The anomaly emerged in 1990, when NASA's Galileo spacecraft whizzed by Earth to get a boost from our planet's gravity and gained 3.9 millimetres per second more than expected. And the European Space Agency's Rosetta spacecraft had an unexpected increase of about 1.8 millimetres per second during a previous fly-by of Earth in 2005.
Scientists have ruled out various mundane explanations like atmospheric drag or the effect of deviations in Earth's shape. This has led some to propose that exotic new physics is involved, such as modifications of Einstein's general relativity, the currently accepted theory of gravity.
All eyes are now on Rosetta, which is set to swing by Earth again at 0745 GMT on 13 November. It is en route to a comet, and will travel around 2500 kilometres above our planet's surface at over 13 kilometres per second. If it gains an extra 1.1 millimetres per second relative to Earth, it would vindicate a formula that reproduces the anomalies seen so far.
The formula, published in 2008 by ex-NASA scientist John Anderson and his team, hints that Earth's rotation may be distorting space-time more than expected and thus influencing nearby spacecraft, though no one can explain how. General relativity predicts that spinning bodies distort the fabric of surrounding space, but the expected amount is far too small to explain the observed anomalies.
"I am definitely looking forward to this one," says Anderson, who is working with members of the Rosetta team to watch for an anomaly.
However, any anomaly will not be immediately obvious because the expected change is tiny. "I anticipate a few days or weeks before we know if an anomaly occurred," he says.
Curiously, Rosetta's 2007 flyby of Earth produced no anomaly. That might be because of its much higher altitude, about 5300 kilometres above Earth's surface, Anderson says. He suggests the effect may get weaker with distance from Earth: "There is most likely some dependence on distance – we just do not know what it is."
He found that the blast didn't send out the right kind of chemical elements to have been a Type II event.
Instead the explosion looked more like a Type Ia supernova, a known type of blast that involves a pair of stellar corpses called white dwarfs.
But unlike Type Ia explosions, SN 2002bj blazed as bright as ten billion suns but faded away into invisibility within 20 days.
"Other supernova types typically last about three times longer," taking three to four months to totally fade, Poznanski said.
He and his colleagues therefore think the outburst might be the first known "Type .Ia" supernova—so named because the blasts are only a fraction as bright as Type Ia supernovae and last for just a fraction as long.
Lars Bildsten, a physicist at the University of California, Santa Barbara, predicted the existence of Type .Ia supernovae two years ago.
According to Bildsten, a Type .Ia blast requires two white dwarfs of unequal masses circling each other.
The more massive star is made of carbon and oxygen, while its companion consists mostly of helium.
Gravity from the larger white dwarf slowly pulls helium from the surface of its neighbor, and the siphoned gas builds up into a shell around the star.
After tens of millions of years, that shell reaches a critical mass threshold, at which point it detonates in a luminous but short-lived explosion.
Since only the helium shell explodes, both white dwarfs remain intact after the blast, and the cycle could potentially repeat.
SN 2002bj fits this description almost perfectly, based on the new analysis of its chemical signatures and duration.
The find adds to the likelihood that other supernova mechanisms are awaiting discovery, study author Poznanski said.
(Related: "'Brightest Supernova' Reveals New Kind of Star Death.")
"The universe is big," he said. "If something is physically possible, it probably exists somewhere."
At least one aspect of the 2012, end-of-the-world hype is, for some people, all too real: the fear.
NASA's Ask an Astrobiologist Web site, for example, has received thousands of questions regarding the 2012 doomsday predictions—some of them disturbing, according to David Morrison, senior scientist with the NASA Astrobiology Institute.
"A lot of [the submitters] are people who are genuinely frightened," Morrison said.
"I've had two teenagers who were considering killing themselves, because they didn't want to be around when the world ends," he said. "Two women in the last two weeks said they were contemplating killing their children and themselves so they wouldn't have to suffer through the end of the world."
(Related gallery: "Apocalypse Pictures—Ten Failed Doomsday Prophecies.")
Fortunately, with the help of scientists like Morrison, most of the predicted 2012 cataclysms are easily explained away.
2012 MYTH 1
Maya Predicted End of the World in 2012
The Maya calendar doesn't end in 2012, as some have said, and the ancients never viewed that year as the time of the end of the world, archaeologists say.
But December 21, 2012, (give or take a day) was nonetheless momentous to the Maya.
"It's the time when the largest grand cycle in the Mayan calendar—1,872,000 days or 5,125.37 years—overturns and a new cycle begins," said Anthony Aveni, a Maya expert and archaeoastronomer at Colgate University in Hamilton, New York.
The Maya kept time on a scale few other cultures have considered.
During the empire's heyday, the Maya invented the Long Count—a lengthy circular calendar that "transplanted the roots of Maya culture all the way back to creation itself," Aveni said.
During the 2012 winter solstice, time runs out on the current era of the Long Count calendar, which began at what the Maya saw as the dawn of the last creation period: August 11, 3114 B.C. The Maya wrote that date, which preceded their civilization by thousands of years, as Day Zero, or 188.8.131.52.0.
In some 2012 doomsday prophecies, the Earth becomes a deathtrap as it undergoes a "pole shift," courtesy of an asteroid impact (illustrated above), a rare alignment with the center of the Milky Way, and/or massive solar radiation destabilizing the inner Earth by heating it.
The planet's crust and mantle will suddenly shift, spinning around Earth's liquid-iron outer core and sending cities crashing into the sea. (Interactive: pole shift theories illustrated.)
Princeton University geologist Adam Maloof has extensively studied pole shifts, and tackles this 2012 myth in 2012: Countdown to Armageddon, a National Geographic Channel documentary airing Sunday, November 8.
Maloof says magnetic evidence in rocks confirms that continents have undergone such drastic rearrangement, but the process took millions of years--slow enough that humanity wouldn't have felt the motion (quick guide to plate tectonics).
(The National Geographic Society owns National Geographic News and part-owns the National Geographic Channel.)
AS MEDIEVAL CASTLE bedrooms go, this one looks the part. Disturbing Flemish tapestries share the walls with stern portraits. On close inspection, the ornate fireplace's iron firedogs turn out to have devils' heads. This place is supposedly haunted by the ghost of Tom Skelton, a 16th-century jester said to have committed murder. The malevolent face of "Tom Fool" stares from a dimly lit oil painting just outside the bedroom.
My assignment is to stay overnight in the Tapestry Room at Muncaster Castle in Cumbria, UK. Having earlier reassured my editor that I laugh at ghost stories, my bravado is crumbling. I still don't believe in ghosts, but I'm scared the atmosphere will wind me up into a panic. Two previous guests have bolted in the night, one a premiership footballer, the other a diehard sceptic who came to scoff. Then I learn that I will not be able to leave the room without tripping the castle's burglar alarms. What have I let myself in for?
I am here because of a controversial theory that some reports of ghosts could be caused by unusual magnetic fields triggering strange reactions in the brain. There's a long tradition of hunting for such fields at supposedly haunted locations - and even of trying to produce them in the lab. So far, results have been mixed, so I have followed neuroscientists and psychologists to Muncaster Castle to see if, in this case at least, science can lay a ghostly mystery to rest.
Chief investigator Jason Braithwaite is a cognitive psychologist at the University of Birmingham, UK. Braithwaite is a sceptic with a long-standing interest in the psychology of paranormal experiences and beliefs. "These weird experiences appear to be part of the normal operation of the brain," says Braithwaite. "No model of brain function can be viewed as complete until it explains them."
It was in the 1970s that Michael Persinger, a neuroscientist from Laurentian University in Sudbury, Ontario, Canada, proposed that some hallucinations could be triggered by magnetic fields. It is well established that magnetic pulses of 1 or 2 teslas can stimulate neurons in the brain; it is sometimes used to treat depression. Persinger, however, was interested in much weaker fields, of about 1 to 10 microtesla, which can arise from electrical equipment such as a hairdryer, or simply exist in natural background fields.
This means that the gamma-ray burst offers an unprecedented peek into a mysterious period known as the cosmic dark ages, which lasted from shortly after the big bang until about 900 to 800 million years ago.
Astronomers think the first stars started forming during the dark ages. But few such stars have ever been spotted, because the early universe was fogged with hydrogen gas that shrouded the starlight.
"Our group, and many others worldwide, have been working for years to catch such a rare event," said Ruben Salvaterra of Italy's Brera Astronomical Observatory, who was lead author on one of the studies.
The discovery gives researchers hope of spotting still older objects, including the first generation of stars that ever formed.
"Gamma-ray bursts are the most luminous phenomena in the universe," said Dale Frail, whose team tracked radio emissions from the dying star using the National Radio Astronomy Observatory in Socorro, New Mexico. (See pictures of a gamma-ray burst that was visible from Earth to the naked eye.)
"This means that a bright gamma-ray burst could be detected out to the earliest times in the age of the universe."
Text Message From Space
The newfound gamma-ray burst, dubbed GRB 090423, was first picked up in April by sensors aboard a NASA satellite called Swift.
The probe instantly swiveled its mirrors to monitor the burst, and soon after astronomers worldwide received alerts.
Thirteen unexplained radio blips have turned up in radio telescope observations since the 1980s. They emerged in spots where there are no stars or galaxies to be seen, last anywhere from hours to days, and do not seem to repeat. The blips could be traces of a vast population of stellar corpses – neutron stars that roam the universe largely unseen, suggests a team led by Eran Ofek of the California Institute of Technology in Pasadena.
Most of the galaxy's estimated billion neutron stars are invisible. Some of the newly formed ones have been detected because their rapid rotation sends radio pulses our way multiple times per second. These are thought to fade with age.
If each of the neutron stars produces a radio burst every few months, perhaps after absorbing interstellar gas, the close ones would be detected at the rate observed, the team calculates.
"Neutron stars are a good possibility as the explanation for these events," says Geoffrey Bower of the University of California, Berkeley, whose team found seven of the outbursts in archived data from the Very Large Array telescope at the National Radio Astronomy Observatory near Socorro, New Mexico. "They are ubiquitous throughout the galaxy."
Bower and his colleagues plan to scrutinise the locations of the radio blips using the orbiting Chandra X-ray Observatory, looking for X-ray emissions characteristic of neutron stars.
Researchers worldwide are developing robots that look and act like aquatic creatures. That's because biomimetic gadgets--bots that take inspiration from nature--are often more efficient than their clunkier counterparts.
"In a fishlike fish, the whole of the animal is muscle--its propeller," said Gymnobot developer William Megill of the University of Bath, U.K. "That's not particularly conducive to putting in circuit boards."
To allow more room for cameras and other electronics, Megill's team took cues from the knifefish, which keeps its body rigid to sense electric currents in the water. In the same way, Gymnobot uses its lower, bladelike "fin" to propel itself through the water while the body remains rigid.
Megill and colleagues hope the bot can be used to study marine life near the shore, where a propeller would kick up too much sediment or get tangled in weeds.
The Northrop Grumman Lunar Lander ChallengeMovie Camera is intended to promote innovative ideas for a new generation of vehicles that could land humans on the moon.
It is divided into two levels. For the lesser $350,000 level 1 prize, a rocket must rise 50 metres from its launch pad, move 100 metres horizontally and land on a concrete pad, staying in the air for a total of at least 90 seconds. It must then repeat the feat, returning to its starting point within 2.5 hours. Texas-based Armadillo Aerospace won that prize in October 2008.
To qualify for the $1 million level 2 prize, a rocket must make a similar flight, but this time it must stay aloft for 180 seconds and land on a bumpy surface that simulates that of the moon.
Armadillo became the first team to qualify for the prize in September.
But on Friday, Masten Space Systems of Mojave, California, was poised to wrest the prize from Armadillo, after making qualifying flights that outperformed its rival in landing accuracy.
While Armadillo's vehicle landed on average 90 centimetres from its target in the second-level tests, Masten's two Friday flights appeared to be only about 25 centimetres away, according to William Pomerantz of the X Prize Foundation. Judges have yet to release official numbers for the Masten flights.
"It really looks like if you're not dreaming about it, you're not getting better," says Robert Stickgold of Harvard Medical School, who carried out one of the video game studies.
The studies don't prove that dreaming about games makes players better. But they strongly suggest that dreaming and learning are intertwined.
That sleep can help with learning and memory is well established. What's more, the more people dream during the light sleep characterised by rapid eye movements (REM), the better they recall memories. But whether the specific content of dreams plays a role in this sleep-learning process wasn't clear.
To find out, Sidarta Ribeiro and André Pantoja of the Edmond and Lily Safra International Institute of Neuroscience of Natal in Brazil turned to the visceral, monster-filled, first-person shoot-'em-up game Doom.
This ice will lie next to the northern coasts of Greenland and the Canadian Arctic archipelago, the region where the oldest and thickest ice now occurs. This region will therefore offer at least a limited sanctuary for species that prefer, or rely on, year-round sea ice. Projections published in February indicate that by the middle of the century optimal polar bear habitat will have disappeared across most of the Arctic, but will persist north of the Canadian Arctic archipelago and Greenland.
The continued existence of this habitat lays the foundation for the long-term survival of ice-dependent species. But to ensure they do survive, we urgently need to draw up a management plan. As ice-covered areas open up, the Arctic will experience more human activity than ever before.
New developments in shipping, tourism and resource extraction, for example, will put pressure on ecosystems already struggling to adapt to environmental changes. We need to start an international assessment now, before Arctic countries establish their development schemes.
The management plan will have to extend to cover the "ice shed" that delivers ice to the region. Our research indicates that, in the past, some of the ice was formed locally, but some of it also drifted in from the central Arctic and as far away as the continental shelf waters of northern Alaska and north-eastern Russia. Even when most of the sea ice is gone in the summer, ice formed in the winter will be transported by wind and ocean currents into this region.
Because sea ice is dynamic, we will need an international system of monitoring and managing the remaining habitat and the areas that supply its ice. If we are able to do this successfully, we could maintain a viable habitat for polar bears and other species for decades into the future.
Three examples are shown here. Edward Burtynsky's work is informed by the transformation of nature by colossal industrial processes, and exposes the detachment most of us have from them. His Quarries series of precisely framed photographs of mines, including this one in Portugal (far right), reveals the massive scale of these operations.
The landscapes Darren Almond calls Fullmoons (lower left) are from the Huangshan region of Anhui province in China, an area that inspired "shan shui" (the term translates as "mountain water") landscape painting. They get their eerie beauty from being shot as very long exposures, lit only by moonlight.
Tokyo-based Naoya Hatakeyama's Blast series (upper left) captures the moments following blasting in limestone quarries in Japan, using a high-speed remote-controlled camera. Hatakeyama examines the past, present and future of the city and its relationship with nature. The thread running through his work is building materials - from raw materials via processing to construction and ultimately demolition.
For years women seeking to get pregnant have been advised by friends and family to stop stressing about it - an idea that not all obstetricians and gynaecologists have embraced.
But research presented at a meeting of the American Society for Reproductive Medicine in Atlanta suggests there may be something to it.
Dr Alice Domar, who runs a fertility centre in Boston and also works at Harvard Medical School, found that women who took part in a stress management program while having a second round of assisted fertility treatment had a greater chance of falling pregnant than women getting IVF alone.
"Reproductive health experts have long wondered about the impact that stress may have on fertility, thus impeding a woman's ability to conceive," says Domar.
"This study shows that stress management may improve pregnancy rates, minimising the stress of fertility management itself, improving the success rates of IVF procedures, and ultimately, helping to alleviate the emotional burden for women who are facing challenges trying to conceive."
Second try charm
She and colleagues randomly assigned 97 patients at the clinic to take part in a 10-session mind/body program while undergoing in-vitro fertilisation treatments.
The program had no effect on how many women conceived during the first attempt, Domar told the meeting, with 43% of the women getting pregnant.
But for women who failed the first time and were having a second attempt, 52% who took part in the mind/body program became pregnant, compared to only 20% of those who did not.
"It's clear based on this carefully designed study, that a holistic approach to infertility care leads to better outcomes for patients," says Dr R Dale McClure, president of the American Society for Reproductive Medicine.
But a second study found that while complementary and alternative medical therapy was popular among couples getting infertility treatments, it did not make women any more likely to get pregnant.
A team at the University of California, San Francisco questioned 431 couples undergoing infertility therapy and found that 28% had tried some kind of alternative medicine, mostly acupuncture or herbs, but they were not any more likely to achieve pregnancy.
Pedestrians who talk on a mobile phone are slower, change direction more, have difficulty navigating and are less likely to notice obvious distractions like a unicycling clown, according to a new study.
Researchers at Western Washington University observed 317 pedestrians as they crossed the main square of the campus along the 114 metre long main diagonal pathway.
The people observed were either talking on a mobile phone, listening to a personal music player, in conversation with another pedestrian, or walking alone, without any electronic devices.
The researchers noted the time it took them to cross the square, whether they stopped, zig-zagged or stumbled; how many times they changed direction, and whether they collided with another person, or nearly did.
The pedestrians were also monitored to see if they noticed the "unusual stimulus" the researchers had placed just off the walking path: a brightly-coloured unicycling clown.
"Unicyclists are very rare on campus pathways," wrrte the authors of the study, which will be published in the December issue of Applied Cognitive Psychology.
Only 25% of people using their mobile phones noticed the clown, while more than half of people in the other groups noticed him.
Failure to see the clown could not be blamed on the use of an electronic device per se, because 61% of people using a music player saw the unicyclist. It couldn't be blamed on having a conversation either: chatting couples were the most likely (71%) to see the clown.
Instead, the study suggests that mobile phone users fail to notice what is going on around them, a phenomenon called "inattentional blindness."
"This means that they may miss more than the unicycling clown and experience difficulty recognising and using information needed to navigate through a complex and changing environment."
They go on to write that this might not be overly dangerous when walking in a pedestrian zone, but can be when bikes or cars are introduced into the equation, or the mobile phone user is driving.
Should that future arrive, the society reluctantly recommends seriously considering the following five global-cooling ideas.
Even so, the scientists caution that such projects would likely cost many billions—or even trillions—of U.S. dollars and could spark fights over who would control the planet's thermostat.
"The greatest challenges to the successful deployment of geoengineering may be the social, ethical, legal and political issues," the report says, "rather than scientific and technical issues."
Volcanic eruptions can quickly cool the planet by spewing tiny droplets containing sulfur dioxide into the atmosphere, where they reflect some of the sun's rays back into space.
(See "Extreme Global Warming Fix Proposed: Fill the Skies With Sulfur.")
Researchers have proposed fighting global warming with their own "flying volcanoes"—jets or balloons that release similar droplets. (Related: "'Volcano Cure' for Warming? Not So Fast, Study Says.")
Millions of tons of these droplets would need to be sent into the air every year to cancel out current global warming, at a cost of tens of billions of U.S. dollars, the report estimates. Even so, the flying volcanoes would be one of the most cost-effective types of geoengineering.
Because of the droplets' rapid cooling effect, they "could be useful in an emergency, the reports says, for example to avoid reaching a global warming 'tipping point'," such as the thawing of the Arctic. Widespread thawing of permafrost could release huge amounts of methane—a powerful greenhouse gas—causing even more global warming.
Human fat is "an abundant natural resource and a renewable one," said Stanford University plastic surgeon Michael Longaker, whose liposuction patients donated the fat for the study.
Longaker envisions a future in which doctors will be able to use fat from a patient to grow, in a lab, new tissues and organs for that patient.
The opportunity wouldn't be limited to the obese.
"Even if you're in great shape, there is still enough fat to be harvested from the vast majority of patients," added Longaker, who co-authored the study.
From Fat to Stem Cells to New Organs?
The reprogrammed cells, called induced pluripotent stem cells, or iPS cells, are capable of turning into most types of cells in the body.
Scientists are keen to obtain these cells to study disease and, one day, use them to grow new tissue and replacement organs.
Previously, researchers had shown that they could derive this type of stem cell from ordinary skin cells.
But the fat technique is about twice as fast and 20 times more efficient, said Joseph Wu, the study's senior author.
The flight, scheduled for next week, comes as the Obama administration considers whether to continue the Ares 1 rocket program.
Besides positioning crews in Earth orbit for transport to the Moon, Ares 1 is intended to serve as a taxi for the International Space Station.
Competing concepts endorsed by a presidential review of NASA's human space program include launching astronauts on commercial vehicles, such as Space Exploration Technology's Falcon 9 rocket, which is scheduled for a debut flight in late 2009 or early 2010.
NASA has spent nearly four years and US$350 million (AU$377 million) on a predecessor rocket, known as Ares 1-X. The 99 metre tall vehicle, the tallest rocket made since the 1960s-era Saturn rocket, was hauled out to a refurbished space shuttle launch pad at the Kennedy Space Center in preparation for liftoff - no earlier than 11:00pm, 27 October (AEDT).
Even if Ares 1 is cancelled, NASA says, the flight is crucial.
"It's been a long time since NASA built a new vehicle," says mission manager Bob Ess. "The whole purpose of this test is to get information so we understand and can correlate our computer models. From that, we learn how to use that data for the next launch vehicle."
About 40% of new rockets fail on their debut launches, but NASA is so confident in its test vehicle that it cleared the space shuttle Atlantis to be on a second pad just 2.4 kilometres away during the Ares 1-X flight.
The shuttle is being prepared for a space station outfitting mission in November.
"My personal opinion is that if we really thought that 1-X was going to have a problem, then we're not ready to go launch, even on a test flight," says shuttle program manager John Shannon.
Shannon adds that he believes the 40% failure rate does not apply to Ares 1-X since the rocket is based on the space shuttle solid-fuel boosters, which have been flying since 1981.
Those boosters, however, have only flown in pairs and are part of a larger launch system that includes three liquid hydrogen-fuelled engines mounted at the rear of the shuttle.
"The point of the (demonstration) flight is to verify that we can steer a rocket this tall, this shape, this weight," says deputy mission manager Jon Cowart.
The test vehicle is outfitted with more than 700 sensors to relay data during the flight. The booster will fire for 2.5 minutes, just like the shuttle boosters do, then parachute down into the Atlantic Ocean for recovery. The flight also will test the new, larger parachutes designed for the Ares 1 rocket.
If Ares 1-X fails its debut, NASA says that shouldn't affect debate about whether to continue the Ares 1 program.
"You should never not test because you're worried about the outcome," says space station program manager Mike Suffredini. "Personally I'm not aware of anybody that's waiting for this test to decide the outcome of Ares 1."
It's long been known that the female redback who is roughly twice the size of her male counterpart, regularly eats a number of her male courtiers, although exactly what determines who gets eaten has been unclear.
New Canadian research suggests that it depends on whether the female has been satisfied by the duration of the stimulatory courtship, which entails the male vibrating the female's web for approximately 100 minutes.
The report appears in the latest edition of the journal Proceedings of the Royal Society B.
Parasites of love
Once the threshold has been reached, a female is unlikely to eat the male upon copulation. She is also unlikely to eat other males who attempt to mate with her, whether or not they were involved in the courtship.
University of Toronto researchers Jeffrey Stoltz and Dr Maydianne Andrade, point out that it means that weaker - and perhaps smarter - males can exploit the courtship work of their rivals.
But in the end, they say the best odds for a redback male to mate successfully and avoid being eaten afterwards are when he has the female all to himself and can perform the vibrating courtship at length and uninterrupted.
The work was able to be done using a cluster of redbacks originally imported from Australia, but now living, breeding and cannibalising each other in the Ontario laboratory.
The redback mating process is full of curiosities including that the tips of the male mating organs are broken off inside the female after copulation.
It's thought that this occurs in order to plug the female genitalia to prevent other males from depositing their sperm.
The female produces a number of batches of eggs from that sperm deposit during her lifespan.
Having lost their mating organs, it had been thought that the males offered themselves to be eaten by the female to ensure she had the strength to go on and produce the next generation.
The theory was that a male's strength and size determined whether he survived the ordeal to copulate again.
The work published in today's edition of the journal Science, outlines how the disease caused by the fungus Batrachochytrium dendrobatidis, causes a loss of electrolytes which in turn saps muscle power throughout the frog, eventually stopping the heart.
The finding is seen as an important step towards better understanding the disease which has contributed to the extinction of nine frog species in Australia and 200 worldwide.
The disease affects the frog's skin and its symptoms include difficulties in balance, problems in motor skills, convulsions and paralysis.
Limited treatments for the condition are available, but before now it was not known how the fungus led to death as it did not appear to damage any of the internal organs.
Theories have ranged from suffocation as a result of the skin damage, to poisoning by a paralysing toxin secreted by the fungus, or a fatal immune reaction.
Affected heart muscles
In 1998, Dr Lee Berger of James Cook University in Townsville led the research that identified the fungus disease for the first time. She was also involved in the most recent work by Australian and US researchers, led by Dr Jamie Voyles of James Cook University.
"We did blood tests and they showed that all the organs were working as they should do and all the levels were normal, except for electrolytes, especially sodium and potassium, which are really vital to lots of functions of the cells," says Berger.
She says the disease reduced the concentration of sodium and potassium in infected green tree frogs by 20% and 50% respectively.
Electrolytes are essential for nerves and muscles to work properly. Tiny cardiac electrograms showed that as the concentrations reduced, the frogs' hearts slowed and eventually stopped.
The researchers were also able to show that by providing affected frogs with an electrolyte supplement their symptoms improved significantly.
"By understanding how they die it could potentially be useful in working out why some frogs can survive," says Berger.
Step back 150 million years and Spitsbergen was covered by a cool, shallow sea swarming with marine reptiles. The creatures died out and their fossils became part of an island stuffed full of bones. Nowhere else in the world are so many marine reptiles found in one place.
For a few short weeks the sun never sets and temperatures soar to just above freezing. Knowing that before long the ground will be frozen solid, the researchers dig like crazy. "It's like a gold rush, there are so many fossils waiting to be found," says team leader Jørn Hurum. "The site is densely packed with skeletons. As we speak there are probably more than 1000 skeletons weathering out."
Hurum's Arctic discoveries are part of a remarkable renaissance in interest in the marine reptiles of the Mesozoic era, 251 to 65 million years ago – including this week's announcement of a colossal new marine reptile from the "Jurassic coast" of Dorset in southern England. We now know more about this group of creatures than ever before.
Marine reptiles were among the first vertebrate fossils known to science and were key to the development of the theory of evolution. In the late 18th century the massive jaws of a lizard-like beast were found in a mine in Maastricht in the Netherlands. Later named Mosasaurus, the creature helped convince scientists that animals could become extinct, a radical concept in its day. In the early 19th century, ichthyosaurs and plesiosaurs discovered by legendary fossil hunter Mary Anning around Lyme Bay in south-west England helped establish the science of palaeontology. Marine reptiles were among the best-understood extinct creatures of the first half of the 19th century and played a major role in the intellectual debate nurturing Darwin's theory of evolution.
Yet they faded from view as their terrestrial relatives moved to centre stage. It took nearly a century for marine reptile research to emerge from the shadow cast by the dinosaurs. "Scientists thought they knew all there was to know," says plesiosaur expert Leslie Noè of the Thinktank museum in Birmingham, UK. "The idea was that they weren't worth studying. Nobody would say that now. Our understanding of marine reptiles is phenomenally greater now than it was even 10 years ago."
In the modern world, marine reptiles are few and far between: saltwater crocodiles, turtles and sea snakes are rarities of coastal waters. However, in the ice-free greenhouse of the Mesozoic, reptiles cruised the oceans from pole to pole, occupying the ecological roles now largely filled by whales, dolphins, porpoises, seals and even sharks.
The recently unearthed fossil is the size of a squirrel and would have dined on fruit and insects 150 million years ago.
Scientists say Fruitadens haagarorum is the world's smallest known ornithischian dinosaur, a group that included horned, duck-billed and armored dinosaurs, along with many other diverse species.
"The smallest known dinosaurs - just slightly smaller than Fruitadens - are from China and they represent some of the closest relatives of birds," says co-author Dr Luis Chiappe.
"(The new dinosaur) may look bird-like because of its size, but in fact it isn't very closely related to birds or Archaeopteryx (the world's first known bird)," says Chiappe, who is director of the Natural History Museum's Dinosaur Institute in Los Angeles.
He and an international team of experts describe the new species in the latest Proceedings of the Royal Society B.
The dinosaur's name was not inspired by edible fruit, but instead by the Fruita Paleontological Area in Colorado, where its remains were discovered.
Fruits were probably on its menu, however, along with eggs and almost anything else it could get in its mouth.
"The shape of Fruitadens' teeth suggests it was probably eating both plants and small animals, that is insects," says co-author Dr Laura Porro.
She says that in addition to being an ornithischian dinosaur, it was also a member of a family of dinosaurs called heterodontosaurids, meaning "different-toothed lizards." The teeth of these dinosaurs, like those of fellow omnivore humans, erupted in different shapes, with some resembling canines, others looking like molars and so on.
Most modern reptiles, such as alligators and iguanas, have more uniform teeth.
Relatives of Fruitadens, which have been found in England, South Africa and other countries, lived when "all continental land masses were connected into a single, giant continent called Pangea," says Chiappe.
Some of these dinosaurs probably then travelled to North America, explaining how the bones of the tiny dinosaur wound up in Colorado.
"Colorado is the place where the rocks containing the fossils of Fruitadens are exposed, but presumably the species lived elsewhere in North America," he says, mentioning that it would have coexisted with other, much larger dinosaurs, such as Diplodocus and Brachiosaurus.
The research, published in today's edition of Nature Photonics, could inspire the next generation of liquid crystal displays and DVD devices.
Marine biologist Professor Justin Marshall of the University of Queensland says mantis shrimps have eyes made up of hundred of individual compartments.
He says each compartment has a photoreceptor in it, which he says detect visible light and turn it into a signal the brain can read.
But Marshall says mantis shrimp also have a special group of photoreceptors, known as R8 cells, which can also detect UV and polarised light.
Polarised light is light that is travelling in one plane, as compared to non-polarised light, like that from the Sun or a light bulb, which travels in all planes.
Marshall says polarised light comes in two forms, linear and circular.
Linear polarised light vibrates, says Marshall, because humans don't have a polarising filter in their eyes, light travelling in multiple linear planes appears as glare.
"Polarised sunglasses cut down glare and allow us to see into water."
Marshall says, unlike most other animals, shrimp have sophisticated eyes they can turn linearly polarised light into circular polarised light and vice versa.
To do this, R8 photoreceptor cells act as quarter-wave retarders, which alters the plane of the polarisation as the light travels through it, he says.
"They do that in order for the cells beneath them to pick up circular polarised light - it's a co-operative filtering."
Marshall says quarter-wave retarders use the same process of turning linearly polarised light to circular polarised light as in CD and DVD players.
But he says these artificial devices are far less efficient than the shrimp's biological mechanism.
"We don't fully understand how they do it, but it's got to do with the structure of the R8 cells."
Contrary to popular belief, no federal rule mandates that U.S. states or territories observe daylight saving time.
Most U.S. residents set their clocks one hour forward in spring and one hour back in fall. But people in Hawaii and most of Arizona—along with the U.S. territories of Puerto Rico, American Samoa, and the Virgin Islands—will do nothing. Those locales never deviate from standard time within their particular time zones.
The federal law first passed in 1918 and, thanks to a 2005 revision that went into practice in 2007, now stipulates areas that observe daylight saving time must switch back to standard time at 2 a.m. on the first Sunday in November. (Read about the 2007 daylight savings time change and its purported energy savings.)
Likewise, the new daylight saving time rule requires that regions that observe daylight saving time begin at the same time on the second Sunday in March.
The Dawn of Daylight Saving Time
The U.S. Naval Observatory in Washington, D.C., sets what is known as standard time in the country through its maintenance of atomic clocks. But the observatory has nothing to do with regulating daylight saving time.
Oversight of daylight saving time first resided with the Interstate Commerce Commission. In 1966 the U.S. Congress transferred that responsibility to the newly created Department of Transportation.
Congress ordered the transportation agency to "foster and promote widespread and uniform adoption and observance of the same standard of time within and throughout each such standard time zone."
So why is a transportation authority in charge of time laws? It all dates back to the heyday of railroads.
"In the early 19th century … localities set their own time," said Bill Mosley, a public affairs officer at the U.S. Department of Transportation.
"It was kind of a crazy quilt of time, time zones, and time usage. When the railroads came in, that necessitated more standardization of time so that railroad schedules could be published."
In 1883 the U.S. railroad industry established official time zones with a set standard time within each zone. Congress eventually came on board, signing the railroad time zone system into law in 1918.
The heat is transmitted to a Stirling engine that transforms it into mechanical power to generate electricity.
The new SunCatcher design is being developed by the US firms Stirling Energy Systems (SES), based in Phoenix, Arizona, and Tessera Solar, based in Houston, Texas.
Pros: Can track the sun, operates at high temperature (around 790 °C), high heat-to-electricity conversion, modular and easily expandable, low water requirement.
Cons: No commercial installations, cannot store heat, cannot produce in low sunlight or at night.
In 2003, the Wilkinson Microwave Anisotropy Probe found a patch of particularly energetic microwave radiation in the centre of our galaxy - dubbed the "WMAP haze". It was proposed that this could be caused by collisions of a new type of dark-matter particle.
Instead, the signal could be produced by amplified cosmic rays generated when particularly large stars explode, says Peter Biermann of the Max Planck Institute for Radioastronomy in Bonn, Germany, and colleagues.
The centre of our galaxy has a high number of massive stars compared with elsewhere. These stars are surrounded by particularly strong magnetic stellar winds. At the star's polar regions, the wind's magnetic field is parallel to the direction of travel of any escaping cosmic rays kicked out by the supernova. This configuration - plus the particularly high turbulence in the galactic centre caused by the high concentration of stars - may be increasing the energy of the cosmic rays, says the team. They have submitted the paper to The Astrophysical Journal.
Dan Hooper at the University of Chicago points out that while it's prudent to consider scenarios other than dark matter as a cause, very little is known about the inner region of our galaxy and the magnetic fields there.
A man wrapped in a wet suit slid belly down near the crowd of 200 people gathered at Christopher Columbus Park, home to one of more than 5,200 events in 181 countries organized for the 350.org International Day of Climate Action.
“I want the earth to survive,’’ said 60-year-old Susan McLucas, a red snorkel pushing up her gray hair. “I don’t want our children and grandchildren to have to rush for higher ground.’’
As people hoisted green and yellow kayaks in the air, Seth Itzkan of Medford held a hockey stick and a poster that read: “Bring back the ice!’’
“People need to understand how important ice is to our climate,’’ Itzkan said. “We need a healthy North Pole.’’
Billed as the world’s largest political environmental effort, yesterday’s events sought to push 350 - the parts per million some leading scientists say is the safe limit for carbon dioxide in the atmosphere - into the spotlight. (The carbon dioxide rate hung at 387 parts per million yesterday, according to 350.org.) Industrial pollution kicks up the rate.
The international gatherings, organized by 350.org founder and Lexington native Bill McKibben, ranged from a submerged group of scuba divers in the Great Barrier Reef in Australia to a potluck in Wellfleet.
“We’re taking the most important number in the world and trying to make it the most well known,’’ said McKibben, who was interviewed by phone yesterday from New York.
Red-shirted climbers in Middlebury, Vt., took their cause to the hills, forming a large 3, 5, and 0 on a craggy mountain.
While the Orionids are not as flashy as some other meteor showers, she said, "it's a known shower that comes along regularly, … and the moon will be down, so that will help."
A big, bright moon can make it hard to spot streaking meteors. But the moon will be new during this year's Orionids peak, she said, meaning it'll be dim and will dip below the horizon not long after sunset.
Orionids' "Very Recognizable" Region
The Orionids are so named because the meteors appear to radiate from near the constellation Orion, aka the Hunter.
This easily spotted constellation "kind of looks like an hourglass with a very recognizable belt of stars," said astronomer Mark Hammergren of the Adler Planetarium in Chicago.
(Related: "Famous Star Is Shrinking, Puzzling Astronomers.")
In addition, "the constellation is visible from pretty much anywhere in the world, because it appears along a line of sight close to the Equator," he said.
How to See the Orionids
At this time of year, Orion rises at about 11 p.m. local time worldwide, so the best time to view the Orionids will be after midnight, Hammergren said.
For the best views, Hammergren and Cochran both recommend going to a dark site away from city lights and allowing enough time for your eyes to adjust to seeing fainter objects in the sky.
"You don't need binoculars," Cochran added. "Just lie back in a reclining chair or on a blanket and enjoy the show."
But dress warmly, Hammergren advised: "You always cool off more than you think you will just lying there—that's a lesson novice astronomers learn real fast!"
"Conceptually, protons which come from the solar wind get absorbed by the surface [of the moon], and they may interact with oxygen, which is in minerals there" to produce water and hydroxyl, said Stas Barabash, of the Swedish Institute of Space Physics in Kiruna.
"Much more research is needed to prove or disprove this idea," he cautioned. (See pictures of moon exploration.)
But in an unexpected twist, data from India's Chandrayaan-1 moon probe show that one out of every five protons that impacts the moon gets bounced straight back into space. Previously astronomers had thought that virtually all solar particles that reach the moon are absorbed by the lunar soil.
(Related: "India's First Moon Probe Lost, But Data May Yield Finds.")
Like taking photographs by capturing light bouncing off an object, Barabash and colleagues hope to make a new class of images by mapping where these rejected protons are bouncing off the moon.
"This method provides a way to really see what happens when the solar wind impacts the surface," Barabash said.
When a proton bounces off the moon, it picks up an electron from the lunar surface and becomes a neutral hydrogen atom.
"Because they are neutral, they are not affected by any electromagnetic forces … and the [moon's] gravitational force affects them so little that they continue moving straight forward," Barabash said.
Since the atoms are such straight shooters, they should provide a highly accurate picture of which places on the moon are being most affected by solar wind.
For example, some pockets of the moon have local magnetic fields that shield them from solar wind. These areas wouldn't absorb or reflect protons and so would show up in the new maps as dark spots.
The method should also apply to other solar system bodies that have thin atmospheres, Barabash added.
A similar instrument to the one Chandrayaan-1 used to record the bouncing protons is on the European Space Agency's BepiColombo spacecraft, due to set off toward Mercury in 2013.
The 32 previously unseen planets range from five times the mass of Earth up to eight times the mass of Jupiter, scientists said.
In addition, the new planets were found around different types of stars, challenging existing theories for where and how planets form.
Overall, the research suggests that 40 to 60 percent of all planetary systems in the universe contain low-mass planets.
Since lower masses most likely mean Earthlike sizes, such planets are considered to be the best candidates in the search for extraterrestrial life. (Related pictures: "3 Worlds Most Likely to Harbor Life Named.")
"The models are predicting even larger numbers of low-mass planets like Earth, so I am pretty confident that there are Earth-type planets everywhere," said team member Stephane Udry of the Observatory of Geneva in Switzerland.
"Nature doesn't like a vacuum," he added, "so if there is space to put a planet, it will put the planet there."
New Planets: Super-Earths, Gas Giants
The 32 new planets were found over the past five years using an instrument called a spectrograph at the European Southern Observatory in La Silla, Chile.
Known as HARPS, for High Accuracy Radial velocity Planetary Searcher, the spectrograph detects wobbles in a star's orbit caused by the pull of an unseen exoplanet.
The HARPS team selected stars like our sun, as well as lower-mass dwarf stars, to watch for wobbles.
Red dwarf stars were targets because they are dimmer, low-mass stars, which makes it easier to detect wobbles from low-mass satellite planets, said team member Nuno Santos, of the University of Porto, Portugal.
The 32 newfound exoplanets include several super-Earths, such as two planets no more than five times Earth's mass and two about six times Earth's mass, the Observatory of Geneva's Udry said.
The largest newly discovered exoplanet is a monster at seven to eight times Jupiter's mass, he estimated.
In addition, several Jupiter-mass planets were found around stars that don't have many metals.
Previous theories had stated that planets wouldn't tend to form around metal-poor stars, since planets are thought to take shape inside the metal-filled disks of debris left over from stellar birth.The new finds suggest that astronomers might need to revise theories of planet formation—and may increase the number of possible star systems in the universe