Sunday Mercury - Weird Science

Star system targeted in life hunt

2013-04-23T12:43:56Z

A star system containing two potentially habitable Earth-like planets is being targeted by scientists searching for extra-terrestrial intelligence.

In the coming months, astronomers will turn an array of radio telescope dishes towards Kepler-62, a star smaller and dimmer than the Sun about 1,000 light years away in the constellation Lyra.

A pair of so-called "super-Earths" have been detected within the "habitable zone" of the star, the orbital region where temperatures are just warm enough to allow bodies of surface water such as oceans and lakes.

]]> Although no-one knows what the planets are made of, they are believed to be rocky. One, Kepler-62f, is thought to have a radius about 1.4 times greater than the Earth's.

The other, Kepler-62e, is estimated to be 1.6 times larger.

The planets' parent star is around two billion years older than the Sun, raising the possibility of intelligent life more advanced than it is on Earth.

Both will be priority targets in a new Search for Extra-Terrestrial Intelligence (Seti) programme focusing on habitable zone worlds.

They were discovered by Nasa's Kepler space telescope, which has so far detected almost 3,000 candidate planets outside the Solar System. A fifth of these are believed to be "super-Earths" between 1.25 and twice the size of the Earth.

Scientists at the Centre for Seti Research in the US are listening in for radio signals from the stars that display signs of technology and intelligence. The search is being conducted from the Allen Telescope Array, a collection of small six-metre wide dishes in the Cascade Mountains of northern California.

The array, launched in 2007 with 42 dishes, will ultimately comprise 350 receivers operating round the clock.

"Our surveys improve on previous, generally narrow band Seti by covering the radio frequency range where Earth's atmosphere is most transparent, including many frequencies never before observed," said Dr Gerry Harp, director of the Centre for Seti Research.

"We expect to complete a meaningful survey of these stars in less than one year. Be sure to check back soon."

Kepler is designed to detect planets by looking for the minute dimming of starlight as they pass in front of or "transit" their parent stars. By studying the effect and the length of the transit, scientists can work out a planet's size and probable orbit.

Dr Jon Jenkins, a member of the Seti Institute team based at Nasa's Ames Research Centre in California, whose Kepler-62 data is reported in the journal Science, said: "These discoveries move us farther down the road to discovering planets similar to Earth.

"While we don't know if Kepler-62e and f are rocky or whether they have liquid water pooling on their surfaces, their existence shows that the incidence of small worlds in the habitable zone of Sun-like stars is high.

"Thus we can look forward to the discovery and detailed characterisation of Earth's cousins in the years and decades to come by future missions and telescopes."

The research suggests that both planets are solid and likely to have mostly dry rocky surfaces or be ocean-covered water worlds.

Three other planets close to the size of the Earth are also thought to be orbiting Kepler-62, but not in the habitable zone.

Strange world of powerful forces

2013-04-19T23:01:21Z

To the doom merchants he will always be Dr Strangelet, the mad scientist meddling with forces that should be left well alone.

Professor David Evans, from the University of Birmingham, heads a British team working right on the frontiers of science at the Large Hadron Collider.

From early on, his experiments have fuelled fear and suspicion among groups who believe they are living in an episode from Quatermass.

]]> Black holes were one reason to be afraid - another was an elementary particle called the strange quark.

A court action was even mounted to stop the professor's crazy boffins creating "killer strangelets" that could finish us all off.

"The killer strangelet produces a chain reaction that causes the rest of matter on the planet to turn into strange matter," says Prof Evans, speaking under a shower of photons in the sunlit grounds of Restaurant 1 at Cern, the European Centre for Nuclear Research.

With a characteristic twinkle, he adds: "Not only would this destroy the Earth in five minutes, but it would go on to destroy the universe. I thought if that was going to happen, Birmingham University ought to be involved."

Like many of his colleagues, Prof Evans has learned to put up with crank phone calls and abusive letters.

Perhaps this is only to be expected when you are emulating God by replaying the birth of the universe.

The Large Hadron Collider (LHC) is the world's biggest particle accelerator - £2.6 billion worth of the highest tech hardwire imaginable straddling the French and Swiss borders near Geneva.

Housed in a 27 metre (17 mile) circular tunnel 100 metres below ground, the LHC fires streams of protons - the hearts of atoms - at each other at more than 99.9% the speed of light.
When they smash together they produce super-hot fireballs in which new kinds of matter are forged, conditions that have not existed since just after the birth of the universe.

The process of destruction and creation is observed at four detector points - Atlas, CMS, Alice and LHCb - spaced around the ring.

Last year the LHC hit the headlines when scientists found what has now been confirmed as some form of Higgs boson - a long-sought elementary particle that according to theory is responsible for mass. Next, the particle hunters hope to capture dark matter, the mysterious invisible material that glues galaxies together and makes up around a quarter of the universe.

But right now the LHC is in the midst of a two-year shutdown for an upgrade and health check.

Just over a week after it was first powered up in 2008, calamity struck the machine. A dud soldered joint allowed an escape of super-cooled helium, causing several magnets to overheat.

Despite the fault being fixed, the LHC has never operated at full power since. During the shutdown engineers will check every one of more than 10,000 similar joints to ensure a similar accident cannot happen again.

Then, when the machine is switched back on in March 2015, the combined energy of the beams will be ramped up from eight to 14 trillion electrovolts (Tev). Each beam will have a total energy equivalent to a 400 tonne train travelling at 150 kilometres per hour.
That's enough energy to melt 500 kilograms of copper.

The reason the LHC needs so much energy is because, as Einstein tells us, energy and mass are interchangeable. Within the LHC, energy is converted to mass. And if you want heavy, exotic particles, you need a lot of energy.

"We're doing the opposite of what a (nuclear) bomb does," says Prof Evans. "An atomic bomb turns a small amount of mass into energy, and we're turning energy into mass."

Alice (A Large Ion Collider Experiment), the detector Prof Evans works on, is arguably producing some of the weirdest science at the LHC.

The Alice team is investigating one of the least understood forces of nature. Known as the strong force, it cements quarks, the tiniest building blocks of matter, firmly together in the nuclei of atoms.

It was not always this way. A millionth of a second after the Big Bang that kicked off the universe, quarks milled around in a hot brew of free-wheeling elementary particles called a quark gluon plasma.

By smashing together heavy lead nuclei stripped of electrons, the Alice scientists are recreating this primordial creation soup. In so doing, they entered the Guinness Book of Records for producing the most extreme temperatures and pressures on the planet.

At six trillion degrees, the fireball produced in Alice - albeit for less than a nanosecond - is 600,000 times hotter than the centre of the Sun.

The "soup" is also pretty thick - in fact, 50 times more dense that the material in a neutron star, a teaspoonful of which weighs a billion tonnes.

Despite being so dense, the quark gluon plasma flows like a "perfect" liquid, a super-fluid state of matter with peculiar properties.

Other teams of scientists at the LHC are continuing to study the Higgs boson, looking for dark matter, and trying to find out what happened to all the antimatter that should have been around after the Big Bang.

Antimatter is a sort of mirror image of normal matter, possessing an opposite electrical charge. Today it is very rare indeed, but one unlikely source of antimatter is the banana.

This is the kind of invaluable information that can only be obtained by meeting particle physicists. It seems the humble banana contains an unstable isotope of potassium that releases an antimatter particle once every 75 minutes. Eat enough bananas, and you could get a stomach ache, since matter and antimatter annihilate each other when they meet.

One advantage of the shutdown is that it allows free access to the LHC tunnel and detector caverns, both of which are radiation hotspots when the machine is working.

Entry to the tunnel at the LHCb, or "beauty", detector is through two sets of giant green steel doors.

Within, the beam pipes disappear into the distance interspersed by shiny and complex looking machinery.

Electric buggies, like those used by all supervillains to zip around their underground lairs, enhance the Bond movie-set atmosphere. But two bicycles with baskets propped against the opposite wall are a reminder that we are 100 metres below the rolling French countryside.

Nevertheless, it is a good place to have Bond encounter one of his famous close shaves.
"Either side of the Atlas or CMS detectors you would be dead in an unspecified number of minutes," says our guide, operations group leader Dr Mike Lamont.

So where is all this costly big science leading, and what practical use is it? The stock answer is, nobody knows - yet. The LHC scientists are like their 18th century forbears experimenting with electricity. No-one in Benjamin Franklin's time could have foreseen TV, refrigerators and the internet.

Speaking of the strong force, Prof Evans says: "In 100 years from now it could be generating our power or sending spacecraft beyond the solar system, we don't know.
"History tells us that when you do this research it does eventually get used."

'Small bandit' dinosaur discovered

2013-04-18T21:00:39Z

A new species of dinosaur whose translated name means "lonely small bandit" has been discovered in Madagascar.

Dahalokely tokana was between nine and 14 feet (2.75 to 4.3 metres) long and lived around 90 million years ago.

Its name, derived from the Malagasy language, refers to the animal's carnivorous diet and the fact that it evolved when India and Madagascar were one landmass cut off from the rest of the world.

]]> Scientists believe it belonged to a family of dinosaurs known as the abelisauroids.

Dahalokely could be an ancestor of later dinosaurs that lived both in Madagascar and India, said the researchers writing in the journal Public Library of Science ONE.

Lead scientist Dr Andrew Farke, from the Raymond M. Alf Museum of Paleontology in California, US, said: "We had always suspected that abelisauroids were in Madagascar 90 million years ago, because they were also found in younger rocks on the island. Dahalokey nicely confirms this hypothesis."

Creature bridged ape-human gap

2013-04-15T12:25:33Z

A creature bridging the gap between apes and humans with a "mosaic" of missing-link features has been described by scientists.

Several partial skeletons of the two million-year-old species Australopithecus sediba were discovered in South Africa in 2008.

After four years of work, an international team of scientists today presented results from one of the most extensive studies of an extinct hominin, or human-like animal, ever conducted.

]]> Six research papers on the way the creature chewed and moved uncovered a complex mixture of traits. Some shared features seen in more evolved humans from the family Homo, while others were suggestive of more primitive apes.

A. sediba had a small, chimp-like heel and appears to have walked in a unique way, with its feet slightly twisted inwards.

The odd gait may have been a compromise between upright walking and tree climbing, according to the authors, writing in the journal Science.

The creature also had ape-like upper limbs equipped for climbing and hanging from branches, but its hand and wrist were distinctly human.

A high shoulder joint would have given A. sediba an ape-like "shrugged" appearance, and its narrow upper rib cage was also reminiscent of large-bodied apes.
Yet the lower rib cage was more like that of a modern human, and while the creature had the same number of spinal vertebrae as people living today, its back was longer and more flexible.

A study of A. sediba's jaw and teeth, meanwhile, showed strong similarities with later human ancestors.

"All of the research so far shows that sediba had a mosaic of primitive traits and newer traits that suggest it was a bridge between earlier australopiths and the first humans," said Professor Debbie Guatelli-Steinberg, one of the study authors from Ohio State University in the US.

A. sediba is in the same genus family as two other ancient hominins discovered in Africa, A. afarensis - the famous "Lucy" skeleton unearthed in Ethiopia in 1974 - and A. africanus, also from South Africa.

Both are up to a million years older than A. sediba.

The dental research indicates that both sediba and africanus are more closely related to modern humans than afarensis.

Zoo hopes panda mating 'imminent'

2013-04-10T11:47:41Z

Fingers are crossed that the UK's giant panda couple Tian Tian and Yang Guang will mate within days.

Edinburgh Zoo said female Tian Tian is about 10 days away from her short fertile window, perhaps less.

The pair were introduced to each other before last year's breeding season but did not mate.

]]> The Royal Zoological Society of Scotland (RZSS) revealed that Tian Tian will shortly be in heat after tests showed the necessary hormonal crossover in progesterone and oestrogen had occurred.

Iain Valentine, director of giant pandas, said: "We are now able to predict that the important 36-hour breeding window when both pandas are likely to meet is imminent.

"Scientific results alone would suggest the day is just less than 10 days away; however, as Tian Tian's behavioural changes are coming in so strongly, we cannot rule out that the key 36-hour window may be much sooner.

"Every individual giant panda is different and this is only the second time Tian Tian has come into season in Scotland, so it is difficult to make a precise prediction at this stage.

"The next steps are to continue behavioural observational and hormone testing to confirm when the annual window has arrived."

Tian Tian and Yang Guang are the first giant pandas to live in the UK for 17 years.
Edinburgh Zoo, where the pair have lived since their arrival from China in December 2011, has employed a number of measures to synchronise the breeding cycles of the pandas, including controlled lighting, urine testing for hormone levels and enclosure swapping.

Mr Valentine said: "When the 36-hour window is here, Tian Tian and Yang Guang will meet several times to have the opportunity to mate and then, as Tian Tian finally ovulates and her hormones fall off, artificial insemination will also take place."

If Tian Tian does fall pregnant, it will be July or the first half of August when Edinburgh Zoo experts will be able to confirm it by using ultrasound scans.

The majority of giant panda cubs are born at the very end of August or beginning of September.

Monkeys show signs of speech

2013-04-09T13:34:39Z

Friendly lip-smacks made by a large African monkey show striking similarities with human speech, say scientists.

Geladas, close cousins of the baboon that only live in the remote mountains of Ethiopia, produce "unnerving" sounds that can easily be mistaken for human voices.

Researchers who analysed recordings of the vocalisations uncovered a structural rhythm that closes matched that of people speaking.

]]> They believe the evidence points to lip-smacking - a friendly behaviour displayed by many primates - being an evolutionary step towards speech.

"Our finding provides support for the lip-smacking origins of speech because it shows that this evolutionary pathway is plausible," said lead scientist Prof Thore Bergman, from the University of Michigan in Ann Arbor, US.

"It demonstrates that non-human primates can vocalise while lip-smacking to produce speech-like sounds."

Prof Bergman became fascinated by the geladas' sounds while observing the monkeys in 2006.

"I would find myself frequently looking over my shoulder to see who was talking to me, but it was just the geladas," he said. "It was unnerving to have primate vocalisations sound so much like human voices."

Geladas are a highly gregarious species with a large vocal repertoire, expressed using complex facial movements.

The new research, reported in the journal Current Biology, showed that the rhythm of gelada lip-smacking closely mirrored the gaps between syllables in many human languages.

In both, the rhythm corresponded to the opening and closing of parts of the mouth.
Lip-smacking displayed by other primates does not have the same speech-like quality.

Calls of other monkeys and apes typically consist of just one or two syllables and lack the geladas' rapid fluctuations in pitch and volume.

Gelada lip-smacks are thought to serve a similar purpose to "small talk" between friends by helping to bond individuals together.

"Many verbal exchanges appear to serve a function similar to lip-smacking," said Prof Bergman.

Warning of greater weather extremes

2013-03-25T13:32:18Z

Climate change will bring greater extremes in weather, the Government's outgoing chief scientific adviser has warned as he called for urgent action to tackle global warming.

Professor Sir John Beddington said the effects of climate change on the weather were already being felt in the UK.

"In a sense we have moved from the idea of global warming to the idea of climate change, and that is rather important - yes, indeed, temperatures are increasing but the thing that is going to happen is that we are going to see much more variability in our weather," he told BBC Breakfast.

]]> "I think you only have to look at the last few years to see how that is actually starting to manifest itself even in the UK."

Sir John said there were "massive problems" in the world of food, water and energy security as the global population increases, all of which would be exacerbated by climate change.

Even if effective action was taken now on global warming, he said there would be

"significant" climate change over the next 20 to 25 years as results of past global emissions.

"We have massive problems in the world - in 12 years' time there will be another billion people on the planet and we have big issues of food security, water security and energy security and many, many people will start to be living in cities," he said.

"These are massive problems; climate change is just going to make it worse."

He said there were some "uncertainties" in the analysis of climate and climate change.

"But those uncertainties are completely outweighed by the enormous body of evidence that shows it is happening and is happening in the sort of ways climate models would expect," he said.

"For example the Arctic is heating up vastly faster than other parts of the world - this is exactly what the climate scientists are predicting."

Sir John's remarks were made as Britain experienced freezing cold weather and snow, with thousands of homes across the UK without power and many roads still impassable.

Almost 8,000 homes and businesses were flooded in 2012, as the UK was battered by repeated heavy rain, storms and floods.

England and Wales experienced 10 separate flooding events between April and December last year after widespread drought gave way to the wettest summer in a century, with unusually high rainfall totals and river levels around the country.

Sir Mark Walport, currently director of the Wellcome Trust, takes over as the Government's chief scientific adviser on April 1.

Nasa finds more signs of water on Mars

2013-03-19T14:48:14Z

More signs of past water on Mars have been uncovered by the American space agency Nasa's Curiosity rover.

Powder drilled from a Martian rock last week revealed evidence of drinkable water and conditions favourable to life.

Now instruments on the rover have found more water-bearing minerals in the area around the rock.

]]> Curiosity is exploring a region within Gale Crater, near the Martian equator, called Yellowknife Bay.

Scientists believe that billions of years ago water poured down the rim of the crater and formed streams that might have been up to three feet deep.

The new discoveries were made using the infrared imaging capability of Curiosity's mast camera, and an instrument that shoots neutron particles into the ground to probe for hydrogen.

Differences in brightness between near-infrared wavelengths of light can indicate the presence of some hydrated minerals that have been altered by water.

"With Mastcam, we see elevated hydration signals in the narrow veins that cut many of the rocks in this area," said Dr Melissa Rice, from the California Institute of Technology in Pasadena.

"These bright veins contain hydrated minerals that are different from the clay minerals in the surrounding rock matrix."

The Russian-made Dynamic Albedo of Neutrons (DAN) instrument detected hydrogen in water molecules bound into minerals in the soil beneath the rover.

Yellowknife Bay contained more water than other areas previously visited by Curiosity, the results showed.

"More water is detected at Yellowknife Bay than earlier on the route," said DAN deputy principal investigator Dr Maxim Litvak, from the Space Research Institute in Moscow. "Even within Yellowknife Bay, we see significant variation."

The findings were presented at the Lunar and Planetary Science Conference in The Woodlands, Texas.

Astronomers detect water on distant planet

2013-03-18T12:12:43Z

Astronomers have detected clouds of carbon monoxide and water vapour around a huge gassy planet orbiting a star 130 light years away.

The study is the most detailed yet of the atmosphere of an "exoplanet".

In future, scientists hope to use similar techniques to uncover signatures of life in the atmospheres of Earth-like worlds.

]]> The planet, known as HR 8799c, has seven times the mass of Jupiter and is one of four similar planets distantly orbiting the star.

Observations suggest the solar system was created in a similar way to our own, with gas giants forming far away from their parent star and smaller, rocky planets closer in.

If this model is correct, there could be as-yet undetected Earth-like planets waiting to be found.

"The results suggest the HR 8799 system is like a scaled-up Solar System," said Dr Quinn Kanopacky, one of the astronomers from the University of Toronto in Canada.

Light wavelength "colours" act like fingerprints for different elements. By studying the light from a distant planet, scientists can make assumptions about what elements are contained in its atmosphere.

The presence of oxygen's cousin ozone or carbon dioxide, for instance, could indicate that a world harbours life.

Because HR 8799c is so big and far out - about the same distance from its star as Pluto is from the Sun - astronomers were able to image it directly rather than infer its presence.

The observations were made using the Keck II 10-metre telescope in Hawaii, one of the two largest optical telescopes in the world.

Dr Bruce Macintosh, from the Lawrence Livermore National Laboratory in California, US, one of the co-authors of the research published in the journal Science, said: "This is the sharpest spectrum ever obtained of an extrasolar planet.

"This shows the power of directly imaging a planetary system. It is the exquisite resolution afforded by these new observations that has allowed us to really begin to probe planet formation."

Life may not be out there after all

2013-03-11T12:58:00Z

ET may not be calling any time soon, according to an expert who claims belief in a universe teeming with life is misplaced.

Professor Charles Cockell argues that Earth may be a lonelier place than is popularly thought. This is despite recent discoveries of a plethora of distant solar systems and potentially habitable planets.

On Earth, living organisms fill just about every environment capable of supporting them.
This leaves the wrong impression that life is bound to arise anywhere it can, says Prof Cockell.

]]> "The pervasive nature of life on Earth is leading us to make this assumption," said the professor, director of the UK Centre for Astrobiology at the University of Edinburgh.

"On our planet, carbon leaches into most habitat space and provides energy for micro-organisms to live.

"There are only a few vacant habitats that may persist for any length of time on Earth, but we cannot assume that this is the case on other planets."

Even though habitable planets might be abundant in the universe, that does not mean the same is true of Earth-like life, says the professor.

More than 800 "extrasolar" planets orbiting stars beyond the Sun have been detected since the early 1990s.

Advanced techniques are now allowing astronomers to identify smaller, rocky planets within the "habitable" zones of their parent stars.

The habitable or "Goldilocks" zone is an orbital pathways just the right distance from a star to allow mild temperatures and surface water, a pre-requisite for life as we know it.

Prof Cockell warns against expecting too much from the search for extraterrestrial life in a talk at the Royal Society in London today.

"It is dangerous to assume life is common across the universe - it encourages people to think that not finding signs of life is a 'failure', when in fact it would tell us a lot about the origins of life," he said.

Not assuming that life is "out there" would make it possible to approach the question in a more scientific way, the professor claims.

Even if another planet did harbour life, it might be so alien that we do not recognise it, he added.

Chemical signatures of life that could in future be detected by astronomers - such as oxygen or carbon dioxide - would be dependent on biology evolving the same way that it does on Earth, said Prof Cockell.

A completely different kind of life that did not have the same fingerprints could easily be missed.

Prof Cockell is one of a number of experts attending a discussion meeting at the Royal Society entitled "Characterising exoplanets: detection, formation, interiors, atmospheres and habitability".

Giant camels roamed the Arctic

2013-03-05T16:00:38Z

Camels might be known as ships of the desert but they had giant ancestors that once roamed the Arctic.

Bone fragments belonging to a camel almost a third larger than any now living have been recovered from a remote site in the far north of Canada.

The animal lived 3.5 million years ago, when the High Arctic was warmer than it is today and covered in forest.

]]> Scientists believe camels might have originated in North America before migrating across Asia via a land bridge between Alaska and Russia.

Today they still bear features that could have evolved to cope with harsh polar winters.

Among these are the famous hump - used to store energy in the form of fat - wide flat feet that perform equally well on sand or snow, and large eyes for peering through the Arctic winter gloom.

Bones of another giant camel dating back around two million years were previously found 1,200 kilometres south in the Yukon.

The new camel, as yet unnamed, may be a close relative of this animal, thought to belong to the family Paracamelus from which all modern camels are descended.

Fossil fragments from a lower leg bone were collected from Ellesmere Island, deep within the Arctic Circle off the northern coast of Greenland.

Scientists at the University of Manchester used a pioneering molecular fingerprinting technique to test tiny samples of preserved connective tissue extracted from the bones.

The collagen was compared with that of the Yukon camel and 37 modern mammal species.

The findings, published in the journal Nature Communications, show an almost identical match to the modern day one-humped camel, the dromedary, as well as the Yukon camel.

Anatomical data, combined with the collagen information, suggested that the leg bone was roughly 30% larger than the same bone in a modern camel species.

Dr Natalia Rybczynski, from the Canadian Museum of Nature, who led the expedition that found the fossils, said: "The first time I picked up a piece, I thought that it might be wood.

"It was only back at the field camp that I was able to ascertain it was not only bone, but also from a fossil mammal larger than anything we had seen so far from the deposits."

She added: "We now have a new fossil record to better understand camel evolution, since our research shows that the Paracamelus lineage inhabited northern North America for millions of years, and the simplest explanation for this pattern would be that Paracamelus originated there. So perhaps some specialisations seen in modern camels, such as their wide flat feet, large eyes and humps for fat may be adaptations derived from living in a polar environment."

During the mid-Pliocene epoch, when the camel was alive, the Earth was around 2C to 3C warmer than it is today, and the Arctic may have been up to 22C warmer.

However, it would still have been a frigid environment. Average annual temperatures would have been slightly below freezing, and the long winters much colder.

Writing in the journal, the scientists said fat deposits - as seen in camels' humps - could have been "critically important for allowing populations to survive and reproduce in harsh climates characterised by six-month long, cold winters".

Dr Mike Buckley, from the University of Manchester's Institute of Biotechnology, said: "This is the first time that collagen has been extracted and used to identify a species from such ancient bone fragments.

"The fact the protein was able to survive for three and a half million years is due to the frozen nature of the Arctic. This has been an exciting project to work on and unlocks the huge potential collagen fingerprinting has to better identify extinct species from our preciously finite supply of fossil material."

Rare comet makes Earth fly-by

2013-03-04T11:40:21Z

A comet with a glowing tail makes a once-in-a-lifetime appearance in the evening sky this month.

Comet 2011 L4 Panstarrs has taken millions of years to travel out from the Oort cloud - a huge colony of icy objects at the edge of the Solar System.

Throughout the month Panstarrs will be visible low in the west.

]]> There could be good picture opportunities on March 12 and 13 when it brushes past the crescent moon.

However, it might be difficult to see the object without binoculars or a telescope.

"It's going to be in the twilight sky and not as bright as we had originally hoped, but comets are terribly unpredictable," said Robin Scagell, vice-president of the Society for Popular Astronomy.

Towards the end of the month the comet will fade but rise higher in the sky, possibly making it easier to see.

On around March 30 its northward path will take it close to the Andromeda galaxy.
"That could provide a good picture for sky watchers," said Mr Scagell.

Panstarrs is not expected to revisit our skies for 110,000 years.

Another comet is expected to make a more dramatic appearance in November.
Comet Ison will fly closer to the Sun, causing it to light up. Experts say it could be bright enough to see in daylight, but from the UK it will only be visible low in the sky.

"It might be fantastic for a few days, but it's difficult to predict ahead of time," said Mr Scagell. "As ever we have to be cautious. What you might see is the tail of the comet sticking up above the horizon."

One million Romans in Britain

2013-02-26T13:12:06Z

Around one million men in the UK can claim to be direct descendants of the Romans, scientists have revealed.

The Roman army invaded Britain in 43 AD and left around 400 years later, in the early 5th century.

But historians and scientists claim that the legions left behind their legacy in the genes of many Britons.

]]> A study by BritainsDNA, a commercial DNA testing company, compared Y chromosome markers found in men in Britain with those found in modern Italy.

The results found five major types of DNA which were likely to have come from the Roman legions.

The first, known as Alpine, was found in 13% of Italian men, 6.5% of men in England and Wales, 4.3% in Scotland and 1.8% in Ireland.

As Ireland was never conquered and Scotland was only occupied for a short time, the researchers said these figures suggested this DNA was a "probable candidate" to be linked to the Romans.

When applied to the total population of the UK, it was estimated that 1.6 million men carried the Alpine marker, of which half a million may be descended from the Roman armies.

When the researchers included the four further markers - known as Balkan, Ancient Caucasians, Herdsmen-Farmers and Anatolian - they calculated that at least one million British men may be direct descendants of the Romans.

The study concluded: "Since the number of Italians or descendants of Italians in the legions did reduce very much over time, we estimate conservatively that one million men in Britain descend from Romans in the direct male line.

"What this fascinating piece of research shows is that the Romans did indeed do something for us, for about a million of us in fact."

Geese tracked to solve vanishings

2013-02-20T00:01:32Z

British conservationists are tracking endangered red-breasted geese to solve the mystery of thousands of birds lost in migration.

More than 90 birds were caught and tagged in Bulgaria to try to find out what happened to more than 50,000 geese which disappeared from their wintering grounds along the Black Sea coast about 10 years ago.

British conservationists from the Wildfowl & Wetlands Trust (WWT) are working with the Bulgarian Society for the Protection of Birds (BSPB) to identify whether the birds found a new site in Asia or fell victim to hunting, development or changes in farming along their 6,000km migration to breeding grounds in Arctic Russia.

]]> Peter Cranswick, head of species recovery at Gloucestershire-based WWT, said: "Almost overnight, we were unable to account for around half the world's red-breasted geese.

"The reasons are still unclear and we are tracking these individual birds to find out more.

"It is also possible that, as the climate has changed, some birds have started to winter further east. We hope our tagged birds will reveal as yet unknown sites, so we can assess their importance and - if necessary - ensure their protection.

"The data we get will be invaluable to our work with local communities in Bulgaria - the farmers, shooters and landowners - to work out how we support the remaining geese, while still meeting their needs."

Mystery slime at nature reserve baffles boffins

2013-02-18T12:16:59Z

A weird "slime" is baffling boffins at a nature reserve.

The jelly-like substance has been found at the RSPB Ham Wall Nature reserve in Somerset.

As yet the mystery slime has not been identified.

]]> Steve Hughes, the RSPB site manager at Ham Wall, said: "This past week we've been finding piles of this translucent jelly dotted around the reserve.

"Always on grass banks away from the water's edge.

"They are usually about 10cm (4in) in diameter.

"We've asked experts what it might be, but as yet no one is really sure.

"Whatever it is, it's very weird."

Scientific speculation as to the nature of the jelly is varied.

One of the more favoured explanations is that it is a form of cyanobacteria called Nostoc.
Some, however, suggest that it is the remains of the regurgitated innards of amphibians such as frogs and toads and of their spawn.

Alternatively, it may be related to the intriguingly named crystal brain fungus.

Tony Whitehead, an RSPB spokesman for the South West, said: "Although we don't know what it actually is, similar substances have been described previously.

"In records dating back to the 14th Century it's known variously as star jelly, astral jelly or astromyxin.

"In folklore it is said to be deposited in the wake of meteor showers."
Mr Whitehead added: "It's great that in this day and age that there are still mysteries out there.
"We've read a few articles now and much speculation.

"One suggested it was neither animal nor plant, and another that it didn't contain DNA, although it does give the appearance of something 'living'.

"Our reserve team will be looking out for the slime over the next few days, but if anyone can offer any explanations we'd be glad to hear."

The public are being warned not to touch the mystery substance, and to inform nature reserve staff.