NASA Urges Vigilance For Weird Fireballs

A strange breed of fireball is streaking through the skies this month, and NASA is urging folks on the ground to take notice.

February's fireballs -- a term that describes meteors that appear brighter in the sky than Venus -- aren't more numerous than normal, but their appearance and trajectory are odd, experts say.

"These fireballs are particularly slow and penetrating," meteor expert Peter Brown, a physics professor at the University of Western Ontario, said in a statement. "They hit the top of the atmosphere moving slower than 15 kilometers per second (33,500 mph), decelerate rapidly and make it to within 50 kilometers (31 miles) of Earth’s surface."

Beginning February With a Bang

The month's fireball action began on Feb. 1, when a meteor lit up the skies over central Texas, putting on a dazzling show for people in the Dallas-Fort Worth area.

"It was brighter and long-lasting than anything I've seen before," said eyewitness Daryn Morran. "The fireball took about eight seconds to cross the sky. I could see the fireball start to slow down; then it exploded like a firecracker artillery shell into several pieces, flickered a few more times and then slowly burned out."

The fireball was about as bright as the full moon, and was spotted by NASA cameras in New Mexico, more than 500 miles (805 km) away. It was likely caused by an object 3 to 6 feet (1 to 2 meters) wide, NASA researchers said.

And the meteors have kept coming, well into February.

"This month, some big space rocks have been hitting Earth's atmosphere," said Bill Cooke of the Meteoroid Environment Office at NASA's Marshall Space Flight Center in Huntsville, Ala. "There have been five or six notable fireballs that might have dropped meteorites around the United States."

Oddball Fireballs

So far in February, NASA's All-Sky Fireball Network -- which currently consists of six cameras set up in Georgia, Alabama, Tennessee and New Mexico -- has photographed about half a dozen of these strange slow-moving, deep-diving fireballs. They have ranged in size from basketballs to buses.

Cooke has analyzed their orbits and determined where the strange meteors are coming from.

"They all hail from the asteroid belt, but not from a single location in the asteroid belt," he said. "There is no common source for these fireballs, which is puzzling."

The "fireballs of February" have puzzled astronomers for decades. Skywatchers first noticed an increase in the number of deep-penetrating, bright meteors during February back in the 1960s and '70s, Brown said.

Read more at Discovery News

European Neanderthals Were On the Verge of Extinction Even Before the Arrival of Modern Humans

New findings from an international team of researchers show that most Neanderthals in Europe died off around 50,000 years ago. The previously held view of a Europe populated by a stable Neanderthal population for hundreds of thousands of years up until modern humans arrived must therefore be revised.

This new perspective on the Neanderthals comes from a study of ancient DNA published February 25 in Molecular Biology and Evolution.

The results indicate that most Neanderthals in Europe died off as early as 50,000 years ago. After that, a small group of Neanderthals recolonised central and western Europe, where they survived for another 10,000 years before modern humans entered the picture.

The study is the result of an international project led by Swedish and Spanish researchers in Uppsala, Stockholm and Madrid.

“The fact that Neanderthals in Europe were nearly extinct, but then recovered, and that all this took place long before they came into contact with modern humans came as a complete surprise to us. This indicates that the Neanderthals may have been more sensitive to the dramatic climate changes that took place in the last Ice Age than was previously thought”, says Love Dalén, associate professor at the Swedish Museum of Natural History in Stockholm.

In connection with work on DNA from Neanderthal fossils in Northern Spain, the researchers noted that the genetic variation among European Neanderthals was extremely limited during the last ten thousand years before the Neanderthals disappeared.

Older European Neanderthal fossils, as well as fossils from Asia, had much greater genetic variation, on par with the amount of variation that might be expected from a species that had been abundant in an area for a long period of time. “The amount of genetic variation in geologically older Neanderthals as well as in Asian Neanderthals was just as great as in modern humans as a species, whereas the variation among later European Neanderthals was not even as high as that of modern humans in Iceland”, says Anders Götherström, associate professor at Uppsala University.

The results presented in the study are based entirely on severely degraded DNA, and the analyses have therefore required both advanced laboratory and computational methods. The research team has involved experts from a number of countries, including statisticians, experts on modern DNA sequencing and paleoanthropologists from Denmark, Spain and the US.

Read more at Science Daily

Large Hadron Collider at CERN: Einstein 'was right all along'

They shocked the scientific world by claiming to have disproved Albert Einstein’s theory of special relativity.

But a report in the Science Insider journal claims that “a bad connection between a GPS unit and a computer” may have affected the reading.

Einstein's theory of special relativity, proposed in 1905, states that nothing in the universe can travel faster than the speed of light in a vacuum.

But researchers at the CERN lab near Geneva claimed they had recorded neutrinos, a type of tiny particle, travelling faster than the barrier of 186,282 miles per second.

Scientists at CERN claimed that neutrinos arrived 60 nanoseconds earlier than the 2.3 milliseconds taken by light.

The report in Science Insider said the "60 nanoseconds discrepancy appears to come from a bad connection between a fiber optic cable that connects to the GPS receiver used to correct the timing of the neutrinos' flight and an electronic card in a computer. "

"After tightening the connection and then measuring the time it takes data to travel the length of the fiber, researchers found that the data arrive 60 nanoseconds earlier than assumed," it added.

"Since this time is subtracted from the overall time of flight, it appears to explain the early arrival of the neutrinos. New data, however, will be needed to confirm this hypothesis."

Read more at The Telegraph

Black Swan Shipwreck Ordeal Comes to End

A fabulous sunken treasure recovered from a Spanish wreck in the Atlantic Ocean is flying back home from the United States, ending a five-year legal battle.

The treasure was put aboard two Spanish military C-130s planes. They took off Friday from a Florida Air Force base with 595,000 silver coins and other gold aboard. They are expected to land in Madrid's Torrejon Air Base after a 24-hour flight after two stops -- New Jersey and the Azores.

"Today a journey that began 200 years ago is finally ending. We are recovering a historical legacy and a treasure. This is not money, is our history," Spain's ambassador to the United States, Jorge Dezcallar de Mazar, was reported as saying as the planes took off.

Consisting of 18t- century silver coins weighing more than 17 tons, hundreds of gold coins, worked gold and other artifacts, the treasure has been at the center of an acrimonious international legal battle ever since it was discovered in 2007 by underwater robots from Odyssey Marine Exploration, a Florida-based treasure-hunting company.

Valued at as much as $500 million -- the richest shipwreck haul in history -- the trove was handled by Odyssey and shipped straight to the United States.

The company, which, according to earnings statements, spent $2.6 million to retrieve, transport, store and conserve the precious cargo, has been unable to remove the silver and gold coins from warehouses at the Numismatic Guaranty Corporation in Sarasota, Fla.

Immediately after the treasure was recovered, Spain filed a claim arguing that the treasure originated from the Nuestra Senora de las Mercedes. This was a 36-gun Spanish frigate which sunk off the coast of Portugal in 1804 with 200 people aboard following a battle with four British Navy ships.

According to an international maritime law known as doctrine of sovereign immunity, active-duty naval vessels on a non-commercial mission remain the property of the countries that commissioned them. Spain thus claimed the exclusive property of the wreck and its cargo.

Odyssey argued there was not enough evidence to prove the wreck, which they codenamed "Black Swan," was the Mercedes and even if that were the case, the ship’s last voyage, from Montevideo to Cadiz, was commercial in nature. The majority of coins on board were owned by private merchants, not by Spain, Odyssey insisted.

After a five-year court battle, and staggering revelations from WikiLeaks documents, a U.S. federal judge established that the United States had no jurisdiction in the case and ordered the treasure returned to Spain by Friday.

For days, a team of Spanish numismatic experts examined the precious coins, overlooking their packing into the same white plastic containers in which the coins were brought to the U.S. in 2007.

The cargo planes took off with the treasure despite an emergency appeal made by Peru to the U.S. Supreme Court on Thursday.

Read more at Discovery News

Dry Spells Caused Mayan Civilization Fall

The collapse of the ancient Mayan civilization may have been linked to relatively modest dry spells, researchers now say.

The ancient Mayan empire once stretched across an area about the size of Texas, with cities and fields occupying what is now southern Mexico and northern Central America, including the countries of Guatemala, Belize, El Salvador and Honduras. The height of the Mayan empire, known as the Classic period, reached from approximately A.D. 250 to at least A.D. 900.

The ancient Maya had what was arguably the most advanced civilization in the Americas. For instance, they made dramatic breakthroughs in astronomy that helped them very accurately predict where the moon and other planets would be in the sky centuries in the future. They also left behind many books and stone inscriptions regarding the stories of their gods and the history of their divine kings and queens.

For unknown reasons, the ancient Mayan civilization then disintegrated more than a millennium ago. The number of people declined catastrophically to a fraction of the empire's former size, and the ruins of its great cities are now largely overgrown by jungle.

Scientists have long drawn connections between the slow decline of the ancient Maya, which took about two centuries, "to climate change, and especially to drought," said researcher Martín Medina-Elizalde at the Yucatan Center for Scientific Research in Mexico. "No sound estimates had been made about the severity of this drought, but some have suggested extreme scenarios."

To see how much rainfall the ancient Maya saw before the demise of their civilization, the researchers combined the four most detailed records of past climate changes known regarding the civilization's collapse — three from nearby lakes and one from a stalagmite, a mineral formation that grows upward from a cave floor. This helped develop a model of "the region's balance between evaporation and rainfall," Medina-Elizalde said.

The scientists found that rainfall in the region decreased episodically for periods as long as a decade at a time.

"Our results show rather modest rainfall reductions between times when the Classic Maya civilization flourished and its collapse between 800 to 950," said researcher Eelco Rohling, a paleoclimatologist at the University of Southampton in England. "These reductions amount to only 25 to 40 percent in annual rainfall, but they were large enough for evaporation to become dominant over rainfall, and open water availability was rapidly reduced. The data suggest that the main cause was a decrease in summer storm activity."

The timing of these dry spells might help explain why modest reductions in rainfall still may have helped cause the demise of a well-established civilization.

"Summer was the main season for cultivation and replenishment of Maya freshwater storage systems and there are no rivers in the Yucatan lowlands," Rohling said.

It appeared to Rohling that the ancient Maya had become reliant on continuous rainfall supplies, and had stretched the capacity of their farmlands to a fine limit based on normal levels of rain. "Then, even a rather subtle climatic change was enough to create serious problems," he told LiveScience. "Societal disruptions and abandonment of cities are likely consequences of critical water shortages, especially because there seems to have been a rapid repetition of multiyear droughts."

Rohling emphasized they are not saying that climate ended the ancient Mayan civilization. "We are documenting that there was a reduction in rainfall, and that reservoirs of water were evaporating," he said. This may in turn have led to societal unrest or diseases or both, "which are more likely to explain the actual collapse of society."

Read more at Discovery News

Did Life Start in a Pond, Not Oceans?

Life may have gotten its start inland, inside ponds of volcanic condensate, not in the oceans.

Modern life is more chemically compatible with conditions in venting geothermal fields, such as Yellowstone National Park, than in the ocean, even a primitive ocean, new analysis shows. The finding challenges a widely accepted theory that modern life began in a marine environment.

The study, led by biophysicist Armen Mulkidjanian with Osnabruck University in Germany, suggests life evolved inside cooled inland ponds formed from condensation from volcanic activity deep inside the Earth. Life later would have spread into the oceans.

Stoking scientists’ interest in the chemical origins of life is a long-standing puzzle about why it has such high amounts of potassium, relative to the amounts of sodium.

“The basic question is whether the observed high potassium-sodium ratio reflect the historical environment in which life originated or underwent early evolution, or instead reflects some underlying chemical necessity, such as better functioning of certain cellular components, such as RNA or protein enzymes in a high potassium environment,” Harvard Medical School biologist Jack Szostak wrote in an email to Discovery News.

The new research provides a possible explanation for the potassium-sodium mismatch. Scientists say the composition of inorganic ions in all modern cells matches the chemistry of geothermal vapor condensate -- not the ocean.

If this vapor condensed into ponds filled with carbon, nitrogen, phosphate and other building blocks for life, the environment would have been a natural starting point for cells to evolve biochemical processes, the scientists say.

In contrast, water of the early oceans should have contained 40 times more sodium than potassium, among other conditions not conducive to the origin of the first cells, Mulkidjanian wrote in an email to Discovery News.

“We have proposed that protocells evolved in habitats with a high potassium-sodium ratio and relatively high concentrations of zinc, manganese and phosphorous compounds,” he said.

o suggest otherwise, he added, means that the first cells already had sophisticated membranes as well as the enzymes to transport and/or block ions.

“We believe that it is too much of a stretch,” Mulkidjanian wrote. “The scenario that we suggest is physically and geochemically plausible.”

Read more at Discovery News

Chemical Clues On Formation of Planetary Systems: Earth 'Siblings' Can Be Different

An international team of researchers, with the participation of IAC astronomers, has discovered that the chemical structure of Earth-like planets can be very different from the bulk composition of Earth. This may have a dramatic effect on the existence and formation of the biospheres and life on Earth-like planets.

The study of the photospheric stellar abundances of the planet-host stars is the key to understanding how protoplanets form, as well as which protoplanetary clouds evolve planets and which do not. These studies, which have important implications for models of giant planet formation and evolution, also help us to investigate the internal and atmospheric structure and composition of extrasolar planets..

Theoretical studies suggest that C/O and Mg/Si, are the most important elemental ratios in determining the mineralogy of terrestrial planets, and they can give us information about the composition of these planets. The C/O ratio controls the distribution of Si among carbide and oxide species, while Mg/Si gives information on the silicate mineralogy. In 2010 Bond et al. (2010b) carried out the first numerical simulations of planet formation in which the chemical composition of the proto-planetary cloud was taken as an input parameter. Terrestrial planets were found to form in all the simulations with a wide variety of chemical compositions so these planets might be very different from Earth.

Delgado Mena et al. (2010) have carried out the first detailed and uniform study of C, O, Mg and Si abundances for 61 stars with detected planets and 270 stars without detected planets from the homogeneous high-quality unbiased HARPS GTO sample. They found mineralogical ratios quite different from those in the Sun, showing that there is a wide variety of planetary systems which are unlike the Solar System. Many planetary-host stars present a Mg/Si value lower than 1, so their planets will have a high Si content to form species such as MgSiO3. This type of composition can have important implications for planetary processes like plate tectonics, atmospheric composition and volcanism.

'There could be billions of Earth-like planets in the Universe but a great majority of them may have a totally different internal and atmospheric structure. Building planets in chemically non-solar environments (which are very common in the Universe) may lead to the formation of strange worlds, very different from the Earth! The amount of radioactive and some refractory elements (especially Si) may have drastic implications for planetary processes such as plate tectonics and volcanic activity,' concludes Garik Israelian.

The latest numerical simulations have shown that a wide range of extrasolar terrestrial planet bulk compositions are likely to exist. Planets simulated as forming around stars with Mg/Si ratios less than 1 are found to be Mg-depleted (compared to Earth), consisting of silicate species such as pyroxene and various types of feldspars. Planetary carbon abundances also vary in accordance with the host stars' C/O ratio. The predicted abundances are in keeping with observations of polluted white dwarfs (expected to have accreted their inner planets during their previous red giant stage).

'The observed variations in the key C/O and Mg/Si ratios for known planetary host stars implies that a wide variety of extrasolar terrestrial planet compositions are likely to exist, ranging from relatively "Earth-like" planets to those that are dominated by C, such as graphite and carbide phases (e.g. SiC, TiC),' Delgado Mena stresses.

The results of Delgado Mena et al. (2010) were used in this study as they are the first to determine the abundance of all of the required elements in a completely internally consistent manner, using high quality spectra and an identical approach for all stars and elements, for a large sample of both host and non-host stars.

Read more at Science Daily

Physicists Pinpoint W Boson, Narrow Search for Higgs

Scientists have produced the most precise measurement of a fundamental particle called the W boson. It will help them search for the elusive Higgs boson, the discovery of which would be an epoch-making event.

The W boson’s new mass is 80.387 giga electron volts, or GeV, plus or minus 0.019 GeV. (Scientists often give a particle’s mass in units of energy because, according Einstein’s famous E=MC² equation, the two are interchangeable.) The most precise previous measurement had an uncertainty of about 0.060 GeV.

At the subatomic scale, such little differences are immense.

The new result is “exquisite” and places the uncertainty “in another category with respect to the past results,” wrote physicist Tommaso Dorigo in his blog. The finding was presented Feb. 23 at the Fermi National Accelerator Laboratory in Illinois.

Researchers with the CDF collaboration at Fermilab produced the estimate using data from the now-closed Tevatron, formerly the world’s premier particle accelerator, where measurements of collisions between protons and antiprotons fired around a 4-mile-long track provide insight into the subatomic world. Though CERN’s Large Hadron Collider has eclipsed the Tevatron, the result shows that the U.S. lab still has a few tricks up its sleeve.

The W boson, along with its counterpart the Z boson, are responsible for carrying the weak force, much the same way that photons convey electromagnetic force. Together with gravity and strong nuclear force, these comprise the four fundamental forces of nature. The W boson’s discovery in 1983 was a major success for the Standard Model, developed by physicists to explain the interactions of all subatomic particles and forces, and its mass is an important input for many nuclear and astrophysical calculations.

It’s also intimately linked to two other subatomic particles: the top quark, the heaviest of the six types of quarks, and the Higgs boson. “If you know the mass of any two, you know the mass of the third,” said physicist Rob Roser, co-spokesman for the CDF collaboration.

That potential extrapolation is crucial. While the Higgs boson has been theoretically predicted to exist, and is believed integral to the very essence of mass, it hasn’t actually been spotted.

Last December, researchers at the Large Hadron Collider saw hints of what may be the Higgs boson, and pegged its mass at about 125 GeV. The extra-precise measurement of the W boson fits with this measurement of the Higgs. The result also means that physicists shouldn’t expect to find the Higgs anywhere higher than 145 GeV.

All eyes are now on this final sliver of energy where the Higgs may be hiding, said physicist Ashutosh Kotwal of Duke University in North Carolina, who presented the latest results from the CDF collaboration. If the Higgs turns up there, it will confirm scientists’ theories. If it doesn’t, they will have to start looking for new, more exotic ways to explain the universe.

“It’s basically make it or break it for the Standard Model,” said Kotwal.

Read more at Wired Science

Stone Age Pebble Holds Mysterious Meaning

A colorful pebble bearing a sequence of linear incisions may be the world's oldest engraving.

The object, which will be described in the April issue of the Journal of Archaeology, dates back approximately 100,000 years ago and could also be the world’s oldest known abstract art. It was recovered from Klasies River Cave in the Eastern Cape Province of South Africa.

“Associated human remains indicate that the engraved piece was certainly made by Homo sapiens,” co-author Riaan Rifkin of the University of Witwatersrand’s Institute for Human Evolution told Discovery News.

Rifkin and colleagues Francesco d’Errico and Renata Garcia Moreno performed extensive non-invasive analyses of the object. Methods like X-ray fluorescence and microscopic analysis enabled the researchers to examine every minute detail of the ochre pebble, which appears to have split off from a once larger piece.

The scientists conclude that humans intentionally made the sub-parallel linear incisions on the Middle Stone Age pebble.

“Upon engraving the piece with a sharp lithic implement, it is likely to have produced a markedly bright and dark red-maroon powder,” Rifkin said. “The design may therefore have been strikingly visible shortly after it was produced.”

Ochre is a mineral-rich, naturally tinted clay that primarily consists of hydrated iron oxide. Ochre was among the earliest pigments used by humans and possibly other hominids for artistic purposes. Some even refer to it as the caveman's "crayon."

The Klasies River object measures close to 3 inches in length and contains a series of seven “deep broad engraved lines and several, about 16 or so, narrower and somewhat shallower linear features,” Rifkin said. “The fragment is a remnant of a formerly semi-circular ochre pebble that likely contained a much more extensive engraved design on its surface.”

Of particular interest now is whether or not the engraver made the design with symbolic intent. Use of symbols and meaningful images is thought to have been a significant breakthrough in human development. Language, math and countless other studies are tied to this basic skill, in addition to improved communication. To this day, art permits communication of identity and other things among diverse cultures.

Both linear and crosshatch engraved patterns may have been common thousands of years ago. Similar designs appear on engraved ochres from Blombos Cave, also in South Africa, and on ostrich eggshell fragments found in the Diepkloof Rock Shelter in the Western Cape Province. Some of these, and other, similar objects may even predate the Klasies River pebble, but studies on them are ongoing.

“The employment of red ochre for symbolic purposes likely played an important role in mediating increasingly complex social relations that emerged during the Middle Stone Age,” Rifkin explained.

Christopher Henshilwood, a researcher at the University of Witwatersrand, did not work on this study, but he has examined other very early probable engravings. For example, he studied abstract markings of another piece of ochre dating to around 70,000 years ago.

In that case, the engraving consisted of a more complex geometric pattern that looks like the letter “X” repeated in a connected series.

Read more at Discovery News

'Little Horny Man:' Oldest Rock Carving of Americas

A stick figure man with a giant phallus dubbed "the little horny man" by its discoverers is the oldest rock carving found yet in the Americas, researchers say.

These findings might shed new light on when the New World was first settled, scientists added.

The time frame during which humans first reached the Americas remains hotly debated. One key to settling this controversy would involve uncovering early examples of human artifacts, such as art.

Scientists discovered one ancient sample of such art in a cave named Lapa do Santo in central-eastern Brazil. The region is home to Luzia, the oldest human skeleton found to date in South America.

Lapa do Santo is one of the largest rock shelters excavated yet in the region, a limestone cave covering an area of about 14,000 square feet (1,300 square meters). Here, researchers have found buried human remains, tools made of stone and bone, ash from hearths, and leftovers from meals of fruit and small game.

In 2009, digging about 13 feet (4 meters) below the surface, the scientists found a rock carving or petroglyph of a man packed into the side of the cave. The figure, which appears to be squatting with his arms outstretched, is about 12 inches (30 centimeters) tall from head to feet and about 8 inches (20 centimeters) wide.

"We discovered this petroglyph in the final moments of excavation at the site," said researcher Walter Alves Neves, an archaeologist and biological anthropologist at the University of São Paulo in Brazil.

The engraving is also depicted with a relatively oversized phallus about 2 inches (5 cm) long, or about as long as the man's left arm.

"We named the figure 'the little horny man,'" Neves said.

"The figure is probably linked to some kind of fertility ritual," Neves told LiveScience. "There is another site in the same region where you find paintings with men with oversized phalluses, and also pregnant women, and even a parturition (childbirth) scene."

Carbon dating and other tests of the sediment covering the petroglyph suggest the engraving dates between 9,000 and 12,000 years old. This makes it the oldest reliably dated instance of such rock art found yet in the Americas.

When this carving is compared with other examples of early rock art found in South America, it would seem that abstract forms of thinking may have been very diverse back then, which suggests that humans settled the New World relatively early, giving their art time to diversify. For instance, at one site in Argentina named Cueva de las Manos, paintings of hands predominate, while at another site there, Cueva Epullan Grande, engravings have geometric motifs.

Read more at Discovery News