A new study cites spikes of ammonium in Greenland ice cores as evidence for a giant comet impact at the end of the last ice age, and suggests that the collision may have caused a brief, final cold snap before the climate warmed up for good. sciencenewsIn the April Geology, researchers describe finding chemical similarities in the cores between a layer corresponding to 1908, when a 50,000-metric-ton... 

Bats are nocturnal, but some need sunlight to set their internal compass. “Recent evidence suggests that bats can detect the geomagnetic field,” wrote Max Planck Institute ornithologists Richard Holland, Ivailo Borissov and Bjorn Siemers in an article published March 29 in the Proceedings of the National Academy of Sciences. “We demonstrate that homing greater mouse-eared bats calibrate a magnetic... 

Early this morning, two proton beams collided in the Large Hadron Collider’s 17-mile-long ring at a combined energy of 7 TeV, three times higher than ever before. Finally, the flood of data particle physicists have been anticipating for years for has begun. “It’s a great day  to be a particle physicist,” said General Rolf Heuer, director of CERN where the LHC is located, in a press release... 

Bats can subtly adjust the frequency of the sounds they use to do echolocation to adjust to particularly cluttered terrain. In a laboratory testing room filled with dangling plastic chains, bats wearing tiny, half-gram microphones were recorded flying through the obstacle course. When confronted with the forest of chains, the bats tended to reduce or increase the sounds they emitted by a few kilohertz.... 

Lines at the grocery store might become as obsolete as milkmen, if a new tag that seeks to replace bar codes becomes commonplace. sciencenewsResearchers from Sunchon National University in Suncheon, South Korea, and Rice University in Houston have built a radio frequency identification tag that can be printed directly onto cereal boxes and potato chip bags. The tag uses ink laced with carbon nanotubes... 

A new member of the human evolutionary family has been proposed for the first time based on an ancient genetic sequence, not fossil bones. Even more surprising, this novel and still mysterious hominid, if confirmed, would have lived near Stone Age Neandertals and Homo sapiens. sciencenews“It was a shock to find DNA from a new type of ancestor that has not been on our radar screens,” says geneticist... 

A survey of 200 sites in 20 countries around the world has found that bisphenol A, a synthetic compound that mimics estrogen and is linked to developmental disorders, is ubiquitous in Earth’s oceans. Bisphenol A, or BPA, is found mostly in shatter-proof plastics and epoxy resins. Most people have trace amounts in their bodies, likely absorbed from food containers. Its hormone-mimicking properties... 

Hot water really can freeze faster than cold water, a new study finds. Sometimes. Under extremely specific conditions. With carefully chosen samples of water. sciencenewsNew experiments provide support for a special case of the counterintuitive Mpemba effect, which holds that water at a higher temperature turns to ice faster than cooler water. The Mpemba effect is named for a Tanzanian schoolboy,... 

Geologists have turned a series of 200 million-year-old lake-bed sediments into an epic narrative of the dinosaurs’ journey from ecological obscurity to Earthly supremacy, a mystery that has lingered even as their disappearance is explained. The dino path to dominance appears to have been cleared when the supercontinent Pangea cracked, setting off 600,000 years of volcanic activity that wiped out... 

Despite a penchant for hanging out in trees, human ancestors living 3.6 million years ago in what’s now Tanzania extended their legs to stride much like people today do, a new study finds. If so, walking may have evolved in leaps and bounds, rather than gradually, among ancient hominids. sciencenewsThe discovery comes from the famed trackway site in Laetoli, Tanzania, where more than 30 years ago... 

The Planck space telescope, which is surveying the entire sky in four massive sweeps, has nearly finished its first scan. Rotating in orbit, Planck takes data of the sky in strips, almost the reverse of a chef peeling an apple in one long, thin strip. This image, taken from the scan, shows the structure and form of dust clouds within about 500 light-years of the sun. The bright band in this far-infrared... 

The Large Hadron Collider set a new record for the creation of energetic particle beams this morning. The particle accelerator, which surpassed Fermilab’s Tevatron in December as the baddest atom smasher of them all, smashed its own record, charging particles to 3.48 trillion electron volts. That’s three times the energy of any beam ever created by human beings and just a shade under half the... 

Paleontologists have stumbled across a scientific first that’s sure to inspire both fascination and disgust: coprolites, or fossilized fecal matter, bearing the distinct impressions of a creature’s teeth. sciencenews The coprolites — one chunk of rock is fist-sized, the other is about 30 percent larger — were discovered on a beach along the western shore of Chesapeake Bay, says Stephen Godfrey,... 

A bitter controversy is brewing over a captive colony of endangered Virginia big-eared bats, founded in November as a hedge against disease driving the species to extinction in the wild. Of 40 bats put in the colony, only 10 have survived. According to environmental activists and a consultant to the project, their demise wasn’t just an unfortunate consequence of the animals’ sensitivity, but a... 

Extrasolar planet hunters are excited about a not-so-hot discovery. For the first time, they’ve found a relatively cool extrasolar planet that they can study in detail. sciencenews The finding is a milestone, says study co-author Hans Deeg of the Instituto de Astrofísica de Canarias in Tenerife, Spain, because it is the first time astronomers have found an extrasolar planet that not only is cool... 

The best thermal images of Jupiter’s Great Red Spot yet captured have revealed surprising weather and temperature variation within the solar system’s most famous storm. The darkest red part of the spot turns out to be a warm patch inside the otherwise cold storm. The temperature variation is slight: “Warm” in this case translates to -250 degrees Fahrenheit while cold is an even frostier -256... 

A fierce attempt to keep endangered Virginia big-eared bats alive in captivity has shown just how difficult that noble task may be. The effort was prompted by the discovery of white nose syndrome, an extremely virulent disease that has killed more than a million bats since 2007, in one of the handful of caves where Virginia big-eared bats live. Of 40 bats moved to the Smithsonian National Zoo last... 

A one-of-a-kind killer whale population appears to be threatened by human appetites for Antarctic toothfish, better known to restaurant-goers as Chilean Sea Bass. As fishing fleets patrol their waters, catching what was their primary source of food, the whales are vanishing. It’s not certain whether they’ve only moved on, or are dying out, or both. But something is happening, with potentially... 

SALT LAKE CITY — Nearly two decades after vets began returning from the Middle East complaining of Gulf War Syndrome, the federal government has yet to formally accept that their vague jumble of symptoms constitutes a legitimate illness. Here, at the Society of Toxicology annual meeting, yesterday, researchers rolled out a host of brain images — various types of magnetic-resonance scans and brain-wave... 

Wind power has made incredible inroads into the U.S. energy system thanks to big, efficient machines standing hundreds of feet tall. But the future of wind power may be underground. In the abandoned mines and sandstones of the Midwest, compressed-air storage ventures are trying to convert the intermittent motions of the air into the kind of steady power that could displace coal. Compressed-air energy...