May 9, 2015
Published by the Royal Astronomical Society and led by the University of Warwick, the research finds evidence for numerous planetary bodies, including asteroids and comets, containing large amounts of water.
The research findings add further support to the possibility water can be delivered to Earth-like planets via such bodies to create a suitable environment for the formation of life.
Commenting on the findings lead researcher Dr Roberto Raddi, of the University of Warwick's Astronomy and Astrophysics Group, said: "Our research has found that, rather than being unique, water-rich asteroids similar to those found in our Solar System appear to be frequent. Accordingly, many planets may have contained a volume of water, comparable to that contained in the Earth.
"It is believed that the Earth was initially dry, but our research strongly supports the view that the oceans we have today were created as a result of impacts by water-rich comets or asteroids."
In observations obtained at the William Herschel Telescope in the Canary Islands, the University of Warwick astronomers detected a large quantity of hydrogen and oxygen in the atmosphere of a white dwarf (known as SDSS J1242+5226). The quantities found provide the evidence that a water-rich exo-asteroid was disrupted and eventually delivered the water it contained onto the star.
The asteroid, the researchers discovered, was comparable in size to Ceres -- at 900km across, the largest asteroid in the Solar System.
"The amount of water found SDSS J1242+5226 is equivalent to 30-35% of the oceans on Earth," explained Dr Raddi.
The impact of water-rich asteroids or comets onto a planet or white dwarf results in the mixing of hydrogen and oxygen into the atmosphere. Both elements were detected in large amounts in SDSS J1242+5226.
Research co-author Professor Boris Gänsicke, also of University of Warwick, explained: "Oxygen, which is a relatively heavy element, will sink deep down over time, and hence a while after the disruption event is over, it will no longer be visible.
Read more at Science Daily
According to the Daily Mirror, the photos “were found by former journalist Adam Dew, who has taken steps to verify the pair of alien snaps and said Kodak experts had dated the film to 1947….The photos were supposedly found in Arizona, hidden in a collection of snaps owned by oil geologist Bernard Ray and his wife Hilda Ray, who have both died.”
Assuming that a representative from Kodak authenticated the film as old stock dating back to the 1940s doesn’t mean that Kodak “authenticated” the subject of the photo; all it means is that it’s a genuine old photo, and not, for example, on film produced in the 1980s.
If it’s a genuine old photo, what could it be? An important clue about the real explanation can be seen in the photos, since the small figure appears to have been photographed in a display case (it even has what appears to be a sign explaining what it is, though the image is washed out and the quality is not good enough to read it).
It doesn’t look alien so much as a skeletal human with a large head, which is characteristic of a child’s body. And that’s likely what it is: a child’s mummified body. In fact, it is not the first time that a mummified child’s body has been mistaken for an alien. Long-dead bodies with deformed skulls have previously been mistaken for extraterrestrials, but there is nothing unusual about finding deformed skulls in the Americas; archaeologists have found them for years.
Cranial deformation is a widely known practice, and in 2012 archaeologists in Mexico found a burial ground of twenty-five skeletons; of those, more than half showed intentional skull deformation. Mummified fetuses and babies have been on display in museums around the world for decades, including in South America.
If it is indeed a mummified baby corpse, it would be only the latest of many to have been reinterpreted as something unknown or mysterious. Earlier this year a pair of mummified cats found in Chile was mistaken for the mysterious vampire creature called the chupacabra. The felines had disproportionately large heads compared to the rest of their bodies and were likely kittens.
Part of the reason that these objects seem so bizarre and mysterious is that very few people outside of the fields of archaeology and anthropology are familiar with the process and appearance of mummification.
For most people the word “mummy” evokes bandaged, slow-moving monsters from ancient Egypt. We typically think of bodies being reduced to a skeleton not long after death, but in fact bodies may be preserved for centuries or millennia, either through intentional preservation (such as mummification) or because the environment where a person died helps preserve the bodies (for example high in the cold Andes mountains, or in deserts where the lack of moisture inhibits decay-causing bacteria).
Adult mummies are strange enough, but baby mummies are even rarer and stranger looking. Because babies have disproportionally large heads as compared to the rest of their bodies, their dessicated remains seem all the more inhuman. A Reuters news story featured video of UFO proponent Richard Dolan at the conference claiming, without providing any evidence or documentation, that unnamed experts somehow ruled out the mummy explanation.
Of course extraterrestrials have never been proven to exist, and no photographs of alien bodies have ever been authenticated, and thus the belief or assumption that aliens would have disproportionately large craniums is sci-fi pop culture speculation promoted in entertainment media ranging from “The X-Files” to Steven Spielberg’s seminal 1977 film “Close Encounters of the Third Kind.”
If the “standard” alien depicted decades ago -- and since embraced by UFO buffs -- had an unusually small head and three legs, for example, this and other mummified babies would not be associated with anything extraterrestrial.
Even if it is a genuine extraterrestrial, there’s reason to doubt that the carcass was recovered in Roswell in 1947: None of the original eyewitnesses to the debris found on the New Mexico ranch described any alien bodies or even spacecraft. In fact the first person to find the wreckage described it as “made up of rubber strips, tinfoil, a rather tough paper and sticks.”
Read more at Discovery News
May 8, 2015
Until now, little was known about Hosn Niha, a Roman-Byzantine village located in the Bekaa Valley in Lebanon, the researchers said. Built in approximately A.D. 200, the village was home to a Roman temple and a small settlement, they said.
In the early 1900s, German archaeologists studied the remains of the temple but paid little attention to the neighboring settlement, which they described in a 1938 study as “a picture of complete ransacking,” adding that hardly a trace remained of the settlement’s inhabitants.
During the Lebanese Civil War (1975 to 1990), military activity and looting took a heavy toll on the remains of Hosn Niha. In the late 1980s, treasure hunters riding bulldozers scraped through the village, moving and damaging ancient clues buried in the ground, according to the new study.
But “even though the core of the village has been irreparably damaged, a significant amount of the site remains in situ [in its original place] and with enough surviving features and structural evidence to warrant further investigation,” the researchers wrote in the new study, detailed in the April issue of the journal Antiquity.
Their diligence paid off. An analysis of pottery shards scattered around the village shows evidence of a large Greco-Roman settlement and a later medieval occupation, likely during the 13th or 14th centuries, the researchers said.
“What we were trying to do is show that sites that have been quite badly damaged by conflict shouldn’t just be ignored and forgotten,” said study researcher Ruth Young, a senior lecturer of archaeology at the University of Leicester in England. “I think that what we have now is a lot more knowledge about how villages operated and connection with the temple.”
‘Blimey, what a mess’
When the researchers arrived at Hosn Niha, they found bulldozed piles — some reaching 13 feet high (4 meters) — of pottery fragments mixed with dirt, the researchers said.
“When you first look at the site, you think, ‘Blimey, what a mess. Where do we even start?’” Young told Live Science.
But the bulldozers hadn’t pushed the pottery fragments far from their original spots, usually less than 164 feet (50 m), the researchers said. They quickly got to work, using a precise form of global positioning system (GPS) called differential GPS to map architectural fragments, such as door thresholds, columns and stone walls.
The researchers’ understanding of the settlement grew as they carefully mapped the structures and dated the pottery fragments. They suggest a settlement was firmly in place by A.D. 200, with a dense area of dwellings in the central village and more dispersed courtyard dwellings skirting the village, the researchers said.
The village likely diminished by the 600s during the early Islamic period, though it’s unclear why, they said. Today, the most complete remains of the site belong to the Roman temple, which still has walls standing 33 feet (10 m) high, the researchers said.
The early inhabitants likely farmed in the valley, possibly growing grapes for wine, the researchers said. “This might explain why they were able to build such big temples,” said study co-author Paul Newson, a professor of history and archaeology at the American University of Beirut in Lebanon. “If they were doing wine, they could do it as a cash crop.”
The researchers also found glazed pottery shards, characteristic of the early medieval period, scattered around a stone structure, suggesting the structure was a medieval development, he said.
Looters had robbed a cemetery to the east of the settlement, but the archaeologists still studied the tomb types, including stone sarcophagi, individual cist (stone-lined) tombs and communal rock-cut tombs, they said.
Read more at Discovery News
Marine archaeologist Barry Clifford told reporters he had found a 50-kilogram (110-pound) silver bar in the wreck of Kidd's ship the Adventure Gallery, close to the small island of Sainte Marie.
Captain Kidd, who was born in Scotland in about 1645, was first employed by British authorities to hunt pirates, but he turned himself into a ruthless criminal of the high seas.
After looting a treasure-laden ship in 1698, he was caught, imprisoned and questioned in front of the British parliament before being executed in Wapping, close to the River Thames in 1701.
The fate of much of his booty, however, has remained a mystery, sparking intrigue and excitement for generations of treasure-hunters.
Clifford, who was filmed by a documentary crew lifting the silver bar off the sea bed, handed it over to Malagasy President Hery Rajaonarimampianina on Sainte Marie. Soldiers guarded the apparent treasure at the ceremony, which was attended by the US and British ambassadors.
"We discovered 13 ships in the bay," Clifford said. "We've been working on two of them over the last 10 weeks. One of them is the Fire Dragon, the other is Captain Kidd's ship, the Adventure Galley."
Read more at Discovery News
The NASA/ESA Hubble Space Telescope stumbled across this finding after archival data of distant quasars was analyzed.
“Halos are the gaseous atmospheres of galaxies. The properties of these gaseous halos control the rate at which stars form in galaxies according to models of galaxy formation,” said Nicolas Lehner, of the University of Notre Dame, Ind., lead author of the new study published in The Astrophysical Journal.
This halo is a big deal; it is estimated to contain half the mass of all the stars in the galaxy itself and is 1,000 times more massive than previous estimates suggested. Galactic halos are thought to form the same time as their host galaxies and Lehner’s team have determined that Andromeda’s halo is enriched with heavy elements.
These heavy elements came from periods of intense supernova activity — when massive stars run out of fuel and explode — within the galactic disk and powerful stellar winds blew the heavy element-laced gases into intergalactic space, into Andromeda’s halo. It is thought that nearly half of all the heavy elements generated by supernovae over Andromeda’s lifetime can be found in this extended halo.
Interestingly, if our galaxy also possesses a halo comparable to Andromeda’s it is conceivable that both halos are currently in contact and mixing galactic material. Both galaxies are currently on a collision course and expected to merge in 4 billion years time. Therefore, understanding halo dynamics may reveal that, well before galactic mergers, the respective galaxies’ halos merge quiescently.
The discovery of the Andromeda halo’s immense scale and mass came from the study of distant quasars. Over the past 5 years, Hubble has amassed a wealth of quasar data and the researchers were able to focus on quasar data in the direction of Andromeda. As Andromeda’s halo is dark, it was only detectable by the dimming of quasar emissions. As several quasars have been studied beyond Andromeda, a picture of the halo’s landscape could be constructed (as described in the diagram below.
Read more at Discovery News
|Someone get this lady a tiny "Mother of the Year" mug.|
Such is the life of the Stegodyphus lineatus spider. It’s springtime in Israel’s Negev Desert, and mom has built a cylinder-shaped web in a bush, with sheets of silk extending from the entrance. This time of year, the hunting is good, as insect populations peak—and inevitably stumble into the spider’s silk sheets. Mother spider grows fat, standing guard over 80 or so eggs, all bundled up in a silk disk, keeping an eye out for infanticidal males, which, like male lions, will kill her young so she’s available to mate again.
But these young ‘uns make it. “The point that she opens the egg sac is the point that she stops feeding,” says Mor Salomon, a biologist at the Israel Cohen Institute for Biological Control. “We have tried giving them food in the lab, but it just doesn’t work—they just don’t feed.”
|Feeding time, as a mother spider gives whole new meaning to the term “baby-faced.”|
That is, unless something goes wrong with her young within the first five days. Should they fall victim to an infanticidal male spider, she can actually shut down the dissolving. And with her ovaries still intact, she can mate with him and start the process anew.
But if her young make it those two weeks, she’ll have digested and regurgitated herself to death, losing 41 percent of her body mass. She leaves them with one last gift, though: the rest of her. They clamber over her abdomen and pierce it and suck out the remaining fluid, gorging themselves. “So when they finish her,” Salomon says, “you can see they are very tiny, tiny heads on this very big balloon of an abdomen swollen from all the food they took from her.”
Their mother, on the other hand, isn’t looking so well after losing an additional 54 percent of her body mass, bringing the grand total loss of flesh to 95 percent. “When they finish her, you can see only a hollow exoskeleton,” says Salomon. “You see the abdomen is shrunken, like a balloon whose air came out.”
|A dead mother. Notice her abdomen at bottom, shrunken like a deflated balloon. I’m even ruining balloons now, aren’t I.|
Now motherless, the young stick around for a few weeks to a month, fighting among themselves for insects that get caught in the silk. Unable to compete, the smaller siblings must find other means of feeding. “So what happens is that the small spiderlings leave first; they disperse from the female’s nest,” Salomon says. “And each one sits on a different branch or a different bush and starts its solitary life, making its own nest and web.” For the females among them, life will be short: They mate the next spring and consequently dissolve themselves.
|If you see this in the Negev Desert in the springtime, something very weird is about to happen.|
It gets rather more intriguing when you consider that there’s a related species of spider, called Stegodyphus dumicola, that forms into social groups—quite the rarity for arachnids, which typically are lone guns. Only about half the females in this group will feed enough to mature into breeding adults; the other half plays an interesting role. When the group’s eggs hatch, not only will the moms dissolve and regurgitate their insides, but their immature sisters will do so as well, giving up their lives for their nieces and nephews.
If it doesn’t seem to make sense for a mother to kill herself for her young, it would seem to make even less sense for her sisters to sacrifice themselves when the brats aren’t even theirs. But behaviors don’t evolve to the detriment of a species (well, maybe except Juggalo culture—could have gone without that one). It turns out that this actually makes good evolutionary sense. It’s known as kin selection: By helping guarantee their nieces and nephews survive, the sisters are indeed helping pass some of their genes along.
Sure, not as many of those genes if they’d given birth themselves, but still, it’s better than passing along none at all. The same principle goes for other cooperative species like bees and ants. Evolution should drive species to be selfish in the pursuit of siring the next generation, but in fact banding together can be a good evolutionary strategy in its own right.
Read more at Wired Science
May 7, 2015
The over 500-million-year-old brain, described in the latest issue of the journal Current Biology, suggests that rudimentary brains emerged before defined heads. Defined heads likely emerged later to protect brains.
The ancient brain belonged to a crustacean called Odaria alata, which had a pair of large eyes on stalks that made it look like the tiny organism was wearing deely boppers. Scientists also often say that Odaria alata looked like a submarine. You can see the resemblance more in this video.
Javier Ortega-Hernández, who authored the study, determined that the eye-like features were connected to a hard, thin and flat body part called the "anterior sclerite." The connection was made possible via nerve endings originating from the front part of the brain.
"The anterior sclerite has been lost in modern arthropods (insects, spiders and crustaceans), as it most likely fused with other parts of the head during the evolutionary history of the group," Ortega-Hernández, a postdoctoral researcher at the University of Cambridge, explained in a press release.
For the study, he compared the remains of Odaria alata with another very ancient creature: a soft-bodied trilobite. Trilobites were marine creatures that were abundant during the Paleozoic Era, 542–251 million years ago. Fossil collectors love trilobites, due to their incredible age, relative commonness, different types and other factors.
Ortega-Hernández next compared the creatures with anomalocaridids, a group of large swimming predators that lived at around the same time as the other studied species. These larger organisms, like Odaria alata, were found to have a natural plate in the brain region.
"What we're seeing in these fossils," he said, "is one of the major transitional steps between soft-bodied worm-like creatures and arthropods with hard exoskeletons and jointed limbs–this is a period of crucial transformation."
Read more at Discovery News
The fire ant’s digging prowess taps the same concepts behind kids’ building blocks, according to a new study that looks at the micro-mechanics of their ability to move giant particles in tiny spaces.
“They love to dig,” said Daniel Goldman, physics professor at Georgia Tech and an author on the paper in this week’s Journal of Experimental Biology.
“You can get them to dig in anything. When the particles are big, they grab a grain and remove it. It’s not a trivial task. They have to carefully to hold the particle in their jaw. They have another mode of digging where they can rake and scrape the soil into a pellet, and use their mandibles and antennae in a new way to help shape that pellet.”
Goldman and his colleagues conducted several lab experiments with fire ants using different size particles of sand and tiny glass pellets. They also took X-rays of the ants’ tunnels and found something surprising. The ants carefully constructed the tunnel walls like Jenga blocks, each particle precariously supporting the one on top. When the researchers probed the tunnels with a metal rod, they collapsed, just like the kids’ wooden tower.
“They are doing some nice manipulations that we don’t understand yet,” Goldman told Discovery News.
The research team – which included lead author and postdoctoral researcher Daria Monaenkova – also noticed that the ants built tunnels faster in coarser soils, and didn’t do as well in extremely dry soil as compared to wetter soil.
Since arriving from South America in the 1930s, fire ants have spread throughout the southern United States. In recent years, they have spread westward to Texas, New Mexico and Southern California, occupying an estimated 300 million acres of territory. Their massive colonies contain several hundred thousand individuals, and extend several feet below ground.
Their colonies are considered a “superorganism,” a group of individuals that acts as a single creature. Part of their success is linked to their incredible tunneling abilities, Goldman says, and their ability to squeeze past each other in tiny spaces while carrying big chunks of soil.
Read more at Discovery News
MESSENGER’s four-year mission at Mercury ended last week with the spacecraft, out of fuel to raise its orbit, crashing into the planet’s surface. But for months before its demise, MESSENGER gave scientists a parting gift: unprecedented, close-up images and data about the solar system’s innermost planet.
Mercury, situated just 36 million miles from the sun (compared to Earth’s 93 million-mile roost) has proven to be an odd world, both scorchingly hot and frigidly cold, and the only planet in the solar system besides Earth that has a global magnetic field generated by a dynamo – motions of metallic fluids in the core.
MESSENGER’s close-ups allowed scientists to pick up trace signals of magnetization in Mercury’s crust. Based on the number of impact craters, the magnetized regions are very old, dating back 3.7 billion to 3.9 billion years. (Counting craters is a common technique to approximate the age of a planet’s surface, with younger areas showing fewer impacts than older ones.)
The findings push back the clock for the start of Mercury’s magnetic field to about 700 million years after the planet’s formation. Researchers, however, cannot yet say if Mercury’s magnetic field has been operating continuously since then.
“The simplest possible explanation is that you switched a magnetic field on and then it just continued to the present day … but it may turn out that it would have been easier for that field to have switched on and off,” MESSENGER guest investigator Catherine Johnson, a geophysicist with the University of British Columbia in Vancouver, told Discovery News.
“At the moment we don’t know anything about (the magnetic field) between 4 billion years ago and today. Obviously, that’s something that we’re going to be looking at,” she added.
Read more at Discovery News
Through the analysis of observational data from NASA’s Cassini Saturn-orbiting spacecraft and computer modeling, scientists are beginning to realize that when it comes to Enceladus’ geysers that erupt from the moon’s polar “tiger stripes”, there’s more than meets the eye.
“We think most of the observed activity represents curtain eruptions from the ‘tiger stripe’ fractures, rather than intermittent geysers along them,” said Joseph Spitale, a participating scientist with the Cassini mission at the Planetary Science Institute in Tucson, Ariz. “Some prominent jets likely are what they appear to be, but most of the activity seen in the images can be explained without discrete jets.”
In short, in new research published today (May 7) in the journal Nature, Spitale’s team think that Enceladus’ discrete geysers are an illusion.
Called “curtain eruptions”, the researchers believe that vapor is being ejected along Enceladus’ tiger stripes, which are often wavy fissures. As the vapor is ejected along these wavy features, depending on the angle you’re viewing the eruptions from, you will sometimes be looking through the bend or ‘fold’ in the curtain of vapor. These folds will make the scattered light from the vapor appear more intense, giving the illusion of being a discreet geyser.
“The viewing direction plays an important role in where the phantom jets appear,” said Spitale. “If you rotated your perspective around Enceladus’ south pole, such jets would seem to appear and disappear.”
Curtain eruptions occur on Earth in regions of volcanic activity — such as Hawaii, Iceland and the Galapagos Islands. Molten rock can erupt from long fissures, often creating impressive curtains of fire.
Read more at Discovery News
May 6, 2015
The X2-class flare exploded from the sun’s limb over a region of intense magnetic activity designated AR (active region) 2339. Although it wasn’t Earth-facing, the flare still had a dramatic effect on Earth — the high-energy extreme-ultraviolet and X-ray radiation bathed our planet’s uppermost atmosphere, causing waves of ionization.
Known as the ionosphere, these uppermost layers are used to bounce global radio communications around the globe and, shortly after the solar flare that occurred at 22:11 UT (6:11 p.m. ET) yesterday, radio operators reported a wide-spread outage of frequencies below 20 MHz, writes Spaceweather.com. This frequency would have likely impacted mariners, aviators and ham radio operators.
The eruption also generated its own radio burst at shortwave frequencies that could be recorded by ground-based receivers. These radio emissions were caused by the rapid acceleration of electrons trapped within the powerful magnetic fields in the lower corona (the sun’s superheated atmosphere).
A coronal mass ejection (CME) was also observed accelerating into interplanetary space from the flaring region, but as AR2339 is facing perpendicular to Earth’s location, it’s not thought to be Earth-directed, though space weather forecasters will be keeping a close eye on the trajectory of the magnetic bubble of solar plasma. If the CME were to be aimed at Earth, dramatic geomagnetic storms could result, boosting the intensity of solar radiation around Earth and triggering auroral activity in higher latitudes.
This is the second X2-class flare to erupt in 2015, proving that, although the sun may be gradually waning in activity for this solar cycle, it can still pack a powerful punch.
From Discovery News
This 505-million-year-old phallus-like creature actually had a throat full of teeth.
Now, scientists who took a close look at the teeth of fossilized penis worms (or priapulids) have discovered a new species.
Paleontologist Charles Walcott first discovered O. prolifica in 1911 in the Burgess Shale, a geologic formation in the Canadian Rockies that contains fossils of bizarre critters, such as trilobites and velvet worms, from the middle Cambrian period.
At just a few inches long, O. prolifica lived inside burrows and had a proboscis that was lined with rows of little hooks, teeth and spines. This mouthpart could be inverted into the creature’s trunk (as this animation from the Royal Ontario Museum shows), and it allowed O. prolifica to feast on shelled creatures known as hyolithids (although O. prolifica may also have occasionally cannibalized other penis worms), according to the Smithsonian National Museum of Natural History.
In a new report, researchers led by Martin Smith of the University of Cambridge in England created a “dentist’s handbook” of O. prolifica teeth. Under a microscope, they looked at 40 O. prolifica fossils from a location called the Upper Walcott Quarry that are now in a collection at the Smithsonian Institution, and 70 other specimens from the Lower Walcott Quarry that are housed in the Royal Ontario Museum.
The researchers found some unexpected differences between the teeth in the two groups of fossils. For example, the specimens from the Lower Walcott Quarry had some teeth with a central prong that was flanked by just two skinny, hollow “denticles,” whereas up to eight denticles were common in the corresponding teeth of the Upper Walcott Quarry specimens.
Read more at Discovery News
The organism is single-celled, technically called an archaeon. But on a genetic level, it also has what the researchers called a starter kit that could have given rise to complex genetic and cellular organisms like animals, plants and fungi, collectively called eukaryotes.
The newly found organism was dubbed Lokiarchaeota and nicknamed Loki. The researchers, from Uppsala University in Sweden, were shocked by what they found in Loki.
“When we started to have a more in-depth look at the genes of this new Loki genome, we found that something was strange about it quite early on,” Ettema told the Washington Post. “We found genes that were much more like eukaryotes.
“First we had to convince ourselves it was true. And once we were certain, we did further analysis of the genes. And it turns out that they’re quite special.”
At one point long ago, Ettema told the Post, complex organisms and Loki went their seperate ways: one became life as we know it and the Lokis of the world stayed stuck in the mud.
From the paper: “Our results provide strong support for hypotheses in which the eukaryotic host evolved from a bona fide archaeon, and demonstrate that many components that underpin eukaryote-specific features were already present in that ancestor. This provided the host with a rich genomic “starter-kit” to support the increase in t he cellular and genomic complexity that is characteristic of eukaryotes.”
From Discovery News
The galaxy EGS-zs8-1 lies 13.1 billion light-years from Earth, the largest distance ever measured between Earth and another galaxy.
The universe is thought to be about 13.8 billion years old, so galaxy EGS-zs8-1 is also one of the earliest galaxies to form in the cosmos. Further studies could provide a glimpse at how these early galaxies helped produce the heavy elements that are essential for building the diversity of life and landscapes we see on Earth today.
EGS-zs8-1 is one of the brightest objects observed in this region, which is around 13 billion light-years from Earth. The authors of the new research say other galaxies likely lie at similar distances or even further from Earth, but they are too faint for scientists to measure their exact distance.
"We have a lot of sources that we can see with Hubble that are probably farther way" than EGS-zs8-1, said Pascal Oesch, a postdoctoral researcher at Yale and lead author of the new study. "But we cannot measure their exact distance yet."
To measure the separation between Earth and a far-off cosmic object, astronomers often look at how quickly those objects are moving away from Earth. The universe is expanding; space itself is growing like a balloon or a loaf of bread in the oven. Objects in the universe thus move away from each other, like raisins in the bread dough.
As these objects move away from Earth, the light they emit becomes shifted. The more far-flung an object is, the faster it appears to move away from Earth, and the more the light is shifted. So, by measuring the degree of shifting — known as "redshift" — astronomers can also measure distance. A higher redshift equals a larger distance, and galaxy EGS-zs8-1 has the highest redshift ever measured, according to the new research (the previous record holder has a redshift that is only slightly smaller).
Galaxy EGS-zs8-1 was originally identified by the Hubble Space Telescope and the infrared Spitzer Space Telescope, and stood out because of the unique colors it emitted. The new research used observations conducted with the MOSFIRE instrument on the W.M. Keck Observatory's 10-meter (33 feet) telescope in Hawaii.
The light from EGS has traveled a distance of 13.1 billion light-years, so the light shows EGS-zs8-1 as it was 13.1 billion years ago. At that time, the universe was only about 670 million years old, or about 5 percent its current age of about 13.8 billion years, according to a statement from Yale. The first stars began forming about 200 million to 300 million years after the Big Bang, according to Oesch.
By combining observations from Keck, Spitzer and Hubble, the researchers say they can estimate that the stars in EGS-zs8-1 are "between 100 and 300 million years old." But Oesch said it is difficult to know how old EGS-zs8-1 is compared to other galaxies at a similar distance from Earth. It is, however, one of the oldest galaxies yet measured.
The new observations also show that EGS-zs8-1 is forming stars 80 times faster than the Milky Way. In addition, the still-growing galaxy has "already built more than 15 percent of the mass of our own Milky Way today," Oesch said in a statement from Yale University.
The unique colors observed in EGS and other early galaxies by the Spitzer Space Telescope present questions about what took place in these primeval environments. According to the statement, these colors could have been caused by the rapid formation of massive, young stars that interacted with the primordial gas in these galaxies. Oesch said further study of the galaxy could reveal the types and amounts of heavy elements that formed there.
Read more at Discovery News
May 5, 2015
The ultimate early bird, Archaeornithura meemannae, lived 130.7 million years ago -- pushing back the evolutionary record of modern birds by around 6 million years.
At 145 million years old, Archaeopteryx is still the oldest and most primitive known bird, but it has no living descendants. A. meemannae, on the other hand, has been placed in the clade Ornithuromorpha, which is the same evolutionary branch that gave rise to all bird species currently living. It's described in the latest issue of the journal Nature Communications.
The newly found bird looked "nearly" like today's shorebirds, senior author Zhonghe Zhou told Discovery News, although A. meemannae "could have been preyed upon by carnivorous dinosaurs."
Zhou is director of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences. He and his colleagues analyzed the remains of the bird, represented by two very well-preserved specimens.
"Its forelimbs were shorter than its hind limbs, which is quite unusual," lead author Min Wang said.
Because of its long legs and other anatomy, the researchers think the ancient bird spent much of its time near the shores of a lake, patrolling the area looking for insects and other small prey to eat. To this day, long-legged birds like cranes and herons have a somewhat similar lifestyle.
It sported feathers and was capable of flight, yet its wings were short, so the scientists think the bird had a mostly terrestrial existence.
Feathered dinosaurs lived during the Jurassic and Cretaceous Periods in China, with only some evolving to become birds like A. meemannae. Scientists haven't pinpointed which dinosaurs are the direct ancestors to birds, but possible candidates are dromaeosaurids, troodontids and scansoriopterygids, Wang and Zhou said.
Such dinosaurs "probably lived in a forest environment," according to Zhou, and were "climbing, jumping and gliding." These feats were possible, in part, since the dinosaurs had feathered or bat-like wings.
Non-avian (meaning not-bird) dinosaurs died out during a mass extinction event that occurred 65 million years ago. Some birds, such as a bizarre group that had teeth and clawed wings, bit the dust then too.
As for why other birds, including some relatives of A. meemannae, survived, Zhou said, "These birds had a lot of advantages...better flight, and more modern physiology, and they could escape from predators more easily and could get access to more food resources."
He said that they "probably survived better in extreme environments as they were warm-blooded."
Ornithologist and evolutionary biologist Alan Feduccia of the University of North Carolina told Discovery News that "the research is important," due to what it reveals about the evolutionary history of birds.
Read more at Discovery News
According to historic documents, the Hanneke Wrome was one of two ships that left Luebeck, Germany, for Tallinn, Estonia, on Nov. 11, 1468.
Records also indicate the cargo included 10,000 gold coins and gold jewelry — a treasure estimated to be worth more than $150 million today.
Strong east winds, actually very rare in Finland, caught both vessels. While the other ship managed to get to Tallinn, the Hanneke Wrome went down in the storm with more than 200 passengers and crew.
“It was one of the major maritime casualties of the time and it wasn’t the only one to occur on that route,” team leader Rauno Koivusaari said.
In 1994 the Ms Estonia sank while crossing the Baltic Sea, en route from Tallinn to Stockholm. Taking 852 lives, the sinking was one of the worst disasters at sea of the 20th century.
An experienced wreck researcher who also discovered the treasure-filled Vrouw Maria in 1999, Koivusaari found what he believes is the Hanneke Wrome’s wreck south of the Finnish island of Jussarö.
“The wreck is scattered in east-west direction, confirming the dynamic of the sinking during the eastern storm,” Koivusaari told Discovery News.
He added that documents in Tallin state archives record two different distances for the ship sinking, one 10 miles from Tallin and other 14 miles from Tallin.
“Both of them were right. One measured the distance in Hanseatic nautical miles and the other used the league, a unit of lenght invented by Romans and still in use at that time. The ship was found right at that recorded distance,” Koivusaari said.
Measuring some 130 feet in length, the Hanneke Wrome appears in an underwater video shot by team member Micke Ahgren.
The footage shows well-preserved sections of the wooden hull and even an anchor.
“It is right the kind of anchor used in the Hanseatic ships,” Koivusaari said.
He added the wreck shows it was built in the construction style of a cog ship, but it is bigger and may be a hulk ship instead. Hulk ships were mostly used as a river or canal boats.
“The wreck has more than one mast, perhaps even three. I could see a joint knee integrated with the ship ribs. This is strange, but really nobody knows much of this ship style,” Koivusaari said.
Koivusaari and his team have so far identified a few items.
Read more at Discovery News
But new radiometric dating of rocks and a detailed look at the impact sites suggests the two craters are a "false doublet," created by two separate asteroid impacts about 180 million years apart.
"Even though we did think they formed simultaneously, it looks like they actually didn't,” said geologist Gordon "Oz" Osinski of Western University in Ontario. On Monday Osinski presented the results of the research conducted by he and his colleagues in Canada, Germany and Australia, at the Joint Assembly meeting of U.S. and Canadian geoscientists in Montreal.
The twin craters were recognized as having been created by asteroids about 50 years ago, and at that time it was assumed that a binary asteroid – a pair of asteroids traveling through space together – had made the two lakes. Binary asteroids have been observed for centuries, and the cratering of the Moon and other heavily cratered worlds in our solar system makes it clear multiple crater impacts are not uncommon.
The research into the Clearwater Lakes involved measuring the amounts of radioisotopes in minerals of rocks that were melted by the impact. Radioisotopes are elements that change at known rates into what are called daughter isotopes. Working out the ratios of the parent and daughter isotopes enables scientists to figure out how much time has passed since a mineral – and usually the rock it belongs to – has been molten.
Osinski and his colleagues measured Argon-40 and Argon-39 from impact melt rocks at the 36-kilometer (22-mile) wide West Clearwater Lake and got a date of 286.2 million years, give or take 2.2 million years. Rocks from the 26-km (16-mile) wide East Clearwater Lake were dated to somewhere between 460 to 470 million-years-old.
"We get no ages whatsoever in the 200-million-year range" at East Clearwater Lake, Osinski said. "They are all upwards of 400 million years."
The older age of East Clearwater Lake was glimpsed before, in a radioisotope study done 25 years ago. But that single measurement of about 460 million years was thrown out as unreliable.
"Since day 1 we've assumed they formed from the impact of a binary pair," said Osinski. And so the older date, just didn't fit – until now.
Read more at Discovery News
Over a period of two years, the team, led by University of Cambridge researchers, noted a three-fold change in temperature on the surface of 55 Cancri e. The super-Earth planet orbits a sun-like star 40 light-years away in the constellation of Cancer. It is twice the size of Earth and eight times our planet’s mass.
55 Cancri e is well-known to exoplanet hunters as the “diamond planet” — a world thought to be carbon-rich, possibly covered in hydrocarbons. But this new finding, published today in the arXiv pre-print service, has added a new dimension to the planet’s weird nature.
“This is the first time we’ve seen such drastic changes in light emitted from an exoplanet, which is particularly remarkable for a super-Earth,” said co-author Nikku Madhusudhan, of Cambridge’s Institute of Astronomy, in a press release. “No signature of thermal emissions or surface activity has ever been detected for any other super-Earth to date.”
“We saw a 300 percent change in the signal coming from this planet, which is the first time we’ve seen such a huge level of variability in an exoplanet,” said lead author Brice-Olivier Demory of the Cambridge’s Cavendish Laboratory. “While we can’t be entirely sure, we think a likely explanation for this variability is large-scale surface activity, possibly volcanism, on the surface is spewing out massive volumes of gas and dust, which sometimes blanket the thermal emission from the planet so it is not seen from Earth.”
Spitzer measurements of the “day-side” of the exoplanet revealed a temperature swing of 1,000 to 2,700 degrees Celsius (1800-4900 degrees Fahrenheit), hinting that the surface of 55 Cancri e is molten and undergoing intense volcanic eruptions as it orbits its star, 55 Cancri. The exoplanet is the innermost world in the 55 Cancri system of five known exoplanets with an extremely compact orbit around the star. It completes one orbit every 18 hours and is tidally locked with its star (one hemisphere is in constant daylight, facing the star).
In our solar system, we know of one place that is wracked by volcanic activity as it completes its orbit around Jupiter. The moon Io is driven by intense tidal interactions with the solar system’s largest gas giant planet, causing intense volcanic activity that can be seen from Earth. The volcanism on 55 Cancri e, however, is many more times intense than Io’s.
This discovery, although preliminary, has thrown a wrench in the previous “diamond planet” model of 55 Cancri e.
Read more at Discovery News
Believed to be the genesis of a possible star system, this dusty cloud — called LDN1774 — may collapse under mutual gravity in the future, eventually sparking the birth of a protostar and eventual system of planets.
This feature was observed in visible light by the Wide Field Imager, an instrument attached to the European Southern Observatory’s 2.2-meter MPG/ESO telescope at La Silla, Chile, but it’s not the only example of such an ominous looking black cosmic cloud.
Located around 500 light-years from Earth, another pitch black molecular cloud called Barnard 68 resides. Extensively studied by ESO telescopes, this cloud can be probed in infrared wavelengths — this form of radiation can pass through the star-forming material, allowing astronomers to see the earliest stages stellar birth.
From Discovery News
May 4, 2015
So far the deadly syndrome has killed 6 million bats in North America alone, so the findings, published in the Proceedings of the National Academy of Sciences, provide some hope that remaining bats can be saved.
The disease is named for the white fungus, Pseudogymnoascus destructans. It infects the skin of the muzzle, ears, and wings of hibernating bats.
The fungus is sinister because it penetrates the bodies of the resting bats. The resulting injuries wake the bats, which in their discomfort, begin moving in their caves and flying when they should be hibernating. Eventually, most victims succumb to emaciation, since they run down their body fat stores meant to last them through the hibernation.
The HIV drugs, called protease inhibitors, appear to knock out much of the fungus. The word “protease” refers to enzymes that can break down proteins and peptides, so inhibiting these damaging enzymes holds many benefits.
“This study suggests that proteases may help in infection and so addition of protease inhibitors could block degradation and invasion of bat tissues by the fungus,” Brown University biologist and co-author Richard Bennett said in a press release.
Bennett and his team discovered an enzyme, called “Destructin-1,” which is secreted by the white nose syndrome fungus. This protease, along with other components of the fungus, can attack collagen, a primary protein found in animal connective tissues.
Read more at Discovery News
But the purpose of the desert etchings may have changed over time.
The earliest Nazca Lines were created so pilgrims could view the markings along a ritual processional route, the researchers said. But later people may have smashed ceramic pots on the ground where the lines intersected as part of an ancient religious rite, according to a study presented here on April 16 at the 80th annual meeting of the Society for American Archeology.
What’s more, the Nazca Lines may have been created by at least two different groups of people who lived in different regions of the desert plateau, researchers said.
In one of the driest places on Earth, locked between the Andes Mountains and the coast, more than a thousand geoglyphs dot the landscape. People from an ancient civilization created the shapes between 200 B.C. and A.D. 600, by removing the reddish rocks on the surface of the desert, revealing the white-hued earth beneath.
The strange shapes in the desert include animals such as camelids, dogs and monkeys, as well as fanciful supernatural beings, scenes of decapitation and trophy heads, and geometric designs such as trapezoids, lines and triangles. Though the mysterious shapes gained widespread attention in the 1920s, when plane passengers saw them from above, people who lived there likely saw them even earlier while walking the hilltops in the Nazca plateau.
Archaeologists have long puzzled over the purpose of the Nazca Lines. Some researchers have argued the Nazca lines form a labyrinth. Others have said the lines and figures matched up with the constellations in the sky or with subterranean water routes. And still others have said the Nazca Lines were part of an ancient pilgrimage route.
In recent years, researchers at Yamagata University in Japan have uncovered 100 geoglpyhs, as well as shards of broken ceramics at the intersection points of some of the lines.
To understand exactly how all of these images fit together, Masato Sakai of Yamagata University and his colleagues analyzed the location, style and method of construction for some of these newfound geoglpyhs. Sakai found that about four different styles of geoglyphs tended to be clustered together along different routes leading to a vast pre-Incan temple complex in Peru known as Cahuachi. Archaeological evidence, such as several temples and pyramids, as well as a trove of severed heads, suggests that Cahuachi was once a religious center where pilgrims brought offerings.
In addition to showing different content, the geoglyphs were also constructed differently from each other, made by removing rocks from the interior of the images in some cases and the border in others, Sakai said. For instance, images of animals such as condors and camelids were found along a route that started from the Ingenio River, which the team roughly categorized as type A and type B, respectively.
“The geoglyphs of type A and B are located not only in the area adjacent to the Ingenio Valley but along the pathway to Cahuachi. Therefore it seems reasonable to assume that type A and B geoglyphs were drawn by the group from the Ingenio Valley,” Sakai told Live Science.
Meanwhile, a separate style of images, such as the supernatural beings and the trophy heads, were concentrated in the Nazca Valley and its route to Cahuachi, likely made by a distinct group of people who lived in that region. A third group of geoglyphs, likely made by both groups, was found in the Nazca Plateau between the two cultures.
The purpose of the geoglyphs may have also changed over time from what archaeologists call the final Formative period, which spanned until A.D. 200, to the early Nazca period, which ended in A.D. 450. The smashed ceramics dated to the later period.
“Our research revealed that the Formative geoglyphs were placed to be seen from the ritual pathways, while those of the early Nazca period were used as the loci of ritual activities such as intentional destructions of ceramic vessels,” Sakai said.
Read more at Discovery News
In a new study, researchers using a brain scanner and some fancy camera work gave study participants the illusion that their bodies were located in a part of a room other than where they really were. Then, the researchers examined the participants’ brain activity, to find out which brain regions were involved in the participants’ perceptions about where their body was.
The findings showed that the conscious experience of where one’s body is located arises from activity in brain areas involved in feelings of body ownership, as well as regions that contain cells known to be involved in spatial orientation, the researchers said. Earlier work done in animals had showed these cells, dubbed “GPS cells,” have a key role in navigation and memory.
The feeling of owning a body “is a very basic experience that most of us take for granted in everyday life,” said Dr. Arvid Guterstam, a neuroscientist at the Karolinska Institutet in Sweden, and co-author of the study published today (April 30) in the journal Current Biology. But Guterstam and his colleagues wanted to understand the brain mechanisms that underlie this everyday experience.
Rubber hands and virtual bodies
In previous experiments, the researchers had explored the feeling of being out of one’s body. For example, the researchers developed the so-called “rubber hand illusion,” in which a person wearing video goggles sees a rubber hand being stroked, while a researcher strokes the participant’s own hand (which is out of sight), producing the feeling that the rubber hand is the participant’s own. The researchers have used a similar technique to give people the feeling of having a manikin’s body, or even an invisible body, as they described in a report published last week in the journal Scientific Reports.
In the new study, Guterstam and his colleagues wanted to understand the brain mechanisms behind the perception of where one’s body is located. Experiments in mice and other animals have shown that neurons called GPS cells are involved in navigating one’s body in space (as well as in memory), a finding that was awarded the Nobel Prize in physiology or medicine in 2014.
These studies have typically involved animals running in a virtual maze, while electrodes are hooked up to their brains. “But we don’t know what the animals perceive,” Guterstam told Live Science. To better understand how the process works in people, the researchers scanned the brains of people who were experiencing the illusion of being outside their body, Guterstam said.
In the latest experiment, the participants lay in an MRI scanner while wearing a head-mounted display that showed video from a set of cameras elsewhere in the room. The cameras were positioned to look down on the body of a stranger, while an image of the participant’s own body lying inside the scanner was visible in the background.
To produce the out-of-body illusion, the researchers touched the participants’ body with a rod while simultaneously touching the stranger’s body in the same place, in view of the cameras. For the participants, this technique produces the illusion that their body is in a different part of the room than where it actually is.
“It’s a very fascinating experience,” Guterstam said. “It takes a couple of touches, and suddenly you actually feel like you’re located in another part of the room. Your body feels completely normal — you don’t feel as it’s floating around,” he added.
Then, the researchers analyzed the brain activity in the participants’ temporal and parietal lobes, which are involved in spatial perception and the feeling of owning one’s body. From this activity, Guterstam and his colleagues decoded the participants’ perceived location.
The researchers found that the hippocampus, a region where GPS cells have been found, is involved in figuring out where one’s body is. They also found that a brain region called the posterior cingulate cortex is what binds together the feeling of where the self is located with the feeling of owning a body.
The findings could one day lead to a better understanding of what happens in the brains of people with a condition called focal epilepsy, who have seizures that affect only one half of the brain, as well as people with schizophrenia. Out-of-body experiences are more commonly reported by these groups.
Read more at Discovery News
Using the MUSE instrument on the European Southern Observatory’s Very Large Telescope (VLT) in Chile, the Eagle Nebula was studied in unprecedented detail, bringing a new perspective to the Pillars — large columns of dust and gas cocooning young stars sparking to life.
These young O and B-class stars are pumping out powerful ultraviolet radiation, destroying the remaining wisps of gas and dust, blasting out cavities in the material and carving the tell-tale shape of the Pillars of Creation that were first imaged in detail by the Hubble Space Telescope some 20 years ago.
MUSE has now added some depth to the Pillars, showing that the left pillar is facing us, but located behind NGC 6611 — a star cluster within the Eagle Nebula. The other pillars are located in front of NGC 6611. The tip of the left pillar is bearing the brunt of the powerful radiation from NGC 6611′s young stars, causing it to glow bright in reflected light. The tips of the other three pillars are facing away from us and are therefore darker.
Within the pillars are dense knots of gas, the locations of protostars in the process of being born.
Using observations such as this ESO view into the Eagle Nebula, scientists hope to better understand how O and B-class stars influence the production of subsequent stars within the nebula in which they themselves had been spawned. The intense radiation and powerful stellar winds can compress the remaining gas, correlling it to accumulate and spark new star formation. But they also destroy the star-foming material inside the nebula, hindering further star birth.
Which process dominates can transform the future landscapes of star-forming nebulae like the Pillars of Creation, so understanding their formative years by creating a 3-D look deep inside these clouds should help us better model the mechnics of stellar evolution.
Read more at Discovery News
The newfound exoplanets, known as HD 7924c and HD 7924d, are "super Earths" with masses about 7.9 and 6.4 times greater, respectively, than that of our home planet, researchers said. The planets orbit the star HD 7924, which lies just 54 light-years from the sun — a mere stone's throw considering the size of the Milky Way, which is on the order of 100,000 light-years wide.
The discovery brings the number of known planets in the HD 7924 system to three. (Another super Earth, called HD 7924b, was spotted there in 2009.) HD 7924b, HD 7924c and HD 7924d all lie closer to their host star than Mercury does to the sun. They complete one orbit in five, 15 and 24 days, respectively, researchers said.
"The three planets are unlike anything in our solar system, with masses seven to eight times the mass of Earth and orbits that take them very close to their host star," study co-author Lauren Weiss, a graduate student at the University of California, Berkeley, said in a statement.
The research team discovered HD 7924c and HD 7924d using three different ground-based facilities — the Automated Planet Finder (APF) Telescope at Lick Observatory in California, the Keck Observatory in Hawaii and the Automatic Photometric Telescope (APT) at Fairborn Observatory in Arizona. (Keck also found HD 7924b in 2009.)
The research team, which was led by University of Hawaii (UH) graduate student BJ Fulton, used the combined observations of the three telescopes to detect tiny wobbles in the star HD 7924 caused by the gravitational pull of the two newfound planets, and then to verify the worlds' existence.
Read more at Discovery News
May 3, 2015
This process of film deposition is common for traditional semiconductors like silicon or gallium arsenide -- the basis of modern electronics -- but Cornell scientists are pushing the limits for how thin they can go. They have demonstrated a way to create a new kind of semiconductor thin film that retains its electrical properties even when it is just atoms thick.
Three atom-thick layers of molybdenum disulfide were cooked up in the lab of Jiwoong Park, associate professor of chemistry and chemical biology and member of the Kavli Institute at Cornell for Nanoscale Science. The films were designed and grown by postdoctoral associate Kibum Kang and graduate student Saien Xie. Their work is published online in Nature, April 30.
"The electrical performance of our materials was comparable to that of reported results from single crystals of molybdenum disulfide, but instead of a tiny crystal, here we have a 4-inch wafer," Park said.
Molybdenum disulfide, which is garnering worldwide interest for its excellent electrical properties, has previously been grown only in disjointed, "archipelago"-like single crystal formations, Park said. But making smooth, flat, ultrathin sheets, like paper, is the ultimate goal, and the bridge to actual devices.
The researchers pulled off the feat by tuning the growth conditions of their films using a technique called metal organic chemical vapor deposition (MOCVD). Already used widely in industry, but with different materials, it starts with a powdery precursor, forms a gas and sprinkles single atoms onto a substrate, one layer at a time.
Park's group systematically optimized the technique to make the films, tweaking conditions and temperatures not unlike experimenting in the kitchen. They found that their crystals grew perfectly stitched together, but only with a little bit of hydrogen and in completely dry conditions, for example. In addition to advanced optical imaging techniques, researchers led by co-author David Muller, professor of applied and engineering physics and director of Cornell's Kavli Institute, contributed advanced transmission electron microscopy to test and characterize the quality of the films as they went along.
The team also demonstrated their films' efficacy when stacked layer by layer alternating with silicon dioxide and employing standard photolithography. This effectively proved that these three-atom-thick semiconducting films can be made into multi-level electronic devices of unsurpassed thinness.
The MOCVD method for thin film generation is seemingly generic. The researchers showed the ability to simply change the precursor to make other films; for example, they also grew a tungsten disulfide film with different electrical properties and color. They envision perfecting the process to make atomically thin films of all varieties, like a packet of colored paper, from which new, exciting electronic and optoelectronic devices can be derived.
"These were only the first two materials, but we want to make a whole palette of materials," Park said.
Read more at Science Daily
The penguins poop on their frozen landscape in the Antarctic to melt it, creating the ideal location to rear their young when the time comes, new video footage suggests.
Though most humans wouldn’t consider poop an appropriate decoration for a child’s nursery (although it is certainly a common element in them), poop seems to play a key role in penguins’ breeding behavior. This poop “landscaping” is probably unintentional: The birds most likely aren’t considering the feng shui of their feces and deliberately pooping to make room for their chicks’ nurseries, researchers said.
The new insight came from thousands of hours of video taken by researchers from the University of Oxford in England, along with the Australian Antarctic Division. The researchers spent a year videotaping the behavior of a colony of Gentoo penguins on Cuverville Island, off the Antarctic Peninsula. The team also used snow gauges to measure how fast snow melted as the tuxedo-clad birds came and went.
The frosty region is usually blanketed by snow and ice, but that changed at certain times of the year. The birds aggregated in large groups, leaving huge piles of guano, or poop. The dark color of the poop allowed the light from the weak Antarctic sun to be more quickly absorbed.
That, in turn, fueled the melting of the ice and left a lot of bare rocky shelters — perfect nesting grounds for rearing their adorable penguin chicks.
Gentoo penguins, or Pygoscelis papua, are among the rarest of the Antarctic birds, with fewer than 300,000 breeding pairs on the icy continent, according to the British Antarctic Survey.
Read more at Discovery News