Mike Brown's Planets

Thank you from the future

2009-06-13T15:31:00.000-07:00

Being a professor at Caltech, I get to dress up in a gown and funny hood one morning every June and sit on stage, watch hundreds of new Doctors and Masters and Bachelors go by and listen to a commencement speaker impart words of wisdom on the graduates. One June, a few years ago, I even got to be one of those commencement speakers. I spoke at the graduation ceremony for Cal State LA in their football stadium, with 20,000 people in the audience – a personal record that I suspect will never be exceeded – and my image projected, rock star style, on multiple giant screens around the stadium. I had a few butterflies in my stomach that morning. But I managed to give a speech that I ended up liking. It went something like this:

First, I’d like to thank President Rosser for inviting me to be here to share this morning with you. I’d like to thank all of the students for inviting me, too, except that I can see all of you down there discretely picking up your programs and flipping through saying “um, who exactly is this guy again and why is he here?” So let me help you out with those two because really if you ask your neighbor he or she probably won’t know either, but that’s OK.

Who am I? You got the quick intro: astronomer, professor at that much smaller university about 5 miles north of here, discoverer of the 10^th planet or perhaps destroyer of the 9^th planet depending on who you talk to. And I guess those are the official qualifications for why I’m here talking to you today. But let me tell you how I would actually introduce myself if we met out in the parking lot. I’d probably ask where you were from and I’d say “oh I’m your neighbor; my house is about 10 miles up the road that way.” And then I would probably tell you that I teach geology classes to large groups of Caltech freshmen many of whom seem to have never been outside during the daytime before I take them and make them look at the world around them. And then I would start talking about my wife and our 11 month old daughter and you’d have to find a way to get me to shut up because, you know, you need to be somewhere by dinner time and I might keep talking for weeks.

OK. So that’s who I am. The next question is: why am I here? The goal of a commencement speech is to give you a seed of advice at this precise turning point in your life – some seed that is going to implant in you and grow and help steer you as you commence on your new life. It’s a powerful idea that that I could do that, that I could transfer a little bit of wisdom from me to you to help steer through all of the cross currents and distractions of real life to finally get to your ultimate goal. Now that would be seriously influential.

But I’ve got bad news for you, though. I’ve got no advice to tell you how to get along in life. No little words of wisdom. No seeds to plant. As my wife will attest, I barely know how to get along in life myself, and if I had any seeds I probably set them down somewhere in the other room and now I can’t remember where I put them even though I just had them a second ago. I can’t really give you any advice on how to get to the future because the most important thing that you will realize – which you probably already realize since you have made it this far -- is that really you just have to figure it all out on your own. OK maybe that even counted as advice, but if that’s all you get after all of those years of classes and driving and rearranging schedules to get here on time then you should really ask for your money back. No, really, I’ve got no advice to give, unless, of course, you wanna run off and find planets, then I’m definitely your guy. But otherwise? Nothing really.

So I thought: what can I do? No advice to give, but I’m supposed to talk for ten minutes I can just try to be funny for a few more minutes then we can get on with the serious business of whooping and hollering as all 3600 of you walk across the stage. Then I remembered what my wife told me: scientists are not funny people. Why do you think they put them all in the far back of the stadium there? Not funny at all. Don’t even try.

So I’m going to go out on a limb and try to do something that is a lot harder than trying to be funny, which is trying to be serious. I do have something I want to tell you, which is maybe better – or at least more rare – than advice. I want to tell you thank you. Thank you for everything that you’ve done to be sitting right there right now. But really this is not from me, I really want to tell you thank you from the future. And you might think that I am uniquely qualified to talk about the future since I’m an astronomer and all, but, um, really, being an astronomer has very little to do with predicting the future. That’s an ASTROLOGER. They’re the ones that get paid better. But people do get confused all the time.

So it’s not that I am an astronomer and thus know the future, no, I think that the one qualification maybe I have for talking about the future really is my 11 month old daughter. Some of you down here – and certainly many of you out there – know what having a child does to you: you immediately start projecting to the world of the distant future, but you also start thinking a lot about the past and your own parents.

So before I start talking to much about the past, first let me ask: How many of you are in the first generation of your family to go to college? (At Cal State LA first generation college students make up the majority of the population.) This thanks goes to you, but the rest of you need to listen to because it will be your job to pass this thanks on to the right person in your own family.

So first, let me admit: I’m not one of you. I’m in the second generation to go to college.

My father grew up in a small Missouri cotton farming town along the Mississippi River. My mother grew up in a small Illinois manufacturing town along the Mississippi River Neither of their parents had gone to high school in their little river towns. My mother’s family came from recent German immigrants and ran a series of grocery stores in town. My father’s family came from all over – Ireland, France, Nebraska, Pennsylvania – before settling down along the river and opening a small business repairing the newly invented TV sets. By the end of the 1950s with college opportunities beginning to expand around the country they both set off to do something no one in their family had never done: go to college. My mother traveled down the river to the big town of St. Louis; my father went up the river to the big town of St. Louis; and they both arrived at St. Louis University with little idea of what was in store for the next 4 (or 40) years

My mother and father both went to college in the 60s and so in my family there really wasn’t much question of college vs. no college. It was simply a where (in Alabama the choice was usually based on whether you were a fan of the University of Alabama or the Auburn University football team). But things were different for my parents. My father grew up in a small cotton farming town along the Mississippi. My mother grew up in a manufacturing town further north along the Mississippi populated by German immigrants.

And, so, in case you haven’t figured this part out yet, my parents are you.

And if my parents are you, I am your children.

You are my parents. I am your children. Your children, though, will never quite understand this well enough to thank you for all that you did. So I’m going to thank you instead.

I’ve got a second thank you that I need to say this morning. It’s not really for you, so I’m only going to give it to you so that you can pass it on. And this is the thanks for the parents and the siblings and aunts and uncles and grandparents and cousins and everyone else who is here supporting you today and who has been supporting you through all of this. Those people – all of you out there – are like my grandparents pushing their children from opposite ends of the Mississippi River in the same direction towards their own goals. The funeral for my grandmother – the last of my living grandparents – was just this last Monday in that little Mississippi River town. Until I sat down to think about what I was going to say this morning to you it never really occurred to me to think very hard about all that she had gone through that allowed me to be where I am today. It certainly never occurred to me to tell her thanks. But she deserves the same thanks that I just extended to you. I wish this one could be from me to her, but I’ll have to settle for from the future to all of you. For your parents out there, your grandchildren – present and future – thank you for all of the things that you did that will make their lives better, even though they won’t really know most of them.

Once you start thanking people it actually gets kind of addictive. Particularly when you are actually doing the thanking for someone else in the future. I’ve thanked you from your children and from your grandchildren, but I’ve got one more that is a little closer to home for me. I think a lot about my daughter these days and I think a lot about the future that she is going to have. In maybe 21 years or so – let’s say June of 2027 -- she could be sitting down right there where you are now. What will the world be like then? I sometimes think the bad thoughts: with 20 more years of global warming will LA be a place that we can live? Will the WORLD be a place we can live? Will the top speed on the freeways be 10 MPH? Will some psychopath figure out how to get a nuclear device into LA before Jack Bauer can stop him? But you think the good thoughts, too: in 20 more years maybe people will have learned to be nicer and more understanding. For the most part, though, most of these things are going to be imposed on us all from the outside and there will be little we can do. [sorry; this is a commencement speech faux pas. I’m not supposed to admit to you that much of what happens in the world you can do little about. Ok, for the record everything is possible you can be anything you want to be and completely change the world and we all believe in you to do anything. OK? OK. Now back to the real world]. OK, no, but really most of the thoughts that I have when I think about what the world will be like in my daughter’s future involve things that few of us – no matter how influential Time magazine says we are – can do much about. They are just the fabric of life, the collective interactions of the millions of people living out their lives at the same time in our community. And I can’t tell the future, so as much as I try to use the Tarot cards they issue you with the astronomy degree to predict what is going to happen, I really have absolutely no clue whatsoever. But there is one thing that I know – one part of my daughter’s life and future – that will be a constant no matter which of these things – good or bad – comes about. That one part will be you. You are the future fabric of this community of Los Angeles. You know, somewhere out there might be my daughter’s mayor – and by now you gotta trust that I don’t mean that in the cheesy commencement speech “you can be anything” kind of way – I mean that in the very literal “somewhere out there might be my daughter’s mayor or maybe city council member or Senator or whatever” way. Really. It actually seems pretty likely doesn’t it? Somewhere out there might be the high school English teacher that inspires my daughter to go write the great American novel. Somewhere out there might be her older next door neighbor who feeds her cats when she is out of town. Somewhere out there might be the parents of her husband. [If so we will need to talk right after this ceremony is over]. Somewhere might be the owner of the first company she ever works for. Somewhere might be the doctor who delivers my own daughter’s own daughter. Big parts of the fabric of her life, of the fabric of this city are sitting right here.

So, as her father, I’d like to thank you. It will never occur to her to thank you for anything since you’re the fabric and people tend to take fabric for granted, but I’ll thank you from the future for making and being the city and community of her future.

And, OK, I have one request. Really just one thing for you to remember to do when you leave here today. (And, of course, don’t forget what I said before about thanking those people who are here for you today). I still really don’t have meaningful advice, but I do have this one request. You guys are the Los Angeles of my daughter’s future, the fabric of her life in this community. And I just ask that you be nice to her. And to look out for her. It’s not too much to ask of you is it? Just to be nice to someone? Like she’s your own daughter, or your baby sister, or your favorite niece? And I meant to bring with me a big poster board picture of what she looks like so you could know who you were promising to look out for and be nice to, but I got up way too early this morning – astronomers aren’t traditionally morning people – so I just plain forgot. No baby pictures for you, so you really don’t have any way of knowing what she looks like – although you probably wouldn’t go wrong by looking for someone who looks an awful lot like me but is a good bit shorter and much much much cuter– but still, you’ll never know for sure which one of the toddlers then kids then teens then adults that she is, so really I guess the only safe way to honor my request to be nice to my daughter is just to be nice to everyone. And look out for them. You are the future of everyone’s community of Los Angeles and I want you to look out for everyone. It will make the Los Angeles of all of our futures a better place to be.

Sony Pictures and the end of the world

2009-06-07T20:27:00.000-07:00

Based on all the email inquiries that I’ve been getting lately, it seems pretty clear that the world is going to end in 2012, and it is at least partially my fault.

The email inquiries are, of course, generally misguided: the world is not going to end in 2012, and whether it does or doesn’t has little to do with me.

For years I’ve been getting these emails, asking if Eris, the biggest of the dwarf planets, and something that actually does exists, is somehow related to Nibiru, a made-up planet allegedly known to the Sumerians that, in fact, does not actually exist. The main reason for the confusion is that both the real Eris and the mythical Nibiru have extremely elliptical orbits. The non-existent Nibiru does things that the real Eris can never do, however: in 2012 this made-up planet is supposed to swing close by the earth and, well, destroy life as we know it. Bummer.

I try to respond to most of the email that I get from people who are generally interested in understanding more about the universe around them, but I tend to simply ignore inquires about 2012 or Nibiru or Sumerians. People interested in this type of pseudo-science tend to be uninterested in understanding the scientific reasoning which shows that those beliefs are unfounded. But lately I have been getting an ever-increasing amount of this email along with frequent phone calls from 2012 people. What is different this time is that these people sound truly worried. One voice mail I received said “I’ve got kids; this really scares the hell out of me. Is there something I should be doing? Is this real?” He left an email address. Slightly shaken at his tone, I wrote back saying that, no, this is one of those crazy internet hoaxes and that I’ve got a four year old myself and my biggest worry for 2012 is what she is going to be like as a seven year old. He wrote back relieved. Weird, I thought. This didn’t seem like typical pseudo-science wackiness. This guy was inherently skeptical about the 2012 claims, and was happy when someone with a ring of authority told him there was nothing to it, but, still something had made him worried enough that he had tracked down some astronomer he had never met and called him to reassure him about the safety of his family.

What gives?

Curious about why some people are more than usually worried about this sort of stuff, I actually read a piece of spam I got this week from something called the “Institute for Human Continuity.” It seemed ever so slightly more slick than usual:

Greetings,

As the Communications Director of the Institute for Human Continuity, I'd like to thank you for taking an active role in preparing yourself for 2012. Please note your ticket is only valid for one person. Therefore, we strongly suggest that you encourage your friends and family to register for lottery numbers at TheIHC.com.

The IHC has uncovered evidence indicating that the disasters of 2012 are both real and unavoidable. We believe with 94% certainty that exactly four years from today, cataclysmic events will devastate our planet and many who inhabit it. December 21, 2012 cannot be ignored.

Though the future is uncertain, there are several things we can and must do to prepare. You have already begun by entering the IHC lottery and visiting our website. In the coming weeks, I will be hosting an online discussion during which I will answer your questions and provide additional knowledge on how you can continue to prepare. You may submit your written questions to me via twitter and email. We will also be accepting video questions and will have more details for you in the coming weeks.

I look forward to receiving your questions and working together to ensure that the end is just the beginning.

Sincerely,

Dr. Sorën Ulfert, PhD
Communications Director
The Institute for Human Continuity
Twitter: sorenulfert
Email: s.ulfert@TheIHC.com

-----------

Curious, I decided to check out the web page linked above. As I ran my mouse over the link, though, my eye was momentarily caught by the real address that popped up at the bottom of my browser:

http://news.sonypictures.com/sb40/c4.php?SPT/231494770/49919474/H/N/V/http://www.theihc.com/?hs308=email

Sony Pictures?

OK, now I was really intrigued.

Check out the web site yourself. It’s got press releases, an “education” section all about Planet X, a history of the IHC, and a list of the Ph.D.-heavy staff. Some even wear bow ties. And, hey, you can participate in a poll! (“Which sport would you like to see reestablished first after 2012?” I vote for stock car racing, though basketball and football might be doing better so far.) You are encouraged to sign up for a lottery to see if perhaps, by the grace of the IHC, you will survive the cataclysm. But your chances are limited, and the number of slots is almost full. Best act quickly, you are told. An odometer showing how many people have already signed up for their chance to live continuously increases in the upper right corner of the web site (8,422,601, as of this moment). Most of these people, sadly, are destined to die.

On occasion – usually late at night at a telescope trying to stay awake -- I amuse myself by going to similar apocalyptic sites. They all have a similar look and feel, sort of like the web equivalent of a typewritten piece of paper that has been Xeroxed dozens of times. It’s clear that they’re kooky just by looking at them.

This one is different. It is slick. It is professional. There is no obvious sign anywhere that this is the work of kooks.

And then, if you look ever so closely, you might note at the bottom that all of this is copyright 2009 by Sony Pictures. And you might see a link to the “2012 Movie Experience.” But you’d be forgiven if you missed these, what with the end of the world happening and all.

Wow.

So the entire web site and spam that I received that directed me here is an advertisement. Except that it never says that. It purports to be a real site from real scientists with real concerns about the end of the world, but, in the end, it just wants to make a buck by having you go to what is likely to be a crummy movie.

If the spam email had tried to scare me about the end of the world and then directed me to a web site which turned out to simply advertise the movie, that would have been distasteful. But what is the right word for a spam email that tries to scare me to go to a web site which then tries to scare me even more and doesn’t even admit to being simply an ad for a movie. Well beyond distasteful. Disgusting? Outrageous? Putrid? Reprehensible?

Am I overreacting? It’s just a movie, right? And a witty viral ad campaign, right? At some point they will break the silence and say “Surprise! The world is not ending! This is just a movie! Aren’t we clever?” And we’ll all be so happy that we’ll decide the best way to celebrate is to go see a movie. Any movie except one from Sony Pictures.

Maybe at that point I’ll quit getting phone calls from people who are scared for the continued existence of their families. Or maybe not. Maybe this fear-mongering ad campaign is not the reason I’ve gotten so many more scared phone calls and email messages lately. Sadly, though, if it is the fault of the ad campaign, Sony Pictures would presumably be pleased.

Homeward bound

2009-06-02T20:12:00.000-07:00

I’m on my way home today from a quick trip a third of the way around the world to use a telescope.

Astronomers are, of necessity, vagabonds. Sometimes the thing that you want to look at in the sky is only viewable from the southern hemisphere, so down to Chile you go. Sometimes the thing is so faint that only the biggest telescopes around are worthwhile, so it’s off to Hawaii. What’s rare, though, is to spend 24 hours flying from Los Angeles all the way to the Canary Islands – a group of high volcanic crags off the coast of Africa with a latitude almost identical to that of southern California – to use a telescope smaller than the one that is just a three hour drive from my house.

When, after a day of travel, I got to La Palma, the island whose highest peak is strewn with telescopes, and I stepped outside into the dark dark night sky, I was greeted with exactly the same sky that I see in Los Angeles. OK, there were many many more stars, but they were all in their right places, and nothing was there that I couldn’t have seen from home.

So why spend all of that time to travel to a telescope smaller than my local one when all of the same sights were visible? Because when it was night time in the Canary Islands the sun was still high overhead in southern California. And the thing I was hoping to see only happened right then. If I had stayed home and waited eight hours to look later I would have seen nothing.

Here is what I hoped to see: that night the funny oblong fast spinning dwarf planet Haumea was passing directly in front of one of its satellites (Namaka is its name). If I could determine precisely when it happened and how long it lasted I could learn many things about Haumea (its size and crazy shape, maybe also its interior structure) and also about Namaka (how big it is, how much it is being tugged around by the other satellite, Hi’iaka). But all of this was happening so far away that the only way I could tell when Namaka disappeared behind Haumea was that the total amount of light coming from Haumea should dip by about 1%, So at the telescope I spent two entire nights doing nothing but staring at Haumea and measuring precisely how bright it was every two minutes. For comparison, I also checked a couple of stars nearby at the same time. If they stayed steady while Haumea dipped in brightness I would know I was in business.

It all sounds so simple.

In reality, though, stars never stay the same all night long. They get brighter as they get higher in the sky and fainter as they drop. Even on the clearest nights they fluctuate due to changing atmospheric conditions. Seeing this tiny drop in brightness of Haumea in the face of all of this intrinsic variability is a tough task.

But I tried.

After two nights at the telescope I am leaving with my laptop filled with pictures of the sky and my hopes high. Did we see it? Did we detect this tiny dip which told us that Namaka disappeared? I think so. I have a plane ride from London to Los Angeles tomorrow to look at the data more closely and convince myself what might or might not be there. But I think so.

If we didn’t detect anything it’s bad news. Perhaps our predictions are off, or it’s just too small of a blip for us to ever really see. But if we did detect it then our work is really just begun. Turning that little blip in the sky into concrete information about Haumea and Namaka will take a lot longer than tomorrow’s plane ride. There will be many more such trips around the world to be in precisely the right place when it happens again. There will be detailed computer models of the exact time and depth and duration of the blips. There will be confusion and ambiguity. But that is all in the future. For now I have the simple pleasure of long uninterrupted plane ride where I can stare and poke at the data, catch up on some reading, and think about these dwarf planets. And at the end I get to pick up my daughter from school and she’ll ask “Daddy daddy daddy did you see any stars?” and I’ll tell her that I did, but that the stars here at home are always the very best ones in the sky.

Heavens above!

2009-05-18T21:20:00.000-07:00

Almost ten years ago I got to be involved in an astronomical experiment. The US Air Force had recently completed a technologically sophisticated telescope on Haleakela, the highest peak on Maui, for the purpose of spying on satellites as they went overhead. The National Science Foundation was interested to know if the new telescope might prove useful for astronomers, too, so they recruited a few test cases to come see if they could make it work.

The tests were, ultimately, ambiguous. We were trying to observe Saturn’s moon Titan to see if we could take images of hurricane-sized storms moving across its surface. We were stymied as much by horrendously bad weather (on Haleakala, not on Titan), as we were by cultural differences between astronomers and the Air Force. (My favorite: our observations of Titan were temporarily classified, because “Titan” is the same word as “titan” which is a missle. The people doing the classifying thoroughly understood that we were observing the moon of Saturn but, by the rules, any observations of “[T]itan” were to be classified.)

But though we were generally stymied, one moment at that telescope will stick in my memory forever. We were waiting for Titan (the moon of Saturn) to rise high enough in the sky that night and watching over the operators’ shoulders as they spied on satellites. Whenever they were foreign satellites we were kicked out of the room. But whenever they were U.S. satellite we could stay and watch.

At 4am the night before, as we were driving down the mountain after a night of observing, we had listened intently to the news of the Space Shuttle parked at the International Space Station and the installations to be done that day. They were having problems, apparently, with getting a solar panel to unfurl correctly. We went to sleep not knowing what had happened. As we drove back up the mountain the next day we had still not heard any news.

Around 8pm, though, Elvis, one of the operators, said “ISS coming!” meaning that the International Space Station was soon to fly overhead.

“Hey, you guys seen the ISS before?” Elvis asked.

“Not that I know of” I said.

“This a sight to see; hold on.”

And the giant telescope swung to the horizon and started tracking the space station as it went across the sky and the other operator came in and starting making adjustment on the computer and then, suddenly, the Space Station came into focus.

It looked much like all of the other pictures of the Space Station that I had ever seen before with two exceptions. First, the solar panels were unfurled.

“Ah ha!” we said. “I guess they were successful last night.”

Second, we could see the Space Shuttle parked next to it. Every other picture I had ever seen had been taken from the Space Shuttle, so I had never seen what it looks like when the shuttle is parked right there.

The view was so good that if a spacewalk had been happening right then and an astronaut had turned around to wave at the earth we would have seen him well enough to know to wave back.

The telescope tracked the Space Station for about 4 minutes. When it was over, I picked my jaw up off the floor. It was, perhaps, the most amazing pictures I had ever seen a telescope make before, and it was just over our heads, rather than in the remote depths of space.

Only a few weeks ago, on these very pages, I tried to remind people to Look Up! To remember that stars and planets and galaxies are not abstract things that we read about but are real concrete and viewable things in the sky above. But, really, for most of my life, I’ve been just as guilty when it comes to those other things that occupy our night skies: the satellites. It’s not that I don’t see them all the time when I am looking at the sky, but I never think of them as anything more than spots of light moving across the heavens. Sure, I know all about the Space Station. I use the Hubble Space Telescope as often as I can. I think about the astronauts and the Space Shuttle and watch NASA TV to make sure the launch and the walks go ok. But somehow I still fail to make that cognitive leap that reminds me that these things are real, and are really in the skies over head.

Until this week.

Knowing that the Shuttle was up visiting the Hubble Space Telescope for the last time, I got an overwhelming urge to see them both, to somehow make a visual connection with the astronauts who are up there risking their lives so that people like me can continue to make astronomical discoveries. I knew that, in theory, you should be able to see such things, but I didn’t really know how. I did what any rational person would do in 2009, which is to search Google. And I found my new obsession: www.heavens-above.com

Simply tell the web site your latitude and longitude and it will tell you all of the bright satellites that will go overhead tonight.

I tried it the other night. The Space Station was making what I now realize was a particularly favorable pass. At 9:51pm I went outside (a full 2 minutes early, just in case, though I need not have). I waited. I traced precisely where I thought it was supposed to go and stared and stared just in case it was a bit faint to see in the glow of the Los Angeles skies. And then, precisely, on schedule, it silently and majestically moved from the southwest horizon to nearly overhead to the northern horizon over the course of about 4 minutes. It was brighter than anything else in the sky at the time.

I had seen it before, I am certain. But I had never seen it and known what I was seeing. I ran back inside and said to my wife Diane:

“I just saw the Space Station go overhead. It was one of the most amazing sights in the sky I have ever seen!”

She looked at me, nodded, and went back to the email she was writing.

OK. I get it. Satellites aren’t for everyone. But they’re out there. They’re real. They’re waiting. That bright light travelling across the sky contained three people who at that precise moment could have been looking down and seeing the crescent earth with the sun still illuminating the Pacific while California was now bathed in dark. Those people are really there.

As for the Space Shuttle, which set me on this mission, it hasn’t been visible yet. You can only see satellites when – like an airplane high in the sky at sunset – they are still illuminated by the sun while you are in the dark. By chance that has not happened over California yet while the Shuttle has been up. I might get a chance on Friday, when it is low in the sky around 5am. I will definitely wake up for it. It’ll be my last chance to see the Hubble Space Telescope and the Shuttle together and to remind myself that up there these things that we built, these people that fly to them, are all real, and finally on their way back home.

Godspeed

2009-05-10T18:03:00.000-07:00

We astronomers like to toy with the ideas of life and of death. We name distant objects after gods of the dead and underworld, like Orcus or Pluto, we eagerly discuss cannibalistic galaxies and gamma ray bursts that would wipe out civilizations for light years in radius. We talk about catastrophic impacts and the possible slow death of the entire universe. But, usually, it is just a vicarious show. Nothing that we study out there in the universe will is likely to actually affect anything down here on earth. Nothing that we do is really a matter of life and death.

Except for this week.

This week, for the sake of astronomy, seven people will strap themselves on to the top of a controlled explosion and launch themselves almost 200,000 stories into the air. If all goes well, they’ll spend nearly two weeks confined to a tiny container holding the only patch of livable space for 400 miles in any direction, before they drop back to earth in a flaming descent that transforms into a supersonic glissade to the ground.

The seven are the astronauts on the final Space Shuttle servicing mission to the Hubble Space Telescope. If they are able to carry out everything on their extensive list, they will leave behind an enormously capable telescope capable of years more of distinguished and fascinating scientific inquiry.

Astronomers the world over will rejoice, but I will rejoice a bit more than average. A year ago, I proposed to the committee in charge of the Hubble Space Telescope that they allow me to spend a significant amount of time on the telescope to use one of the brand-new instruments being put in by the astronomers to study the origin of the Kuiper belt. It was a bit of a long shot, I thought. These committees tend to favor things such as figuring out the origins of distant things, like galaxies, or the universe itself. Our local neighborhood is often overlooked. But the committee liked the idea and now all that stands between me and getting to use this fantastic new instrument in space is the fact that the instrument itself is currently sitting in Florida. At least as of this moment. But come blast-off it and the seven astronauts will be on their way to space.

This moment almost never happened. If I were in charge, it never would.

After the 2003 Space Shuttle Columbia break up over Texas, NASA declared that the only safe way to fly the Space Shuttle was to go to the Space Station where it could be inspected and, if problems were found, astronauts could temporarily stay while repairs or rescues were mounted. But because of their very different orbits, you can’t get to the Space Station if you go to the Space Telescope. Thus, there would be no more flights to the Space Telescope and it would soon plummet to the earth and burn up in the atmosphere.

There was a great outcry. Hubble is invaluable! Hubble is a national treasure! It seemed as if every astronomer out there had stories to tell about why Hubble was spectacular.

I agreed. I had my own stories, even. Many of the fabulous finds about dwarf planets over the past decade have been made by or aided by the Hubble Space Telescope. And there are many many more things that I still want to do with it. And then I said that it was OK to let it die. Hubble had had a spectacular decade and a half, and if it was not safe to refurbish it anymore we astronomers needed to celebrate its legacy, mourn its loss, but accept that it was for the best. This was no longer an abstract matter of galactic life and cosmic death: this was a matter of real life and, quite possibly, death. This actually mattered.

I grew up in Huntsville, Alabama, a thoroughly dedicated space town, and reminders that things do not always go as planned are strewn throughout the city. The high school to which I went was named after Gus Grissom, who died during a pre-launch test of the Apollo 1 mission. Ed White and Roger Chaffee – who died along side Grissom – have their own schools just across town. You can see the Challenger school from the back deck of my parent’s house.

I love space exploration. I love human space exploration. I grew up on it. I wanted to be part of it. I became an astronomer because of it. I understand – I think – the risks, and am even willing to accept them. Sometimes. But not blindly. I feel that many of the astronomers pushing and pushing and pushing to get the Shuttle to fly to the Space Telescope never once thought about the risks, never drove around a town with schools memorializing astronauts who never came home. This actually mattered.

What are the risks of catastrophic failure, as the worst-case scenario is known? I have heard absurdly precise estimates of 1 chance in 187, though I neither know how these numbers are arrived at nor put much faith in them. I do know that this next mission is designated STS-125 – the 125^th Shuttle flight. Two have ended in disaster. That’s 1 in 64. While that’s not quite Russian roulette with a six-shooter and a single bullet, neither is it a short drive to the office in light traffic. It was worth thinking hard about this. This actually mattered.

In the end, the tea leaves were clear from the beginning. The outcry was too loud for the Hubble to be allowed to fall from the sky. The Space Shuttle would go after all.

It’s probably good that I wasn’t in charge. I don’t think I ever want to be in the position of making decisions that could directly lead to someone never coming home to their family again. But someone has to make those decisions. I would have chosen differently, but I understand the choice. The astronauts themselves know what they are getting in to and are itching to go. Who am I to say no? And, since the decision is made and they are indeed going, I’ll be the one watching from down here on earth cheering loudly, remembering the excitement I’ve felt with every blast off I remember from Apollo on. And this time I’ll be cheering even more loudly, thinking about the years of discovery ahead and the origins of the Kuiper belt and things about which I have not even begun to dream.

You will likely not be surprised to learn that I am a non-religious person. I draw my spiritual inspirations from Etruscans and Inuits and small children and the full moon itself. And yet, when searching for the right incantation, the right words of encouragement and amulet against harm, the best one that comes to mind describes something that those seven astronauts will both have in an almost literal sense and certainly need in the intended sense:

Godspeed, STS-125, godspeed.

Encore: Yelping at Saints

2009-05-05T14:09:00.000-07:00

[I've been watching the moon, which made me remember a much earlier column that almost no one read. Forgive the rerun, but watch the moon!]

If your skies have been clear for the past week you might have been noticing -- as I have been -- the slow but unstoppable growing of the moon. There's nothing new here. It does essentially the same thing every 28 days, but it is still a show worth watching.

In my backyard I see this: each night as the moon moves further and further in its circle around the earth and we see more and more of the illuminated half, the moon is getting just a little brighter. In a few days, as the moon finally goes from just-barely-not-full to finally-completely-full, the moon will finally brighten its last incremental amount and it will be its brightest of the month, though only a little brighter than it was the night before.

This gentle brightening to a muted peak sounds prosaic and reasonable. But it is not true.

I remember once being out on a backpacking trip in the wild mountains inward of the Pacific coast south of Monterey. Some friends and I had hiked all day to make it over a range and down to the bottom of a creek where a little stream of hot water poured out of the earth making a tiny pool in which to soak sore legs and shoulders. We camped a bit away from the hot pool, ate a warm dinner as the sun was going down, and finally began climbing our way to the top of the little ridge separating us from the hot spring. We didn't even bother with flashlights in the dark because the full moon had made the entire woods faintly glow -- plenty of light to get around at night even in the dark of the wilderness. As we had almost reached the top, though, somebody silently flipped a switch and a blinding spotlight was suddenly tracking us from the ridge.

This was miles away from any roads or machinery down a long windy trail, so perhaps I could have reasoned my way out of the situation given a little time for relaxation, but, in the instant, I did what I think most anyone would do when unexpectedly illuminated by a spotlight deep in the woods far from where anyone or anything should be: I yelped. Loudly.

My yelping didn't affect the spotlight, which refused to flinch. It refused to flinch, I realized an embarrassed moment later, because it was no spotlight, it was the moon. It had been hiding behind the ridge until we had gotten near the top, and as we rose over one bump it suddenly revealed itself like the flip of a switch. My credibility as a young astronomer (I had just started graduate school that year) was seriously diminished amongst the friends who had seen me frightened of the moon.

Which is to say that the full moon is really bright.

The fact that the full moon is bright is perhaps not a startling fact, but what is startling is that if I had been coming over the ridge on my way to the hot pool and I had seen the moon a day earlier or a day later, I would never have mistaken it for a spotlight.

You don't have to take my over-tired-from-hiking-all-day's impressions for it. If your skies are clear this week as the moon is finally puffing towards full, go outside and see for yourself. Go out on Wednesday, two days before the full moon, and look around. Check out the barely visible shadows. See what fuzzy shapes you can make out in the distance. Look up and notice that the moon is definitely not fully illuminated, but it is getting close.

Go out Thursday. To really do the job right you should go out an hour later than you did the night before, since the moon will have risen an hour later. Look around. You probably won't be able to tell any difference at all from the night before. Same vague shadows, same fuzzy details. And then look at the moon. Definitely bigger, but one edge is still a little flattened. Tomorrow it will indeed be full.

Finally, go out on Friday, an hour later still if you can. Stare right at the moon, if your eyes can stand it. It does look like a spotlight up there in the sky. It is much brighter than it was just the day before. Look at the now-crisp shadows on the ground and the sharp details on the rocks and the plants that you can now pick out. Now go ahead, if you need to, and let out a little bit of a yelp. I'll be understanding.

What is going on with the moon? How can it get so much brighter in just a day? Who turned on the spotlight?

In medieval paintings, saints and anyone else holy are always depicted with a halo around their heads. Unlike modern halo depictions, which look like a gold ring hovering slightly above the hat line, these medieval halos appear more like a general glow coming from behind the entire head. Whenever I see one of these glowing medieval halos I think about how bright the full moon is.

I have a hypothesis -- totally without the benefit of supporting research, necessary expertise, or, likely, even minor merit -- that the medieval painters painted halos like this because they had seen such halos around their own heads. And I know what the painters saw, because I have a halo around my head, as well.

Here's another experiment to try. Go outside on a bright sunny day and start watching your shadow. Walk along until you find a place where the shadow of your head is falling on grass. Focus on your head shadow while you continue to walk, letting the background grass blur in you vision. You will gradually notice that there is a diffuse glow around the shadow of your head. It won't be around any other part of your body, and you won't see the slightest hint around anyone else's head. Point out your halo to any else and they will see precisely the same thing: a halo around their own heads and nothing around yours. Everyone is holy to themselves.

In reality what you are seeing is not some sort of corporeal representation of your own ego or a mystical aura of self-realization, but simply a literal trick of lights and shadows. When you are looking at the shadow of your own head, you are looking, by necessity, directly in the opposite direction of the sun. Stop focusing on your glowing halo for a minute and now focus on the grass itself. You'll notice that in the region where your halo is you will not see a single dark spot due to a shadow of one blade of grass on another. There can't be any shadows; with the sun directly behind you, any piece of grass that you can see can see the sun, so it can't be in shadow. Start looking away from your head shadow and you notice that you are now starting to see collections of tiny shadows, so the overall scene gets darker and darker even though it, too, is fully illuminated by the sun. Your halo is simply the total lack of shadows that can only occur when you are looking almost exactly opposite the sun. I've seen my halo from many places, on many surfaces: on grass or rough dirt or asphalt while walking, even on the tops of a forest full of trees while looking out of the window of an airplane flying low enough right before landing that I could pick out the shadow of the fuselage and see a beautiful glowing ring around. Anywhere you have sunlight and a surface rough enough to make millions of tiny shadows you get to glow the glow of the saints.

And so it is with the moon. When you look at the full moon you are almost looking at where the shadow of you head would be. The sun, though it has set over the horizon, is directly behind you as you face the full moon. If you could see down to the surface of the moon, you wouldn't see a shadow anywhere, not in the craters, not amongst the craggy mountains, but, more importantly not even at the finest scales of the rocky dust that covers most of the surface. The next day, when the moon is just past full, the shadows will begin to reappear and the spotlight will be extinguished.

It happens every month. It's just a trick of light and shadows. But, every now and then, I still look up at the full moon and think about saints and I feel a little bit of a yelp deep inside.

Baby Pictures

2009-04-26T17:16:00.000-07:00

Last night, for the second time this decade, I got to have dinner and give a talk on the floor of the dome of the famous 200-inch Hale telescope at Palomar Observatory. It’s rare for anyone to give a talk on the floor of the 200-inch telescope, because Palomar, like every other large telescope around the planet, is used night after night after night looking at everything from the nearest asteroids to the edge of the universe. Few or no pauses are allowed for frivolities such as dinners and talks (in this case we got in, had dinner, gave a talk, and vacated the floor just as the sun was setting). So it was a treat when I got invited to speak to an intimate gathering of supporters of Palomar and Caltech – the university where I work and the one which, not incidentally, owns and operates Palomar – on the floor of the dome. It was even more of a treat because I had been the speaker at the last one of these dinner 8 ½ years ago, and it was particularly interesting to reminisce about what had happened in the almost-decade since then.

When I gave that first talk, in September of 2000, I was a young assistant professor at Caltech who had embarked on what I think it is fair to say was an audacious project: I was going to go find the 10^th planet. I had spent the previous two years systematically scanning a wide swath of sky using the seemingly ancient technology of manually slapping giant glass photographic plates to the back of a wide-field telescope, exposing the photographic plates to the sky for half an hour at a time, developing the photographic plates in the darkroom downstairs, and then looking at repeat exposures of the same patch of the sky to see if – perhaps! – I could find something that had moved. It was exactly what Clyde Tombaugh had done 70 years earlier that had led to the discovery of Pluto, but, no, I had the advantage of a much larger telescope and the use of computers to help analyze the final photographic plates.

At the time of the talk 8 ½ years ago I was in the third year of the project, where I was going back with a larger telescope to try to confirm anything that I thought I had detected during the first two years with the photographic survey. I told my audience sitting under the 200-inch telescope about what I was doing and about what I hoped to find. I told them about photographic technology versus the new digital cameras now widely in use. I told them about why I thought that after this third year I was going to have made that discovery I was hoping for and the 10^th planet would be in our grasp. It was, I daresay, a talk full of exciting promise.

It’s a good thing I wasn’t asked to give a follow up talk right away.

By the following year it was clear that my three year survey had found a grand total of absolutely nothing.

I told that story last night at the 200-inch telescope and everyone chuckled. They chuckled, of course, only because they knew what came in the years that followed. What came next? We scraped the photographic plates, installed experimental digital cameras, roboticized the telescope, and kept scanning and scanning and scanning. With the benefit of the faster and more sensitive digital cameras we slowly surveyed the whole northern sky and blew the outer solar system open.

Last night I showed my baby pictures from the past decade. I showed Quaoar, the first large Kuiper belt object that we found, the one named for the creation force of the local Tongva Native American tribe, the harbinger of larger objects to come. I showed Orcus with its newly named moon Vanth, and talked about its odd mirror-image orbit to Pluto. I showed Sedna, far beyond the Kuiper belt, in an orbit that takes 12,000 years to go around the sun, named for the frigid Inuit goddess of the sea, a beacon pulling us even further in the distant solar system. I showed Haumea, with her two moons Hi’iiaka and Namaka, spinning her was across the sky, I showed lonely Makemake, bird god of the Rapa Nui, the runt of the litter that produced the Big Three of Makemake, Pluto, and Eris. And then, of course, I showed Eris her, in all of her discord and strife, with her tiny moon Dysnomia circling her.

I really do feel like each one of these is like a child to me. And, like children, whenever the rest of them are not in the room, I will secretly tell you that this one is my favorite. They’re all my favorites. I can tell you stories about their little quirks, their odd habits, and a funny thing that this one did the other day when it thought no one was watching (did you know that the night before Namaka went right behind Haumea playing a little hide-and-seek with us? Silly little moon.).

Something else was particularly interesting to me about my talk 8 ½ years ago at Palomar. Something happened that day that I am certain I will never forget. I was inside the telescope waiting for the group of Caltech supporters to arrive, and finally hearing the knock on the outside door, I opened the door, and, as my eyes adjusted to the blinding outside light, I was greeted by the director of the group of Caltech supporters. She had worked on the Caltech campus for years, but somehow our paths had never crossed. I had certainly never seen her before. How do I know for sure -- you might ask. Trust me -- is my answer. I would have remembered. She walked in the door, and I fumbled my words introducing myself. Her name was Diane Binney.

Diane Binney doesn’t work at Caltech anymore, but she came on the trip to Palomar last night anyway. It was her first time back to the mountain since that time 8 ½ years ago when I gave a talk up there. She came to see old friends and revisit old places. And, since she hadn’t seen many of the people in a long time, she brought baby pictures of her own. She has a 3 ½ year old daughter named Lilah. Lilah has Diane’s last name as a middle name, but she gets the last name from her father. Me. Lilah Binney Brown.

Look up!

2009-04-19T20:32:00.001-07:00

My wife noticed, many years ago, that every time I walk outside at night, the first thing I do is to look up. For a while she assumed that it was because I had a telescope operating somewhere and I wanted to see the condition of the sky, the locations of the clouds. Then she realized that I would even do it when she knew that I wasn’t using any telescope anywhere. It’s just what I always did: walked outside, looked up. Finally, she asked me about it. My first reaction was: I do? But then, after awhile, I realized: I do. I am always curious about clouds and about clarity, but mostly I just want to make sure that everything is right with the universe, that all of the stars are in place, that the moon has moved to whichever new spot in the sky it should be that night, that any of the planets that might be up are where they are supposed to be.

Sometimes I get a bit of a jolt, even though I know it is coming. When I fly to Hawaii and go use the telescopes out there I look up at night and see, oddly, that Orion is almost straight overhead, instead of low in the south like it is supposed to be. At that point my eye always travels north to try to find Polaris, now dangerously close to the horizon. Then I take a glance as far to the southern horizon as possible and I see something unsettling: stars I don’t know. I might as well be in another universe.

For all of my traveling the globe to go to telescopes, I’ve only been south of the equator once, for my honeymoon. When I went outside and looked up there, it was an odd combination of familiar and bizarre. In the north, Orion was flying overhead, but upside down. The bright red Betelgeuse, which translates as armpit of the giant, should really be called kneecap of the giant from there. The moon was also much further north than I was prepared for and it, too, was upside down. It really did give me that feeling that I was standing on the opposite side of the world, that my head really was pointing in a different direction than when I was at home.

One of the reasons that I was surprised when my wife mentioned to me that I always look up is because I was a little surprised that everyone else doesn’t do the same thing. The grand vista of the stars and the planets is above us night after night, and all you have to do is to look up. Most people are shocked when you explain to them, for example, that you can look at Betelgeuse and you can look at Sirius, and you can see that they are different colors. They’re amazed to know that that bright light in the twilight sky is not an airplane but is indeed the planet Venus. They are truly floored when you suggest to them that they get out a pair of binoculars and look at Saturn – high over head in the sky these days and you can see the rings. Or the moons of Jupiter. All of the stuff is out there for the taking.

I was in New York City this past week to give a lecture at Sarah Lawrence College. To get to Sarah Lawrence I walked my way down to Grand Central Station in the late afternoon, stared at the board of departures trying to figure out which was the right train to take, bought my ticket at an automated dispenser, and then had a few extra minutes to kill before the train left, so I stepped back against a wall to watch the people go by. Everyone was in a hurry across the floor, trying to catch a train or make their way home. But somebody on the other side of the concourse was doing something that no one else was doing, so it caught my eye. She was looking up. Curious what might be attracting her attention, I did the same, and there, inside of the building, a hundred feet up on a huge dome ceiling, was the sky.

Not just any sky, a spectacular painted sky with stars in place but also the constellations drawn and the ecliptic and celestial equator drawn through! Orion (with a gleaming Betelgeuse in his armpit) battles Taurus the Bull in the heart of the flowing Milky Way while winged Pegasus watched high above. Castor and Pollux look, to me, like they are plotting mischief to the side.

And, with thousands of people streaming through the concourse, there was one – now two – people actually looking up to notice. It reminded me of, well, of Los Angeles at night, where no one bothers to look up.

Because the constellations were painted along with the stars, I concentrated on the constellations. They were what was new to me. When I look at the real sky, I look at the stars, and don’t think much of the constellations, since no one has taken the time to paint them in the sky. But here they were beautifully drawn with sparkling stars as highlights.

Something was a little funny, though. At first, since I was concentrating on those new drawings, instead of on the real stars, I didn’t quite get it. But then it hit me: Taurus is on the wrong side of Orion. Castor and Pollux are switched. And what is Pegasus doing high to the left instead of to the right? It was like the real sky, only backwards.

Backwards is not the same as upside down. Backwards is like a mirror. Backwards it like you never ever really see it anywhere on earth, or, really, anywhere else in the Universe.

My scientific, educational self was offended. What? They spend all of this effort to put the sky on the ceiling and they get it wrong?

The ceiling, though, was copied from artwork that was supposed to be illustrating what the sky looks like from outside the Celestial Sphere. Except for one thing: there is no such thing as a Celestial Sphere. The Celestial Sphere is what you would think was out there if you considered the whole night sky to be a planetarium with little points of light a small distance away. Imagine now that you can sit outside the planetarium and see the stars. This is what the ceiling at Grand Central looks like.

And then I went from slightly offended by the inaccuracy, to thoroughly charmed by the historical accuracy. Yeah, I thought. People really used to think that you could step outside and look in and this is what they would see. This ceiling is fantastic.

It is the International Year of Astronomy.

A few weeks ago I participated in a panel discussion with 4 other astronomers as part of the celebration of the Internation Year. The event was sponsored by, among others, Discover Magazine. In this month’s issue they have a [heavily edited] transcript of the discussion amongst the five of us from the event. I am proud to say that, in the [heavily edited] transcript, I got the last word from the night, based on a question from the audience. Discover Magazine gets the last word:

Audience: What are your hopes for this year’s International Year of Astronomy

Brown: If there is anything I can convince people to do, I want people to not just sit here and listen to astronomers and think about astronomy but to look at the sky. So what I want everyone to do where you walk out tonight is to look up. You’ll see Orion, you’ll see Sirius. Just look up at the sky for a minute and think about what’s out there. That’s what I want.

Kant's Crowded Universe

2009-04-12T09:32:00.000-07:00

I was asked by a magazine to review Alan Boss's new book The Crowded Universe. They asked for a review that was a much an essay on the field as a review of the book itself, which made it a very fun exercise. The following is based on the review that I got to write.

Two hundred fifty years ago, Immanuel Kant, in his Universal Natural History and Theory of the Heavens, laid out a remarkably modern-sounding account of the state of the universe. Moons go around planets. Planets go around stars. Stars go around the Milky Way. The Milky Way and other galaxies (“other Milky Ways,” he called them) go around something even larger. The solar system had an understandable origin, and inevitable consequences:

The planetary structure in which the sun at the centre makes the spheres found in its system orbit in eternal circles by means of its powerful force of attraction is entirely developed, as we have seen, from the originally distributed basic stuff of all planetary material. All the fixed stars which the eye discovers in the high recesses of the heavens and which appear to display a kind of extravagance are suns and central points of similar systems.

To paraphrase: gravity takes stuff and turns it into stars surrounded by planets, and it has done so everywhere you see a star in the sky.

For the first 240 years after the publication of Kant’s assertion, this fact could only be verified for only a single star in the sky: the sun. In 1995 Michel Mayor and Didier Queloz announced the discovery of the first planet orbiting a star other than the sun. Now, fourteen years later, almost 300 stars are known to have planets around them. It is not quite “all of the fixed stars which the eye discovers,” but it’s getting close. Kant was substantially correct. It had been accepted since the 17^th century that our sun is not special, but is, instead, but one of many stars in the universe. Now, at the beginning of the 21^st century, it is clear that our planets aren’t special either.

Except that some of our planets are still special.

It is tempting to describe the many planetary systems that have been discovered in the past decade and a half as simply weird. Rather than the orderly arrangement of planets that we have here in the solar system, with small planets close, large planets far, and everything going around the sun in satisfyingly circular orbits in a common disk (each one of these properties is “inevitable”, according to Kant, and according to most astronomers up until late 1995), we have instead found planets the size of Jupiter that orbit their stars closer than Mercury, planets with orbits as elliptical as some of the comets in the solar system, and planets with separations from their central star far beyond even the most distant objects detected in our solar system. Weird, indeed. The only type of planetary system that we haven’t found, it seems, is one like our own. Nowhere out there has there been anything quite like the solar system; nowhere out there is another Earth.

But even this special position that our home planet holds is now in jeopardy.

Alan Boss’s new book The Crowded Universe tells the story of the development and launch of NASA’s Kepler spacecraft, which was recently launched from the earth to go into orbit around the sun. Kepler’s 3 1/2 year mission is simple to state: find the Earths. Kepler, along with a similar ESO mission CoRoT, will be the first to finally have a chance to tell us whether planets like the one on which we live are as common as Kant would hope or as rare as some astronomers think.

Boss weaves the story of Kepler (surely a must-read cautionary tale for anyone contemplating a life in NASA mission development) with the larger story of the entire, now booming, field of exo-planets. As someone whose astronomical career has spanned the period Boss discusses, I’m glad someone was taking notes. It is fun to be able to go back to those days when each new planetary discovery was an exciting event with multiple teams struggling to outdo the others with firsts. First planet at the distance of the earth! First transiting planet! First multiple planet system! With the current richness of the exo-planet field it is easy to forget that almost all of this is under a decade old.

Boss gives the insider story not only of the Kepler mission development and the birth and childhood of the entire exo-planet field, but, in a stroke of luck for us all, he got to play a intimate role in the definition of planets in our own solar system, and he gives what I believe is the first account of some of the inner workings of the International Astronomical Union committee that first started trying to figure out what to do with Pluto and Eris and the things that we now call dwarf planets. The demotion of Pluto was unassailably reasonable, but the events leading up to this eventual demotion were some of the more publicly comical occurrences in recent astronomical history. Reliving these moments is an excellent reminder that for all of their command of the physics of the universe around them, astronomers, being human, have the capacity for nearly infinite folly.

But for Boss and The Crowded Universe, Pluto is just a distraction, and rightly so. The meat of his book is the race for finding something like the Earth. Sitting in the middle of the events, it would be easy to get caught up in the day-to-day (or perhaps committee meeting to committee meeting) details. But Boss, while detailing the daily work of himself and other scientists involved in the field, never ceases to forget that we’re privileged to live in such at a time when a nearly-Copernican-magnitude revolution is unfolding.

Yet even if Kepler and CoRoT find an abundance of planets, the 250 year old Kantian revolution will not be complete. The planets that these spacecraft might find could be the precise size of the Earth and could orbit their stars at the exact distance of the Earth, but while an astronomer might be willing to call such a thing Earth-like, most people will still want to know more. Does it have liquid water? Does it have a recognizable atmosphere? And, inevitably, the only thing that really matters, could it – no: does it – support life?

The answer to these questions will take decades or more to answer. Kepler and CoRot are simply first steps along the way. In the meantime, we can perhaps take solace from Kant:

I am of the opinion that it is not particularly necessary to assert that all planets must be inhabited. However, at the same time it would be absurd to deny this claim with respect to all or even to most of them.

It took 240 years to prove him mostly right the first time. With a little bit of luck and a little bit of perseverance and, as Boss shows, a lot of the day-to-day work of astronomers around the world, the final step might come just a little bit faster.

Orcus Porcus

2009-04-06T14:12:00.000-07:00

No, that’s not going to be the name for the satellite of Orcus. But it was suggested a surprising number of times, and it did make me laugh every time I read it.

When I decided, on a whim, to throw open the naming of the moon of Orcus, I thought I’d get a few suggestions here and there and make a quick decision. More than 1000 suggestions later I’m a bit overwhelmed and thoroughly torn. There were good names, silly names, scholarly names, names of people’s pets and wives and girlfriends (never husbands or boyfriends, though, which is interesting). Names came from came – not surprisingly – from Etruscan mythology, but also Norse, Aztec, Greek, Hindu, and many more. There were references to current media in all forms, there was word play, and there were made up names that simply sounded good (or at least someone thought they sounded good).

After sorting through all of the suggestions, as few interesting names/themes stand out.

First, many attempts were made to fit in to the Etruscan origins of Orcus itself. I will admit that these always had the inside track in my mind. We’ll get back to this in a minute, but first, some of the more popular names and themes that I had not originally anticipated:

Disney-related. With Orcus being described as the anti-Pluto there was some sentiment to pull in Disney mythology instead of Etruscan mythology. I’m not opposed to the general idea of moving beyond ancient mythology, so I thought about these. But the problem with all of these names, I felt, was that there was no connection to Orcus, only to Pluto.

Dungeons and Dragons related. Unbeknownst to me, Orcus has been a major figure in the role-playing game Dungeons & Dragons for the past 30 years. To be fair, though, the phrase “unbeknownst to me” is not exactly true. It really should be “unremembered by me.” My father bought one of the original Dungeons & Dragons sets for my brother and I back in 1976 as a way of keeping his nerdy science fiction loving boys occupied during weekend visits. I will admit to having been an avid player throughout high school. It was a great outlet for a nerdy science fiction loving boy. And though I haven’t thought about it in nearly 30 years, I got sudden senses of nostalgia from all of the D&D related suggestions. I thought of those first few times sitting with my brother and my father (my sister thought we were all crazy) in his apartment trying to figure this stuff out.

But, but, but… Could I really give a name that will stick around for years (hundreds of years? thousands of years? I have no idea) based on a fantasy game that has only been around for thirty years? Would astronomers in 200 years look back on a name like that and think it was a quaint anachronism or just kind of dorky? Maybe. The connections to Orcus are good, even if the mythology is recent.

Tokien related. Many people noted that the word “Orc”, the foot-soldier bad guys from Lord of the Rings, is said to be derived from Orcus (possibly by way of Beowulf) and suggested related names. I should have the same flash backs to nerdy-science-fiction childhood for these suggestions, but I don’t, and I suddenly realized why. Those flashbacks memories seem to keep being overrun by replaced mental images of Elijah Wood and friends running around New Zealand.

There is the same concern about ephemeral popular culture, though these days Orcs are pretty mainstream. But, still, the connection is to the potential origin of the word Orc, as opposed to being to Orcus himself. Somehow, again, that seems not quite right to me.

Silly related. Perhaps the biggest laugh I had when reading these came from someone suggesting “Mindy.” Mindy, of course, was the counterpart to Robin Williams’ Mork. Who was from Ork. The other surprisingly common silly suggestion was “Fiona.” As in, Fiona, bride of Shreck. Shreck, of course, is an Ogre. And then there was – frequently! – “otulP” as in Pluto, backwards. Surprisingly, the more appropriate “norahC’ as in Charon, backwards, rarely showed up.

Un related. People, don’t even start with me. Colbert? Seriously? When people were talking about my discovery of Eris did Stephen Colbert have me on his show? No, he did not. He instead had Neil Tyson. When Pluto was demoted from planet to dwarf planet did Stephen Colbert have me on his show? No, he did not. He instead had Neil Tyson. When Neil Tyson wrote a book about the demotion of Pluto did Stephen Colbert have me on his show? No, he did not. He instead had, well he had Neil Tyson. People, I have this to say: Stephen Colbert is dead to me. And I don’t mean “dead” in a “now-that-he’s-dead-and-in-Hades-hanging-out-with-Orcus-I-can-name-the-satellite-after-him” sort of way, either.

Whale related. Orcus sounds an awful lot like Orcas, as in the “killer whales.” The name Shamu was a shoe-in here, but I liked better the names of the real-life Shamu’s real-life children. Someone even suggested that the name be related to Orcas Island, the largest of the San Juan Island off of the coast of Seattle. It is a well kept secret that part of the appeal of the original name “Orcus” for this Kuiper belt object was that it sounds like the island. My wife Diane lived on Orcus Island through her high school years. We go back to visit as often as we can. The name was a small present to her. She has, of course, thoroughly forgotten about this by now. But I could indeed revive her memory by naming the satellite after something related. One summer while we were visiting and playing our typical game of “let’s pick up a real estate guide and fantasize about houses we can’t afford” I became enamored of this one house that was on a tiny island just off of Orcas Island. You have to go back and forth to Orcas by motorboat to get your groceries, visit your favorite coffee shop, or walk more than 200 yards at a time. I talked about it all the time and how much I would love to have a house on an island like that. Diane became worried that I might actually be serious. I have, in the past, lived in odd places like sailboats and cabins in the woods with no running water. I might have it in me. I think that just to keep Diane a little on her toes, it would be fun to remind her of this time and name the satellite “Crane Island.” But, really, Orcus is not Orcas. And not even Shamu. So I sadly have to pass on this one.

Finally, we get to the more ancient mythology. As I admitted earlier, my heart was always here, though I was willing to consider these other themes.

Overall, the suggestions of and votes for Greek, Roman, and Etruscan mythological characters exceeded all of the other suggestions by a large amount.

The top contenders were Prosperina (a Latinized version of Persephone, wife of Pluto), Vanth (an Etruscan goddess associated with the dead), Phlegyas (a boatman for the dead), and Cerberus (the three headed dog guarding the fates)

At this point, I believe it best to revert to the analysis offered by readers here.

From Sovay:

Vanth and Charun are traditionally paired in Etruscan iconography, so her association with Orcus forms a nice parallel to Charon and Pluto; in keeping with the satellite's unclear origins, Vanth's role is not cut-and-dried (she is generally accepted as a psychopomp, possibly a benevolent counterpart to the demonic Charun) and where Orcus and Charon can be traced into other mythologies, Vanth is attested only in Etruscan; and if she accompanies dead souls from the moment of death to the underworld itself, then of course her face is turned always toward Orcus.

From JohnD

I suggest "Cerberus", the many-headed guard-dog of Hades. The name has been used elsewhere in the Solar System and the constellations, but not for a semi-planetary body, so I think it would still be allowed. And Cerberus was, in Virgil's words,

"Orcus' warder, blood-besmeared,
Growling o'er gory bones half-cleared
Down in his gloomy den"

so a classical connection with Orcus.

From Tim:

My suggested name is Prosperina. Sources differ, but as far as I can tell, Orcus and Dis Pater (the origin of ‘Dis’, which of course we see as the capital of hell in the Divine Comedy) were synonyms for the same godProsperina was the Roman name for his wife, and you will know her as Persephone, doomed to live for 4 months in hell and for 8 months in heaven because of her consumption of a single pomegranate seed. I like this because I imagine this little moon captured and dragged out on Orcus’ great elliptical orbit, destined to wander far from the plane of the planets for all eternity, a little icy queen of the void. Gosh, I need to go and have a cup of tea to cheer me up now.

From Matthew:

Pluto was god of the underworld in Roman mythology, and Charon ferried souls across the river Acheron in early Greek and Roman mythology. Pluto has his equivalent in Orcus, being used as an alternative name for Pluto, and having separate connections to the underworld. Charon, too, has an equivalent in Phlegyas, ferrying souls across the river Styx. Since the Kuiper belt object Orcus can be considered the anti-Pluto and therefore is named due to this relation, it seems fitting to name the first moon of Orcus in a way that fits the connection between Pluto and its first moon, Charon. This, of course, would lead to the name Phlegyas being chosen for “S/1 90482 (2005)”. In addition, Charon, in mythology, seems to be completely connected with the underworld with no indication that he ever existed apart from it. On the other hand Phlegyas does not enter the underworld until Apollo kills him for burning his temple. If Pluto and Charon formed out of a giant collision, as is believed, then Charon's entire lifetime is linked to Pluto. However, if Orcus captured its moon,which may be the case, then it would have existed before its connection with Orcus. This is even further correlation between the connections in mythology of Pluto to Charon and Orcus to Phlegyas and the objects in our solar system. So, to be true to the connection between named objects in the solar system and mythology, as well as to the connection between Pluto and Charon and Orcus and its first moon, I propose the name "Phlegyas" be given to the object “S/1 90482 (2005)”.

And so finally I have to chose, after all of these good names and great discussions. And so. And so. And so…..

Prosperina has a great connection to Orcus, but she is more strongly associated with Pluto than with Orcus. I like the idea of keeping Orcus and Pluto distinct. Cerberus suffers from the same problem.

I am strongly drawn to Matthew’s description of Phlegyas, in particular the strong link to the mystery of the formation of Orcus’s moon. That’s good. Really good. I was almost about to say OK, let’s do it, but I got stuck. Phlegyas is being punished for burning down Apollo’s temple after Apollo killed his daughter. He now wanders Hades reminding people to respect the gods. Are kidding me? If Apollo ever came down and killed my daughter he would get much worse than just his temple being burnt down. And when I went to Hades I would not talk about respecting the gods. Every time I read his story I just get mad. Maybe putting Phlegyas in space releases him from his punishment in Hades.

And finally Vanth. I will tell you this: Vanth got the most votes. It was never my intention that this become an election, but, if it had been, Vanth would be the winner. The appeal to me – and to everyone who voted for Vanth I would guess – is pretty clear. Vanth is one of the few purely Etruscan deities, and a chthonic one at that. She is a psychopomp. I mention these last two facts mainly because I had no idea what they meant until I looked them up (she is an underworld god who conveys dead souls, is what it means). She likes to hang out with Charun, a name which derives, unsurprisingly, from Charon, which makes a nice parallel. And while she’s associated with the underworld, she is a guide rather than an avenger. She awaits the dead and brings them to their new home.

Vanth doesn’t do nearly a good a job of telling the potential story of the formation of the satellite of Orcus, though. So until yesterday I was still unsure. But yesterday while reading about Vanth and reading about Phlegyas, I stumbled across a picture of very nice fresco at the tomb of Anina. Vanth is waiting for the dead, as she is often depicted. It even appears to me that she is silently crying while she waits. Admittedly, I might be misinterpreting, but still, the tear made me think of my sister, waiting for my father – guiding my father – as he took his last breaths.

In a solar system filled with Apollos (asteroid #1862, discovered in 1932) who might kill your daughter, Zeuses (asteroid #5731, discovered in 1988) who might abduct your daughter (or your son, for that matter), Tantaluses (asteroid #2102, discovered in 1975) who might feed you his son, or Erises (the largerst dwarf planet, discovered in 2005) who might start a world war, wouldn’t it be nice to have someone who weeps for the dead? Wouldn’t it be nice to have a guide to light the way?

So it will be Vanth.

The citation submitted to the IAU has to be short and can only hint at the richness of everything that has gone on here. It will read:

S/1 (90482) (2005) Vanth

Discovered 13 Nov 2005 by M.E. Brown and T.-A Suer.

Vanth is a daimon in Etruscan mythology who guides the dead to the underworld. She often appears on tomb paintings and sarcophagi where she is depicted with wings and a torch, and she is frequently shown in the presence of Charun, a guard of the underworld. Name suggested by Sonya Taaffe.

Thanks to everyone for participating. Having gone through all of this, I realize that naming a moon was perhaps a bit too constraining, as the theme was already in place. Next time perhaps we will try to find a name for one of the many many other objects out there that are deserving and for which the field is wide open. As always, stay tuned.

We'll always have Regulus

2009-03-29T11:45:00.000-07:00

I find Paris disorienting.

First, I missed an entire nighttime. When my wife and I arrived at the airport to embark on our vacation it was a southern California late afternoon. When we landed – first in Zurich – it was a Swiss early afternoon. Somehow I had missed an entire fast-forward cycle of the sun setting, the stars rising, and the sun rising again, all in the space of about 4 hours. When I first closed my window shade and then closed my eyes on the airplane – somewhere over Salt Lake City, I think – I made a mental note to be sure to try to open up and see the sunrise – over Greenland, I guessed. But even for the fitful sleep of a bumpy airline seat the sunrise came too quickly. When the thought to open my eyes and look out the window finally solidified sufficiently inside my head we were already over Ireland. I slid the window shade open a tiny crack to take a peak and the entire darkened airplane cabin was blasted with late morning glare. My wife, still attempting to sleep in the seat next to me, added her own glare to that of the sun and I quickly closed the shade. By the time we landed in Zurich and then finally continued on to Paris the sun was already on its way down again, but, still, I feel like a lost nighttime in there somewhere. Nights are precious things, and one should not lose them lightly.

If losing a nighttime were not disorienting enough, I believe that the streets of Paris are uniquely designed to make me lose my sense of direction. I pride myself, most of the time, with having a finely tuned sense of direction. I tend to be able to get from point A to point B by dead reckoning, no matter how many twists and turns and detours are along the way. So on the streets of Paris my general navigational strategy is to take a look at a map to see where we are and where we would like to be, and then I head off in what seems to be the correct general direction knowing that I will get to where I’m going. But the streets of Paris are tough. It’s not just that they aren’t oriented along a north/south axis. It’s not even that they aren’t oriented along any single axis. And it is not even that the streets sometimes curve. It’s that all three of these occur in small quantities. A street that I am on starts out general north-northwest, which, in my head, I probably think of as “northish” and then the street slowly, imperceptible turns west or even perhaps a little south. I then take a left turn onto a street which I think of as going westish when, in fact, it is more like the north-northwest direction I was originally headed. Do that a few times and there is no telling which way you are really going.

The first night we arrived, jetlagged and awake at midnight, I thought it would be fun to walk down to the Seine to see Notre Dame lit up at night. Point A: our hotel. Point B: Isle de la Cite. Direction: north-nothwest. After about 45 minutes of walking in the bitter bitter cold (ok, I live in southern California, so the fact that it was only a few degrees above freezing qualifies as freezing for me) we stumbled out of some small twisty city streets directly into the Pantheon, which was indeed spectacular all lit up after midnight. I’d never been to the Pantheon before and didn’t quite know where we were. I finally got out the map. We were a block from our hotel. Point A to Point A in just 45 near-freezing minutes. My wife gave me a similar glare to the one from earlier that morning.

Paris is a city to which my wife and I have both been a few times, but which we do not know well. We’re staying in a part of town which I have never visited. Our college French is rusty. An after flying for 12 hours and missing a full sunset and sunrise and finding myself unable to make it to one of the most obvious landmarks in town and struggling to remember the French phrase for, say, “Excuse me, madame, but do you know why I seem to keep walking in circles?” I feel very very far away from home in Pasadena. Looking at the globe you can see just how far it is, as I kept explaining to Lilah, our 3 ½ year old, who wanted to understand exactly where we were going to be (a place she calls “Parisfrance”) while she stayed home with her grandparents. “Parisfrance is really really far away Daddy. If I were on the airplane I would have to fall asleep.” A wise girl, I think.

But then, still trying to straighten out my post-midnight rambling route, we hit a slight opening to the sky and the clouds clear a bit and there, a bit low in the sky in about the direction we’re heading is a bright star and a little backwards question mark of fainter stars. The constellation is unmistakably Leo. The star is Regulus.

“Let’s turn around” I say to my wife. “We’ll be going in exactly the right direction.”

It’s the same sky. Pasadenacalifornia or Parisfrance look out into the same night and lie underneath the same stars. Fly 12 hours, miss a sunset and sunrise, forget the language if you want, but Regulus will still be there. I used Regulus once to get myself unlost while driving in New Jersey trying to figure out the direction of the shore (my friend in the car with me couldn’t figure out why I pulled off the road, stuck my head out the door, and looked up, before making a U-turn, but that was the best you could do pre-GPS navigation) and used it to find Notre Dame.

I’ll show it to Lilah when I get home. “Hey Lilah, that star is called Reguls and I could see it from Parisfrance” and she might find it wonderful and mysterious and amazing that you can see the same thing from such different places. Or she might ignore me and say “Daddy Daddy I’m going to draw a picture of a ghost for you” or who knows what else. But I will remember that it is wonderful mysterious and amazing that that’s the same star that showed me which direction to turn on a tiny street after midnight in a big city halfway across the world.

[next week: a name for Orcus's moon. I haven't had a chance to read any of the suggestions yet (being on vacation in Paris), but I see that there will be many many to chose from. Stay tuned.]

S/1 90482 (2005) needs your help

2009-03-23T05:58:00.000-07:00

“S/1 90482 (2005)” is really not much a name as a license plate number. As does a license plate number, it tells you pretty much everything you need to know to identify the object in question. “S” is for satellite. “/1” means it is the first discovered. The “2005” at the end tells the date of discover, and the “90482” tells whose satellite it is, but only by yet another number. This number refers to the 90482nd minor planet (in the old terminology; no one quite knows what the new terminology is, but the numbers keep coming) to be officially recorded. That object is more commonly referred to as the large Kuiper belt object Orcus. We don’t ever call the moon of Orcus by its official name of S/1 90482 (2005). Instead, around here, it is referred to mostly as “the moon of Orcus.”

It’s time to change that.

Not all of the Kuiper belt objects known and number have names, and, as I have written here earlier, I think most don’ t need them. It is OK to consign them to semi-anonymous license plate numbers if they are never really going to be thought about as more than one of the crowd. But a few special objects get studied and talked about and written about enough that need not so much just names, but also personalities. Orcus was one of those objects. Its personality was quite apparent from the beginning.

We discovered Orcus in early 2004. At the time it was the 4th largest known Kuiper belt object, though by now it has dropped to something like 8th. The most interesting thing about Orcus to me was that it appeared to be the anti-Pluto.

Pluto has what was originally thought to be a peculiar orbit. It circles the sun precisely two times for every three times that Neptune goes around the sun. Though it took astronomers a long time to realize it, this peculiarity is not a coincidence. Neptune’s gravity so dominates the region of space where Pluto is that Neptune has herded Pluto into this very special orbit. Pluto is not the only one that Neptune is pushing around. We now know of hundreds of similar objects in the Kuiper belt, including, now, Orcus.

Pluto’s orbit has a few other interesting features to it. It is so elongated that, for a brief time during its revolution about the sun, it actually comes close to the sun than does Neptune. So does Orcus. When Pluto comes close to the sun, though, it is never actually close to Neptune, partially because at that point in its orbit it is high above the disk of the planets, hitting the most extreme spot of its tilted orbit. Just like Orcus.

In fact, if you look at the orbits of Pluto and Orcus (and I encourage you to do it if you never have; check out the extremely cool orbit plotter at JPL but you'll have to zoom out to find Orcus), you will see that they are nearly identical except for 2 things. Their elongated orbits point in nearly opposite directions, and, right now, Pluto is nearly as close as it ever comes to the sun while Orcus is nearly as far away as it ever comes. In fact, because Pluto and Orcus are forced by Neptune to have precisely the same orbital period, they will always stay in opposite phases of their orbits.

Orcus is the anti-Pluto.

Several years ago, when searching for a name for what was then known only as 2004 DW, we decided to concentrate on the anti-Pluto aspect of the object’s personality, and we came up with Orcus. In the version of the Orcus myth that I like to tell, Orcus was, essentially, the early Etruscan grim reaper, collecting the dead and bringing them to the underworld where another god – Pluto – ruled. As the Etruscan mythology was incorporated into Roman mythology and blended with Greek mythology, Orcus lost his separate identity and Pluto became the master of all of the functions of the dead. Orcus became in some ways simply an alternate name for Pluto, but it also remained a slightly more evil and punishing incarnation of Pluto. In that incarnation, the Latin word Orcus was the origin of words such as ogre and orc.

In my new mythological/astronomical view, Pluto the Kuiper belt object is now named after that earlier version of Pluto, before the Romans came along and swept everything together. And Orcus is his counterpart, destined to eventually be pushed aside by the rising Pluto. Orcus seemed a very appropriate name for this new object in the Kuiper belt.

About a year later, while looking carefully at Orcus with the Hubble Space Telescope, we realized that it had a moon. In the past year we have been studying the moon of Orcus intensely and are in the final stages of writing a scientific paper on all of the interesting things about this moon. Which means it is time to stop calling it “this moon” and give it a proper name. But what?

Here’s where you come in. Send me suggestions! I’ll submit the best suggestion to the International Astronomical Union on Sunday, April 5th (about 2 weeks from now) with your name as part of the official citation (if you want it to be).

If you make a suggestion I would like to know not just what the suggestion is, but why you think its appropriate. As you can tell by now, this is the part that matters to me!

To help you out, let me tell you some of the other interesting things about the satellite. It has about a ten day orbit around Orcus, in a tight precise circle. We suspect – though can’t yet prove – that Orcus and its satellite have their same faces locked towards each other constantly, like an orbiting dumbbell. Only one other Kuiper belt object and satellite are known to do this. Who? Pluto and Charon, of course.

The origin of the satellite of Orcus is confusing. Pluto and Charon are thought to have formed in a giant collision. Haumea clearly had a shattering blow to disperse moons and other family members. But small Kuiper belt objects are thought to acquired moons by simple capture.

Orcus is right in the middle. Was the satellite from a collision or a capture? We had hoped to answer this question by observations from the Hubble Space Telescope. If the satellite had looked just like other known collisional satellite, we would have been pretty convinced. It doesn’t. Unfortunately that tells us less. We can’t rule out either. We have some ideas of new Hubble Space Telescope observations to try to tell the difference. For now, though, we’re just confused.

While the scientific paper will have more details and calculations, that will be the gist of it, and those properties are all you get to know to try to discern the personality of the moon of Orcus and to try to pull out the right name.

You can send suggestions as comments to these pages (www.mikebrowns planets.com in case you are reading this elsewhere) or simply email me (mbrown@caltech.edu ), but please put “Orcus” in the subject line so I don’t mistake you for a potentially business partner from Nigeria.

Good luck. S/1 90482 (2005) is counting on you.

To the moon

2009-03-16T06:00:00.000-07:00

My father was a rocket scientist. Well, OK, not precisely. More specifically he was a rocket engineer. Or, more precisely still, he was an engineer who worked on the computers that went into space and navigated the rockets. He worked on the Saturn V that lifted Apollo astronauts toward the moon, he worked on the Lunar Module, which touched down on the moon, he worked on the Lunar Rover, which drove astronauts around on the moon. All of this before he was 30 years old.

I never remember him talking about it at all, talking about what it was like to send men to the moon, to be involved in such a tremendous adventure, but, ten years ago, in the little farming town on the edge of the Mississippi River where he grew up, I had a conversation with one of his friends from those days, and he told me that they all felt like they had lived in a magical time. After the Apollo missions ended, they all later worked on the Space Station and more mundane things like the ticket-taker on the BART trains that I used to take when I was a graduate student living on the San Francisco Bay. But nothing in their lives was ever quite like a being a bunch of thirty-year-old kids living in northern Alabama having the blind optimism to think that if there was a rocket being built they knew enough to put the computers together to make those rockets bring people to the moon. And back. And then actually doing it.

I wish I could ask him about it, but that opportunity is a decade gone.

Being the mid nineteen seventies, he had a marriage and he had three children – me, my older brother Andy, my younger sister Cammy – all before he turned 30, and we all lived in what now seems to me like a huge house in northern Alabama. Being the mid nineteen seventies, the marriage didn’t last. He moved to an apartment across town, then to Maryland, then to North Carolina, then to Houston, and finally, for his last few weeks, back to North Carolina to stay in the house of my sister.

In those last few weeks my brother and I were there at my sister’s house, too. I was in the middle of my third year of being a professor at Caltech and I was still trying to get on my feet. But, that quarter, I simply canceled my class midway through and gave everyone in attendance an “A.” Oddly, I had no complaints. I then flew across the country to meet my father and my sister and soon my brother and we all stayed in North Carolina for a while.

It was too late then to say much. He was mostly groggy from the pain medication. But we talked some about what was happening in all of our lives. Though he never would say such a thing directly, I think he was proud that I done well enough at school to land a job being a professor at Caltech. I remember complaining about some of the more mundane aspects of the job to him and having him softly glare back and whisper: “do you know how lucky you are?”

I told him about a new project I was starting that I was quite excited about. We had just started using an old telescope at Palomar Observatory to make repeated wide-field observations of the night sky in search of particularly large objects in the outer solar system. I told him that I was certain there would be things larger than Pluto out there to see and that I really hoped to be the one to find them. He always liked long-term plans and was happy to see that I finally seemed to have one. “But what if there isn’t anything out there?” he asked, in his always not-quite-so-encouraging way. There will be, I said. I’m sure there will be.

We talked about the long term relationship I was in that, though I didn’t know it at the time, was within a month of finally falling apart. I told him why the relationship was hard and not going so well. I remember perhaps the only words of relationship advice he ever gave me: “There shouldn’t be any fighting. Find someone you don’t fight with.” Though the words resonated with me, my father’s accumulated lifetime credibility in this realm was not high. So I filed the advice away.

He died a few days later. It was ten years ago today.

I’ve missed not having a father for the past decade. I feel we were still, that late in both of our lives, getting to know and understand each other, something we had never had much of an opportunity to do when I was younger.

But, today, I am thinking of the things that I wish I had the opportunity to show him over the past decade. I don’t have much in the way of spiritual beliefs about any afterlife, but, if there is one, and the deceased person can pick his form of communication with the corporeal world, I am pretty sure that my father would pick the web. When he first got cancer nearly 20 years ago he immediately took to the then-new internet as a means of educating himself and everyone else about everything to do with the cancer, the treatments, the options. It’s the sort of thing that everyone does routinely these days, but, back then, it was still quite novel. So if he’s out there anywhere, I like to think of him hooked in through some vast astral server. So this is for him, vial HTML, which he first introduced me to:

Dad –
A lot has happened in the past decade that I think you’d have been proud to have heard about, but there are three that I really wish I could share with you.

Remember that project I told you about ten years ago? The one that started looking over vast swaths of sky for things that moved? The one where I thought I would find another planet? Well, it took a few years before it began paying off, but it has been a pretty spectacular ride. There were indeed things out there to be found. One – so far – was even bigger than Pluto. I wouldn’t have guessed at the time, but all of it caused a big shakeout in the solar system leading to the new decision to recognize only 8 planets. That’s a pretty big change from your lifetime, where Pluto was a planet when you were born and Pluto was a planet when you died. I think you would have enjoyed watching the changes happen. And I sort of suspect that, though you would never actually say it directly to me, you would be somewhat proud of me. I’m sorry you weren’t around to see it.

Some other big news of the past decade: you were right about relationships and fighting, I think. Who would have guessed that? It took me another four years after that conversation, but I did find that person you were trying to guide me towards. I got married to Diane six years ago. I know that you were perhaps always convinced that no one was ever good enough for one of your kids, but, I have to admit, I think you would be charmed. I look at the picture that was taken on our wedding day sometimes, the one that has Diane and me and my brother and his wife and my sister and her husband and their two kids and my mother and my step-father and I wish that you were in the picture too. It would have been a bit awkward, these extended family things always were, but the awkwardness would have been better than the empty spot that I now see every time I see that picture.

There’s one more thing I wish I could show you. Her name is Lilah, and she is a 3 ½ year old bundle of silliness, stubbornness, curiousness, sweetness, and talkativeness. It is part of the mythology from my childhood that you were not particularly pleased about having that third child, but when it turned out to be a baby girl you pretty quickly got over your misgivings. I think you would like Lilah, and I think it would be pretty hard for you to hide. She asks about you sometimes. She asked about you this morning, even. “But Daddy, who was your daddy?” and I tell her about you. “Why did he die?” she asks. I explain about being sick, about having cancer. She understands a little, but, clearly, only a little. “Do you get another daddy when yours dies?” No Lilah. You never do. You never, ever, do.

What Lilah doesn’t yet know is that you don’t want another daddy when yours dies. You just want yours back. And when you realize that that is never going to happen, you at least want a chance to tell him a few things. And you hope that he has some chance of listening in, at least every ten years or so.

Snow White needs a bailout

2009-03-10T13:17:00.000-07:00

I was reading the business section of the Sunday New York Times this morning – something I do only when it is still a little chilly outside and I am not quite motivated enough to get on my bike and head up the nearest mountain – and I got engrossed in an article about how ten or so billion of dollar had been given to this or that bank and how much of it had evaporated. The main thing I thought was “Ten or so billion dollars. That’s really not that much these days.”

It’s true. A year ago the loss of that much money would be front page of every newspaper, instead of buried inside of an analysis in the business section. We were all getting used to such numbers that only hundreds of billions – or perhaps trillions – matter much anymore.

It reminds me a lot of the Kuiper belt.

Almost seven years ago we discovered our first truly large object in the Kuiper belt. It was given the license plate number of 2002 LM60, but we quickly named it Quaoar, after the creation force of the Tongva Native American tribe indigenous to the Los Angeles basin, in homage to the fact that the discovery was made by us right here in the Los Angeles basin. Quaoar made the front page of most major newspapers (except, amusingly, the Los Angeles Times).

At the time of the announcement of the discovery, the most important thing that we knew about Quaoar was that it was about half the size of Pluto. It was thus likely bigger than anything that had been found in the solar system in the past 72 years. The main part of the story that newspapers honed in on was, of course, whether or not Pluto should actually be called a planet. My very favorite quote, published in the Birmingham, Alabama newpaper, quotes me saying “Quaoar is a big icy nail in the coffin of Pluto as a planet.” Pretty good quip, I thought.

The hunt continued.

The next year we announced the discovery of Sedna, both larger than Quaoar and on a distant elongated orbit that made it more distant than anything else that we had ever found. Explaining that odd orbit has been a task I have been trying to continue to this day. I still don’t know the answer, but the mystery made the front page of Discover magazine.

The hunt continued.

A year later we hit the jackpot, with the discoveries of Haumea, Eris, and Makemake. With Eris being larger than Pluto and eventually providing the silver bullet into the heart of Pluto’s planethood, it received a lot of attention.

The hunt continued.

After some time we started all over again, looking specifically for really super distant things like Sedna. We found a lot of things, but only one thing really far away. It wasn’t as far as Sedna, or even as far as Eris, but it was indeed the third most distant thing we had ever seen.

By now we understood the distant Kuiper belt to know that, basically, we should never see it. The only reason we ever see things is when they are brighter – or more reflective – than they are supposed to be. The only reason that things are more reflective than they are supposed to be is that they are big. The only thing that made sense is that this new thing we had found was big and reflective.

We nicknamed it Snow White.

The survey that found Snow White was specifically looking for quite distant things like Sedna; things that would help us better understand the beginning of the solar system.

Snow White, we finally learned, was not like Sedna at all. It was just a normal Kuiper belt object found slightly far away. Bigger than most, but otherwise, as far as we knew, unremarkable.

What to do?

Our normal policy is to delay the announcement of particularly interesting Kuiper belt objects until we have prepared a full scientific paper on them. Snow white perhaps deserved the same treatment. It is big; big is inherently interesting. But… we had nothing interesting to say about this one. It has a typical Kuiper belt object orbit. Its reflectance spectrum shows nothing particularly unusual.

It’s just a big Kuiper belt object. Perhaps even the 5^th largest one known. It probably fits between Sedna and Quaoar in size. A few years ago it would have been front page news. Now? Yawn. Nothing.

A few people have written me asking why the press has been so kind as to ignore Snow White. But don’t blame the press. Just blame me. We didn’t even write a press release to warn the press that there was anything interesting to write about. Because, in the end, I couldn’t think of anything interesting to write about.

It’s just a big Kuiper belt object. I don’t think that it individually tells us anything particularly new about the outer solar system. Quaoar was a good signal that Pluto’s demise would come soon; Sedna was a sign of an entirely unknown distant population; Haumea and Makemake and Eris were each scientifically rich in the things they taught us about what it is like to be a tiny icy body.

Snow white? Well, it’s just a big Kuiper belt object.

Someday we’ll learn more. Perhaps it will have a moon. Perhaps our quick look at surface composition overlooked something particularly interesting. If so, we’ll be ready with a bail out: prepare a full scientific paper, maybe even tell the press this time and use the opportunity to educate the public, once again, about what is fun and interesting out there at the edge of the solar system.

Lilah Brown's Planets, Part II (or, Season II preview)

2009-03-01T15:34:00.000-08:00

Friday night my wife and my 3 ½ year old daughter Lilah picked me up at work to go have some dinner. When I opened the car door, Lilah, who it appears was about to explode from waiting to tell me something, blurted out “Daddy, daddy, daddy LOOK!” and pointed off to the west with an excited look in her eye. I followed her finger to a spot above the horizon where a thin sliver moon was shining down with Venus just a finger width to its right. “It’s Venus and the moon,” she breathlessly exclaimed, “and the moon is little but it is pretending to be full,” her words to describe the ghostly outline of the full moon seen in the background of the bright glint of the crescent moon.

“Daddy daddy daddy do you remember when we saw Venus and the moon and Jupiter, too?”

I do indeed remember that. That moment was the December crescent moon, three full lunations ago. It was also the moment that I like to think of as the final episode of the first season of Mike Brown’s Planets. Like any self-respecting TV production, I’ve been taking a summer hiatus. It’s just that my hiatus occurred during southern summer rather than northern summer.

I’m not sure what TV production crews do during a hiatus but we’ve been pretty busy here at Mike Brown’s Planets, doing a bit of science. You’ll get to hear all about it in upcoming installments. Some of the highlights upcoming include:

Name a satellite of a Kuiper belt object! I’ll tell you about the Kuiper belt object and its satellite and then I’ll take suggestions of what to name the satellite (and why). The best suggestion will get forwarded to the IAU as the official recommendation.
Life, death, and the Kuiper belt.
More and more and more moon shadows. Last season readers here were the first to hear about the ongoing shadow crossing of Haumea by Namaka (and why they are both important and cool). Much much more is to come (and you can read more about it in an ongoing technical blog intended more for research astronomers, but, nonetheless, occasionally entertaining)
My father, rocket scientist, RIP
A (slightly belated) look forward at discoveries that might be made in 2009 and a look back at the 2008 predictions to see how many, if any, came true.
Why Pluto is still not a planet and should remain that way.
Things in the sky that make me smile.

Stay tuned for Season II!

Lilah Brown's Planets

2008-11-30T17:36:00.000-08:00

Since late summer, my three year old daughter Lilah has been mesmerized by Jupiter. Every night for a few months now it has been high in the evening sky, one of the first things to pop out of the murky twilight and reveal itself night after night after night. Back in the summer we would have to go outside right at her bedtime, when it was just barely dark enough to make out Jupiter, so she could say good night. These days it is plenty dark as we drive home every day, and , for her, the highlight of the drive is the moment after we’ve climbed the little hill to our neighborhood and we take the final left hand turn to point west, and Jupiter suddenly appears in her window, high enough in the sky to even be seen from the moderate depths of her child car seat.

Anyone who, like Lilah, has been following Jupiter has noticed that it is no longer the king of the evening skies. A while back Venus crept up into the twilight to start to steal the show from Jupiter. Or, at least, in Lilah’s view, to share the show. She went from having only one planet to now having two planets to say goodnight to every night.

Lilah sees planets everywhere. You never quite realize – until you have an obsessed 3 year old – how prevalent images of planets are in everyday life. She’s got them on her lunchbox (a gift from friends who thought it would be funny if Lilah carried a lunchbox where Pluto is a planet); she sees pictures in magazines and catalogs; she sees mobiles and puzzles at stores. I would tend to just walk by them without noticing, but she always runs up – “Daddy daddy daddy daddy LOOK!” She always quickly picks out Jupiter (the big one) and, of course, Saturn. She recognizes the globe-like look of Earth. And she gets Venus right more often than I think she should.

A few nights ago, after a long cloudy spell when we couldn’t see the planets at night, Lilah looked up at the sky and was a bit startled. “Daddy daddy daddy daddy daddy daddy daddy LOOK! Jupiter MOVED!’ And she was right. While Venus and Jupiter had been slowly edging closer to each other over the past few weeks, you wouldn’t notice it unless you were watching closely. But now they were suddenly so close that even a three year old could look and see that something had changed.

As much as I am charmed by Lilah picking out pictures of planets in magazines to show me, having her point out to me that Jupiter moved was – for me – the pinnacle of planetary charm. While most kids and adults can name the planets and point out pictures, almost nobody notices the real thing even when it is blazing in the evening sky. Planets are not just things that spacecraft visit and beam back pictures from. They’re not just abstractions to put on lunch boxes. They are really there night after night after night, doing what only planets do: moving.

Last night – Saturday – the show got even better. The sliver moon showed up low in the early evening sky anda began working its way toward Jupiter and Venus. For half of the month, Lilah and I watch the moon get bigger and move east night after night in the evening sky, so we both know what is going to happen next. Based on how far the moon is from Venus and Jupiter, it looks like on Monday night the moon will be packed tightly in the evening sky with Jupiter and Venus. It will, I suspect, be a spectacular sight, with the three brightest objects ever visible in the night sky in an unmistakable grouping in the southwest just after sunset. It’s the sort of site that I think – that I hope – will make even non-night sky watchers suddenly look up and wonder. And when they look the next night, to see if it is still there, they will notice the moon has already moved further east and gotten a little bigger, and they will see that two other bright lights – Jupiter and Venus – are in slightly different spots. Maybe even a person or two will follow the moon’s movement for the next week as it grows to full. Maybe a lucky few will watch as Jupiter gets lower night after night, leaving Venus alone in the sky by next month. It’s a show worth following. I know Lilah and I will.

I’m on a flight across the country tonight. I touch down long after Jupiter and Venus and the Moon will all have set in Florida. As I was packing my bags this morning Lilah asked: “Daddy, are you going away to go talk about planets?” Yes, Lilah. I’m going away to talk about planets. I forgot to tell her, though, that I’m going to see some, too. I was sure to pick a window seat on the south side of the airplane so I could watch the show from the air. And when I arrive I’ll call back home and tell Lilah all about it and tell her to go outside right now and LOOK! she can see all of our favorite planets and LOOK! the moon has moved and grown and I’m sorry that planets are taking me far from home tonight but I’m glad we have these here in the sky to share tonight and forever.

A winding path

2008-11-22T17:17:00.000-08:00

I’m in Tucson this week and right now about to go out to dinner as part of three days of talks and meetings and lunches all in conjunction with me being awarded the Marc Aaronson Memorial Lectureship this year. I do not tend to talk much about things like this because it seems a bit unseemly, but I am going to break my usual silence and tell you why this particular award is particularly meaningful to me.

The award is given every 18 months to an astronomer who makes a significant contribution to observational astronomy at a young age. I’m happy they didn’t check the birth date on my driver’s license. The lecture itself was last night, at the University of Arizona, and I began my lecture with a story I have never told anyone before. I said something like this:

There are several reasons why I am quite flattered and honored to be receiving this award. First, the list of the people who have received the award over the past two years is particularly impressive. It is thoroughly flattering to be considered to be in the same company as people who I think of as superstars in the field. It’s also gratifying to receive such an award from what I still can’t help but think of as “real astronomers.” Astronomers who study the solar system have long been considered the ugly step-sisters of astronomy. Nobody really wants to give us telescope time or accolades or awards. In fact, we had to set up our own societies so we could give each other awards and not feel totally left out.

Both of those reasons for being honored to receive the award, however, would be reasons I could give no matter what the award was. But, to me, receiving the Aaronson award means even more.

When I was a senior in college in 1987 [which, by the way, means I just had a 20^th college reunion, which I am pretty sure disqualified me from being considered “young”] I found what I thought was going to be the field in which I was going to make my career. I had been doing research projects with physicists who were interested in the large-scale structure of the universe – where galaxies are, why they have the distributions they do – and I thought that that was about the most interesting thing that any human could possibly study. The only problem with the projects on which I was working was that there were more theoretical or computational than observational. I wanted to be someone who went out to telescope and collected data and discovered things myself. I didn’t want to just sit in the computer lab in the basement and make endless computer models about how the universe might be, I wanted to go out look at the night sky and figure out how it actually is.

Nobody did that at my university, so I started looking around to see if anyone did that anywhere. Every time I looked up the topic or anything related, a single name would always pop to the top: Marc Aaronson. Aaronson was an astronomer at the Steward Observatory at the University of Arizona, and he was doing exactly what I wanted to be doing. I decided that what I really wanted was to be Marc Aaronson, but that, since this seemed unlikely, I was going to go to graduate school at the University of Arizona and I was going to work with Marc Aaronson.

That spring, Aaronson was crushed to death by the dome of telescope where he was working.

I decided maybe I wouldn’t go to graduate school. I went biking around Europe instead.

The following year I was ready to go, but Arizona didn’t seem right anymore. I ended up at U.C. Berkeley working with someone who did generally similar research on distant galaxies. Which, through a path that is convoluted to explain but extremely clear in my head, led to my Ph.D. thesis on the magnetosphere of Jupiter and my current work on the outer solar system. Which led me to Tucson, to receive the award. The citation reads:

2008

Marc Aaronson Memorial Lectureship

Awarded to

Dr. Michael E. Brown

California Institute of Technology

November 21, 2008

for his outstanding research and lasting contribution to astronomy through the characterization of the outer solar system and the discovery of objects comparable to Pluto

To which, they could have added, which all came about through a winding complicated path whose direction was never certain, but whose start was clear after being pointed out by Aaronson.

I never met Marc Aaronson, but, based on his wife and daughter, who I met yesterday, I think I would have liked him. If I’d had a chance, I’d like to have said “thanks.”

Land ho!

2008-11-16T11:17:00.000-08:00

If you pay any attention to space news, or even just to the front page of the LA Times you will know that this week brought reports of the first-ever pictures of planets beyond our solar system.

I had no inside scoop on this one, so I learned it the hard way: a reporter called me up to ask for commentary. My immediate comment: “uhhhh…. Can I go and read the scientific paper first?” A good reporter will say “of course” but many less good ones will say “well I just want a quick quote; can you give me a reaction?” Luckily, this one said “of course.” I read the paper. Papers, actually. Two groups of astronomers had taken pictures of planets around other stars at about the same time. I went into reading-a-scientific-paper mode and started asking the standard questions that I ask whenever a read a scientific paper:

· Do I believe the results? I tend to be quite skeptical of results, whether they are mine or anyone else’s. Cutting edge science is hard, or someone would have done it already. There are many ways to make mistakes and to misinterpret data, particularly when you desperately want a certain result to occur. These astronomers clearly want their results to tell them there are planets. Did they take any shortcuts that could have led them astray? Did they stray into wishful thinking? I read carefully looking for sloppiness, as I would do when reading any other scientific paper.

In this case there appeared to be no sloppiness, and no wishful thinking. The observations were quite meticulous. The analysis solid. I don’t see any reason not to believe that they had indeed seen something. So far so good.

· Do I believe the interpretation? At this point, I believed that, yes, indeed, the thing that had caught their attention in their data was probably real. I d something. But what was it? Was it really a planet, like they claimed? Many scientific papers can be meticulous about discovery and then sloppy about interpretation. The reason for the sloppiness is often, again, wishful thinking. The astronomers here saw something, and they really wanted that something to be a planet. That desire for discovery can lead to data cherry picking just like that that has often been discussed about the intelligence community interpretation that there were weapons of mass destruction in Iraq. You pay close attention to the data that supports what you want to be true, you discount data which is less supportive. Scientists are supposed to be driven purely by facts and immune to such thinking, right? Well, no. Science is supposed to be driven by facts, but scientists are just people who can’t help but be influenced by many outside things.

Did it happen here? I kept reading. I couldn’t find any flaws in their interpretation. They did all of the things that they needed to do to really prove that what they were seeing was a planet going around a distant star. They didn’t ignore any of the counter evidence. The news was good. I believed the results and the interpretation. Only one question more to go!

· Do I buy the spin? Any paper that is being covered by the press is being spun, whether the authors intend for it to be or not. Sometimes the spin is fair, sometimes it is a bit oversold, and sometimes the spin can be so off that it takes an accurate scientific paper and turns the public interpretation into bad science. These papers about imaging planets around other stars were, in my opinion, a bit oversold. These pictures of planets around stars were more of a long-expected technical milestone than astounding discovery.

OK! I was ready to talk to the reporter. What to say? I thought through my reactions: yes, these really were the first images of planets outside of the solar system; yes, the scientists are good and credible; yes, people have been working for a long time to achieve this thing. But how was I going to deal with the other thoughts that I had? No, this was not nearly as exciting as people were making it out to be. We have known about planets around other stars for more than a decade now, and taking a few pictures adds very little to our scientific understanding of them. There was a race to see who could take these pictures first, not because anyone really had many questions about what the planets would look like, but simply so that someone could be declared the winner and put the feather in his cap.

That’s not a very kind thing to say about work by a colleague who has worked hard to achieve this result. And it’s not really what a reporter – searching for the breathless quote – wants to hear. Yet that was my initial reaction.

o o o o o o o

Five years ago today I discovered Sedna. Sedna is an unexpected oddity in the outer solar system. It is on a looping 12,000 year long (!) orbit around the sun that carries it as far away as 1000 times the distance from the earth to the sun and as close as 76 times the earth-sun distance. Nothing else known has such an orbit, and no one really knows how Sedna got there. For five years we’ve been searching hard for something else like Sedna, and, so far, we’ve come up blank.

Four and a half years ago, we had a big press conference to announce the discovery. As usual, the reports called up other astronomers around the world for comment. Some were indeed quite excited by the discovery, but more than a few told the reporter some version of “well, it’s true, but it’s really no big deal. We’ve know to expect things like this for a long time so it is not surprising that someone found one.”

Most scientists don’t talk to the press that much, and, when they do, they talk to them like they would talk to another scientist. When talking to a fellow astronomer, for example, I am able to step back and freely say that the discovery of Eris was not particularly a big deal. It was simply an object slightly larger than Pluto with very few intrinsic scientific implications (Sedna, in contrast is a big deal and has huge implications, but that discussion will have to wait). It became a big deal culturally, as it precipitated the long-discussed downfall of Pluto, but, scientifically, it really didn’t change much of the way that we view the solar system.

When reacting to scientific papers, scientists are more used to the idea of peer review (more on this next week!), where you are supposed to be detached and point out the good and the bad and the utterly mistaken parts of a paper. You are certainly not supposed to be excited.

But commenting to the public on scientific papers is not peer review. Reporters are not scientists. They are not reporting to scientists. They are reporting to people who have a million other bits of news coming in and may or may not pay attention to this one. But if they do pay attention to this one, they will actually think about and learn a little bit about science that day. Any scientist should be happy when that happens. The role of the commenting scientist in this case is not to downplay the significance of some other scientist’s result, but to explain the excitement.

After the experience with Sedna (and, later, Eris and Haumea and Makemake, which all went through the same process) I thought hard about the right way to interact with scientific news. These days, I try to keep in mind my:

Five Rules for a Scientist Talking to the Press about Someone Else’s Result

1. Momentarily forget scientific detachment: If the result is exciting, allow yourself to be excited. Explain why you’re excited.

2. Re-explain the science. More often than not, the person talking to you has heard more of the spin than the science. The science is actually the cool part. Emphasize it.

3. Resist the cliché. In commentary about exo-planets, someone will invariably say “and this will help us discovery earth-like planets.” For Mars the cliché is “and we can look here for life.” For Titan: “and no we will better understand the origin of life.” Clichés are nice things to say, since you don’t have to think much to say them, but, as a consequence, they don’t actually mean much, either. And, since they are clichés which can be used for almost anything, they don’t do much to actually explain the science. The real science is probably much more interesting than the cliché.

4. Never ever hesitate to point out bad science. Bad science is worse than no science. Never hold your nose and pretend to be excited when things smell funny. In many circumstances, explaining why something is bad science provides an excellent education as to what good science should be. If the science is good but the spin makes it bad, unspin. Talk about what the science really says.

5. Congratulate and thank your colleagues. Someone did something good that allowed you to have a chance to do a little public scientific education. Send him or her a quick email and say thanks and job well done.

The reporter called back to talk about planets. I was excited. I re-explained the science and why it mattered. I talked about how interesting it is to me to start to see the architecture of other planetary systems and what this will tell us about planets near and far. At the end of the interview I summed up my thoughts in a way that, in retrospect, I like enough to repeat here:

I can’t say the pictures are surprising. We have known for a long time that these planets are out there and that someone someday would take pictures of them. But that doesn’t take away from the exciting fact that we are seeing planets around other stars for the first time. When you start to sail across the ocean you know that you are finally going to reach shore, but, still, when you see land for the first time it is the most beautiful and exciting thing in your universe. “Land ho!” is never said in a quiet voice.

And then I hung up the phone and sent congratulations to my colleagues for their exciting discoveries.

Moon shadows galore

2008-10-26T21:06:00.000-07:00

Last spring I was extremely excited about the possibility that there was a possibility that the orbit of the satellite of the Kuiper belt object 2003 EL61 might be precisely edge-on when seen from the earth (you can re-read all about it here). As I explained then, such a thing only happens twice each orbit – so only once every 140 years in this case – and has the possibility to teach us an amazing number of things. When we finally got the data and precisely figured out the orbit we were excited – it is edge on – and dismayed – it was only going to be edge on for one more month. We had basically missed all of the action by 2 years and would have to wait 140 more years to see it again.

Things have changed since the spring.

First, 2003 EL61 is now, of course, Haumea, and the satellite with the edge-on orbit is the small inner one, Namaka. Haumea also has an outer satellite Hi’iaka. And Hi’iaka changes everything. When we did our preliminary calculations in the spring we did the comparative simple job of considering Namaka in isolation. It took us the remainder of the summer to get a solution to the full problem, where we also figured out how the orbit of Namaka changes due to the gravitational influence of Hi’iaka (“us” and “we” here is a euphemism for “my graduate student Darin Ragozzine” who actually did all of the work as part of his Ph.D. thesis). We knew there would be an effect, but we assumed early on that it would be a minor perturbation. It is, in a sense, a minor perturbation, but it makes all of the difference in the world.

Hi’iaka ever-so-slightly twists the orbit of Namaka, slowly changing the direction it is pointing. It doesn’t change by more than a degree or two a year – almost imperceptible! But, due to luck or fate or karma or cosmic design, it is changing it just enough to keep the orbit edge-on as seen from the earth for longer than usual. Normally the edge-on events would last for maybe two years. Because of Hi’iaka, they are going to last eight years! So, OK, we have missed the first two years, but we have six more years of this to go!

What are we going to see?

Namaka goes around Haumea once every 19 days. So every 9 ½ days Namaka either goes in front of or behind Haumea. We don’t have any telescopes that are good enough to see the actual event take place; it’s all much much too small. Instead, we’ll simply notice that at the moment Namaka goes behind Haumea and disappears, the whole system gets a little fainter.

Measuring a lot of these disappearances means that we will be able to reconstruct the shape of Haumea pretty precisely. Haumea is that strange object that we think is shaped like a squashed football; a precise measurement will teach us much about how and why such a crazy thing could exists.

So we need to measure a lot of these disappearances.

The problem is, they happen at specific times. It’s only nighttime over half of the earth at a time. And Haumea can only be seen by half of the earth at a time. And those two halves are not precisely the same. So there are sometimes only little slivers of the earth when it is night time and also Haumea is up in the sky. And we don’t have telescopes on all of those little slivers. So what to do?

We don’t have telescopes everywhere, but other people have them in many places. We are right now attempting to encourage a huge international collaboration to all measure these events from wherever they can best be seen (you can see the web site where we explain to astronomers what is happening). We will then all pool our data together and see what comes out. These observations are a strong case for such cooperation; a small number of measurements from just one location are almost worthless, but the full set will be priceless.

We’ve started signing people up already. First, we will be observing from our own telescopes at Palomar Observatory east of San Diego. We quickly enlisted people in Hawaii and Australia. These three telescopes cover the western US and the Pacific. We then have a huge gap of India and China and Russia and Europe until we get to a telescope that we hope to be able to use in the Canary Islands. We’ve contacted and had encouraging responses from the two largest telescopes in India and from a telescope in Armenia.

We’ve got much to do. The first good event occurs on December 7^th and then they occur every 9 ½ days until about June when Haumea is too close to the sun again to see. We’re in good shape for about half of them but still struggling to get more telescopes. By next year, though, perhaps we’ll know what we’re doing a little better and we’ll get it all down smooth. And then we’ll still have 5 more years of events to go!

It’s hard to predict just how much we’ll learn about Haumea in these five years, but I think it is safe to say that Haumea, which I’ve long said is the single most interesting object out there in the Kuiper belt, will only get more and more interesting with time.

The End

2008-09-28T20:21:00.000-07:00

This evening I am going to do something I have rarely done in past 11 years. I am going to go outside and hope for a pretty sunset.

Pretty sunsets generally require clouds. Clouds generally ruin astronomy. But tonight I don’t mind. After 11 years of (robotically) scanning the skies almost every single night looking for planets – or at least dwarf planets – I am done, as of last night. No more fretting when a cloud appears at night. No more getting up every morning to look outside to see if it might have been clear the previous night. No more looking at the weather forecast and only wondering how it will help or hinder the search for planets. From now on, I get to mainly be a nighttime civilian.
It’s been a good 11 years. In fact, I think it is not too much of an exaggeration to say that these 11 years of scanning the skies have made a bit of astronomical history. So forgive me if I do a little reminiscing here.

The sky-scanning has evolved greatly over the past 11 years.
The very first version, started in July 1998, consisted of real people at the telescope taking real photographic plates (!) of the sky. Night after night, after our nightly pre-sunset strategizing discussions, Jean Mueller and Kevin Rykoski at Palomar Observatory would crawl out into the dark dome, load up photographic plates in the complete dark, expose them to the sky, develop them, check them, and do it all over again. When the photographic plates were finished we sent them to David Monet at the U.S. Naval Observatory in Flagstaff who digitized the photographic plates using an outrageously precise mega-scanner he had painstakingly develop just for these purposes. Finally I would get boxes and boxes of computer tapes, load them into my computer, and start searching. After three years of hard work, we had found, precisely, nothing. It was a lot of work to find nothing, too. And it was more fun than you could possibly imagine.

Soon after the initial survey ended, the telescope got a giant digital camera and a robotic brain. This refurbishment was the beginning of the golden period, when we had the privilege and fun of being the first people to ever do a modern digital camera survey of most of the sky looking for things in the outer part of the solar system. Chad Trujillo, a recent Ph.D. from the University of Hawaii, came on board to lead this new effort. Within a year we had a first major discovery: Quaoar. At about half the size of Pluto, Quaoar was the first of the huge Kuiper belt objects. It helped keep the Pluto-planet debate going strong in late 2002. I was quoted in my hometown paper as saying that Quaoar was a “huge icy nail in the coffin of Pluto as a planet.”

The robotic telescope soon got a second generation camera (which, in the end, turned out to be worse than the first generation camera; such is the way of progress), Chad moved on to a new job in Hawaii (though he stayed an important collaborator in the ongoing search), and David Rabinowitz from Yale University (who had helped build the new camera) began working with us. From 2003 until 2005 we came closer and closer to the jackpot. First we found Sedna, about 2/3 the size of Pluto, well beyond the edge of the Kuiper belt, whose orbit is still unexplained. Next was Orcus, half the size of Pluto, whose orbit is a near-mirror-image to that of Pluto. Then, in one four month period, we found the big three: Haumea (3/4 the size of Pluto), Makemake (2/3 the size of Pluto), and Eris (5% bigger than Pluto!).

That was the end of that major survey. We had finally covered as much sky as Clyde Tombaugh had 70 years earlier in the survey that led to the discovery of Pluto. But we weren’t finished.
Since 2006 we have retooled again and started searching for more things out in the distant region where we found Sedna. To do it, we basically had to cover the sky all over again. So we did. Most of this survey was carried out by a new graduate student of mine, Meg Schwamb.
And then, last night, it finished. The telescope is being fitted with a third generation digital camera which will, it is hoped, actually be better than the 1st and 2nd generation cameras. But that will be for someone else to find out. We have done pretty much everything that there is to be done from this telescope, so we decided to bow out of this new generation.

People often ask me: “Do you have any new dwarf planets that you’re tracking that you’re going to announce soon?” “Anything big coming up?” “What aren’t you telling?”
I always try to give a slightly cagey response. I never want to give away what might be coming soon.

But, now, finally, I can give you the final answer: No. That’s it. No more coming up. We have nothing up our sleeves (well, OK, we haven’t completed the analysis of last night’s data, so there is a miniscule chance that we happened to make a huge discover on the last night of our 11 year program, but that doesn’t seem so likely).

Does that mean there is nothing more to be found? Not necessarily. We estimate that we were only ~70% efficient at finding things, so there are certain to be 1 or 2 big bright dwarf planets left to be found in the places we already looked. The most likely people to find them are a group running a new survey out of the University of Hawaii. Someday I expect that I will open my newspaper and read that they discovered something bigger than Eris, or more distant than Sedna, or something else that I’ve never thought of. They’re in for a fun ride. I’ll be the one cheering them on in the stands.

---------

I am going to enjoy my new nighttime civilian status. I am going to revel in those beautifully cloudy sunsets that used to make me feel so nervous. Well, I will enjoy it for at least for a few months. Starting next January my new student Michele Bannister is going to start a new project; she will be looking for new planets every night. But this time I won’t have the luxury of looking up at the sky to check the status. She’ll be doing it from Australia. The southern sky is the last pristine territory to search for dwarf planets. So, starting in 2009, if you see me on the street and start to casually chat about the weather, you might find that I haven’t noticed that, for example, it is raining on top of my head right now. I might instead tell you about how wonderful and clear the outlook is for the next week in southeastern Australia.

What is a dwarf planet?

2008-09-20T12:35:00.000-07:00

Now that the IAU has officially declared the fifth dwarf planet (in order of size: Eris, Pluto, Makemake, Haumea, Ceres), we are likely in for a dry spell on new dwarf planets. The preliminary searches of the sky are all but complete, and (as far as I know) no one has any new objects the size of Haumea hiding in their back pockets. We'll probably be at five official dwarf planets for a while.

Now is a good time, then, to remind ourselves what a dwarf planet really is.

When the final vote on the definition of "planet" was made, and the eight dominant bodies in the solar system were declared (quite rationally) a class separate from the others, a new class of objects was defined. The "dwarf planets" are all of those objects which are not one of the eight dominant bodies (Mercury through Neptune) yet still, at least in one way, resemble a planet. The best description I can come up with is that a dwarf planet is something that looks like a planet, but is not a planet. The official definition is that dwarf planets are bodies in the solar system which are large enough to become round due to their own gravitational attraction.

Why do astronomers care about round? If you place a boulder in space it will just stay whatever irregular shape it is. If you add more boulders to it you can still have an irregular pile. But if you add enough boulders to the pile they will eventually pull themselves into a round shape. This transition from irregularly shaped to round objects is important in the solar system, and, in some ways, marks the transition from an object which is geologically dead and one which might have interesting processes worthy of study.

[Haumea is, of course, not round, but that is only because it is spinning so fast. If you stopped it spinning it would become a sphere. That still counts.]

So how many dwarf planets are there? Five, of course. The IAU says so.

But let's ask the more scientifically interesting question: how many (non-planet) objects in the solar system are large enough to be round due to their own gravitational pull?

Still five, right?

Well, no. Here is where the IAU and reality part ways.

There are many more objects that precisely fit the definition of dwarf planet but that the IAU chosen not to recognize. But if the category of dwarf planet is important, then it is the reality that is important, not the official list. So let's examine reality.

So how many dwarf planets are there? Ceres is still the only asteroid that is known to be round. After that it gets complicated. All of the rest of the new dwarf planets are in the distant region of the Kuiper belt, where we can't actually see them well enough to know for sure if they are round or not.

While we can't see most of the objects in the Kuiper belt well enough to determine whether they are round or not, we can estimate how big an object has to be before it becomes round and therefore how many objects in the Kuiper belt are likely round. In the asteroid belt Ceres, with a diameter of 900 km, is the only object large enough to be round, so somewhere around 900 km is a good cutoff for rocky bodies like asteroids. Kuiper belt objects have a lot of ice in their interiors, though. Ice is not as hard as rock, so it less easily withstands the force of gravity, and it takes less force to make an ice ball round.

The best estimate for how big an icy body needs to be to become round comes from looking at icy satellites of the giant planets. The smallest body that is generally round is Saturn's satellite Mimas, which has a diameter of about 400 km. Several satellites which have diameters around 200 km are not round. So somewhere between 200 and 400 km an icy body becomes round. Objects with more ice will become round at smaller sizes while those with less rock might be bigger. We will take 400 km as a reasonable lower limit and assume that anything larger than 400 km in the Kuiper belt is round, and thus a dwarf planet. We might be a bit off in one direction or another, but 400 km seems like a good estimate.

How many objects larger than 400 km are there in the Kuiper belt? We can't answer this question precisely, because we don't know the sizes of more than a handful of Kuiper belt objects, but, again, we can make a reasonable guess. If we assume that the typical small Kuiper belt object reflects 10% of the sunlight that hits its surface we know how bright a 400 km object would be in the Kuiper belt. As of now, about 50 objects this size or larger are known in the Kuiper belt (including, of course, Eris, Pluto, Makemake, and Haumea). Our best estimate is that a complete survey of the Kuiper belt would double this number, so there are roughly 100 dwarf planets in the Kuiper belt, of which 50 are currently known.

The new dwarf planets in the solar system are very different from the previous 8 planets. Most are so small that they are smaller across than the distance from Los Angeles to San Francisco. They are so small that about 30,000 of them could fit inside the earth.

Does it matter how many dwarf planets we say there are?

I think the answer is "yes." If you believe that there are only 4 dwarf planets in the Kuiper belt then you place an oversized importance on those 4 objects and you get an exceedingly warped picture of what the outer solar is like. The important thing about the Kuiper belt is that beyond Neptune there are many many many objects with hundreds being large enough to be round. The four "IAU Dwarf Planets" in the outer solar system are all fascinating objects -- hey! I discovered 3 of them, I must think there are at least a little interest -- but it would be a gross exaggeration to think of them as the only objects, or even the only important objects, in the fascinating region of space beyond Neptune.

Haumea

2008-09-17T09:00:00.000-07:00

On December 28^th, 2004, I discovered a Kuiper belt object brighter than anything anyone had ever seen before. Being only a few days after Christmas, I naturally nicknamed it Santa.

The discovery was bittersweet. I had made a bet with a friend 5 years earlier that someone – anyone! – would discover a new planet by January 1^st, 2005. The deadline was in 3 days, but I knew that Santa didn’t count. We didn’t know exactly how to define “planet” back then, but we decided that something of a particular brightness would count. Santa was bright , but not quite bright enough. Three days later I had still not found anything bright enough to count, and I lost the bet.

But, still: Santa! How would I have known back in 2004 that Santa would be the single most interesting object ever discovered in the Kuiper belt? It has a moon – wait, no, two moons! It is oblong, sort of like a football (American style) that has been deflated and stepped on. And it rotates end over end every 4 hours, significantly faster than anything else large known anywhere in the solar system.

Large? Well, at least sort of large. The long axis is about the same size as Pluto or Eris or Makemake. Back when I thought that maybe the IAU was going to vote that anything the size of Pluto or larger was a planet I was going to argue that Santa was indeed a planet – as long as you looked at it at exactly the right angle (luckily, the IAU was much more sensible, so I did not have to make such a crazy argument).

Stranger still, Santa has the density of a rock. We think that most things out in the Kuiper belt are about equal portions of rock and of ice, but, apparently, this does not apply to not Santa. It’s only rock. Except that even that is not true. When we finally got a chance to look closely at its surface with the Keck telescope we realized that the surface is nothing but ice. Santa must have a structure like an M&M, except that instead of a thin layer of sugar surrounding chocolate, the thin outer shell is ice and the interior is rock. Don’t bite.

These characteristics already make Santa the strangest object in the Kuiper belt. Several years ago we came up with what thought was a good explanation. What if, eons ago, Santa was an even larger Kuiper belt object and it got smacked – in a glancing blow – by another Kuiper belt object? That would explain the fast spin. And the fast spin would be enough to explain the oblong shape; anything spinning that fast would be pulled into such a big stretch.

What’s more, the initially large Santa could have had a rocky interior and icy exterior, much like the Earth has an iron interior and a rocky interior. When the huge impact occurred, it could have cracked that outer icy mantle and ejected all of that ice into space. The two moons that circle Santa are pieces of that icy mantle.

This explanation was, we thought, pretty good. And then it got really good.

While looking across the Kuiper belt at many different objects, we realized that a small number of objects in the Kuiper belt look like tiny little chunks of ice. How strange. Even stranger, though, was that all of these chunks of ice were, relatively speaking, next-door neighbors of Santa. We had found the other chunks that had been removed from the mantle of Santa. The story was complete.

……………………………….

After we discovered Santa, we worked hard to get the first scientific paper ready to announce the discovery. In science there is always a tension between doing the careful work to make a complete announcement and doing an instant but incomplete announcement in order to make sure you don’t get scooped. We were as worried as anyone about being scooped, but we resisted the temptation for instant announcement. We felt that the science was too important.

On July 7^th 2005, as I was putting the finishing touches on the scientific paper, in hopes of submitting it the next day, I had a minor delay. My daughter was born. I had somehow convinced myself that there was no way that she would be born for another week. I was certain that I had more time. But I had no more time, no more time at all. I forgot about Santa and the rest of the Kuiper belt and turned my obsession from it to her. The announcement about Santa would have to wait, I was too busy sending out announcements about Lilah, instead. What difference would a few months make, really?

…………………………………

The announcement did indeed wait, but only for 21 more days. On a late Thursday night, between changing diapers and filling bottles and descending ever more into sleep deprivation, I checked my email and saw the announcement of the discover of Santa myself. A previously unheard-of Spanish team had just discovered Santa a few days earlier. And they called it the tenth planet.

No no no no no no no no! I was horrified. My discovery had just been scooped by a group who decided not to wait to learn more. They didn’t know any of the information about Santa that we did, in particular that it has a satellite and from the orbit of the satellite you could tell that it was only 1/3 the size of Pluto, and that it was definitely not the tenth planet. Worse, a few months earlier, we had actually discovered something that was bigger than Pluto. This was going to cause nothing but confusion.

That night, on no sleep but much caffeine, I stayed up to finish the paper about Santa that I had put aside three weeks earlier. We would not get credit for discovery, which was painful enough, but at least we would quickly set the record straight about its size and importance. After I sent the paper off, I sent a quick email to congratulate the Spanish team on their discovery and I filled them in on everything that we knew so that they could answer questions from the press correctly. Finally I nodded off to sleep.

I woke to a nightmare. In the intervening hours it appeared that someone had used the knowledge that we had been tracking Santa to start looking into what else we had been doing. Someone had traced where we had been pointing our telescopes for the past months. We had been pointing them at the object that would one day be called Eris – the object bigger than Pluto, the real tenth planet! That morning, the astronomical coordinates of Eris were posted to a public web page with discussions about what might be there that we had been watching. It was clear to me that as soon as the sun went down that night, anyone with a moderately large amateur telescope could point up in the sky at those coordinates and, the next day, claim they had discovered the 10^th planet.

After breakfast, I apologized to my wife; I would have to go in to work today for the first time in three weeks.

I called my wife later in the day to apologize again. I was going to have an international press conference that afternoon and would she mind bringing me some nicer clothes? And a razor, perhaps? And more coffee. Definitely more coffee. That evening, the world learned that there were 10 planets.

……………………………………

After more than three years, Santa received a formal name today. Santa is now, and forever, officially Haumea. From the official citation issued by the International Astronomical Union:

Haumea is the goddess of childbirth and fertility in Hawaiian mythology. Her many children sprang from different parts of her body. She takes many different forms and has experienced many different rebirths. As the goddess of the earth, she represents the element of stone.

The name was chosen by David Rabinowitz of Yale University, one of the co-discoverers of Santa (along with me and Chad Trujillo of Gemini Observatory in Hawaii). He chose the name because Haumea is closely associated with stone, and Santa (as we knew it at the time) appeared to be made of nothing but rock.

But the name is even better than that. Just like the Kuiper belt object Haumea is the central object in a cloud of Kuiper belt objects that are the pieces of it, the goddess Haumea is the mother of many other deities in Hawaiian mythology who are pieces pulled off of her body.

Two of these pieces are Hi’iaka, the patron goddess of the big island of Hawaii, who was born from the mouth of Haumea, and Namaka, a water spirit, who was born from the body of Haumea. These names were chosen for the brighter outer moon and the fainter inner moon, respectively.

Officially:

Haumea I, Hi'iaka, discovered 2005 Jan 26 by M.E. Brown, A.H. Bouchez, and the Keck Observatory Adaptive Optics team

Hi'iaka was born from the mouth of Haumea and carried by her sister Pele in egg form from their distant home to Hawaii. She danced the first Hula on the shores of Puna and is the patron goddess of the island of Hawaii and of hula dancers.

Haumea II, Namaka, discovered 2005 Nov 7 by M.E. Brown, A.H. Bouchez, and the Keck Observatory Adaptive Optics teams

Namaka is a water spirit in Hawaiian mythology. She was born from the body of Haumea and is the sister of Pele. When Pele sends her burning lava into the sea, Namaka cools the lava to become new land.

But wait! Shouldn’t the official discoverer get to name the object? What of the Spanish team?

Yes. The discoverer should.

Several weeks after the Spanish team announced the discovery of Santa which precipitated the announcement of the object that would eventually be named Eris, which precipitated the entire discussion of dwarf planets, it became clear that the Spanish team had not been forthcoming. They themselves had been the first to access the web sites which told where our telescopes looked. And they did this access two days before they claimed discover (you can see a detailed timeline reconstructed from the web logs here)

Did they use this information to claim the discovery for themselves?

As a scientist, my job is to examine the evidence and come up with the most plausible story. Here are some possibilities. It is impossible to disprove this story, claimed by the Spanish team: while looking through two-year-old data, they discovered Santa legitimately, and then, only hours later, accessed information about where our telescopes had been looking and were shocked (shocked!) to realize that the object they had just found was the same object that we had been tracking for months. Wanting to establish priority, they quickly announced, knowing essentially nothing about the object.

Though this story cannot be disproved, it does not have much of an air of plausibility about it. Data that were two years old happened to get analyzed just hours before – whoops! – the team found out that someone else had found the same thing? Hmmmmm. Perhaps most damning, you would think that perhaps the Spanish team would be willing to admit this early on. Instead they appeared to attempt to hide the fact that they ever knew anything about our telescope pointings.

Let’s try a more plausible explanation: the Spanish team found our telescope pointings, used that information to infer the existence of Santa, and assumed that no one would ever know they had not found it legitimately.

No way to prove it, but the later hypothesis certainly sounds more plausible. To be fair, though, I don’t think there is any way to ever know the full extent of the truth, except on the off chance that someone on the Spanish team eventually spills the beans about what really happened. I keep waiting, but I don’t hold my breath.

But wait, there’s more to ask! If the telescope pointings were – even if inadvertently – on a publicly accessible web site, was it wrong to look at them? The obvious answer is that there is nothing wrong with looking at information on any publicly accessible web site, just as there is nothing wrong with looking at books in a library. But the standards of scientific ethics are also clear: any information used from another source must be acknowledged and cited. One is not allowed to go to a library, find out about a discovery in a book, and then claim that discovery as your own with no mention of having read it in a book. One is not even allowed to first make a discovery and then go to the library and realize that someone else independently made the same discovery and then not acknowledge what you learned in the library. Such actions would be considered scientifically dishonesty.

In the end, while we are likely to never know exactly what happened, it appears clear that the Spanish team was either dishonest or fraudulent. They have claimed the facts that merely make them dishonest. If I had to bet, though, I would bet for the later.

…………………………………………….

Officially, the naming of Haumea does nothing to put to rest this three-year-old controversy. The committee that voted to accept the name has said that, while they will take the name proposed by our team rather than the name proposed by the Spanish team, they are not favoring one claim over the other. They will let posterity decide.

OK, posterity, have at it. If I am no longer around to hear the news on the decision, that’s ok, you can tell my daughter Lilah instead. She will have been waiting, nearly precisely, her entire life.

The Joys of Rejection and Lake-effect clouds on Titan

2008-09-13T15:28:00.000-07:00

Remember my new paper that describes my interesting discoveries about Titan (see Your Saturday Newspaper)? submitted it to Science magazine a few weeks ago in the hopes that it will be published and some day make it to your Saturday newspaper. But it won't. It has been rejected.

It was a kind rejection. They didn't say "we think you're paper is wrong." Just, "we don't find it of general enough interest to publish in our journal."

Rejection is always hard. My first response was generic sputtering “wha.. wha… what?” and then disbelief “this can’t be!” and anger and dismissal “those idiots don’t even know what they are missing.” This sequence lasted about 7 seconds, and then I got over it. After about 1 minute I became excited.

Why be excited about rejection from Science? Along with the publicity benefits of publishing a paper in somewhere like Science comes the hard part. You agree not to publicize or discuss the paper before the publish it. This process can take 6 months or longer.

But having been rejected from Science, I quickly turned around and submitted the paper to a more specialized journal -- Geophysical Research Letters (aka GRL) -- which has no such restrictions, and then I went a step further and submitted it to an on-line electronic archive ( which means you can go read it right now! http://lanl.arxiv.org/abs/0809.1841 ).

Scientists these days are increasingly speeding up the slow process of formal publication with an informal process of web publication. Such web publication has good and bad aspects to it. Good: instant. Bad: unreviewed.

Anything that is published in a major journal has had one or two experts read it closely and suggest changes. My paper on Titan is currently undergoing this process at GRL, and, when the reviewers are done, I will modify and respond. But my paper is on the electronic archive for everyone to see before that even happens.

Posting a paper on-line before it has been reviewed can lead to great embarrassment. What if the paper has fundamental flaws and needs to be withdrawn or rejected? What if the referees point out places where major changes need to take part? All of this is certainly possible, and should make any on-line submitted wary. But, for me, the benefits outweigh the risks. I am sufficiently confident in the accuracy of what I did that I am not worried about any of these major problems. While there is no doubt that the reviewers will suggest some improvements, I don’t believe the overall conclusions of the paper will change significantly. And I think the conclusions are sufficiently interesting that I relish the idea that people will begin to read the paper and think about the results now, rather than 6 months from now. So I submitted.

And now, even better, I can talk about the discovery of lake-effect clouds on Titan.

Earlier this summer, while looking through NASA’s on-line archives of images of Saturn’s satellite Titan taken from the Cassini mission, I began to notice a recurring pattern up near the north pole of the satellite. The north pole of Titan has been in the darkness throughout a long long winter (a full year on Titan takes 30 years; winter is almost a decade) and is just now emerging into some spring time daylight. As it began to emerge, I noticed what appeared to be tiny little clouds popping up and disappearing right over the pole.

Titan is in some ways bizarre and exotic yet in some ways very earth-like. Both earth and Titan have mostly-nitrogen atmospheres; on both the surface pressure is about the same (the big difference on Titan: it lacks that minor contaminant – oxygen – that makes the earth a more interesting place….).

Titan and earth are the only bodies in the solar system known to have large expanses of liquid at the surface. On Titan, though, the temperature is so low that water is frozen solid. The lakes of Titan are made, instead, of methane and ethane. If you could figure out a way to get a pipeline there, Titan’s lakes could supply all of our needed natural gas for years to come.

On earth the liquid water is globally distributed. On Titan it appears that the liquid methane and ethane is confined to the poles.

Finally, Titan and earth both have clouds in its atmosphere, and these clouds are made from the dominant liquid on the surface. On earth: water. On Titan: methane.

Now, back to the little clouds I had seen popping up at the north pole during Titan’s early spring.

These clouds surprised me; they appear to be cumulous clouds – like large thunder heads. On the earth we only get such clouds in hot, humid places. Arizona in August. Year-round in the tropics. Temperate latitudes during summer storms. How could such clouds possibly be up at the north pole just as winter is waning?

It occurred to me that we do get winter cumulus-type clouds on the earth in at least one case: lake-effect clouds and storms. Lake-effect storms on the earth are those winter storms that blow across the Great Lakes, pick up moisture, and then proceed to dump many many feet of snow on places like Buffalo, New York.

The effect occurs in many other places around the world. Or, I should say, they same effect occurs in many other places around the solar system. I believe this process is precisely what is causing the sporadic clouds at the north pole of Titan.

Like everything else, Titan and earth have similarities and differences in their lake-effect clouds, too. On the earth, the formation of these clouds is greatly aided by the fact that deep lakes stay relative warm over the winter. So as cold air passes over these lakes the air both picks up humidity and a little heat. This heat causes the air to rise (like a hot air balloon) which, in turn, causes those cumuli and the subsequent snow.

On Titan, a decade of polar winter means that none of the lakes retain any heat, so passing air only picks up humidity (methane humidity, in this case). Something else needs to help push the air higher to cause those cumuli. In the paper, we speculate that there might be mountains at the north pole that help, but really that is just a wild guess.

Cold lakes won’t evaporate, so these clouds have only started to become active in the last few years as sunlight has started to every-so-slightly heat the lakes. Every time the lakes warm up just a bit, a huge dollop of evaporation occurs, which re-cools the lake, and we see a cumulus cloud pop up. The lake then has to wait for some more sunlight before it happens again.

If our general story is correct – and I think it is – then as spring and then summer approaches at the north pole, the sunlight will increase dramatically, and the lake-effect clouds will start to go crazy. And we’ll be watching. The Cassini spacecraft is slated to continue flying past and taking pictures of Titan for several more years. And we might find more exciting things.

And what will we do when we find exciting things? Well, in the end I will probably never learn my lesson. We’ll submit them to Science. Or we’ll submit them to Nature. And then we will have to wait for months to talk about them. And maybe they will get a paragraph in your Saturday paper. But, if we – and you – are lucky, we will instead be rejected, we’ll post to a freely available on-line archive, and everyone can hear early about the latest happenings on this bizarre satellite.

The occult sciences

2008-09-06T15:13:00.001-07:00

Last weekend I had my first experience with the occult sciences.

Maybe I should rephrase that.

Last weekend I did my first occultation science. That’s what I meant.

Occultations are interesting events that can be seen here on earth. They are like miniature total eclipses except that instead of the sun being blocked, it is a star. And instead of the moon doing the blocking it is something else, an asteroid, a planet, a Kuiper belt ice ball. You know an occultation is occurring when a star suddenly disappears and then reappears seconds to minutes later. Something dark must have moved in front of the star.

Scientifically, occultations provide a unique glimpse at the dark object that is passing in front of the star. If you measure how long the star disappears and you know how fast the object was moving, you have just directly measured the size of the object. Or at least measured the size of the object across one line. To really measure the full size of the object you need more than one line. To do that, you station astronomers in something resembling a north-south string over the full expected size of the object. Everyone watches and carefully times the event, and then you combine all of the information to find out the real size and shape of the object. If you’re lucky, you might even detect that the star does not blink out, but fades out, instead. This fading shows the atmosphere of the object. If you’re even luckier, you might see a second disappearance of the star a little before or after the main event. You would have just discovered a moon of your object.

The occultation last week was by a large Kuiper belt object. Kuiper belt objects are so far away and appear so small from our point of view that the probability of one of them covering up a star at any point in time is quite small. Astronomers carefully track these Kuiper belt objects and carefully measure positions of stars over and over in the hopes that one of them will be found to occult.

Sometimes these predictions can be made months ahead of time and astronomers can prepare for the event. Sometimes, like for the one last week, no one knew for sure that the occultation would occur until a last set of careful measurements of the position of the star occurred a few weeks before. Suddenly it appeared that this occultation would be visible across much of North America and that the path would go over some of the major observatories: McDonald, Kitt Peak, Palomar, Lick.

With only two weeks to prepare, though, it is tough to suddenly get a telescope. All of the large telescopes are fully scheduled months in advance, but there sometimes some observatories have smaller telescopes that can be made available at shorter notice if you know the right person.

At Palomar, the right person to know if you want to observer on the brand-new 24-inch robotic telescope is me. I’ve been constructing this new telescope for an embarrassingly long time now, but it is almost finished and ready for real scientific observations. One of its major long-term projects is to monitor Saturn’s moon Titan for signs of major storm activity. But the telescope is still not quite ready yet; we hope to really have it finally commissioned by October.

But when we heard that this occultation was potentially going to be visible from Palomar we decided it was worth going up and trying to use this little telescope even though it was not quite ready.

…….

We arrived Saturday afternoon for the Sunday occultation. Emily Schaller – my now former graduate student (who moved to Hawaii last week to begin a new position as a Postdoctoral Fellow at the Institute for Astronomy at the University of Hawaii) – and I left Pasadena at noon, stopped once for coffee, and arrived at Palomar Observatory at around 3pm. We went right to the small dome of the 24-inch telescope, unlocked the door, and peered inside a bit apprehensively. No one had even been in side for the past few months as we were waiting for the final control systems to be finished. We knew that there was a moderate chance that something would have broken over this time period and the telescope simply would not work. We knew that last winter the dome had leaked. What would we find?

To our relief, everything looked fine. We plugged the telescope and the computer that controls it in and double checked that we could, at least, move things. We could! We set to work to get things going. We had brought some new software up on a laptop to control some important auxiliary functions. But we had forgotten to check if the laptop control ports were compatible with the telescopes, and, of course, they weren’t. We’d have to drive back down the mountain on Sunday to the electronics store and then pray we could get them to work on Sunday.

But still, we could at least try to make sure we could do some basic things, like point to things in the sky.

We did a few daytime pointing tests and, to our sudden horror, realized that the telescope did not move the way it was supposed to. When we said go north, it went south. East was west. Looking carefully through the software we eventually realized that someone the telescope was confused about who it was. It thought it was its [bigger] sister telescope in southern Arizona. Somehow the control software had been switched. The sister telescope had enough different parameters (like which way was east and west) to know that this would never work.

Frustrated, we went to dinner with all of the other astronomers who were at Palomar for the evening, and we brainstormed about how we might fix things. By the end of dinner we had decided that no fix was possible; we needed the right software.

We were in luck, though. Another of my graduate students was awake and looking at her email and realized what we needed and, more importantly, realized where we the software was. We copied it over tested things out, and realized that we were in business.

Because the telescope was not actually ready to be used yet, we had to do some very low-tech things to get it to work right. First, we found nice bright Jupiter up in the sky. Then we used a hand paddle to get the telescope pointing in approximately the right direction. Then I stood up on a ladder, looking down the barrel of the telescope, trying as hard as I could to line up on Jupiter while Emily took continuous pictures with the telescope’s digital camera. We finally meandered around enough that we found it (it helps that Jupiter is so bright that when you get even moderately close to the right place you can see the glow off to one side). Once we were at Jupiter, the telescope was smart enough to know the rest of the sky, so we quickly pressed a few buttons and the telescope automatically slewed to where our occultation was going to be the next night. We weren’t sure how accurate the slew was going to be, but, to our surprise, the star that was going to be occulted was right there in the center just as it was supposed to be. This might work!

We spent the next 2 hours pretending like it was Sunday night and doing exactly what we were going to do that night. Everything worked well except for the occasional problem we had when we forgot that one thing not quite finished yet on the telescope is the dome control software. We had to move the dome by hand to following the moving sky. Sometimes we forgot. We vowed to do better the next night.

………………….

The next morning we woke up and drove down to San Diego to pick up some computer equipment. On the drive back up the mountain we looked up at the sky and groaned. Summer thunderstorm clouds had completely covered the sky while we were going. It was possible that they would abate as the sun went down, but they looked pretty bad.

We got back up to the telescope, installed the new equipment, tested it, and realized, again to our thorough surprise, everything was going to work perfectly. Before dinner time, we finally stuck our heads out of the dome to see what the sky looked like. It was hopeless. The sky was 100% covered, and the possibility of observing at all that night seemed very very remote.

We went to dinner in sour moods and lingered over our deserts longer than usual, knowing that looking outside was going to make matters worse.

But we were wrong. When we finally forced ourselves to look, the sky was miraculously clear. Not a single cloud. I have no idea how it so thoroughly cleared itself in under 45 minutes. We ran back to the 24-inch, opened the dome (we had closed it, fearing thunderstorms!), and waited for it to get dark enough to find Jupiter. As soon as it was visible in the twilight glare, we swung the telescope, pointed it up, and punched in the coordinates of the star. Again, on the screen, was just the right field. It looked pretty crummy though; everything seemed too faint. Ah! The dome! We turned the dome in the right direction and everything looked fine.

It was 8:30pm. The occultation was predicted to begin in an hour, so we started acquiring the data, meaning that we took a picture of the star every 4 seconds (which makes many many pictures of the star). At about 9pm clouds suddenly appeared north of where we were, but we quickly realized they were heading even further north. Still safe. At 9:20pm we took one final look outside: not a single cloud. We then crowded in front of the computer screen to watch our pictures come in. At about 9:26 we started thinking that the star was getting fainter. But really? We made some very rough instant measurements and thought: yeah. Maybe. By 9:27 we were sure. Every single image showed the star consistently fainter. It stayed that way for 4 full minutes before getting back to normal bright again. We had seen it! At 9:40pm we sent a quick email to the other astronomers who were observing around the country. The subject line was “Subj: Report from Palomar: We saw it!”

Over the next hour other reports came in. Many observatories were clouded out, but a handful got good data. A quick comparison revealed that Palomar had, I think, been right down the center, giving the longest of all possible occultations. An even more careful look at the data revealed that the occultation was certainly not sudden; we had without a doubt detected an atmosphere around this Kuiper belt object.

We went to sleep, exhausted but thrilled. Heading back we realized that the sky was 100% covered in clouds again. We had just snuck in some clear skies at the right time.

Enough people had collected good data that useful information would come out of these observations. We would get a nice measurement of the atmosphere and whether or not it has changed recently. Looking at the atmosphere was one of the main hopes of the observations. The Kuiper belt object is currently receding from the sun and many astronomers suspect that its atmosphere will soon freeze out. Of course, only the very largest few Kuiper belt objects even have atmospheres, but this one has been known to have had an atmosphere for a while. The Kuiper belt object we were studying was Pluto.

The great planet debate wasn't

2008-08-17T16:11:00.000-07:00

Last week, in Baltimore, at the conclusion of a conference about planets and definitions, two astronomers faced off in what was termed the Great Planet Debate.

I missed the conference, and thus missed the debate, but, nonetheless, courtesy of a press release supplied by one of the participants, I can already declare a winner by default.

As I have said earlier, there is important science in classification, and that science is really not much of a subject of debate. Everyone can agree which objects in the solar system are dynamically dominant. Everyone can agree which are round. Everyone can agree which are rock or gas or ice. The only debate is about which of the many different important classification schemes should get to use that magical word “planet” to describe its members. And that debate is merely aesthetic, not scientific. So the “Great Planet Debate” is merely a debate about aesthetics, which I guess is OK, but, in my opinion, unlikely to be terribly Great.

But, according to the press release, the astronomer who was arguing against the current 8 planet definition wants, instead, to use a definition that says that anything round is a planet, and thus there should be 13 planets.

STOP!

Suddenly there could be a scientific debate here, and this astronomer should be crushed. Everything round is a planet and there are thirteen round things? Where did that come from?

The planets would be the familiar Mercury through Pluto, for nine. Ceres, the largest asteroid, makes ten. Charon’s moon makes eleven, and my two discoveries, Eris and Makemake, make 12 and 13.

Regardless of your opinion of whether or not this is a fitting definition of the world planet, this is bad classification, and thus bad science.

So how many round things are there?

We don’t actually know the answer to that, since most of the objects in the Kuiper belt are so far away that we can’t see their shapes. Pluto and Charon have been measured to be round, so they count. Eris is assumed to be round because it is more massive than Pluto. Makemake has a poorly measured size and no known mass (it has no moon, which is the only way to measure a mass), but it is big, so probably massive, so probably round.

So what about other objects in the Kuiper belt? We can’t see them well enough to determine whether they are round or not, but we can estimate how big an object has to be before it becomes round and therefore how many objects in the Kuiper belt are likely round. In the asteroid belt Ceres, with a diameter of 900 km, is the only object large enough to be round, so somewhere around 900 km is a good cutoff for rocky bodies like asteroids. Kuiper belt objects have a lot of ice in their interiors, though. Ice is not as hard as rock, so it less easily withstands the force of gravity, and it takes less force to make an ice ball round. The best estimate for how big an icy body needs to be to become round comes from looking at icy satellites of the giant planets. The smallest body that is generally round is Saturn's satellite Mimas, which has a diameter of about 400 km. Several satellites which have diameters around 200 km are not round. So somewhere between 200 and 400 km an icy body becomes round. Objects with more ice will become round at smaller sizes while those with less rock might be bigger. We will take 400 km as a reasonable lower limit and assume that anything larger than 400 km in the Kuiper belt is round.

How many objects larger than 400 km are there in the Kuiper belt? We can't answer this question precisely, because we don't know the sizes of more than a handful of Kuiper belt objects, but, again, we can make a reasonable guess. If we assume that the typical small Kuiper belt object reflects 10% of the sunlight that hits its surface we know how bright a 400 km object would be in the Kuiper belt. Currently there are about 60 objects this size or larger in the Kuiper belt (including, of course, Eris and Pluto and Makemake), and one (Sedna) in the region beyond the Kuiper belt.

We have not yet completed our survey of the Kuiper belt. Our best estimate is that a complete survey of the Kuiper belt would double this number. For now, the number of known objects in the solar system which are likely to be round is about 70, with the number increasing as the survey of the Kuiper belt is completed.

Beyond the Kuiper belt there may be even more dwarf planets than in the Kuiper belt. Our best guess is that the region where Sedna resides could contain another ~2000 round objects.

So the victory in the Great Planet Debate goes, by default, to the 8 planet side. Whether or not you like the aesthetics of the 8 planet side, you have to disqualify the everything-round-is-a-planet side for thoroughly mangling the science of their own classification scheme. This is not to say that an 8 dynamically dominant planet definition is better than a ~70 round planet definition, but there can be no debate that an 8 planet definition is vastly superior to a 13 planet definition based on bad scientific classification.

How can this fundamental mistake have been made? Surely if you believe in the utmost importance of things being round, you would at least try to understand what was round and what was not, right? My speculation (some would say “paranoid speculation”) is that this was done on purpose. There is no doubt that the astronomer arguing the everything-round definition knows that there are many other round things. So why would he pretend there were not? Because, I suspect, he knows that arguing for 13 planets sounds more palatable than arguing for 70 planets. Arguing for 13 planets makes it seem like stingy astronomers are just being mean to the 4 being excluded. Arguing for 70 makes you seem a bit of an extremist.

There are good aesthetic arguments that can be made for the 70 planet everything-round definition. Make them! Argue them! Have a lively aesthetic debate! But don’t start by getting the science wrong. Particularly if it is being done on purpose.