Bronze-Age Wheel Sheds Light on Prehistoric Transport

Archaeologists have unearthed the oldest, largest, most complete wheel ever found in Britain, revealing intriguing Bronze Age technology, Cambridge University announced on Friday.

Dating from 1100-800 BC, the wooden wheel is the latest find from a settlement in the UK county of Cambridgeshire described as Britain's Pompeii.

The site was home to several families who lived in a number of circular wooden houses built on stilts above a river. The settlement was abandoned in haste 3,000 years ago as a dramatic fire caught on the houses. The dwelings fell into the river, where silt and clay preserved the contents.

The wheel, around three feet in diameter, was no exception. Found near the remains of the largest roundhouse, it is exceptionally well-preserved. Made of five panels of solid timber stitched together, it still has its reinforced hub in the center.

Archaeologists are puzzled as the wheel was found in a marshy area by a river where boats were the most common method of transport. Eight canoes of various sizes were unearthed nearby in 2011.

"The discovery of the wheel demonstrates that the inhabitants of this watery landscape had links to the dry land beyond the river," David Gibson, Archaeological Manager at the Cambridge Archaeological Unit, Division of Archaeology, University of Cambridge, said in a statement.

The archaeologists hope to find new insights into domestic life 3,000 years ago as the excavation, which is now half way through the four-year project, continues over the coming months.

"Among the wealth of other fabulous artifacts and the new structural remains of round houses built over this river channel, this site continues to amaze and astonish us," Kasia Gdaniec, senior archaeologist for Cambridgeshire County Council, said.

Previous objects unearthed at the site, such as exotic glass beads that were part of an elaborate necklace, suggested "a sophistication not usually associated with the British Bronze Age," according to Cambridge Archaeological Unit.

Read more at Discovery News

Super-Rare Minerals Make Earth Unique in Cosmos

We all like to think that we’re unique, but our planet probably is, at least in terms of its assortment of rare minerals. Those substances represent Earth’s truest distinction from other planets, according to scientists who’ve developed the first system for categorizing rarities in the mineral kingdom.

Scientists Robert Hazen of the Carnegie Institution and Jesse Ausubel of The Rockefeller University, whose research paper will appear in a future issue of the journal American Mineralogist, have inventoried the world’s rarest mineral species.

Their database includes 2,550 substances that are far rarer than diamonds and gemstones. Several, in fact, are so scarce that the known supply worldwide would be smaller than a sugar cube. Many are incredibly fragile, with a tendency to melt, evaporate or dehydrate, and a few will decompose if they are exposed to sunlight.

And as the scientists note in their paper, many of the rarest minerals develop as a consequence of biological changes in the Earth’s environment. “We suggest that the distribution of rare minerals may not only arise from biological activity, but also may be a robust biosignature of life” on Earth and other planets, they wrote.

Surprisingly, the stuff that we think of as rare often isn’t.

“Uses of the word ‘rare’ in the context of ‘rare earth elements’ or ‘rare metals’ are similarly misleading, as many thousands of tons of these commodities are produced annually,” the scientists point out. And precious gems are found in numerous places around the world, and are bought and sold in commercial quantities.

Diamonds, for example, are found in significant quantities in 11 countries around the world, and the biggest producer, Russia, mined 23,000 tons of them in 2014, according to Geology.com. In contrast, each of the 2,550 rare minerals is found at five or fewer locations worldwide.

Perhaps the rarest mineral is ichnusaite, created from a combination of the radioactive element thorium and lead-like molybdenum underground. Only one specimen has ever been found, in Sardinia back in 2013. And Nevadaite, a combination of vanadium and copper, has been found only in Nevada and Kyrgyzstan.

From Discovery News

Rings May Be Common Around a Weird Kind of Asteroid

Chariklo — affectionately dubbed a “strange little object” by one researcher — is an asteroid that orbits in a weird spot. Instead of residing in the usual locations (between Mars and Jupiter, or beyond Neptune) it resides between Saturn and Uranus. What’s more, Chariklo has its own ring system. The 2014 discovery is still baffling researchers because the only other rings we know of are around huge planets: Jupiter, Saturn, Uranus and Neptune.

After the discovery, planetary scientist Margaret Pan at the University of Toronto was curious as to how those rings came to be. Recent research she led hints at a solution. Using mathematics and observations of Chariklo, her team suggested a new way the rings could have been created for the asteroid and other space rocks (dubbed Centaurs) in its neighborhood.

Their work suggests that as Chariklo moved out of the Kuiper Belt of icy objects (beyond Neptune) towards its current orbit, the sudden heating would have caused outgassing of carbon monoxide or nitrogen gas. This process would have lifted dust particles off the surface, eventually forming the rings. This theory competes with another idea previously brought out in the literature, which is that Chariklo picked up a small moon while in the Kuiper Belt, a moon that eventually broke apart into a ring when Chariklo passed close to Neptune. Pan said the latter scenario is likely rare; only some Centaurs could get rings that way.

“(Our) scenario predicts that all 100 km-class (62-mile) Centaurs should have some kind of orbiting dusty material. We’re eager for future Centaur observations to help distinguish between these formation pathways,” Pan wrote in an e-mail to Discovery News.

Rings are a rare phenomenon in our solar system. Saturn (pictured) has a spectacular set along with Jupiter, Uranus, Neptune and Chariklo.

Why the 100-kilometer limit? Pan says that outgassing on smaller objects wouldn’t have enough mass to stop the dusty material from flying away. She adds that Kuiper Belt objects wouldn’t be expected to have these rings, because they’re too far from the sun and thus too cold to experience this outgassing. Even if a Kuiper Belt object moved close enough to a planet to split a little orbiting moon apart, the trajectory would inevitably change the asteroid into a Centaur.

Uranus and its rings, based on Hubble observations performed in 2003. Chariklo’s rings appear to be the most similar to those of Uranus.

Observations of Chariklo are limited so far, but astronomers have seen that it has two rings. They are wider on one side of Chariklo than the other, with the second ring only containing about one-tenth the mass of the first ring.

Pan’s team suggests that the ring is not quite circular (elliptical). The particles don’t form into a circle due to the individual gravitational interactions between particles. The research implies that for this to happen, you would need to have enough material to create a 1-km (0.62-mile) sized ice ball. A typical particle would also have to be a few meters in size.

When comparing Chariklo’s rings to other ringed bodies in the solar system, it appears most similar to Uranus despite its diminutive size.

“The geometry of Chariklo’s rings, which are fairly dense and narrow, is most like that of the Uranian rings. Interestingly, some of the Uranian rings are also noticeably elliptical, and studies of the Uranian system inspired our treatment of Chariklo’s rings,” Pan wrote.

Read more at Discovery News

The Huge, Bee-Decapitating Hornet That Can’t Survive Group Hugs

Asian giant hornets trying to make friends with some honey bees just kidding they're going to massacre the little things.

Thirty Asian giant hornets, following a scent laid by their scout, descend on a hive of honey bees and get straight to the decapitations. The hornets snag the tiny bees and pop their heads right off using their enormous mandibles. Here a head, there a head. Desperately, the bees try to sting the hornets, yet they can’t puncture the giants’ armor.

Here a head, there a head—pop pop pop. One by one the bees fall, a single hornet taking down as many as 20 victims a minute. At that rate, the tiny band of marauders can wipe out a colony of 30,000 bees in a few hours, a glut of beheadings that makes the French Revolution look like Dance Dance Revolution.

The remarkable Asian giant hornet, Vespa mandarinia, grows to almost two inches in length and can sting through a rain jacket. And unlike a honey bee, it can sting repeatedly, its venom breaking down flesh and overloading kidneys. The hornet is formidable, to say the least, but the native honey bees it menaces have an ingenious defense: They form a ball around the scout hornet and vibrate to cook the invader to death, keeping the colony’s coordinates out of the hands of the scout’s soldiers back at base.

The Asian giant hornet is in many ways a modern winged T. rex. It’s an apex predator, capable of taking down any other insect and incapacitating any mammal dumb or unfortunate enough to disturb it. Should you come across one, don’t move, as the good doctor Grant always said (OK fine, maybe he was wrong about that).

Just ask actual doctor Stephen Martin, an entomologist at the University of Salford. Once while observing a nest, he and a colleague—sans suits—displeased the hornets and got themselves attacked. “You close your eyes, you close your mouth, you grit your teeth, because it’s quite frightening,” he says. “The other guy just couldn’t cope and he ran away, and he got stung several times. I was fine.” If the hornets don’t take you to be a threat, they’ll leave you alone. No sense in wasting venom and risk getting squashed, after all.

Get stung, though, and you’ll want to go ahead and start considering a trip to the hospital. The hornet’s venom breaks down flesh cells, leaving you with a divot, while neurotoxins glitch nerves, resulting in an intense, searing pain that one victim described as having a hot nail hammered into you. (Had he actually ever had a hot nail hammered into him? Seems like a really specific comparison.) Because of its size, the hornet can inject a whole lot of venom—you can end up with a teaspoon of the stuff in your system if a swarm jabs you 30 or 40 times. Catch enough stings and your kidneys will shut down, or even your heart if you have a weak ticker. If you happen to be allergic, it’ll be anaphylactic shock instead.

What makes the Asian giant hornet particularly problematic is its size. Because this thing is so huge, so is its nest, which can weigh more than 20 pounds. That would snap a tree branch, so instead the hornet holes up in, well, holes in the ground—where unsuspecting humans can stroll too close. If you do, don’t bother running. These things can fly at up to 15 miles per hour, and even faster if they’ve got a good tailwind.

This is a lot like a stork delivering a baby except it’s the exact opposite.

While an Asian giant hornet can ruin your day, it can ruin a honey bee’s life. But the native bee it menaces has evolved a rather unconventional way to fight back: group hugs.

Should a hornet scout find itself a beehive, the occupants won’t rush out to intercept it. Instead, the bees will let the scout in to mark the location with pheromones for its comrades to follow. It’s a trap: On cue the workers swarm, forming a frantic, living ball around the intruder. The bees vibrate, revving up their body temperatures to begin cooking the hornet to death. All the while, carbon dioxide builds up inside the ball.

The bees also exploit a unique bit of insect anatomy: The hornet doesn’t have a heart—literally and I suppose kind of figuratively when you think about it—and instead pumps blood with contractions of its body. “The bees just crowd it and crowd it and crowd it like a boa constrictor, so they prevent the hornet from being able to pump blood around its body,” Martin says. This further raises the hornet’s body temperature.

“So it’s this combination of heating them, building up the carbon dioxide in the middle of it, and then restricting their blood flow by effectively squeezing them,” Martin adds. The hornet scout eventually dies, taking with it the coordinates of the hive. It may have picked off a bee here and there in the struggle, and some of the workers themselves may have been crushed or asphyxiated, but the hive is saved.

It’s a remarkable countermeasure that has evolved over millennia. That’s time the introduced European honey bee ain’t got. It hasn’t stumbled upon the swarm countermeasure, so the hornet scout inevitably marks a European bee nest and returns with its friends. The marauders slaughter every adult, yet don’t bother eating their relatively calorie-poor bodies. Instead, the hornets take the bee larvae back to their nest to feed to their own larvae, shuttling back and forth. The hornets will even post guards at the hive entrance to protect their booty overnight if they haven’t finished looting in one day.

Beekeepers tending the European variety in China and Japan don’t so much appreciate all this. Some attach special guards to their hives to keep the hornets out, while others take a rather more active approach, hiring people to volley the things with tennis or badminton rackets. (At least one overachieving beekeeper in Japan employs the enviable trap-plus-badminton-racket technique.) In wealthier Japan, beekeepers actually pay some brave soul to remove nearby hornet nests—apparently they’ve got solid health care over there or something.

The hornet’s apparent attitude problem isn’t exactly great for PR. “With hornets, people ask us often what use are they, they just sting us, they hurt us, we should just get rid of them all,” Martin says. “We’ve got the bees, they make honey, they work really hard, they’re really good.”

Read more at Wired Science

Astronomer detected a new source of intense gamma-radiation in the sky

Analyzing the data collected by the Fermi Gamma-ray Space Telescope Maxim Pshirkov (The Sternberg Astronomical Institute, MSU) discovered a new source that confirmed the fact that binary systems with strong colliding stellar winds comprise a separate new population of high-energy gamma-ray sources. His article was published in the latest issue of 'Monthly Notices of the Royal Astronomical Society Letters'.

Massive binary star systems with highly luminous and hot Wolf-Rayet stars and massive (tens solar masses) OB companion generate strong stellar winds. Its percussion may lead to producing a fierce photon flux with an energetic potential of more than a hundred mega electronvolt (MEV), when a distance separating stars is relatively short. That phenomenon was considered as a possible source of gamma-radiation for a long while.

Strong stellar winds are generated in the binary systems consisting of highly luminous and hot Wolf-Rayet stars and massive ( several tens solar masses) OB companions. Wind collision may produce strong photon emission with photon energies exceeding hundred mega electronvolts (MeV). This phenomenon was considered as a possible source of gamma-radiation for a long while.

Though such radiation was detected only once, with the famous Eta Carinae, which was observed for more than four centuries (particularly intensively -- after 1834, when one of its stars underwebt an explosion and for some time was the most luminous star in the sky) ). Eta Carinae is comparatively close to Earth -- around 7,5 -- 8 thousand light years. The stars in this system weight 120 and (30-80) solar masses respectively, and shine brighter than millions of suns. If they were 10 parsec (30 light years) away from the Earth, they would be just as luminous as the Moon, while the Sun would be invisible on such distance. Naturally, Eta Carinae was the first candidate to consider and seven years ago high-energy radiation from this system was finally detected.

However, one example was not enough to confirm the model of binary stars emitting high-energy radiation, and the search for similar sources was continued, which turned out to be a tricky task.

"Recent calculations proved such star types as Eta Carinae to be incredibly rare -- probably, one per a galaxy like we inhabit, or less,' said Maxim Pshirkov, my colleagues' research resulted in no certain findings. In 2013 an American-Austrian research team composed a list of seven stellar systems containing Wolf-Rayet stars, where a radiation could most probably appear. This research was based on two years of observations and lacked data, so it was only possible to set an upper limit on the HE radiation. I decided toutilize larger set of data seven years of Fermi-LAT observations. As the result -- it was discovered that Gamma Velorum is the source of gamma-radiation at 6.σ. confidence level"

This system contains two stars with masses of 30 and 10 solar masses. Their orbital parameters are well-studied and they are separated by about the same distance as Earth and Sun. The luminosity of this binary system is about 200 thousand times higher than of the Sun and strong stellar winds have very high mass loss rate: hundred-thousandth and two ten-millionth of the solar mass every year . Though these figures seem to be small, actually this amount is huge, particularly comparing to the solar wind which only amounts to 10-14 solar mass per annum As the stellar winds in the Gamma Velorum system collide on a speed exceeding 1000 kilometers per second, particles are accelerated in the shock. Though an exact mechanism of this acceleration is still unknown, it definitely leads to a high energy photon radiation that turned out to be detected by Fermi LAT.

An attentive reader who followed the process of searching for Higgs boson in the Large Hadron Collider has probably faced the standard deviation that Pshirkov mentions and remembered that in physics a hypothesis is proved on a statistical accuracy higher than 5σ. That means it is confirmed with a probability higher than 99,999%. In other words Pshirkov's discovery with its six standard deviations is definitely reliable, though it's still not far away from the threshold. According to the article, it was partly a pure luck that helped the researcher.

Read more at Science Daily

Longest-lasting stellar eclipse: Three-and-a-half year eclipses in binary system

Imagine living on a world where, every 69 years, the sun disappears in a near-total eclipse that lasts for three and a half years.

That is just what happens in an unnamed binary star system nearly 10,000 light years from Earth. The newly discovered system, known only by its astronomical catalog number TYC 2505-672-1, sets a new record for both the longest duration stellar eclipse and the longest period between eclipses in a binary system.

Discovery of the system's extraordinary properties was made by a team of astronomers from Vanderbilt and Harvard with the assistance of colleagues at Lehigh, Ohio State and Pennsylvania State universities, Las Cumbres Observatory Global Telescope Network and the American Association of Variable Star Observers and is described in a paper accepted for publication in the Astronomical Journal.

"It's the longest duration stellar eclipse and the longest orbit for an eclipsing binary ever found...by far," said the paper's first author Vanderbilt doctoral student Joey Rodriguez.

The previous record holder is Epsilon Aurigae, a giant star that is eclipsed by its companion every 27 years for periods ranging from 640 to 730 days.

"Epsilon Aurigae is much closer -- about 2,200 light years from Earth -- and brighter, which has allowed astronomers to study it extensively," said Rodriguez. The leading explanation is that Epsilon Aurigae consists of a yellow giant star orbited by a normal star slightly bigger than the sun embedded in a thick disk of dust and gas oriented nearly edge on when viewed from Earth.

"One of the great challenges in astronomy is that some of the most important phenomena occur on astronomical timescales, yet astronomers are generally limited to much shorter human timescales," said co-author Keivan Stassun, professor of physics and astronomy at Vanderbilt. "Here we have a rare opportunity to study a phenomenon that plays out over many decades and provides a window into the types of environments around stars that could represent planetary building blocks at the very end of a star system's life."

Two unique astronomical resources made the discovery possible: observations by the American Association of Variable Star Observers (AAVSO) network and the Digital Access to a Sky Century @ Harvard (DASCH) program.

AAVSO is a non-profit organization of professional and amateur astronomers dedicated to understanding variable stars. It provided a few hundred observations of TYC 2505-672-1's most recent eclipse.

The DASCH survey is based on thousands of photographic plates taken by Harvard astronomers between 1890 and 1989 as part of a regular survey of the northern sky. In recent years the university has begun digitizing these plates. In the process TYC 2505-672-1 caught the eye of Sumin Tang at the Harvard-Smithsonian Center for Astrophysics.

Rodriguez attended a conference where Tang presented her results on TYC 2505-672-1 and the system piqued his interest as well. He is a member of the survey team for the low-cost Kilodegree Extremely Little Telescope (KELT) system that consists of a pair of robotic telescopes designed to find exoplanets around bright stars operated by astronomers at Ohio State University, Vanderbilt University, Lehigh University and the South African Astronomical Observatory. KELT has an extremely wide field of view (26 degrees by 26 degrees) and he thought it was likely that the KELT database contained a number of recent images of the distant binary system.

After the lecture Rodriguez contacted Tang and they agreed to collaborate. When he searched the KELT database, Rodriguez found about 9,000 images of the obscure system taken in the last eight years that they could combine with the 1,432 images taken over the last century at Harvard. Rodriquez also contacted the AAVSO network and obtained several hundred more observations of the system's most recent eclipse to help fill in the picture. When she became busy with some other projects, Tang agreed to let Rodriguez take the lead.

The resulting analysis revealed a system similar to the one at Epsilon Aurigae, with some important differences. It appears to consist of a pair of red giant stars, one of which has been stripped down to a relatively small core and surrounded by an extremely large disk of material that produces the extended eclipse.

"About the only way to get these really long eclipse times is with an extended disk of opaque material. Nothing else is big enough to block out a star for months at a time," Rodriguez said.

TYC-2505-672-1 is so distant that the amount of data the astronomers could extract from the images was limited. However, they were able to estimate the surface temperature of the companion star and found that it is about 2,000 degrees Celsius hotter than the surface of the sun. Combined with the observation that it appears to be less than half the diameter of the sun has led them to propose that it is a red giant that has had its outer layers stripped away and that this stripped material may account for the obscuring disk. However, they don't know that for certain.

In order to produce the 69-year interval between eclipses, the astronomers calculate that they must be orbiting at an extremely large distance, about 20 astronomical units, which is approximately the distance between the Sun and Uranus.

Read more at Science Daily

Puzzling asteroid observations explained by destruction of asteroids close to Sun

An international team composed of researchers from Finland, France, the United States and the Czech Republic originally set out to construct a state-of-the-art model of the NEO population that is needed for planning future asteroid surveys and spacecraft missions. The model describes the NEOs' orbit distribution and estimates the number of NEOs of different sizes.

The vast majority of NEOs originate in the doughnut-shaped main asteroid belt between the orbits of Mars and Jupiter. The orbit of a main-belt asteroid slowly changes as it is pushed by the uneven release of excess solar heat from the asteroid's surface. The asteroid's orbit eventually interacts with the orbital motions of Jupiter and Saturn changing the trajectory to bring the asteroid close to the Earth. An asteroid is classified as an NEO when its smallest distance from the Sun during an orbit is less than 1.3 times the average Earth-Sun distance.

The team used the properties of almost 9,000 NEOs detected in about 100,000 images acquired over about 8 years by the Catalina Sky Survey (CSS) near Tucson, Arizona, to construct the new population model. One of the most challenging problems facing the team was computing which asteroids they could actually detect. An asteroid appears as a moving point of light against a background of fixed stars but detecting it on an image depends on two factors -- how bright it is and how fast it seems to be moving. If the telescope isn't looking in the right location at the right time when an asteroid is bright enough and slow enough to be detected, we simply may never find that asteroid. Accounting for these observational selection effects required a detailed understanding of the operations of the telescope and detector systems and a tremendous amount of computing time even with novel, fast mathematical techniques. The team produced the best-ever model of the NEO population by combining information about CSS's selection effects with the CSS data and theoretical models of the orbit distributions of NEOs that originate in different parts of the main asteroid belt.

But they noticed that their model had a problem -- it predicted that there should be almost 10 times more objects on orbits that approach the Sun to within 10 solar diameters. The team then spent a year verifying their calculations before they came to the conclusion that the problem was not in their analysis but in their assumptions of how the Solar System works.

Dr. Mikael Granvik, a research scientist at the University of Helsinki and lead author of the Nature article, hypothesized that their model would better match the observations if NEOs are destroyed close to the Sun but long before an actual collision. The team tested this idea and found an excellent agreement between the model and the observed population of NEOs when they eliminated asteroids that spend too much time within about 10 solar diameters of the Sun. "The discovery that asteroids must be breaking up when they approach too close to the Sun was surprising and that's why we spent so much time verifying our calculations," commented Dr. Robert Jedicke, a team member at the University of Hawai'i Institute for Astronomy.

The team's discovery helps to explain several other discrepancies between observations and predictions of the distribution of small objects in our Solar System. Meteors, commonly known as shooting stars, are tiny bits of dust and rock that are dislodged from the surfaces of asteroids and comets that then end their lives burning up as they enter our atmosphere. Meteors often travel in "streams" that follow the path of their parent object, but astronomers have been unable to match most of the meteor streams on orbits closely approaching the Sun with known parent objects. This study suggests that the parent objects were completely destroyed when they came too close to the Sun -- leaving behind streams of meteors but no parent NEOs. They also found that darker asteroids are destroyed farther from the Sun than brighter ones, explaining an earlier discovery that NEOs that approach closer to the Sun are brighter than those that keep their distance from the Sun. The fact that dark objects are more easily destroyed implies that dark and bright asteroids have a different internal composition and structure.

Read more at Science Daily

Oldest Known Dress Made More Than 5000 Years Ago

The first known dress, as well as the earliest known bar and restaurant in France, were identified this week.

The discoveries, reported in the journal Antiquity, provide a glimpse of what early life was like in both ancient Egypt and southern France thousands of years ago.

The garment, which dates to around 3482 B.C., is known as the “Tarkhan Dress,” and now looks like a tattered and stained shirt. When new, however, the linen dress would have looked fashionable even today, as researchers determined it featured a natural pale grey stripe with knife-pleated sleeves and bodice. Its hem is missing, so the original length of the dress is unknown.

“The survival of highly perishable textiles in the archaeological record is exceptional, the survival of complete, or almost complete, articles of clothing like the Tarkhan Dress is even more remarkable,” Alice Stevenson, curator of the University College London (UCL) Petrie Museum of Egyptian Archaeology, said in a press release.

“We’ve always suspected that the dress dated from the First Dynasty, but haven’t been able to confirm this as the sample previously needed for testing would have caused too much damage to the dress,” she added.

Now that the dress’ age has been confirmed, it has been named Egypt’s oldest garment and is the oldest known surviving woven garment in the world.

To calculate its age, Michael Dee of the University of Oxford and colleagues measured a small sample of the dress to determine how much radiocarbon (a radioactive isotope of carbon) remained in the linen. Linen is especially suitable for radiocarbon dating, according to the researchers, because it is composed of flax fibers that grow over a relatively short time.

The dress, currently on display at the UCL Petrie Museum of Egyptian Archaeology, features wear and tear that date back to its earliest days. The researchers believe that a young teenager or a very slim woman wore it.

A separate study in the same journal reports the discovery of a tavern in southern France. The remains of the structure are 2141 years old and are located at a site called Lattara.

“Not only is the tavern the earliest of its kind in the region, it also serves as an invaluable indicator of the changing social and economic infrastructure of the settlement and its inhabitants following the Roman conquest of Mediterranean Gaul in the late second century B.C.,” wrote co-authors Benjamin Luley of Gettysburg College and Gaël Piquès of Montpellier University.

At first the researchers thought that they had found a bakery, since they determined that the site once featured three huge ovens and indoor gristmills. They later, however, found that another nearby room, across from a courtyard, had benches lining its walls.

Bones from fish, sheep and cattle were also unearthed, as were the remains of big platters and bowls. The meat was probably cooked BBQ-style over a charcoal-burning hearth, which was also found at the site.

Read more at Discovery News

Eight New Spiders Grab (Don't Bite) Humans

Eight new species of whip spiders look threatening, but these newly found arachnids from the Amazon region of Brazil don’t bite — they just grab.

The newfound creepy crawlies double the known number of species of this type spider in Brazil, according to new research in PLOS ONE.

Whip spiders worldwide, also known as tailless whip scorpions, have scared many because of their resemblance to venomous stinging scorpions. They are, however, harmless to people, which they grab instead of bite, as this video shows:

You can also get a really good look at another whip spider in the below video.

Researchers Alessandro Ponce de Leao Giupponi and Gustavo Silva de Miranda found the new whip spiders in the Brazilian states of Pará and Amazonas. All of the spiders belong to the order Amblypygi and are of the genus Charinus. They include C. bichuetteae, C. bonaldoi, C. carajas, C. ferreus, C. guto, C. orientalis, C. brescoviti, and C. ricardoi.

“Brazil now becomes the country with the largest diversity of Amblypygi in the world, with 25 known species,” the researchers, both from the Federal University of Rio de Janeiro, wrote.

The name “amblypygid” means “blunt rump,” and refers to the spiders’ lack of a flagellum or tail that is seen in actual whip scorpions. The spiders possess no silk glands or poisonous fangs. When they grab a person, the sensation is a bit like being pricked by a rose thorn. Such attacks can stun or crush the spiders’ tiny insect prey, though.

They are very social and gregarious creatures, so some people even keep them as pets. Half of the new species are already considered to be highly endangered, however, so saving the spiders in their own habitat is the priority now.

Read more at Discovery News

Jerusalem's First Homes Unearthed

Israeli archaeologists have found the earliest known houses in Jerusalem, showing that a thriving settlement existed there as far back as 7,000 years ago, far longer than had been thought.

The discovery was made during the building of a new road in the northern Jerusalem neighborhood of Shuafat, the Israel Antiquities Authority said in a statement on Wednesday.

The archaeologists unearthed two houses, complete with stone floors and well-preserved artifacts such as pottery vessels, flint tools, a stone bowl and even a carnelian gemstone.

Stages of construction and signs of maintenance show the buildings were used for a considerable length of time.

The houses were built in the Chalcolithic period, approximately in the 5th millennium BC. At that time, man started developing the use of copper (chalcos in Greek) while using tools made of stone (lithos).

The remains predate previously found evidence of human settlement in the area by up to 2,000 years.

“The buildings uncovered are of a standard that would not fall short of Jerusalem’s architecture,” Ronit Lupo, director of excavations for the Israel Antiquities Authority, said.

“This discovery represents a highly significant addition to our research of the city and the vicinity,” he added.

He noted the artifacts unearthed at the site reveal the livelihood of the local population in prehistoric times: small sickle blades were likely employed for harvesting crops, while chisels and axes were used for building.

“The bead made out of carnelian indicates that jewelry was either made or imported. The grinding tools, mortars and pestles, like the basalt bowl, attest to technological skills as well as to the kinds of crafts practiced in the local community,” Lupo said.

Read more at Discovery News

Bleached Corals May Have Herpes

Scientists have found that a surprising organism may sometimes be present when coral reefs undergo devastating bleaching events: a form of herpes virus.

In a recent paper in the journal Frontiers in Microbiology, researchers from Oregon State University describe how, while they were studying corals on Australia’s Great Barrier Reef, a bleaching event began to take place. The researchers took samples of the bleaching corals and of the surrounding water, and found that the viral loads in the corals had exploded to levels 2-4 times higher than ever recorded in corals. The viruses included retroviruses and megaviruses; a type of herpes virus was particularly abundant.

It might seem surprising to think of viruses in the context of coral reefs. But in fact marine viruses are by far the most abundant lifeforms in the ocean -- if one does consider them lifeforms, a subject of some scientific controversy. Approximately 1023 viral infections occur in the sea every second, and the approximately 1030 viruses in the ocean, if placed end to end, would span farther than the nearest 60 galaxies.

And while we may associate herpes with cold sores and awkward conversations with potential partners, herpes viruses are ancient and are found in a wide range of mammals, marine invertebrates, oysters, corals and other animals. (However, while part of the same family, herpes viruses that affect corals do not infect humans, and vice-versa.)

However, the researchers could not confirm whether the viral outbreak caused the bleaching, was a consequence of it, or took place simultaneously.

“It’s a total chicken and the egg question,” Rebecca Vega-Thurber, an assistant professor of microbiology in the OSU College of Science and corresponding author on the study, told Quartz. “Did the bleaching event induce  viral production, or did stress induce viruses which help induce bleaching? They’re probably going on at the same time.”

Indeed, the specific proximate causes of bleaching -- so-called because corals expel the symbiotic algae that live within them and give them their color -- remain uncertain, although some combination of environmental stresses certainly plays a part. The most significant appears to be increased water temperature, but others can include pollution and overfishing. The latest study suggests that, as with humans, being under stress can render corals more susceptible to infection.

“This is bad news,” Vega-Thurber said. “This bleaching event occurred in a very short period on a pristine reef. It may recover, but incidents like this are now happening more widely all around the world.”

Read more at Discovery News

4 Billion People Face Severe Water Shortages

It’s no secret that our planet is undergoing a serious water crisis, with population growth putting increasing stress upon the supply of fresh water. But the situation is even worse than we thought.

About 4 billion people across the world have serious difficulty getting enough water for at least one month of every year, according to a just-published study in the journal Science Advances.

Co-authors Arjen Y. Hoekstra, a professor of water management at the University of Twente in the Netherlands, and post-doctoral researcher Mesfin Mekonnen used computer modeling to study a growing shortage that they say is being driven by population growth, improved living standards, changing consumption patterns and the expansion of irrigation in agriculture.

Unlike previous studies that looked at longer-term patterns of availability, which the researchers say underestimated the impact of water scarcity, they looked at how the supply of “blue” water -- that is, fresh surface water and groundwater -- fluctuates in the course of a year.

The result was that in addition to areas with year-round water scarcity -- such as Somalia and northern Mexico, for example -- the researchers identified places where water becomes scarce during certain seasons. In Africa, for example, the researchers identified a band roughly between 5 and 15 degrees northern latitude with low water scarcity from May or June to January but moderate to severe water scarcity from February to April. They found other spots -- such as India and northern China -- which experience water shortages during the spring and summer.

Severe scarcity is defined as the demand being double the supply available in an area.

The researchers also found that about 66 percent of the world’s population suffers from severe water scarcity for at least one month during the year. Of those 4 billion people, 1 billion live in India and another 900 million live in China. About 130 million live in the United States, mostly in western and southern states.

As Hoekstra told the New York Times, water scarcity isn’t just a problem for those who don’t have enough water. “Since the remaining people in the world receive part of their food from the affected areas, it involves us all,” he said.

From Discovery News

Neanderthal-Human Sex Happened Earlier

Remains of a Neanderthal woman who lived around 100,000 years ago in the Altai Mountains of Siberia reveal that human and Neanderthals mated much earlier than previously thought.

One or more of her relatives were actually humans, a new study shows.

It has been known that Neanderthals contributed DNA to modern humans, so people today of European and Asian descent retain Neanderthal DNA in their genomes, but the Neanderthal woman offers the first evidence that gene flow from interbreeding went from modern humans into Neanderthals as well.

The study, published in the journal Nature, "is also the first to provide genetic evidence of modern humans outside Africa as early as 100,000 years ago," Sergi Castellano, who co-led the study and is a researcher at the Max Planck Institute for Evolutionary Anthropology, told Discovery News.

Given the now closely intertwined histories of Neanderthals and Homo sapiens, Castellano added that "it is better to refer to Neanderthals and modern humans as two different human groups, one archaic and one modern, and not different species."

Earlier research determined that Neanderthals and modern humans met and mated outside of Africa sometime between 47,000–65,000 years ago. The Siberian woman shows that such interbreeding could have happened as early as 120,000 years ago, since it is now believed modern humans and Neanderthals were both then present in the region around the Persian Gulf and in the area where the following countries are now located: Cyprus, Egypt, Israel, Lebanon, Syria and Turkey.

Castellano, Martin Kuhlwilm and colleagues analyzed the Siberian woman's DNA and identified portions of her genome that match sequences taken from people who are now living in Africa. The researchers also analyzed the remains of a Denisovan individual and the remains of two Neanderthals that were found in European caves (one from Croatia, and the other from Spain). No modern human DNA was detected in those three other individuals.

The scientists therefore think that a population of Neanderthals likely migrated from Europe through the Near East, where mating with modern humans occurred. They then continued to travel up into the Altai Mountains, where the climate was much milder 125,000 years ago than it is now.

Castellano and his team further believe that the modern humans who were in the Near East at this early time eventually died out and did not contribute to the present day Homo sapiens genome.

Nevertheless, Castellano said, "Some Asians and Oceanians (living today) have more Neanderthal DNA because a second pulse of admixture might have happened with Neanderthals."

The evidence throws a wrench in the widely held view that modern humans first left Africa about 60,000 years ago. Instead, it seems that one or more groups of modern humans were leaving Africa tens of thousands of years earlier, and apparently at least some were mating with Neanderthals along the way.

Montgomery Slatkin is a professor in the Department of Integrative Biology at the University of California at Berkeley. He told Discovery News, "I think the results (of the new study) are important because they show how complex the relationships between the ancestors of modern humans and Neanderthals were. It will be interesting to find out whether the early interbreeding between Neanderthals and humans affects only the Neanderthals found in Asia, or all Neanderthals."

Chris Stringer, a research leader in Human Origins at the Natural History Museum, London, wonders how the interbreeding happened. He speculated that "the possibilities range from relatively peaceful exchanges of partners, to one group raiding another and stealing females -- which happens in chimps and some modern hunter-gatherers -- through to adopting abandoned or orphaned babies."

Read more at Discovery News

Remains Found of 7,000-Year-Old Man Buried Upright

A Mesolithic site in Germany has revealed the 7,000-year-old remains of a young man buried there in a strange upright position.

Placed in a vertical pit, the body was fixed upright by filling the grave with sand up to the knees. The upper body was left to decay and was likely picked at by scavengers.

The unique burial was found near the village of Groß Fredenwalde, on top of a rocky hill in northeastern Germany, about 50 miles north of Berlin.

Dating back 8,500 years, the site belongs to the Mesolithic era when Europe was inhabited by hunter-gatherers who rarely stayed in one place.

Nine skeletons have been excavated so far, including five children younger than 6 years and the 8,400-year-old skeleton of a 6-month-old infant, with arms still folded across the chest.

According to Thomas Terberger, the excavation director at the Lower Saxony Department of Historic Preservation, the site was one of the first true cemeteries in Europe, used by native central European hunter-gatherers and fisherman from about 6400 B.C. to 500 B.C.

“It is evidence for a more stable way of life some 8,000 years ago,” Terberger said.

Detailing their findings in the journal Quaternary, Terberger and colleagues describe the skeleton buried upright as “without any parallel in central Europe.”

From the arrangement of the bones, the researchers speculate the young man was put — probably dead — into a 5 foot vertical pit.

Leaning with its back against the wall of the grave, the body was fixed in standing position by filling the pit with sands to a level above the knees.

“The pit was then left open or was preliminarily covered and subsequently carnivores were able to get at the corpse and gnaw on some of the arm bones,” the researchers wrote.

Read more at Discovery News

Prehistoric Coffee Ancestor Found in Amber

Fossil flowers found perfectly preserved in amber represent a new plant species that’s a 45-million-year-old relative of coffee, according to new research.

Named Strychnos electri, after the Greek word for amber (electron), the flowers represent the first-ever fossils of an asterid, which is a family of flowering plants that not only later gave us coffee, but also sunflowers, peppers, potatoes, mint — and deadly poisons.

The flowers, described in the journal Nature Plants, belong to the dark side of the family. They are in the genus Strychnos, which ultimately gave rise to some of the world’s most famous poisons, including strychnine and curare. The prehistoric flowers’ attractiveness and incredible state of preservation belie their toxicity.

“The specimens are beautiful, perfectly preserved fossil flowers, which at one point in time were borne by plants that lived in a steamy tropical forest with both large and small trees, climbing vines, palms, grasses and other vegetation,” said Oregon State professor George Poinar, Jr., an expert in plant and animal life forms preserved in amber, in a release.

“Specimens such as this are what give us insights into the ecology of ecosystems in the distant past,” he continued. “It shows that the asterids, which later gave humans all types of foods and other products, were already evolving many millions of years ago.”

Poinar and his team recently made the discovery while analyzing amber that had been collected in the Dominican Republic in 1986. He and his colleagues explained that asterids are among Earth’s most important and diverse plants, with 10 orders, 98 families, and about 80,000 species. They represent about one-third of all the earth’s diversity of angiosperms, or flowering plants.

The new find shows that plants in the very poisonous genus existed for many millions of years before humans evolved from our primate ancestors.

Humans have clearly since put asterids to good use, considering how common the edible ones are in our diets. As for the poisonous plants, their toxic compounds have been added to blow-gun weapons, rat control, and have even been featured in classic murder mysteries such as Sherlock Holmes stories and the movie “Psycho.”

Read more at Discovery News

Mystery 'Hobbits' not Human, Study Says

Diminutive humans that died out on an Indonesian island some 15,000 years ago were not Homo sapiens, but a different species, according to a study published Monday that dives into a fierce anthropological debate.

Fossils of Homo floresiensis — dubbed “the hobbits” due to their tiny stature — were discovered on the island of Flores in 2003.

Controversy has raged ever since as to whether they are an unknown branch of early humans or specimens of modern man deformed by disease.

The new study, based on an analysis of the skull bones, shows once and for all that the pint-sized people were not Homo sapiens, according to the researchers.

Until now, academic studies have pointing in one direction or another — and scientific discourse has sometimes tipped over into acrimony.

One school of thought holds that so-called Flores Man descended from the larger Homo erectus and became smaller over hundreds of generations.

The proposed process for this is called “insular dwarfing” — animals, after migrating across land bridges during periods of low sea level, wind up marooned on islands as oceans rise and their size progressively diminishes if the supply of food declines.

An adult hobbit stood a metre (three feet) tall, and weighed about 25 kilos (55 pounds).

Similarly, Flores Island was also home to a miniature race of extinct, elephant-like creatures called Stegodon.

But other researchers argue that H. floresiensis was in fact a modern human whose tiny size and small brain — no bigger than a grapefruit — was caused by a genetic disorder.

One suspect was dwarf cretinism, sometimes brought on by a lack of iodine. Another potential culprit was microcephaly, which shrivels not just the brain and its boney envelope.

Weighing in with a new approach, published in the Journal of Human Evolution, a pair of scientists in France used high-tech tools to re-examine the layers of the “hobbit” skull.

More precisely, they looked at the remains of Liang Bua 1 (nicknamed LB1), whose cranium is the most intact of nine known specimens.

Mystery solved?

“So far, we have been basing our conclusions on images where you don’t really see very much,” said lead author Antoine Balzeau, a scientist at France’s Natural History Museum.

Joining forces with Philippe Charlier, a palaeopathologist at Paris-Descartes University specialized in solving ancient medical mysteries, the researchers secured high-resolution images recently generated in Japan to compute maps of bone thickness variation.

Read more at Discovery News

Hawking: Gravitational Waves Could Revolutionize Astronomy

In the wake of last week’s historic announcement of the discovery of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO), British physicist and black hole theorist Stephen Hawking was quick to congratulate the US-led collaboration, sharing his excitement for the historic news.

“These results confirm several very important predictions of Einstein’s theory of general relativity,” Hawking said in a BBC interview. “It confirms the existence of gravitational waves directly.”

As is becoming clear, the direct detection of these ripples in spacetime not only confirm Einstein’s famous theory of general relativity, they open our eyes to a previously “dark” universe. Astronomy uses the electromagnetic spectrum (such as visible light, X-rays, infrared) to study the universe, but objects that do not radiate in the electromagnetic spectrum will go unnoticed. But now we know how to detect gravitational waves, there could be a paradigm shift in how we detect and study some of the most energetic cosmic phenomena.

“Gravitational waves provide a completely new way of looking at the universe,” said Hawking. “The ability to detect them has the potential to revolutionize astronomy.”

Using LIGO’s twin observing stations located in Louisiana and Washington, physicists not only detected gravitational waves; the gravitational waves they detected had a very clear signal that closely matched theoretical models of a black hole merger some 1.3 billion light-years away. Already, from initial analysis of the black hole merger signal, Hawking has realized that the system seems to align itself with theories he developed in the 1970′s.

“This discovery is the first detection of a black hole binary system and the first observation of black holes merging,” he said. “The observed properties of this system is consistent with predictions about black holes that I made in 1970 here in Cambridge.”

Hawking is perhaps most renowned for his work on melding quantum theory with black hole physics, realizing that black holes evaporate over time, leading to his involvement in the fascinating "Firewall Paradox" that is continuing to rumble throughout the theoretical physics community. But here he refers to his black hole area theorem, which forms the basis of the “second law” of black hole mechanics. This law states that entropy, or the level of disorganization of information, cannot decrease within a black hole system over time. A consequence of this theorem is that should two black holes merge, like the Sept. 14 event, the combined event horizon area “is greater than the sum of the areas of the initial black holes.” Also, Hawking points out that this gravitational wave signal appears to be in agreement with predictions based on the “no-hair theorem” of black holes, basically meaning a black hole can be simply described by its spin, mass and charge.

The details behind how this first gravitational wave signal of a black hole merger agrees with theory are complex, but it is interesting to know that this first detection has already allowed physicists to confirm decades-old theories that have, until now, had little to no observational evidence.

“This discovery also presents a puzzle for astrophysicists,” said Hawking. “The mass of each of the black holes are larger than expected for those formed by the gravitational collapse of a star — so how did both of these black holes become so massive?”

This question touches on one of the biggest mysteries surrounding black hole evolution. Currently, astronomers are having a hard time understanding how black holes grow to be so massive. On the one end of the scale, there are “stellar mass” black holes that form immediately after a massive star goes supernova and we also have an abundance of evidence for the existence of the supermassive behemoths that live in the centers of most galaxies. There is a disconnect, however.

If black holes grow by merging and consuming stellar matter, there should be evidence of black holes of all sizes. But “intermediate mass” black holes and black holes of a few dozen solar masses are astonishingly rare, throwing some black hole evolution theories into doubt.

Read more at Discovery News

Hubble Studies 'Super-Earth' Atmosphere for First Time

For the first time, a super-Earth’s atmosphere has been analyzed — but don’t make any vacation plans to visit. The planet is blisteringly close to its planet star (exhibiting temperatures of 3,600 Fahrenheit or 2,000 Celsius) and has an atmosphere mostly made up of hydrogen and helium, like a gas giant planet.

Hydrogen and helium are common elements in young solar systems as those are the elements that make up young stars. Typically, however, smaller planets tend to lose the hydrogen and helium over time into space because their gravity is so low; the light elements escape, especially if a star’s radiation pushes against the atmosphere. Gas giant planets can hold on to those elements due to their stronger gravity.

On small planets, sometimes the hydrogen/helium atmosphere is replaced by a secondary atmosphere, which was the case on Earth. Our current mix of nitrogen, oxygen and carbon dioxide likely came from internal processes (such as volcanism) and the evolution of plants.

“We did not expect 55 Cancri e to retain this much of its primordial gas atmosphere,” said Ingo Waldmann, a post-doctoral research assistant at University College London who participated in the research, in an e-mail to Discovery News. Waldmann pointed out that the planet is the only known super-Earth with such a high temperature, but the astronomers had thought it would lose most of its atmosphere due to the intense radiation of its parent star. Why it held on to the hydrogen and helium is poorly understood.

Astronomers have a few sample measurements of planetary atmospheres from outside our solar system, but these are from gas giants that are easier to spot in telescopes. As the large planet passes across the face of its planet star, the elements detected in a telescope change slightly. That change is believed to represent the atmosphere of the planet.

The team decided to try for a smaller planet, but one that was orbiting a bright star to make it easier to distinguish the atmosphere of the planet from the elements in its parent star. A strong candidate for this work was the Hubble Space Telescope’s Wide Field Camera 3, which was installed by astronauts in 2009 and usually is used to track star or galaxy formation.

“The WFC3 camera on Hubble is a very sensitive instrument, not initially designed to observe bright stars, and the instrument would overexpose like your cell-phone camera held towards the sun would,” Waldmann said. “In 2012, the scanning mode was introduced to address this. Essentially we now quickly move Hubble across the star and ‘smear’ the spectrum across the detector. This helps the overexposure issue, but makes the data analysis very difficult.”

An additional challenge came from 55 Cancri e’s close distance. It is orbiting a sun-like star that is only about 40 light-years away. Because the star is so bright, Waldmann said, the scan speed had to be much faster than what was used before. The team studied the situation and developed a method that can extract a viable signal from the data, a signal that was strong enough to detect elements in the small planet’s atmosphere.

Read more at Discovery News

The mystery about the Chelyabinsk superbolide continues three years later

In 2013 February 15, the approach of asteroid (367943) Duende to our planet was being closely monitored by both the public and the scientific community worldwide when suddenly a superbolide entered the atmosphere above the region of Chelyabinsk in Russia. Three years and hundreds of published scientific studies later, we are still looking for the origin of such unexpected visitor, that caused damage to hundreds of buildings and injuries to nearly 1,500 people. Finding the precise value of its speed as it touched the top of the atmosphere appears to be the key to determine the orbit of the parent body of the Chelyabinsk superbolide.

"Three years have passed since the Chelyabinsk (Russia) great scare and during this time more than two hundred research papers -50 in the last year- related directly or indirectly to the 19-m wide Chelyabinsk superbolide have been published in scientific peer-review journals," explains Carlos de la Fuente Marcos, co-author of one of these research works. Among these studies, there is a catalog of 960 video recordings, published by the journal Astronomy & Astrophysics, that includes material automatically recorded by security cameras, traffic cameras, dashcams -very popular in Russia- installed on-board of all types of vehicles, and manual recordings made with the video cameras and webcams of the many accidental witnesses of the impressive phenomenon who shared their experiences on the internet.

The images and diverse scientific data compiled during the event have allowed the calculation of the atmospheric entry trajectory of the meteoroid, which turned into a meteor when it crossed Earth's atmosphere, exploding at a height of 20 km and releasing 500 kilotons or energy, approximately thirty times the yield of the Hiroshima nuclear bomb. The shockwave generated by such an explosion caused damage out to a distance of 75 miles breaking the windows, and even the window frames in some cases, of hundreds of buildings and injuring 1,491 people mainly due to cuts inflicted by shattered and broken glass. Approximately five tons of meteoritic material reached the ground, including the 650-kg meteorite that was recovered by divers from the bottom of Lake Chebarkul.

The Chelyabinsk superbolide entry took place the same day, 2013 February 15, the asteroid (367943) Duende approached the Earth. Duende (discovered originally from Spain) passed nearly 27,700 km above the Earth's surface, well inside the boundaries of the ring of geosynchronous satellites but nearly perpendicular to it as expected, 16 hours after the Chelyabinsk superbolide explosion and the fall of the large meteorite on the Russian Lake Chebarkul.

At the beginning, it was thought that both events could be related and that the Chelyabinsk superbolide could have come from asteroid Duende itself or from a companion of this object, but when the orbits of both objects were analyzed and spectroscopic data of both asteroid Duende and the Chelyabinsk meteoritic material were studied in detail, the results obtained indicated that the two objects were completely independent and unrelated. It was a mere, albeit very unusual, coincidence in time of two spectacular cosmic events.

Where in space did the Chelyabinsk superbolide come from? "For a while, it was thought that asteroid (86039) 1999 NC43 was a good candidate for the parent body of the Chelyabinsk superbolide but after the publication of a detailed international study in the journal Icarus, it became clear that the Chelyabinsk impactor and the PHA 86039 (1999 NC43) were not part of the same object; from a dynamical and compositional point of view the relationship between both objects is too weak" explains de la Fuente Marcos.

During the last year, different orbital solutions for the asteroid that gave origin to the Chelyabinsk superbolide have been proposed; one of them has been computed by the Spanish astrodynamicists brothers Carlos and Raúl de la Fuente Marcos and Sverre J. Aarseth , scientist of the University of Cambridge (United Kingdom). Their work has been published by The Astrophysical Journal. These authors have used the recorded impact parameters of the Chelyabinsk superbolide to search for the orbit of its parent, or dynamically related, body by means of a numerical model validated using asteroid Duende's close approach data. "It is like when you are given a certain sample color to reproduce and a set of basic colors. You try all the mixtures, until you get the color that you want." compares de la Fuente Marcos.

The results of de la Fuente Marcos & Aarseth's model suggest that asteroid 2011 EO40 is a good dynamical relative of the parent body of the Chelyabinsk superbolide although there is no spectroscopic evidence linking genetically 2011 EO40 to Chelyabinsk; at least not yet. The common origin of both celestial objects is a possibility that cannot be discarded using the currently available evidence. The results obtained by de la Fuente Marcos and Aarseth indicate that the Chelyabinsk impactor likely passed a gravitational keyhole on 1982 February 15 during a close encounter with our planet at a distance shorter than 0.0015 AU. As a result of this close encounter, the initial 2011 EO40-like trajectory of the Chelyabinsk meteoroid was changed into the one that drove the meteoroid to strike the Earth over three decades later.

In addition, one of the main conclusions of this study, obtained after billions of simulations and a detailed statistical analysis, is that the main obstacle that prevents us from obtaining the correct orbit of the parent body of the Chelyabinsk superbolide is in the controversial value of its geocentric velocity at impact. This parameter has different values depending on the research study considered and this fact leads to slightly different pre-impact orbits.

As a matter of fact, the researchers admit that it is very difficult to know the exact asteroid that gave origin to the Chelyabinsk superbolide because in the neighborhood of our planet there is a tangled web of overlapping gravitational resonances that confines asteroids of heterogeneous, or diverse, origin to very similar orbits.

"These gravitational resonances create an environment like that of the great cities that attract people from different places and with very diverse backgrounds," says de la Fuente Marcos, who adds "Having two very similar orbits today does not imply that these orbits were also similar in the remote past."

This scenario is the one explored by the same authors in their latest research work to be published in March by the journal Monthly Notices of the Royal Astronomical Society, but that is already available online. "Here we demonstrate using statistics that among the objects close to the Earth (NEOs) there are groups of dynamical origin made of asteroids moving in similar orbits that may not be physically related or have the same chemical composition" explains de la Fuente Marcos.

Read more at Science Daily

Eternal 5D data storage could record the history of humankind

Scientists at the University of Southampton have made a major step forward in the development of digital data storage that is capable of surviving for billions of years.

Using nanostructured glass, scientists from the University's Optoelectronics Research Centre (ORC) have developed the recording and retrieval processes of five dimensional (5D) digital data by femtosecond laser writing.

The storage allows unprecedented properties including 360 TB/disc data capacity, thermal stability up to 1,000°C and virtually unlimited lifetime at room temperature (13.8 billion years at 190°C ) opening a new era of eternal data archiving. As a very stable and safe form of portable memory, the technology could be highly useful for organisations with big archives, such as national archives, museums and libraries, to preserve their information and records.

The technology was first experimentally demonstrated in 2013 when a 300 kb digital copy of a text file was successfully recorded in 5D.

Now, major documents from human history such as Universal Declaration of Human Rights (UDHR), Newton's Opticks, Magna Carta and Kings James Bible, have been saved as digital copies that could survive the human race. A copy of the UDHR encoded to 5D data storage was recently presented to UNESCO by the ORC at the International Year of Light (IYL) closing ceremony in Mexico..

The documents were recorded using ultrafast laser, producing extremely short and intense pulses of light. The file is written in three layers of nanostructured dots separated by five micrometres (one millionth of a metre).

The self-assembled nanostructures change the way light travels through glass, modifying polarisation of light that can then be read by combination of optical microscope and a polariser, similar to that found in Polaroid sunglasses.

Coined as the 'Superman memory crystal', as the glass memory has been compared to the "memory crystals" used in the Superman films, the data is recorded via self-assembled nanostructures created in fused quartz. The information encoding is realised in five dimensions: the size and orientation in addition to the three dimensional position of these nanostructures.

Professor Peter Kazansky, from the ORC, says: "It is thrilling to think that we have created the technology to preserve documents and information and store it in space for future generations. This technology can secure the last evidence of our civilisation: all we've learnt will not be forgotten.."

Read more at Science Daily

New semiconducting material could lead to much faster electronics

University of Utah engineers have discovered a new kind of 2D semiconducting material for electronics that opens the door for much speedier computers and smartphones that also consume a lot less power.

The semiconductor, made of the elements tin and oxygen, or tin monoxide (SnO), is a layer of 2D material only one atom thick, allowing electrical charges to move through it much faster than conventional 3D materials such as silicon. This material could be used in transistors, the lifeblood of all electronic devices such as computer processors and graphics processors in desktop computers and mobile devices. The material was discovered by a team led by University of Utah materials science and engineering associate professor Ashutosh Tiwari. A paper describing the research was published online Monday, Feb. 15, 2016 in the journal, Advanced Electronic Materials. The paper, which also will be the cover story on the printed version of the journal, was co-authored by University of Utah materials science and engineering doctoral students K. J. Saji and Kun Tian, and Michael Snure of the Wright-Patterson Air Force Research Lab near Dayton, Ohio.

Transistors and other components used in electronic devices are currently made of 3D materials such as silicon and consist of multiple layers on a glass substrate. But the downside to 3D materials is that electrons bounce around inside the layers in all directions.

The benefit of 2D materials, which is an exciting new research field that has opened up only about five years ago, is that the material is made of one layer the thickness of just one or two atoms. Consequently, the electrons "can only move in one layer so it's much faster," says Tiwari.

While researchers in this field have recently discovered new types of 2D material such as graphene, molybdenun disulfide and borophene, they have been materials that only allow the movement of N-type, or negative, electrons. In order to create an electronic device, however, you need semiconductor material that allows the movement of both negative electrons and positive charges known as "holes." The tin monoxide material discovered by Tiwari and his team is the first stable P-type 2D semiconductor material ever in existence.

"Now we have everything -- we have P-type 2D semiconductors and N-type 2D semiconductors," he says. "Now things will move forward much more quickly."

Now that Tiwari and his team have discovered this new 2D material, it can lead to the manufacturing of transistors that are even smaller and faster than those in use today. A computer processor is comprised of billions of transistors, and the more transistors packed into a single chip, the more powerful the processor can become.

Read more at Science Daily

Light used to measure the 'big stretch' in spider silk proteins

While working to improve a tool that measures the pushes and pulls sensed by proteins in living cells, biophysicists at Johns Hopkins say they've discovered one reason spiders' silk is so elastic: Pieces of the silk's protein threads act like supersprings, stretching to five times their initial length. The investigators say the tool will shed light on many biological events, including the shifting forces between cells during cancer metastasis.

"All other known springs, biological and nonbiological, lengthen in a way that is directly proportional to the force applied to them only until they have been stretched to about 20 percent of their original length," notes Taekjip Ha, Ph.D., the study's lead researcher. "At that point, you have to apply more and more force to stretch them the same distance as before. But the piece of the spider silk protein we focused on continues to stretch in direct proportion to the force applied until it reaches its maximal stretch of 500 percent."

Details of the research were published online in the journal Nano Letters on Feb. 5.

Ha, a Bloomberg Distinguished Professor of biophysics and biophysical chemistry at the Johns Hopkins University School of Medicine, says the new discovery came during follow-up to research he and his team, then at the University of Illinois at Urbana-Champaign, described in the journal Nature in 2010, work done in collaboration with cell biologists led by Martin Schwartz, then at the University of Virginia.

The Virginia team set up those experiments by inserting a repeating amino acid sequence -- taken from the spider silk protein known as flagelliform -- into a human protein called vinculin. Vinculin is responsible for internalizing forces outside a cell by bridging the cellular membrane and the actin network within the cell, making it an important mechanical communicator within the cell.

The scientists also flanked the flagelliform insert in vinculin with two fluorescent proteins to light up and "report" what was going on through fluorescence resonance energy transfer, or FRET. FRET occurs when one fluorescent molecule is close enough to another that it activates the second. So, when vinculin was relaxed within a cell, it "glowed" yellow, the color of the second fluorescent protein being activated by the first. As vinculin stretched, it began to glow blue -- the color of the first fluorescent protein -- because the lengthening distance between the two made FRET activation of the yellow protein impossible.

Using regular fluorescence microscopy, the scientists were able to watch the forces acting on vinculin in live cells in real time. But an issue remained: how to translate the changing colors into measurements of force "sensed" by vinculin.

That's where his team came in, says Ha. The researchers attached one end of modified vinculin to a glass plate and the other to a tether made of DNA with a small plastic bead at the end. They then pulled on the bead with what Ha describes as "chopsticks made of light," focusing a beam of light on a tiny spot nearby and generating an attractive force that pulled the bead toward the light source. That way, Ha says, his investigators could link the amount of FRET with the amount of force on vinculin, allowing them to measure the dynamic forces acting on proteins in live cells just by imaging them.

In that earlier study, the team inserted 40 flagelliform amino acids into vinculin, composed of eight repeats of the amino acid sequence GPGGA. In this new study, the scientists wanted to learn more about the flagelliform tool by varying its length, so they created inserts of five and 10 repeats to test alongside the original insert of eight. What they found is that the shortest insert was the most responsive to the widest range of forces, responding with linear increases in length to forces from 1 to 10 piconewtons. (Ha says that 1 piconewton is approximately the weight of a bacterium.)

The team wasn't expecting the spider silk inserts to show such linear behavior because, according to Ha, they don't form well-defined, three-dimensional structures. "Usually, unstructured proteins show disorderly, nonlinear behavior when we pull on them," says Ha. "The fact that these don't act that way means that they will be really useful tools for studying protein mechanics because their behavior is easy to understand and predict."

Read more at Science Daily

Record for fastest data rate set

Data stream.

A new record for the fastest ever data rate for digital information has been set by UCL researchers in the Optical Networks Group. They achieved a rate of 1.125 Tb/s as part of research on the capacity limits of optical transmission systems, designed to address the growing demand for fast data rates.

Lead researcher, Dr Robert Maher, UCL Electronic & Electrical Engineering, said: "While current state-of-the-art commercial optical transmission systems are capable of receiving single channel data rates of up to 100 gigabits per second (Gb/s), we are working with sophisticated equipment in our lab to design the next generation core networking and communications systems that can handle data signals at rates in excess of 1 terabit per second (Tb/s).

"For comparison this is almost 50,000 times greater than the average speed of a UK broadband connection of 24 megabits per second (Mb/s), which is the current speed defining "superfast" broadband. To give an example, the data rate we have achieved would allow the entire HD Games of Thrones series to be downloaded within one second."

The study, published today in Scientific Reports, used techniques from information theory and digital signal processing to custom build an optical communications system with multiple transmitting channels and a single receiver. As part of the EPSRC-funded UNLOC programme, the project set out to investigate ways to improve the optical network infrastructure to support the explosion of digital content, cloud and e-health services, as well as the ubiquitous connectivity of smart devices referred to as the Internet of Things (IoT).

Professor Polina Bayvel, the principal investigator of the UNLOC programme at UCL, said: "This result is a milestone as it shows that terabit per second optical communications systems are possible in the quest to reach ever higher transmission capacities in optical fibres that carry the vast majority of all data generated or received. A high-capacity digital communications infrastructure underpins the internet and is essential to all aspects of the digital economy and everyday lives."

The team determined the best way of encoding information in optical signals, taking into account the limitations of the transmitter and receiver. They then applied coding techniques commonly used in wireless communications, but not yet widely used in optical communications, to ensure the transmitted signals are adapted to distortions in the system electronics.

Using UNLOC's state-of-the-art lab facilities, the researchers built the new optical system and measured its performance. Fifteen channels, each carrying an optical signal of different wavelength were modulated using the 256QAM format typically used in cable modems, combined and sent to a single optical receiver for detection. By grouping the channels together, the team created a 'super-channel' which although not yet commercially available, is widely believed to be a way forward for the next generation of high-capacity communication systems.

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Imaging with an 'optical brush'

The fibers of a new “optical brush” are connected to an array of photosensors at one end and left to wave free at the other.

Researchers at the MIT Media Lab have developed a new imaging device that consists of a loose bundle of optical fibers, with no need for lenses or a protective housing.

The fibers are connected to an array of photosensors at one end; the other ends can be left to wave free, so they could pass individually through micrometer-scale gaps in a porous membrane, to image whatever is on the other side.

Bundles of the fibers could be fed through pipes and immersed in fluids, to image oil fields, aquifers, or plumbing, without risking damage to watertight housings. And tight bundles of the fibers could yield endoscopes with narrower diameters, since they would require no additional electronics.

The positions of the fibers' free ends don't need to correspond to the positions of the photodetectors in the array. By measuring the differing times at which short bursts of light reach the photodetectors -- a technique known as "time of flight" -- the device can determine the fibers' relative locations.

In a commercial version of the device, the calibrating bursts of light would be delivered by the fibers themselves, but in experiments with their prototype system, the researchers used external lasers.

"Time of flight, which is a technique that is broadly used in our group, has never been used to do such things," says Barmak Heshmat, a postdoc in the Camera Culture group at the Media Lab, who led the new work. "Previous works have used time of flight to extract depth information. But in this work, I was proposing to use time of flight to enable a new interface for imaging."

The researchers reported their results today in Nature Scientific Reports. Heshmat is first author on the paper, and he's joined by associate professor of media arts and sciences Ramesh Raskar, who leads the Media Lab's Camera Culture group, and by Ik Hyun Lee, a fellow postdoc.

Travel time

In their experiments, the researchers used a bundle of 1,100 fibers that were waving free at one end and positioned opposite a screen on which symbols were projected. The other end of the bundle was attached to a beam splitter, which was in turn connected to both an ordinary camera and a high-speed camera that can distinguish optical pulses' times of arrival.

Perpendicular to the tips of the fibers at the bundle's loose end, and to each other, were two ultrafast lasers. The lasers fired short bursts of light, and the high-speed camera recorded their time of arrival along each fiber.

Because the bursts of light came from two different directions, software could use the differences in arrival time to produce a two-dimensional map of the positions of the fibers' tips. It then used that information to unscramble the jumbled image captured by the conventional camera.

The resolution of the system is limited by the number of fibers; the 1,100-fiber prototype produces an image that's roughly 33 by 33 pixels. Because there's also some ambiguity in the image reconstruction process, the images produced in the researchers' experiments were fairly blurry.

But the prototype sensor also used off-the-shelf optical fibers that were 300 micrometers in diameter. Fibers just a few micrometers in diameter have been commercially manufactured, so for industrial applications, the resolution could increase markedly without increasing the bundle size.

In a commercial application, of course, the system wouldn't have the luxury of two perpendicular lasers positioned at the fibers' tips. Instead, bursts of light would be sent along individual fibers, and the system would gauge the time they took to reflect back. Many more pulses would be required to form an accurate picture of the fibers' positions, but then, the pulses are so short that the calibration would still take just a fraction of a second.

"Two is the minimum number of pulses you could use," Heshmat says. "That was just proof of concept."

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