E., Paredes, J. M., García, F., Fogantini, F., Saavedra, E. A., Del Ser, D., & Van Den Eijnden, J. (2026). A Galactic microblazar as a potential accelerator of ultra-high-energy particles. Astronomy and Astrophysics. https://doi.org/10.1051/0004-6361/202661105

See how much you know about black holes with our black hole quiz!

Archaeologists have unearthed evidence that men, women and children were subjected to violence within their communities in ancient Scandinavia — and that these victims were buried in unusual places, such as pits or wells or under a family's house or yard.

During the Scandinavian Iron Age and Viking Age (from roughly 500 B.C. to A.D. 1050), violent encounters between individuals and communities steadily increased, resulting in archaeological evidence of elite warrior burials and mass graves from battles.

To better understand the context of violence in the Iron and Viking ages, researchers analyzed 192 human bones from people buried in domestic areas at settlements in what are now Denmark, Norway and Sweden.

"The fact is that not all bodies ended up in monumental burial mounds in the Iron and Viking Ages, or even in more modest urnfields and cemeteries," the researchers wrote in a study published Sept. 28 in the Journal of Archaeological Method and Theory. Rather, some bodies — or pieces of bodies — were placed in postholes, pits, floors, wells, houses, yards and feasting halls.

The archaeologists discovered that at least 12 of the individuals had sustained a violent injury around the time of death. Half of those cases involved head trauma, while four people suffered multiple injuries. Most of the victims of violence were adult males, but there were two females and a child as well.

In one Iron Age house in Denmark, built sometime between 500 and 1 B.C., archaeologists discovered a frontal bone from the skull of a child who died between the ages of 2 and 4 years old.

"Our DNA analyses show that it is a small boy who has been cut with a sword," study first author Marianne Hem Eriksen, an archaeologist at the National Museum of Denmark, said in a translated statement. "The child's skull was placed on the floor of a house where people continued to live. This means that someone has walked over a child's skull day after day."

Radiocarbon dating revealed that the child's skull is significantly older than the house itself, by as many as two centuries, suggesting the bone may have been kept for some time before being placed in the house floor, according to the study.

At a Viking Age site dated to around 750 to 1050, archaeologists found a young woman's skull in a well near a cluster of four small houses. "The woman's skull bore traces of blows and was buried in a well," Eriksen said. She may have been cut or slashed with a sword or ax and, like the child, her bones may have been kept for a significant amount of time before being buried in the well. "These glimpses of lives lived from the past show how fascinatingly different people must have thought about life and death," Eriksen said.

And at the Viking Age site of Gammel Lejre, a royal feasting hall that many experts consider to be the inspiration for the epic Old English poem "Beowulf," archaeologists found the burial of a man whose skeleton bore numerous blunt force injuries, several of which had healed, and which attested to a difficult and likely painful life. His skeleton was discovered directly south of the feasting hall.

The study of bones in domestic areas "opens up a completely new understanding of Iron Age society, of the occurrence of violence and of the handling of the dead," Eriksen said. "The results show a much greater complexity in the everyday life and world of imagination of the time than we often attribute to Iron Age people."

But it is unclear exactly why these particular people were the victims of violence and why they were buried in such unusual ways. One possible scenario, the researchers wrote in the study, is that these were victims of violent domestic encounters rather than warfare. Their deaths may also have been the result of socially acceptable corporal punishment or some form of aggression within the community.

Given the increase in social inequality and rise in violence in the Iron and Viking ages, the researchers suspect that precarious community members may have been targeted.

"Not all lives were equally grieved and commemorated in the Iron and Viking Ages of Scandinavia," the researchers wrote. "We may question whether some lives were already considered disposable."

See how much you know about ancient norsemen with our Viking quiz!

Rosalind Franklin, whose photographs of the molecular structure of DNA led to a 1962 Nobel Prize for three other scientists, knew that her famous images held the secret of the double helix, new research suggests.

An examination of archival material reveals that Franklin's Photograph 51, which was taken in May 1952 and later published to show the double-helix structure, was specifically taken for the purpose of publication — not, as some narratives have held, an experimental shot that Franklin believed was insignificant. The new research revealed that Photograph 51 was a new exposure of a sample Franklin had already photographed. She started Photograph 51 the same day she saw that photograph, Photograph 49.

"She took it because she wanted to get a really refined version," said study co-author Alistair Sponsel, a historian of science at the Science History Institute in Philadelphia. Making the effort to take a better photograph of the same sample is "a sign she knew she had something really important on her hands," Sponsel told Live Science.

Francis Crick, James Watson and Maurice Wilkins shared the Nobel Prize in Medicine for the discovery of the double-helix structure of DNA in 1962. As Watson told it in his 1968 autobiography, "The Double Helix: A Personal Account of the Discovery of the Structure of DNA," Franklin's photographs were his "aha" moment: "The black cross of reflections which dominated the picture could only arise from a helical structure," he wrote.

Watson further implied that Franklin was a laboratory automaton, good at the X-ray crystallography techniques used to capture the images of the DNA molecule but bad at interpreting her own data. The new archival work, published Monday (Oct. 5) in the Journal of the History of Biology, suggests otherwise.

Franklin's dearth of published notes about Photograph 51 has been used to suggest she missed a major discovery. But Sponsel said her journals show she noted the possible helical shape and rich structural data in her notes for her first picture of the sample, Photograph 49, which she followed up with the more refined image in Photograph 51.

"In Franklin's mind, they were two different types of scientific image," Sponsel said. Photograph 49 was the experimental image revealing exciting new data. Photograph 51 was the showpiece to convey these findings with the most clarity and sharpness possible.

This new understanding of the relationship between the two images, and how Franklin perceived them, is the most important feature of the new work, Sponsel said, which he conducted with molecular biophysicist Brian Sutton of King's College London. The project began when the Science History Institute acquired a new collection of archival material from Rosalind Franklin and her graduate student Raymond Gosling. The two researchers also combed through the archives at King’s College London, where Franklin was working when she took the famous photos.

Sponsel and Sutton think that Franklin's notes and actions reveal why she didn't rush to publish Photograph 51 right away. Her scientific goals, laid out in a report she wrote in February 1952, were to understand the two separate structures of DNA, then known as A and B. Structure B, illustrated in Photographs 49 and 51, turned out to be the double helix that occurs in nature. Structure A is a form DNA takes when it's dehydrated in the lab.

Structure A, when photographed, appeared more data-rich, so Franklin decided to characterize that structure first before studying structure B. But while she did this painstaking work, Wilkins showed Watson her photographs of structure B. The two scientists, together with Crick, then built a detailed model of DNA's double helix and scooped the discovery from under her nose.

Those three men shared the Nobel Prize for the work less than a decade later. Franklin died of ovarian cancer in 1958, making her ineligible for the prize — and leaving her insights to come to light only much later.

Editor's note: This article was updated at 3:23 p.m. ET to fix the caption and subhead, noting that Rosalind Franklin had likely discovered DNA's helical, but not double-helix structure. Also, the top photo is not Photograph 51, but another photo taken by Franklin.

Amazon Prime Day is underway, and we've found some tempting deals on our favorite stargazing equipment at Amazon. The sale ends at 23:59 tonight, Wednesday, October 7, 2026, and we'll keep an eye on the deals so you can keep an eye on the skies.

Fall is a fantastic time to stargaze, with meteor showers, full moons, constellations and planetary oppositions — some of which you can only see with binoculars or a telescope. Shop the best deals on telescopes and binoculars below.

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This eye-catching astronaut photo mosaic shows a rare "sunglint" transforming a snaking reservoir into a giant silver river.

The winding waterway at the heart of this image is a section of Lake Powell in southern Utah. The artifical reservoir starts around 70 miles (110 kilometers) southwest of the town of Moab and ends roughly 60 miles (100 km) northeast of the Grand Canyon in Arizona. When full, Lake Powell holds up to 1.2 billion cubic feet (33.3 million cubic meters) of water, making it the second-largest reservoir in the U.S. — close behind the nearby Lake Mead, which stretches across the Arizona-Nevada border.

Lake Powell is located on the Colorado River, inside a steep ravine known as Glen Canyon. The reservoir emerged in the 1960s, following the construction of the Glen Canyon Dam, which caused water levels to rise by around 200 feet (60 meters) over the next two decades. In addition to generating hydroelectric power, the artificial lake has become a popular tourist destination. (Lake Mead is also located along the Colorado River and was created by the construction of the Hoover Dam.)

This image mosaic, which stitches together several astronaut photos into a single image, was captured during a sunglint, according to NASA's Earth Observatory. This phenomenon occurs when sunlight bounces off a reflective surface directly into the line of sight of an observer in orbit, such as a satellite or an astronaut, giving the object a metallic, mirror-like gleam.

Normally, this effect would be visible only across a small section of the lake. But by combining photos taken as the sunglint moved along the reservoir's length, the entire body of water was illuminated.

The reservoir is named after John Wesley Powell, an explorer and former director of the U.S. Geological Survey, who mapped out Glen Canyon and other parts of the Colorado River in the late 1860s. Powell was particularly captivated by Glen Canyon, which contained a "labyrinth of overhanging cliffs, hanging gardens, sweeping river bends, and natural arches set amidst a backdrop of colorful buttes and mesas," Earth Observatory representatives wrote.

Powell later described his recollections of the canyon. "Past these towering monuments, past these mounded billows of orange sandstone, past these oak-set glens, past these fern-decked alcoves, past these mural curves, we glide hour after hour, stopping now and then, as our attention is arrested by some new wonder," Powell wrote in his 1875 book "Canyons of the Colorado."

Some of the sights that Powell marveled over still exist, including many smaller canyons that branch off the reservoir and are cast in deep shadow. A similar effect is seen in sections of Utah's Green River, a tributary of the Colorado River that has long perplexed geologists due to its ability to flow "uphill."

From above, one of the canyon's most striking geological features ‪—‬ a large, doughnut-shaped depression known as The Rincon ‪—‬ is visible as a dark ring surrounding a bend along one of the widest sections of the lake. This rusty doughnut, which is up to 3 miles (5 km) across, is a former section of the Colorado River that dried out thousands of years ago when part of the canyon collapsed, enabling water to bypass the rocky loop.

However, many of the other wonders that Powell described have been lost beneath the reservoir's elevated water level. These include a side canyon dubbed the Music Temple, which was shaped in a way that gave it remarkable acoustic properties, according to the Earth Observatory.

During periods of drought, when the reservoir's water levels temporarily drop, other lost geological treasures can be exposed. For example, in 2023, researchers found rare fossils from a mammal-like Jurassic creature lurking beneath the lake's high-water line.

In recent years, some environmental groups have petitioned to drain Lake Powell and return Glen Canyon to its former glory as the "heart of the Colorado River," according to Newsweek. Such a change may help to alleviate pressure on the rest of the river, which has lost a significant amount of water in recent decades. But experts told Newsweek that this is unlikely to happen.

See more Earth from space

Mpox spread across the world in 2022, triggering tens of thousands of cases in countries where the infection was once rarely seen. Although the disease has since fallen out of news headlines, mpox (formerly called monkeypox) continues to circulate. Now, recent data suggests that the viral illness may soon be endemic to the United States, meaning it will circulate in the country consistently.

Previously, mpox cropped up sporadically in the U.S. via travelers who had visited African countries where the disease is endemic, as well as imported, infected animals that spread the virus to people. Cases have fallen substantially since the peak of the outbreak in 2022, but they haven't disappeared. A report published in August found that there were 2,800 cases in 2024 and over 2,500 in 2025, with only a small fraction being tied to travel. Nearly all of the viral samples analyzed were descendants of the strain that sparked the 2022 outbreak. In short, once the virus arrived, it never went away.

"There's no set threshold for what constitutes endemicity of monkeypox virus (MPXV) in the United States," Ryan Standford, an epidemiologist in the Centers for Disease Control and Prevention's (CDC) Poxvirus and Rabies Branch and co-author of the report, told Live Science in an email. "But each year provides further evidence of this transition."

Why is mpox still spreading in the U.S., and what can be done to snuff it out? It's likely that too few people have received two doses of the mpox vaccine JYNNEOS, which together are 66% to 90% effective. But beyond low vaccination, there may be other, less-understood factors that are contributing to the continued spread, experts told Live Science.

"We don't quite know how it's able to persist at such low numbers across the entire country," said Joel Wertheim, a professor of medicine in the Division of Infectious Diseases and Global Public Health at the University of California, San Diego.

At the same time, public health efforts around mpox have dwindled. Without a sustained effort on that front, it's unlikely the disease will be eliminated from the U.S.

"We have vaccines, testing, and a much stronger understanding of the disease than we did in 2022," Dr. Demetre Daskalakis, chief medical officer of Callen-Lorde, a LGBTQ+ community health center in New York City, told Live Science in an email. "Our focus now should be making sure those tools remain accessible, especially for communities that continue to face ongoing risk," said Daskalakis, who coordinated the nation's mpox response during the previous presidential administration.

"People at increased risk should know that mpox has not disappeared."

Who is at risk of mpox in the U.S.?

In the U.S., mpox is predominantly affecting men who have sex with men, and current vaccine recommendations are aimed at this group and their sexual partners. Mpox mostly spreads from person to person through close contact, and transmission during sex is playing a major role in the ongoing spread in the U.S.

Men who have sex with men are not more prone to mpox infection than anyone else. Rather, this transmission pattern stems from the outbreak beginning within a specific sexual network and then continuing to persist within the same network. "The mpox virus rediscovered the same transmission network that HIV had explored decades earlier," Wertheim said.

In a paper published in 2025, Wertheim and colleagues described the transmission dynamics of mpox in New York City during the 2022 outbreak. Similar to how HIV previously spread, mpox triggered "densely connected" clusters of infection. Then, as people in the network gained immunity via infection and vaccination, the cases petered out, decreasing to the persistent trickle we see now.

Wertheim noted that he's not surprised that mpox has remained largely confined to the same network, rather than leaping into new groups.

"From an evolutionary, ecological perspective, it's not hugely successful," Wertheim said. "It's sort of barely hanging on as an STI."

Why is mpox still circulating?

So if mpox is not hugely successful and we have a vaccine, how has the virus continued to circulate? One big factor is that too few at-risk people have been vaccinated, experts said.

The CDC's Center for Forecasting and Outbreak Analytics has crunched the numbers to see what percentage of that at-risk group needs to have immunity to stop mpox transmission, Daskalakis said. The at-risk group is estimated by counting the men who have sex with men who are either taking HIV-preventing medicines or have HIV, and then adding 25% to that total to account for additional people in the same sexual network. That estimate comes out to about 2 million people.

To prevent an outbreak bigger than the one in 2022, between 21% and 35% would have to have immunity through vaccination or a past infection. If over 50% of the group had immunity, that would mean there's a "very small probability" of sustained local transmission, the CDC's modeling suggested.

The current case counts suggest we haven't hit the 50% mark, or a total of roughly 1 million complete vaccinations or past infections.

Data from the August report on mpox seems to support the idea that too few people are vaccinated. That said, information about vaccination status was missing for about 62% of the reported cases. Among the remaining cases, 76% were unvaccinated, while 10% had gotten one dose and 14% had gotten two.

In a subset of 860 cases, the effect of vaccination was striking: Unvaccinated people had nearly 10 times higher odds of hospitalization due to mpox than fully vaccinated people did.

Waning public health attention

It's difficult to pin down exactly how many at-risk people are vaccinated, given that that data is no longer tracked at the national level. "My understanding is that there's no mandatory reporting on mpox vaccination data," Wertheim said.

The CDC previously monitored national vaccination trends, comparing the number of people vaccinated to the overall at-risk population. But that tracking stopped in early 2024, when about 23% of the at-risk population had been fully vaccinated.

Some states, such as New York, previously mandated that clinicians provide their state health department data on the number of people given mpox vaccines. But that reporting is now voluntary, a spokesperson for the New York State Department of Health told Live Science in an email.

Meanwhile, "as the emergency phase faded from public attention, awareness and risk perception may have declined," Daskalakis said. Public health messaging about the virus and vaccination has also waned.

"In recent weeks, HHS [the Department of Health and Human Services] has pulled down some of the plain-language guidance, which is not helpful in supporting messaging," Daskalakis noted. This decision to remove online resources about mpox reflects the federal government's current stance against addressing issues that affect LGBTQ+ health, he told Live Science.

Complicating factors

Although JYNNEOS substantially lowers the risk of severe mpox infection, the vaccine is not perfect, said Rachel Roper, a professor of microbiology and immunology at East Carolina University.

The virus typically enters the body through broken skin, the respiratory tract or mucous membranes (thin tissues found in the eyes, nose, mouth, anus and genitals). The mpox vaccine is good at generating systemic immunity, but it's not as good at guarding against the virus's immediate effects at those mucous membranes, said Roper, who studies poxviruses and vaccines against them.

Because mpox is largely spreading through sexual contact that involves those membranes, that slight gap in protection may also help to explain some of the ongoing spread, she suggested.

Plus, "there are also some data supporting asymptomatic infection as a possible route of transmission, making it more difficult to eliminate local transmission of mpox," Daskalakis said.

What can be done?

Given that mpox is already well established within some sexual networks in the U.S., "preventing endemicity entirely may be increasingly difficult," Standford told Live Science.

And notably, some federal funding cuts could undermine efforts to address mpox, Daskalakis said. These include cuts to Medicaid, mental-health services, housing programs, and HIV services such as the Ryan White HIV/AIDS Program.

Thankfully, looking at current mpox trends, "there's no indication we're returning back to 2022 levels," Wertheim told Live Science. So far in 2026, just under 1,000 mpox cases have been reported, according to the CDC. Month over month, the number of cases is generally trending downward. So, at a glance, the current situation seems better than it was in 2025, he said.

"We sort of seem to be on this razor's edge between endemicity and extinction," he said. "And it's not really clear which way it'll go."

Tipping the virus toward extinction will require healthcare providers to be informed and equipped to spot and manage cases, Daskalakis said. And communicating the importance of vaccination is key.

"One lesson from 2022 was that trusted messengers matter," he said. "We [at Callen-Lorde] work closely with LGBTQ+ communities and make information and vaccination opportunities available in settings where people already receive care." The clinic integrates conversations about mpox vaccination into routine health visits, sexual health services, HIV prevention programs and community outreach activities.

Beyond vaccinating at-risk populations, educating patients about how mpox spreads and how to reduce their risk is also key, Standford noted. "Vaccination coverage is a very important factor, but it is not the only one," he said.

Tipping mpox toward extinction will also require enough investment to maintain the disease surveillance, vaccination, testing and treatment capacity that the federal government helped to expand in 2022, Daskalakis said. The vaccine itself is now commercially available to clinics and in adequate supply, he emphasized.

"The fact that we're seeing ongoing circulation underscores the need for sustained prevention efforts rather than viewing mpox as a resolved public health issue," he said. "Infectious diseases don't disappear simply because public attention shifts."

This article is for informational purposes only and is not meant to offer medical advice.

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