Sep 17, 2016

Freshwater stingrays chew their food just like a goat

A bizarre-looking fish from the Amazon evolved chewing behaviors separately from mammals, but chews its food just like a goat, according to researchers.
A new University of Toronto study has found that some freshwater stingrays from the Amazon chew their food in a similar fashion as mammals.

Using a combination of high-speed video and CT scans Matthew Kolmann, a recently graduated PhD in the lab of U of T Scarborough's Nathan Lovejoy found that as the freshwater stingray Potamotrygon motoro eats it protrudes its jaws away from its skull, shearing from side to side in the process.

"It's pretty extraordinary when you think about it -- here's this bizarre-looking fish from the Amazon that evolved these behaviors separately from mammals, but chews its food just like a cow or a goat," he says.

Kolmann was first drawn to the question of how P. motoro and its close relative, Potamotrygon orbignyi, eat their prey after finding out both species feed on aquatic insects, unique for a family that also includes sharks, skates and other stingrays.

Stingrays have fins that encircle their head called a disk. They catch prey by lifting up the front part of their disk, which draws water and prey underneath, much like a suction cup. Once rays have trapped their prey, they grab it by rapidly protruding their jaws, shredding and tearing it apart.

"They don't actually use their mouth to catch their prey, which suggests that parts of the mouth can evolve away from that specific purpose and may be driving the novelty of this chewing behaviour," Kolmann says.

Chewing was thought to be unique to mammals -- including humans -- and one of the key innovations for their success over the past 65 million years, notes Kolmann. Chewing allowed mammals to fuel their warm-blooded (endothermic) metabolism with tough or robust prey that would otherwise be too costly to ingest without breaking it down first.

"Both mammals and these stingrays -- two groups that have little to do with each other -- developed a similar solution to tackling a bio-materials problem, and that is how to break down tough prey," he says.

Freshwater stingrays evolved to eat insects and chew because they had little choice, says Kolmann. Once they invaded the Amazon 20-40 million years ago, aquatic insect larvae were not only abundant but also nutritious, and since insects are difficult to break down, chewing is necessary for digestion. Insect-feeding may have helped rays avoid competition with other fish when they moved from saltwater to the crowded Amazonian freshwater. He adds only a few other groups of animals have been able to do that successfully.

Both species of freshwater stingrays from the study are found in the lakes and rivers throughout the Amazon, from the mouth of the river near the eastern Brazil coast all the way to the foothills of the Andes in Peru. While P. motoro's diet consists of other fish, crustaceans like crabs and prawns as well as insects, P. orbignyi only eats insects.

The study highlights interesting aspects in the diversity of life found in nature, but as Kolmann points out there's plenty of undiscovered biodiversity in the Amazon that is under threat from human activity.

"Mining and dams are threatening stingray habitat in the Amazon. It's displacing Indigenous peoples and also destroying wildlife habitat in the process," he says.

"There's a backlog of interesting and bizarre animals we haven't even described yet and in many ways museums are becoming a time capsule for biodiversity that is disappearing at a faster rate than we can study it."

Read more at Science Daily

Bats use second sense to hunt prey in noisy environments

Like many predators, the fringe-lipped bat primarily uses its hearing to find its prey, but with human-generated noise on the rise, scientists are examining how bats and other animals might adapt to find their next meal. According to a new study, when noise masks the mating calls of the bat's prey, túngara frogs, the bat shifts to another sensory mode -- echolocation.

Echolocation is a way of sensing objects and movement by scanning the environment with high frequency sounds and evaluating the reflections. Studying the ability or inability of animals to shift sensory modes could be important in understanding how to protect threatened or endangered species.

The work appears this week in the journal Science.

Mike Ryan, a professor of integrative biology at The University of Texas at Austin and co-author of the study, says the bats are doing something similar to what we do at a noisy party. Amid all the conversations, we can turn our attention to one speaker and tune out the rest.

"If there's just one person talking and it's quiet, all we have to do is listen with our ears," says Ryan. "But if there are more and more people talking, we have to be looking at them to figure out what each person is saying. So we have to recruit this other sensory channel we have, our eyes, to help us figure out what we're hearing."

In this case, the bats are shifting from detecting one kind of sound -- the low frequency mating calls produced by the frogs -- to the high frequency sounds emitted by the bat to navigate and hunt with echolocation. Unfortunately for the frogs, when they produce mating calls, they're really sending two signals: the sound intended to attract females and the movement of their vocal sacs, which inflate quickly like a balloon.

The researchers speculate that predators that can shift their sensory mode will do better in noisy environments, and this in turn might alter the long-term success of specific predator and prey species.

"Our study ties together behavior, sensory ecology and conservation," says Dylan Gomes, the lead author who conducted the research during an internship at the Smithsonian Tropical Research Institute (STRI) in Panama. "As sources of anthropogenic noise continue to expand, animals will ultimately have to face noise in one way or another."

Research into the effects of human-generated noise on animal behavior has primarily focused on birds and whales, says Gomes, who is now a Fulbright scholar at the Max Planck Institute for Ornithology. The impact of noise on bats, however, is a relatively new field of study.

The team used two robotic frogs that precisely mimic the calls and vocal sac expansion of the túngara frog. The robofrogs were placed inside a flight cage with the fringe-lipped bat. One robofrog played the frog's distinct mating call, with the other playing the call and expanding its robotic vocal sac. When the researchers played a masking noise over the call, the hunting bat's echolocation activity increased and it more often attacked the frog emitting both signals than the frog emitting just mating calls. Without the masking sound, the bat attacked both frogs equally.

"We show how animals can adapt to increased noise levels by making use of their other senses, which has important implications for other species that try to find prey, avoid predators or attract mates in human-impacted environments," says Wouter Halfwerk, a professor at VU University Amsterdam and a former postdoctoral researcher in Ryan's lab.

Read more at Science Daily

Sep 16, 2016

Hubble Watches Comet Die a Slow Spinning Death

It's a comet that has survived 4.5 billion years pottering around the solar system. But through a series of gravitational misfortunes, Comet 332P/Ikeya-Murakami was nudged to a new orbit closer to the sun that ultimately doomed it to a lingering, spinning death. And the Hubble Space Telescope was there to capture the aftermath in a very lucky series of images of one very unlucky comet.

For the most part, being a comet is an uneventful existence.

Formed from the ice, dust and chunks of space rocks left over from the birth of the planets, comets will hang out for billions of years in the outer solar system doing, well, nothing. Many of these primordial chunks of icy material sit in the Kuiper Belt, beyond the orbit of Neptune, feeling the weak gravity from our sun.

But should Neptune's chaotic gravitational perturbations jostle them from their previously stable perches, the sun's gravity may win out, causing these icy bodies to make the long fall into the inner solar system. Many comets will end up in stable orbits around the sun, perhaps periodically visiting the inner solar system, while others will vaporize quickly as they play chicken with the sun and lose.

Others, like Comet 332P, may have their orbits modified by the gravity of the planets, causing them to end up in new orbits that that are far enough away from the sun to avoid being blow-torched, but close enough to die a slow solar-powered death.

After surging in brightness, Comet 332P was discovered in 2010 by two Japanese amateur astronomers Kaoru Ikeya and Shigeki Murakami. When a comet's brightness suddenly increases it can mean only one thing: It's being heated. The brightness increase was caused by jets of sublimating ices blasting vapor and dust into space, scattering sunlight.

In January this year, Hubble took a closer look at this fascinating object to see that not only is it generating a lot of vapor and dust, this comet is in the throes of death, ejecting huge building-sized chunks of material. It is currently located in an orbit beyond Mars.

"We know that comets sometimes disintegrate, but we don't know much about why or how they come apart," said David Jewitt, of the University of California at Los Angeles, in a statement. "The trouble is that it happens quickly and without warning, and so we don't have much chance to get useful data. With Hubble's fantastic resolution, not only do we see really tiny, faint bits of the comet, but we can watch them change from day to day. And that has allowed us to make the best measurements ever obtained on such an object."

Although the comet is pretty small as far as comets go, measuring approximately 500 meters wide, its debris field is huge, with a trail extending over 3,000 miles long. But what's causing this comet to break apart?

"In the past, astronomers thought that comets die when they are warmed by sunlight, causing their ices to simply vaporize away," said Jewitt. "Either nothing would be left over or there would be a dead hulk of material where an active comet used to be. But it's starting to look like fragmentation may be more important. In Comet 332P we may be seeing a comet fragmenting itself into oblivion."

Comet 332P is disintegrating as it has been "spun up" by solar heating. As sunlight gradually heats the comet's surface, ices turn from a solid into a vapor without passing through a liquid phase. This process is known as sublimation and causes the comet to fire jets of vapor and dust into space. As this happens, pressure from the jets cause the comet to spin, like a very slow-moving Catherine wheel firework. As comets are composed mostly of loosely-packed material and not solid lumps, this spinning can cause chunks of comet to break away.

This NASA Hubble Space Telescope image reveals the ancient Comet 332P/Ikeya-Murakami disintegrating as it approaches the sun. The observations represent one of the sharpest views of an icy comet breaking apart.
In the case of Comet 332P, that's exactly what Hubble is seeing -- around 25 large chunks are slowly moving away from the main comet after being broken free by the spinning (centrifugal) force. This is how a comet dies in the inner solar system. And it's beautiful.

As Comet 332P has a six-year orbit around the sun, it's going to endure this kind of outburst every six years, allowing astronomers to estimate how long it has until it's completely disintegrated. "If the comet has an episode every six years, the equivalent of one orbit around the sun, then it will be gone in 150 years," added Jewitt. "It's the blink of an eye, astronomically speaking. The trip to the inner solar system has doomed it."

Read more at Discovery News

Did Ancient Planet Collision Allow Life to Thrive?

Artist's impression of a Mercury-sized body that smashed into Earth early in the solar system's history.
When a Mercury-sized body smacked into the young Earth 4.4 billion years ago, the cosmic collision likely made carbon more available for life to thrive today, a new study suggests.

The finding would explain a paradox puzzling scientists, which is how our planet still has carbon on the surface when it should have disappeared long ago. Theories suggest that early carbon on the surface would have boiled into space, or would have been stuck in the planet's core.

"The challenge is to explain the origin of the volatile elements like carbon that remain outside the core in the mantle portion of our planet," said Rajdeep Dasgupta, who co-authored the study with lead author and former Rice postdoctoral researcher Yuan Li, in a statement.

Previously, some studies suggested the carbon could have come from meteorites, which are small rocks that whiz around the solar system and occasionally crash into Earth. But further study revealed some problems with the theory.

"The problem with that idea is that while it can account for the abundance of many of these elements, there are no known meteorites that would produce the ratio of volatile elements in the silicate portion of our planet," said Li, who is now a staff scientist at the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences.

The key was imagining a different type of core composition from the Earth, based on updated studies of Mercury and Mars in past decades. These other planets suggested that perhaps our core may be more complex than just iron and nickel and carbon.

How a young Earth could have merged with a Mercury-sized object when the two collided about 4.4 billion years ago. "Magma ocean processes could lead planetary embryos to develop silicon- or sulfur-rich metallic cores and carbon-rich outer layers," Rice University wrote in a statement.
Mars is believed to have a lot of sulfur in its core, and Mercury likely contains a lot of silicon. The research team tested different elements in a lab that squeezes rocks in hydraulic presses, mimicking the high-pressure and high-temperature conditions below Earth's surface.

Read more at Discovery News

Harvest Full Moon Rises Tonight

The full moon known as this year's Harvest Moon will rise tonight (Sept.16) and will be shaded by a subtle type of lunar eclipse for some skywatchers in Africa, Asia and Australia.

The Harvest Moon (as with all full moons) officially turns full when it reaches the spot in the sky opposite to (180 degrees from) the sun. In 2016, the Harvest Moon's moment will occur tonight at 3:05 p.m. EDT (12:05 p.m. PDT).

A minor penumbral lunar eclipse will accompany the full moon tonight, and will be visible from Europe, Africa, Asia, Australia and the Western Pacific. The Slooh Community Observatory will offer a live webcast of the eclipse at beginning at 12:45 p.m. EDT (1645 GMT). You can also watch the lunar eclipse webcast on, courtesy of Slooh.

The Harvest Moon is the one that comes the closest to the autumnal equinox, so this year it falls in September, although occasionally this title can be bestowed upon the October full moon. That will happen 12 times from 1970 to 2020, occurring next in 2017. The 2016 version of the Harvest Moon comes six days prior to the autumnal equinox, although it can occur as early as Sept. 8 (as it did in 2014) or as late as Oct. 7 (as happened in 1987).

Many think that the Harvest Moon remains in the night sky longer than any of the other full moons seen during the year, but that is not so. What sets the Harvest Moon apart from other full moons is that it occurs at the climax of the harvest season, so farmers can work late into the night by the moon's light. This moon rises at about the time the sun sets, and — more importantly — at this time of year, instead of rising its normal average of 50 minutes later each day, the moon seems to rise at somewhat the same time each night.

In actuality, from midnorthern latitudes (+40 degrees), the rising of the moon over a three-night span centered on full phase (Sept. 15, 16 and 17) comes, on average, 38 minutes later each night. The night-to-night difference is greatest for the more southerly locations (Miami, located at latitude +25.8 degrees, sees moonrise come an average of 45 minutes later). Meanwhile, the difference is less at more northerly locations (at Edmonton, Canada, located at latitude 53.5 degrees N, the average difference is only 28 minutes).

The reason for this seasonal circumstance is that the moon appears to move along the ecliptic, and at this time of year, when rising, the ecliptic makes its smallest angle with respect to the horizon for those living in the Northern Hemisphere.

In contrast, for those living in the Southern Hemisphere, the ecliptic at this time of year appears to stand almost perpendicular (at nearly a right angle) to the eastern horizon. As such, the difference for the time of moonrise exceeds the average of 50 minutes per night. At Sydney, Australia (latitude -33.9), for instance, the night-to-night difference amounts to 67 minutes.

Interestingly, for those who live near 70 degrees north latitude, the moon does indeed appear to rise at about the same time each night around the period of the Harvest Moon. And for those who live even farther to the north, a paradox occurs: The moon appears to rise earlier each night! At Barrow, Alaska (latitude +71.3 degrees), for instance, the times of moonrise on Sept. 15, 16 and 17 will be, respectively, 9:05 p.m., 9:02 p.m. and 8:59 p.m. Alaska Daylight Time. So from Barrow, Alaska, the moon will seem to rise an average of 3 minutes earlier each night!

Read more at Discovery News

Black Hole 'Engine' Cloaks Itself in Exhaust Fumes

A supermassive black hole in the core of a galaxy churns up hot gas from its own accretion disk to create a cloaking torus.

Many supermassive black holes in the centers of galaxies possess a thick ring of material known as a torus. Appearing like a supersized doughnut, astronomers have long thought that these features were created by churned-up material from the galactic core itself, falling into the black hole's gravitational well.

However, according to powerful new observations by the the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, this conventional model is, apparently, far too simple.

While studying the environment surrounding the supermassive black hole in the core of the barred spiral galaxy NGC 1068 47 million light-years away, ALMA was able to track clouds of material being flung outwards by the black hole, creating its own torus rather than material falling in.

"Think of a black hole as an engine," said astronomer Jack Gallimore, of Bucknell University in Lewisburg, Pennsylvania, in a statement. "It's fueled by material falling in on it from a flattened disk of dust and gas. But like any engine, a black hole can also emit exhaust."

Black holes consuming matter possess accretion disks, which are basically flat and hot features that swirl around the black hole's event horizon. The innermost section of the accretion disk is so hot that it generates X-ray and ultraviolet radiation, but further out, the disk is cooler and emits infrared and millimeter wavelength radiation. ALMA is very sensitive to the latter, allowing the observatory to track the motion of the gases in the outermost portion of NGC 1068's accretion disk.

ALMA image of the central region of galaxy NGC 1068. The torus of material harboring the supermassive black hole is highlighted in the pullout box. This region, which is approximately 40 light-years across, is the result of material flung out of the black hole's accretion disk.
While following cool clouds of carbon monoxide gas inside this cooler accretion disk region, Gallimore's team saw the clouds lift off the disk. As they become ionized by the superheated portion of the accretion disk, the clouds started to interact with the black hole's powerful magnetic field. The gas was then flung away from the accretion disk at high speed, far faster than the rotational speed of the disk itself.

"These clouds are traveling so fast that they reach 'escape velocity' and are jettisoned in a cone-like spray from both sides of the disk," said Gallimore. "With ALMA, we can for the first time see that it is the gas that is thrown out that hides the black hole, not the gas falling in."

Read more at Discovery News

Sep 15, 2016

For 20 million years, the diversity of large terrestrial mammals depended on plant growth

Skull of an extinct cave bear, Ursus spelaeus, from the Pleistocene [locality unknown].
For more than 20 million years, the ups and downs of diversity in terrestrial large mammals were determined by primary production, i.e. net production of plant biomass. This pattern changed with the onset of the ice ages. The reason for this is likely the beginning of human impact on nature, according to a team led by Dr. Susanne Fritz at Senckenberg. The findings were published recently in the scientific journal “Proceedings of the National Academy of Science.” Based on 14,000 fossils, the scientists reconstructed the diversity of terrestrial large mammals and compared it with data on the biomass production of plants during the same time period.

Whether used as food, fire wood or fodder for domestic animals – mankind would not be able to survive without plants, and we use them in manifold ways. But what impact does this use have on the evolution of mammals? The answer can be found in a recent study that correlates the biomass of plant resources with the diversity of large mammals, i.e., the number of genera of ungulates, carnivores, apes and elephants. “For 20 million years, from the early Neogene approximately 23 million years ago until the Pleistocene started around 2 million years ago, this rule applied: The larger the amount of biomass produced by plants, the higher the diversity of terrestrial mammals that evolved. And of course, the reverse is true as well: A decrease in biomass production was accompanied by a decrease in the number of different mammals,” explains the study’s lead author, Dr. Susanne Fritz of the Senckenberg Biodiversity and Climate Research Centre.

Fritz and her team are the first to confirm this correlation on such a large spatial and temporal scale – for North America as well as for Europe. The onset of the ice ages (Pleistocene) put an end to this, as since then the species diversity in North America and Europe is correlated to other environmental conditions. This is the exact point in time when humans appeared on the scene in these regions and presumably began to extract biomass from the nutrient cycle. But the abrupt change in pattern also concurred with another event: Large mammals such as mammoths, cave bears and Saiga antelopes underwent a mass extinction in the study areas. Whether humans or climatic changes were responsible for this remains a controversial question to date.

“The diversity of mammal species in Europe and North America today is much lower than in the past. For example, Europe now hosts a mere 51 species of large mammals in 27 genera; 10 million years ago, there were 130 to 200 genera. As documented by our study, humans at least contributed to the fact that the diversity of species and genera was never able to recover after the mass extinction. Today, only Africa and Asia still host any significant numbers of large mammal species,” says Dr. Christian Hof, also a scientist at Senckenberg and the study’s co-author. Nowadays, humans extract up to 30 percent of the biomass from the global nutrient cycle – and the trend is rising. However, it is difficult to ultimately evaluate what this means for the future of speciation in large mammals.

“The farther back we travel back in the past, the fewer traces we find of the animals that lived in those days, which makes it difficult to directly compare correlations between the rather extensive time period we examined and the situation today. However, it is clear that in the world dominated by humans certain ecological ‘rules,’ such as the correlation between large mammal diversity and plant biomass, no longer apply in the same way as they used to do for millions of years. The consequences of the ever increasing human impact are therefore unique in geological history and difficult to predict,” Fritz sums up.

For the study, the scientists evaluated more than 14,000 fossils from North America and Europe. These fossils represent over 1,600 different species of large mammals from approximately 1,500 sites. They cover the period between 23 and 1.8 million years ago. The results were subsequently compared with data on the primary production of plants from the same time period, which could be deduced from fossilized plant remains. In terms of temporal extent, this constitutes the largest set of data analyzed in this context to date.

Read more at Science Daily

Hawaii's Feral Pig Ancestors Predate Captain Cook

The family tree of Hawaii's feral pigs (Sus scrofa) looks a bit different today, after a new DNA analysis resets their arrival on the islands to several hundred years earlier than previously thought. More than just an interesting genealogy rewrite, the news could also be relevant to efforts to control the animals.

Writing in the journal Royal Society Open Science, an international team of researchers argues that Hawaii's hogs, previously thought to have arrived on the islands with English explorer James Cook in 1778, were brought there hundreds of years earlier by Polynesian settlers who would come to live there.

The scientists reached that conclusion after studying the DNA of more than four-dozen feral pigs, an analysis that told them the pigs arrived on the islands as much as 800 years earlier.

English explorer Captain James Cook stewarded the first European expedition to come upon the Hawaiin Islands in 1778. His mission has been credited with bringing pigs to the islands, but new research argues otherwise.
Researchers from more than half a dozen research facilities contributed to the study, among them lead author Anna Linderholm, Texas A&M assistant professor of anthropology.

"[Cook] almost certainly brought pigs, chickens and other animals with him," said Linderholm in a statement. "But our findings show that the wild hogs there today were introduced much earlier than his arrival, by hundreds of years at least. They likely came from European or Asian descent."

That conclusion could end up helping the hogs.

Hawaii has a sizable wild pig problem at present. The islands are overrun with thousands of up-to-400-pound feral hogs, which have been called "the most prolific large mammal on the face of the Earth" and ruin native plants as well as planted crops. Owning a home or farm in their path can be costly, and this has brought about talk of methods to get the problem under control.

However, the researchers note, pigs hold a special place in Hawaiian culture, with its Polynesian roots, and they urge caution moving forward.

Read more at Discovery News

Oldest Indigo-Dyed Fabric Ever Is Discovered in Peru

The oldest indigo-dyed fabric ever found has been discovered in Peru, pushing back the use of this blue coloring to at least 6,200 years ago.

Previously, the oldest sample of blue-dyed fabric dated to around 4,400 years ago in Egypt, with the oldest written references to blue dye going back to around 5,000 years ago in the Middle East. The discovery in Peru, however, shines a spotlight on the Americas, which are less-discussed in terms of firsts, said study researcher Jeffrey Splitstoser, an archaeologist and textile expert at The George Washington University.

"The people of the Americas were making scientific and technological contributions as early and in this case even earlier than people were in other parts of the world," Splitstoser told Live Science. "We always leave them out. I think this finding just shows that that's a mistake."

The dyed fabric pieces are small scraps made of woven cotton. They were excavated by archaeologists Tom Dillehay and Duccio Bonavia between 2007 and 2008 from a prehistoric site called Huaca Prieta, which is north of the city of Trujillo in coastal Peru. Huaca Prieta was a prehistoric dwelling that was covered by a mound and turned into a temple, Splitstoser said. The temple was made of a sort of concrete mixed from ash, shells and sand; over the years, many layers of this material had been applied to the structure as local people renovated and rebuilt the temple. The fabric scraps were found in bundles lining the ramp that led up to the top of the temple, embedded in the concrete-like layers. They all date to between 4,000 and 6,200 years ago.

"They were literally sealed under these new layers of building, but because the building material had so much ash in it, it leached into the textiles, making them a very dirty, sooty color," Splitstoser said.

The blue color didn't appear until conservationists washed the textiles. Almost all blue dye in nature comes from the compound indigoid, Splitstoser said, which can be made by many plants. But the first tests on the fabric yielded no sign of indigoid. Splitstoser was stumped.

He persevered, finding another chemist -- Jan Wouters of University College London -- with more sensitive equipment. Wouters, using a sensitive technique called high-performance liquid chromatography, was able to tease out the chemical makeup of the dye to discover that it was, in fact, indigo. He tested eight tiny samples of the blue cotton and confirmed indigo in five of them.

"That's when we realized then that we had the world's oldest indigo, by far," Splitstoser said.

The fabric pieces were all cut or torn before they were deposited on the temple ramp, which probably represented a ritual "killing," by peoples who viewed objects as living, Splitstoser said.

"We see that all over the Andes. They not only ritually killed textiles, but they ritually killed ceramics. Anything that was buried was broken," he said.

Some of the fabrics showed signs of being wetted and then squeezed out, possibly as part of the ritual, Splitstoser said. The fabrics weren't just blue — they were woven in patterns made of blue-dyed yarn, natural off-white cotton and bright-white thread made from milkweed, a very rare textile in South America, Splitstoser said. The yarn had also been dipped in red and yellow ochre, an iron pigment often used in rock art. Unlike the indigo, the ochre would have run when wetted.

"If you were to pour water on those and then squeeze it, you'd get colored water pouring out of the textiles, which might have been part of the show," Splitstoser said. No one knows what these rituals might have represented to the people who invented them; the era in which the textiles were made was one of a drying climate, Splitstoser said, so perhaps the rituals had to do with rain or water.

The discovery of indigo dye more than 6,000 years ago couldn't have been mere happenstance. Indigo dye is quite complicated to make, Splistoser said. Many dyes are made from flowers and require simply boiling the blossoms in water to extract the color, he said.

"Indigo does not work that way," he said. "If you put the leaves — and it's leaves, not flowers — in water, nothing will happen."

Instead, the leaves have to be fermented. Then, the fermented mixture must be aerated so that a solid compound falls out of the mixture to the bottom of the tub. This mixture can be taken, dried and stored. To reconstitute it requires an alkaline substance, often urine, which makes white indigo, a water-soluble compound. Yarn dipped in white indigo will turn yellow, green and finally blue, "like magic," Splitstoser said.

Read more at Discovery News

Optical Illusion Made Tiny Dinos Invisible

A recreation shows the dinosaur Psittacosaurus in a setting where it would be more visible to onlookers.
A small dinosaur used an optical illusion to become invisible in dense forests, helping to protect it from larger meat-eating dinos and other predators, a new study shows.

Well-preserved remains of the long-lost species, Psittacosaurus aka "Parrot Lizard," reveal that its body countershading created the camouflage. The findings are presented in the journal Current Biology.

Psittacosaurus fossil
"The fossil preserves clear countershading, which has been shown to function by counter-illuminating shadows on a body, thus making an animal appear optically flat to the eye of the beholder," co-author Jakob Vinther of the University of Bristol said in a press release.

Vinther's University of Bristol colleague, Innes Cuthill, added: "By reconstructing a life-size 3D model, we were able to not only see how the patterns of shading changed over the body, but also that it matched the sort of camouflage which would work best in a forested environment."

Humans and other animals to this day analyze patterns of shadow on an object to help identify what it is. We're usually unaware of this phenomenon. It just happens automatically as part of our visual processing.

The origins of the new study go back to Vinther's work as a Yale graduate student, when he first realized that structures previously thought to be artifacts or dead bacteria in fossilized feathers were actually melanosomes. These are small structures that carry melanin pigments found in the feathers and skin of many animals.

A Psittacosaurus specimen is so well preserved that it shows preserved melanin patterns, which can be seen with the naked eye. Figuring out the distribution of countershading proved to be tricky, though, as the extinct animal had been crushed flat and fossilized.

Read more at Discovery News

Sep 14, 2016

Mystery of Charon's Red Cap Solved

Mosiac of New Horizons images of Charon.
When NASA's New Horizons spacecraft flew through the Pluto system last year, scientists were surprised to find that Charon, Pluto's largest moon, has a dark red polar cap.

A new study may have figured out the reason why: trapped gas.

Lowell Observatory astronomer Will Grundy and colleagues combined analysis of New Horizons imagery with computer models to show that Charon's north pole grew cold enough during its century-long winter to trap methane escaping from Pluto. As sunlight returned to the pole, the methane was then converted into red-colored chemicals, known as tholins, the study shows.

"Who would have thought that Pluto is a graffiti artist, spray-painting its companion with a reddish stain that covers an area the size of New Mexico?" Grundy said in a press release . "Nature is amazingly inventive in using the basic laws of physics and chemistry to create spectacular landscapes."

Surface temperatures during Charon's long winters dip to -430 Fahrenheit, cold enough to freeze methane gas into a solid.

"The methane molecules bounce around on Charon's surface until they either escape back into space or land on the cold pole, where they freeze solid, forming a thin coating of methane ice that lasts until sunlight comes back in the spring," Grundy said.

At point, the methane ice quickly vaporizes, leaving heavier hydrocarbons that were created from it on the surface.

Sunlight further irradiates the hydrocarbons and turns them red.

"New Horizons' observations of Charon's other pole, currently in winter darkness -- and seen by New Horizons only by light reflecting from Pluto -- confirmed that the same activity was occurring at both poles," Johns Hopkins University Applied Physics Lab wrote in a press release about the study.

"The distribution of dark, reddish material around Charon's northern pole is notable for its generally symmetric distribution across longitudes and its gradual increase with latitude, although there are local irregularities associated with craters, topographic features and perhaps subsurface variations in thermal properties," Grundy and colleagues write in this week's Nature.

Read more at Discovery News

3,000-Year-Old Cooking Mistake Revealed

Archaeologists in Denmark have found evidence of a 3,000 year-old cooking mistake that casts some light into the everyday life of Scandinavian Bronze Age people.

Clear evidence for one of the most common mistakes in the kitchen – burning food -- lay in a clay pot that was excavated in central Jutland, Denmark.

The clay vessel was found, upturned and in near mint condition, at the bottom of what was once a waste pit.

"The pot is typical for cooking vessels in this region of Denmark. It was accompanied by several other objects fitting the dating," archaeologist Kaj F. Rasmussen from Museum Silkeborg, Denmark, told Discovery News.

He noted the discovery itself is a lucky breakthrough, since a vessel capable of surviving intact over the last 3,000 years is indeed a unique finding.

"Ordinarily clay pots will have been reduced to shards before deposition, or have been crushed by pressure from the covering earth," Rasmussen said.

Most intriguingly, the pot showed a white-yellow crust onto the inside. Rasmussen admitted they had never seen such burnt substance. Food remains in pots are usually black, charred deposits from corn or seeds.

"We analyzed three samples via gas chromatography at the laboratories of the Danish National Museum in Copenhagen. It emerged the fats were probably bovine," Rasmussen said.

He speculates the bovine fat represents the failed result of cheese making.

"The fat could be a part of the last traces of curds used during the original production of traditional hard cheese. The whey is boiled down, and it contains a lot of sugars, which in this way can be preserved and stored for the winter," Rasmussen told Science Nordic.

Read more at Discovery News

Crows Prove Their Smarts With Twig Tools

A captive Hawaiian crow ('Alalā) using a stick tool to extract food from a wooden log.
Hawaiian crows are among the top tool users in the animal kingdom, according to a new study that also suggests life on remote tropical islands promotes particularly industrious birds.

The critically endangered Hawaiian crow, called 'Alalā by Hawaiians, is now the second island bird found to be clever at crafting and using tools, according to the study, which is published in the journal Nature. The other is the New Caledonia crow, which also hails from a remote, tropical island.

At first researchers thought the New Caledonia crow's tool skills were a fluke of nature, but now they suspect otherwise.

The new discovery "raises the intriguing possibility that there are some undiscovered (bird) tool users out there," project leader Christian Rutz from the University of St. Andrews said in a press release. "We had previously noticed that New Caledonian crows have unusually straight bills, and wondered whether this may be an adaptation for holding tools, similar to humans' opposable thumb."

There are only just over 100 Hawaiian crows left in the world, and all are in captivity via the San Diego Zoo Global's Hawai'i Endangered Bird Conservation Program. They were taken from the wild and brought to San Diego as a last ditch effort to preserve the species through a captive breeding program.

Later this year, some of the birds will be released on the big island of Hawaii to re-establish a wild population, according to Bryce Masuda, who co-led the new research and is conservation program manager of the San Diego program.

Rutz contacted Masuda about analyzing the crows' the tool use before the birds head back to Hawaii.

"We had occasionally seen birds using stick tools at our two breeding facilities, but hadn't thought much of it," Masuda said. "We tested 104 of the 109 'Alalā alive at the time, and found that the vast majority of them spontaneously used tools."

The below unedited scene shows an adult male Hawaiian crow presented with a tool challenge:

Masuda and the other researchers believe that the tool use is part of the species' natural behavioral repertoire, rather than being a quirk that arose in captivity.

During the study, the skill even revealed a bit of drama, showing how the very social birds interact with each other, and perhaps get on each other's nerves from time to time. The following video begins with several scenes of captive Hawaiian crows ('Alalā) using stick tools to extract food from a wooden log. In the second scene, a pair can be seen interacting during the task. The female (on the right-hand side) picks up a stick to use as a tool, but the male (on the left) steals it. The male then uses the tool to extract food, which the female steals!

"Using tools comes naturally to 'Alalā," Rutz explained. "These birds had no specific training prior to our study, yet most of them were incredibly skilled at handling stick tools, and even swiftly extracted bait from demanding tasks."

The birds don't just use the tools; they essentially make them through modifications. The birds were seen breaking twigs to just the right size, sharpening the tips and altering them in other ways to their advantage.

When many of us think of Hawaii, coveted vacations come to mind. Before humans came to dominate the islands and other problems arose (such as climate change, pollution, loss of habitat and introduction of other predatory animals) Hawaii, like New Caledonia, was a paradise for its native birds.

Tool selectivity, modification and manufacture by Hawaiian crows can be seen in this clip:

Rutz said, "It is striking that both (crow) species evolved on remote tropical islands in the Pacific Ocean that lack woodpeckers and ferocious bird predators -- perfect conditions, apparently, for smart crows to become accomplished tool users!"

Even very young birds have tool-using abilities:

World-renowned primatologist Jane Goodall is interested in the new study, as she was the first to document tool use in the wild. Before she and her team determined that wild chimps regularly craft and use tools, it was widely believed that only humans could do such things.

Humans, of course, have taken tool use to a whole other level of complexity, but the essential skills -- ability to manipulate objects to meet the needs of a task and then to share that wisdom with others -- are present in dolphins, wild chimps and other animals.

Read more at Discovery News

The End Is Nigh for Rosetta's Comet Mission

There is no nice way to kill a space probe, particularly one as scientifically productive and endearing as Rosetta, the first comet orbiter. But its demise will come on Sept. 30, assuming it doesn't crash into the comet sooner.

After more than two years circling the Comet 67P/Churyumov-Gerasimenko, Rosetta will drop to its icy surface and shut down, ending communications with Earth.

This time, ground controllers expect Rosetta's landing will stick -- unlike sidekick Philae's bouncing touchdown on Nov. 12, 2014. And unlike Philae, which ran through a two-day series of experiments after landing, Rosetta will not attempt any surface science.

Even though Rosetta will free-fall into the comet at the speed of a sedate walk, it is not designed to withstand the impact. Particularly vulnerable are Rosetta's 105-foot long solar array wings.

The European Space Agency is ending the mission because 67P is racing toward the outer solar system, making charging of Rosetta's batteries increasingly challenging. The spacecraft also has been subjected to the harsh radiation and extreme temperatures of space since launching in March 2004 and is unlikely to last too much longer.

Rosetta will take a last look around as it descends to the comet's surface. Scientists have selected a landing spot on the smaller lobe of the duck-shaped comet, a region that contains many large, active pits. Lumpy structures known as "goosebumps," line the pit walls. Scientists suspect they may be remnants of primordial mini-comets that melded together to form 67P during the solar system's early days.

Rosetta will take close-up images of the pits and collect data about the dust, gas and plasma around them, its final contribution to an ongoing quest to learn more about the origins of the solar system and the development of life on Earth, and perhaps elsewhere.

"Rosetta has been a great mission and it will be sad when its telecommunications signal will soon be lost," said University of Washington astronomer Donald Brownlee, who led NASA's Stardust comet sample return mission.

Read more at Discovery News

Gaia Completes First Mind-Blowing 3-D Galactic Map

The Gaia space probe, launched in 2013, has mapped more than a billion stars in the Milky Way, vastly expanding the inventory of known stars in our galaxy, the European Space Agency said Wednesday.

Released to eagerly waiting astronomers around the world, the initial catalog of 1.15 billion stars is "both the largest and the most accurate full-sky map ever produced," said Francois Mignard, a member of the 450-strong Gaia mission team.

In a webcast press conference at ESA's Astronomy Center in Madrid, scientists unveiled a stunning map of the Milky Way, including stars up to half a million times less bright than those we can see with the naked eye.

The images were captured by Gaia's twin telescopes -- scanning the heavens over and over -- and a billion-pixel camera, the biggest ever put into space.

The resolution is sharp enough to gauge the diameter of a human hair at a distance of 1,000 kilometers (620 miles), said Anthony Brown, a researcher at Leiden University in the Netherlands and a member of Gaia's data processing and analysis team.

He compared the images to those captured by NASA's $2.5-billion (2.2 billion-euro) Hubble Space Telescope, which has recorded some of the most detailed visible-light photographs of space, one section at a time.

"Imagine taking pictures with Hubble, except of the full sky -- that is effectively what you are seeing here," Brown said.

Gaia maps the position of stars in the Milky Way, which straddles some 100,000 light years, in two ways.

Not only does it pinpoint their location, the probe -- by scanning each star multiple times -- plots their movement as well.

Wednesday's map showed the locations of over a billion stars, a bonanza for astronomers but still only one percent our galaxy's estimated stellar population.

For two million of them, it also shows their trajectory.

Over the course of Gaia's five-year mission, the catalog of stars for which both sets of data are known is set to expand 500-fold.

At the same time, it will collect vital data on temperature, luminosity and chemical composition, compiling what astronomers call the "ID card" of each individual star.

Thousands of other previously undetected objects have also been discovered, including asteroids that may one day threaten Earth, planets circling nearby stars, and exploding supernovas.

'How Was Our Galaxy Formed?'

Astrophysicists, meanwhile, hope to learn more about dark matter, the invisible substance thought to hold the observable Universe together.

They also plan to test Albert Einstein's theory of general relativity by watching how light is deflected by the sun and its planets.

Artist impression of the Gaia mission in space.
"There is a new revolution coming," said Antonella Vallenari of Italy's National Institute for Astrophysics, and a member of the Gaia team.

"Gaia is meant to answer a fundamental question: How was our galaxy formed?"

Tracking star clusters and how they move through space -- shedding stars along the way -- will provide crucial clues, she added.

Read more at Discovery News

Sep 13, 2016

NASA's THEMIS sees Auroras move to the rhythm of Earth's magnetic field

An artist's rendering (not to scale) of a cross-section of the magnetosphere, with the solar wind on the left in yellow and magnetic field lines emanating from the Earth in blue. The five THEMIS probes were well-positioned to directly observe one particular magnetic field line as it oscillated back and forth roughly every six minutes. In this unstable environment, electrons in near-Earth space, depicted as white dots, stream rapidly down magnetic field lines towards Earth's poles. There, they interact with oxygen and nitrogen particles in the upper atmosphere, releasing photons and brightening a specific region of the aurora.
The majestic auroras have captivated humans for thousands of years, but their nature -- the fact that the lights are electromagnetic and respond to solar activity -- was only realized in the last 150 years. Thanks to coordinated multi-satellite observations and a worldwide network of magnetic sensors and cameras, close study of auroras has become possible over recent decades. Yet, auroras continue to mystify, dancing far above the ground to some, thus far, undetected rhythm.

Using data from NASA's Time History of Events and Macroscale Interactions during Substorms, or THEMIS, scientists have observed Earth's vibrating magnetic field in relation to the northern lights dancing in the night sky over Canada. THEMIS is a five-spacecraft mission dedicated to understanding the processes behind auroras, which erupt across the sky in response to changes in Earth's magnetic environment, called the magnetosphere.

These new observations allowed scientists to directly link specific intense disturbances in the magnetosphere to the magnetic response on the ground. A paper on these findings was published in Nature Physics on Sept. 12, 2016.

"We've made similar observations before, but only in one place at a time -- on the ground or in space," said David Sibeck, THEMIS project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who did not participate in the study. "When you have the measurements in both places, you can relate the two things together."

Understanding how and why auroras occur helps us learn more about the complex space environment around our planet. Radiation and energy in near-Earth space can have a variety of effects on our satellites -- from disrupting their electronics to increasing frictional drag and interrupting communication or navigation signals. As our dependence on GPS grows and space exploration expands, accurate space weather forecasting becomes ever more important.

The space environment of our entire solar system, both near Earth and far beyond Pluto, is determined by the sun's activity, which cycles and fluctuates through time. The solar system is filled with solar wind, the constant flow of charged particles from the sun. Most of the solar wind is deflected from Earth by our planet's protective magnetosphere.

However, under the right conditions, some solar particles and energy can penetrate the magnetosphere, disturbing Earth's magnetic field in what's known as a substorm. When the solar wind's magnetic field turns southward, the dayside, or sun-facing side, of the magnetosphere contracts inward. The back end, called the magnetotail, stretches out like a rubber band. When the stretched magnetotail finally snaps back, it starts to vibrate, much like a spring moving back and forth. Bright auroras can occur during this stage of the substorm.

In this unstable environment, electrons in near-Earth space stream rapidly down magnetic field lines towards Earth's poles. There, they interact with oxygen and nitrogen particles in the upper atmosphere, releasing photons to create swaths of light that snake across the sky.

To map the auroras' electric dance, the scientists imaged the brightening and dimming aurora over Canada with all-sky cameras. They simultaneously used ground-based magnetic sensors across Canada and Greenland to measure electrical currents during the geomagnetic substorm. Further out in space, the five THEMIS probes were well-positioned to collect data on the motion of the disrupted field lines.

The scientists found the aurora moved in harmony with the vibrating field line. Magnetic field lines oscillated in a roughly six-minute cycle, or period, and the aurora brightened and dimmed at the same pace.

"We were delighted to see such a strong match," said Evgeny Panov, lead author and researcher at the Space Research Institute of the Austrian Academy of Sciences in Graz. "These observations reveal the missing link in the conversion of magnetic energy to particle energy that powers the aurora."

The brightening and dimming of the aurora corresponds to the motion of the electrons and magnetic field lines.

"During the course of this event, the electrons are flinging themselves Earthwards, then bouncing back off the magnetosphere, then flinging themselves back," Sibeck said.

When waves crash on the beach, they splash and froth, and then recede. The wave of electrons adopt a similar motion. The aurora brightens when the wave of electrons slams into the upper atmosphere, and dims when it ricochets off.

Before this study, scientists hypothesized that oscillating magnetic field lines guide the aurora. But the effect had not yet been observed because it requires the THEMIS probes to be located in just the right place over the ground-based sensors, to properly coordinate the data. In this study, scientists collected THEMIS data at a time when the probes were fortuitously positioned to observe the substorm.

"Even after nearly 10 years, the probes are still in great health, and the growing network of magnetometers and all-sky cameras continue to generate high quality data," said Vassilis Angelopoulos, co-author and THEMIS principal investigator at University of California, Los Angeles.

Read more at Science Daily

Astronomers observe star reborn in a flash

This image of the Stingray nebula, a planetary nebula 2400 light-years from Earth, was taken with the Wide Field and Planetary Camera 2 (WFPC2) in 1998. In the centre of the nebula the fast evolving star SAO 244567 is located. Observations made within the last 45 years showed that the surface temperature of the star increased by almost 40,000 degree Celsius. Now new observations of the spectra of the star have revealed that SAO 244567 has started to cool again.
An international team of astronomers using Hubble have been able to study stellar evolution in real time. Over a period of 30 years dramatic increases in the temperature of the star SAO 244567 have been observed. Now the star is cooling again, having been reborn into an earlier phase of stellar evolution. This makes it the first reborn star to have been observed during both the heating and cooling stages of rebirth.

Even though the Universe is constantly changing, most processes are too slow to be observed within a human lifespan. But now an international team of astronomers have observed an exception to this rule. "SAO 244567 is one of the rare examples of a star that allows us to witness stellar evolution in real time," explains Nicole Reindl from the University of Leicester, UK, lead author of the study. "Over only twenty years the star has doubled its temperature and it was possible to watch the star ionising its previously ejected envelope, which is now known as the Stingray Nebula."

SAO 244567, 2700 light-years from Earth, is the central star of the Stingray Nebula and has been visibly evolving between observations made over the last 45 years. Between 1971 and 2002 the surface temperature of the star skyrocketed by almost 40,000 degrees Celsius. Now new observations made with the Cosmic Origins Spectrograph (COS) on the NASA/ESA Hubble Space Telescope have revealed that SAO 244567 has started to cool and expand.

This is unusual, though not unheard-of, and the rapid heating could easily be explained if one assumed that SAO 244567 had an initial mass of 3 to 4 times the mass of the Sun. However, the data show that SAO 244567 must have had an original mass similar to that of our Sun. Such low-mass stars usually evolve on much longer timescales, so the rapid heating has been a mystery for decades.

Back in 2014 Reindl and her team proposed a theory that resolved the issue of both SAO 244567's rapid increase in temperature as well as the low mass of the star. They suggested that the heating was due to what is known as a helium-shell flash event: a brief ignition of helium outside the stellar core.

This theory has very clear implications for SAO 244567's future: if it has indeed experienced such a flash, then this would force the central star to begin to expand and cool again -- it would return back to the previous phase of its evolution. This is exactly what the new observations confirmed. As Reindl explains: "The release of nuclear energy by the flash forces the already very compact star to expand back to giant dimensions -- the born-again scenario."

It is not the only example of such a star, but it is the first time ever that a star has been observed during both the heating and cooling stages of such a transformation.

Read more at Science Daily

Full and New Moons May Be Linked to Big Earthquakes

NASA Space Shuttle imagery from 2000 shows a section of the San Andreas fault in California. A new Japanese study suggests that big earthquakes may be triggered by gravitational pull from celestial bodies.
If you're a fan of classic rock, you're familiar with the Creedence Clearwater Revival song "Bad Moon Rising," in which lyricist John Fogerty warns that "I see trouble on the way / I see earthquakes and lightning."

Well, we don't know about the lightning, but when it comes to the quakes, Fogerty might have been on to something. In a study just published in Nature Geoscience, University of Tokyo researchers report that of the 12 largest recorded earthquakes -- those with a magnitude of 8.2 or more -- over the past two decades, nine occurred on days near new or full moons, when the gravitational tidal pull caused high stress across the fault.

"It's a very interesting and intriguing observation," says Emily Brodsky, an earthquake physicist at the University of California, Santa Cruz, told New Scientist. "If it's right, it's a very big deal."

As far back as the 1800s, scientists have suspected that gravitational force from celestial bodies might be able to trigger earthquakes. The theory fell into disfavor in the 20th century, but recently, researchers have found evidence of a possible link. As this 2015 Scientific American article details, Greek researchers, who analyzed 17,000 earthquakes in southern Greece between 1964 and 2012, found evidence of a link between the quakes and tidal effects of the sun and moon.

But the Japanese study provides much stronger proof of a connection.

As the New Scientist article explains, during full and new moon phases, the sun, moon and Earth align, which causes gravity to pull more strongly on the tectonic plates that make up the Earth's crust. That puts more stress on earthquake faults. It also causes increased tidal movement of water in the oceans, which adds even more stress to the faults.

If substantiated by additional studies, the effect that the Japanese researchers describe would be just one of the factors that cause major earthquakes, and it probably isn't strong enough of a factor to be of much value in making short-term predictions about when they will occur, according to New Scientist. But it would help scientists to better understand the process that results in quakes.

From Discovery News

Healthy Offspring Created Without Female Egg

In a scientific first, full term development of healthy babies has just been achieved in mice by injecting mouse sperm into non-egg cells, according to new research that has future implications for breeding endangered species and for human fertility treatments, including those that could allow gay male couples to have their own biological children.

The discovery, reported in the journal Nature Communications, challenges two centuries of dogma -- originating at around 1827, when early embryologists first observed mammal eggs -- claiming that only an egg cell is capable of reprogramming sperm to permit the development of a mammal embryo.

Ironically, the new research that could empower men builds on a phenomenon known as parthenogenesis, aka "virgin birth," which has been documented in a number of species, such as certain fish, reptiles, insects and amphibians, but not in mammals. When such births occur, an embryo develops from an unfertilized egg cell, allowing females to reproduce without males.

Komodo dragon, which can reproduce by parthenogenesis.
Previously, scientists were able to "trick" mammal eggs into developing into embryos without fertilization, but the resulting embryos -- called parthenogenotes -- died after a few days in the lab because key processes requiring input from sperm did not happen.

For the recent study, scientists overcame this problem by developing a method of injecting mouse parthenogenotes (which consist of mitotic cells, meaning cells that divide to form two identical cells) with sperm (which is a differentiated, or specialized, cell). The outcome resulted in healthy baby mice, with a success rate of about 24 percent.

"This work shows for the first time that a mitotic cell can completely reprogram a differentiated cell, with the outcome being the birth of live young," senior author Anthony Perry, a molecular embryologist at the University of Bath, told Discovery News. "Yes, the cells are special -- a parthenogenote and a sperm -- but imagine if any mitotic cell could reprogram a sperm in the same way. Then there would be no need for eggs."

Sperm moving toward an egg.
"This could revolutionize reproduction," he added. "It would pave the way for gay men to have children; enable oncofertility (fertility among cancer survivors); allow older women, and others with insufficient eggs, to conceive; allow males to self-fertilize, and females (to self-fertilize too) when combined with other technologies," and more, including easier breeding of endangered species "if eggs are difficult to obtain."

For now, mammal males -- including men -- still need females for reproduction and vice versa because, even for this research, the parthenogenetic mice embryos were produced from eggs contributed by females, and females carried the pregnancies to term.

Many unknowns still exist. It's not clear how sperm are able to be reprogrammed to allow for embryonic development with an egg cell, much less without one, as for the new process.

Read more at Discovery News

Second Ship From Doomed Arctic Expedition Found

Explorers believe they may have discovered the long-lost second ship from the ill-fated Franklin expedition. The vessel, HMS Terror, vanished nearly 170 years ago with another ship, HMS Erebus, and a crew of 129 men during an Arctic expedition to search for the fabled Northwest Passage to Asia.

The Terror was found "in pristine condition at the bottom of an Arctic bay," the British newspaper the Guardian reported Monday in an exclusive coverage.

The wreck was discovered 80 feet underwater in Terror Bay on the coast of King William Island in the Canadian Arctic Archipelago. A team from the Arctic Research Foundation found it after receiving a tip from Sammy Kogvik, an Inuk and Canadian Ranger from Gjoa Haven.

The researchers used a small, remotely operated vehicle through an open hatch to capture amazing images of the vessel's interior.

"We have successfully entered the mess hall, worked our way into a few cabins and found the food storage room with plates and one can on the shelves," Adrian Schimnowski, the foundation's operations director, told the Guardian.

"We spotted two wine bottles, tables and empty shelving. Found a desk with open drawers with something in the back corner of the drawer, " he said.

Parks Canada, the main government partner in the search, said it is currently working to validate the discovery, but Schimnowski is confident that a number of the Terror's features have already been identified.

In 2014 experts confirmed that a well-preserved wreck found in the Queen Maud Gulf, along the central Arctic coastline, was HMS Erebus, the Franklin expedition's flagship.

The two wrecks lie some 30 miles apart from each other.

The Erebus and Terror sailed out of the Thames bound for the Arctic on May 19, 1845 with a crew of 129 men. At the helms were John Franklin and Francis Crozier respectively. Their mission was to find the fabled Northwest Passage -- the shortcut between Britain and Asia. They vanished in the ice-choked Arctic.

The expedition's loss at sea was one of the most celebrated mysteries of the Victorian era and a puzzle that continued baffle naval historians throughout the 21st century, when Canada launched a multi-million dollar search.

According to a message found in a cairn on King William Island in 1859, the Erebus and Terror became fatally trapped in sea ice. They were abandoned in April 1848, with Crozier in command of "the officers and crews, consisting of 105 souls." The note explained that Franklin had died on June 11, 1847.

Read more at Discovery News

Sep 12, 2016

World's Oldest Snowshoe Found in Alps

The world's oldest snowshoe was found in the Italian Alps, near the border of Austria.

The 5,800-year old artifact was described on Monday at a press conference in Bolzano, Italy, as belonging to the ancestors of Ötzi the Iceman, the 5,300-year-old ice mummy found 25 years ago near a melting glacier in the Ötztal Alps in South Tyrol.

Simone Bartolini, a cartographer from the Military Geographical Institute in Florence, found the perfectly preserved snowshoe in the summer 2003, while doing a survey on the Gurgler Eisjoch glacier at 10,282 feet above sea level in the val Senales.

"I thought it was a 100-year-old snowshoe that was lost by a farmer. I kept it in my office for years," Bartolini said.

Only last year, after talking to Angelika Fleckinger, director of the South Tyrolean Museum of Archaeology, Bartolini realized the artifact could have been much older.

Indeed, carbon dating from two labs determined the snowshoe was created in the late Neolithic age, between 3,800 and 3,700 BC.

The artifact was made entirely from birch wood, bending a 5-foot-long branch to an oval frame measuring 13 inches in diameter. Several strands were stretched inside the frame.

Until a few decades ago, people in the region wore snowshoes almost identical in style and shape.

"The snowshoe shows that already in the late Neolithic, well-equipped people were staying in the Alps at high altitudes," Catrin Marzoli, director of the Office for Archaeological Heritage, said.

She noted various reasons could explain the prehistoric presence. These include hunting, herding, visiting places of worship or just fleeing from enemies.

Read more at Discovery News

Dolphin 'Conversation' Recorded?

Do the clicks and whistling sounds made by dolphins form discrete words and even full sentences? They do, if you ask Russian scientists who say they have documented conversation between a pair of Black Sea dolphins.

In research published in St. Petersburg Polytechnical University's journal Physics and Mathematics, scientists from the Karadag Scientific Station recorded sound pulses between two bottlenose dolphins (Tursiops truncatus) and now suggest that each recorded pulse represents a "word" and that a "pack" of the pulses together form a "sentence."

Researchers have long known that dolphin sounds carry meaning. They can convey information such as warnings about predators, information about foraging and navigation and emotions such as delight. They've even been shown, in recent research, to denote individual dolphin names.

But this study adds a new wrinkle to that understanding of the highly intelligent creatures.

By changing the volume and frequency of the clicks, the dolphins formed discrete words, using up to five of them in short sentences, the team found. "We can assume that each pulse represents a phoneme, or a word, of the dolphin's spoken language," they wrote.

The recordings "showed that the dolphins took turns in producing pulse packs and did not interrupt each other," said the researchers, suggesting that the marine mammals could be listening to the entire sentence before making responses of their own.

The exchange, they said, "resembles a conversation between two people. "

The dolphins in the conversation, Yasha and Yana, were recorded in a pool the animals call home at the Karadag Nature Reserve in Russia.

Their chatter, say the scientists, was not likely idle.

"As this language exhibits all the design features present in the human spoken language, this indicates a high level of intelligence and consciousness in dolphins, and their language can be ostensibly considered a highly developed spoken language, akin to the human language," the researchers said.

Read more at Discovery News

A Big Earthquake Can Trigger Others in Minutes

The San Francisco earthquake of 1906. It's possible that an earthquake of similar magnitude could be triggered by another quake on an unconnected fault, a new study reports.
Earthquakes that occur on one fault can trigger quakes on other faults as well, a fact known for some time by scientists. Back in 1992, for example, a 7.3 quake that struck in the Mojave Desert,120 miles east of Los Angeles, caused ruptures on five other faults in the region. But In recent years, as we've previously reported, they've discovered that it happens much more frequently than they realized, which has led them to adjust future predictions of earthquake risks.

Now, a new study by researchers at Scripps Institution of Oceanography at the University of California San Diego, published in the journal Science, shows that the cascading effect is frighteningly fast. A large earthquake on one fault can trigger large aftershocks on separate faults within just a few minutes, the researchers found.

The study's authors, Scripps geophysicist Peter Shearer and graduate student Wenyuan Fan, analyzed data from seismic stations that are part of the Incorporated Research Institution for Seismology's global network. They discovered 48 previously unidentified large aftershocks from 2004 to 2015 that occurred within 200 seconds after 27 different magnitude 7 to 8 earthquakes on other faults, some of which were as far as 207.5 miles away.

In one instance cited in the study, a magnitude 7 earthquake off the coast of Indonesia triggered two large aftershocks that were 47 and 137 miles away, respectively, from the main fault, within 68 and 120 seconds of the initial shock.

"The results are particularly important because of their seismic hazard implications for complex fault systems, like California," study-co-author Fan said in a UCSD press release. "By studying this type of triggering, we might be able to forecast hosting faults for large earthquakes."

While most aftershocks occur near the main fault rupture, the study proves that large early aftershocks can also be triggered by seismic waves that jump between faults that aren't directly connected.

Read more at Discovery News

Interstellar Clouds Eroded Martian Atmosphere

An artist's impression of solar wind stripping the Martian atmosphere.
A long time ago, Mars had an atmosphere thick enough to allow running water on its surface. But today these vast gullies -- and features that some scientists interpret as ocean shorelines -- are bone-dry.

Something thinned the Red Planet's atmosphere over time, and there's a mission in orbit to find out how, when it happened and how quickly.

New results based on observations from MAVEN (Mars Atmosphere and Volatile EvolutioN Mission) have found a possible new source for losing the atmosphere. For years, scientists have known that the solar wind -- that stream of charged particles coming from the sun -- can strip away hydrogen molecules on Mars. The new study suggests that interstellar clouds are also partially responsible.

"MAVEN made it clear that ionizing radiation from the sun is the main driver as we it see now. I agree with those results 100%, and am looking at geological timescales where encounters with interstellar clouds also becomes important," said lead author Dimitra Atri, of the Blue Marble Space Institute of Science, in an email interview with Discovery News.

The changes come as our solar system moves around the galaxy, Atri explained. From time to time, we move through interstellar clouds -- vast, dense clouds of gas and dust -- in events that last for about a million years. This has happened at least 135 times since the solar system was formed 4.5 billion years ago, Earth's geological records suggest. Each time, the gas and dust in the cloud strike the solar wind and create a bow shock. This shock accelerates charged particles (protons), which Atri suggests will make Mars lose 0.5% of its atmosphere each time.

Artist's impression of the MAVEN (Mars Atmosphere and Voltaile EvolutioN Mission) spacecraft orbiting the Red Planet.
Because each of these events is so long -- roughly a million years apiece -- Atri's calculations suggest that over time, they contributed to losing half of the Martian atmosphere. Other events attributed to Martian atmosphere loss, such as solar flares and supernovae, have a smaller contribution; Atri says even the strongest solar flare has eight times less magnitude on the escape of the Martian atmosphere than one pass through an interstellar cloud.

Read more at Discovery News

Sep 11, 2016

15 Years After 9/11, Americans Don't Feel Safe

Today marks 15 years since the 9/11 attacks, and memorials will be held around the country in remembrance of the nearly 3,000 lives lost in New York, Washington, D.C. and Pennsylvania that day. Arriving in time for the anniversary are a pair of polls that show that Americans are increasingly concerned about the possibility of a terrorist attack on U.S. soil.

According to a CNN/ORC poll (PDF) released on Friday, half of Americans expressed the feeling that an act of terrorism during the days surrounding Sept. 11 this year is "very" or "somewhat" likely. Five years ago, 39 percent of Americans had the same premonition.

In the last five years, there have been a number of large-scale terrorist attacks both in the United States and internationally, many of which are tied to the rise of ISIS. Within the U.S., the Boston Marathon bombing in 2013, San Benardino shooting last year and the Pulse nightclub massacre earlier this summer were mass-casualty events in the past half decade that increased Americans' sense of unease. In Europe within the last 12 months, terrorists struck in series of coordinated attacks in Paris, airport bombings in Brussels and a truck attack at a Bastille Day event in Nice.

These new attacks are also contributing to the increasing sense of fear and anger Americans feel when reflecting on 9/11, the CNN/ORC polls finds. Forty percent of Americans said they felt fear and around three-quarters anger when looking back to 9/11. Five years ago, those numbers stood at 62 percent and 30 percent, respectively.

A Pew Research Center poll released Wednesday paints a similar picture. Forty percent of Americans says that the ability of terrorists to strike in the United States is greater than it was on Sept. 11, 2001, and 31 percent believes terrorists' ability to launch an attack are about the same.

In Pew's numbers, there is also a sharp partisan divide in terms of how Americans feel about the liklihood of a major terrorist attack, reflecting an increasingly polarized political landscape during an election year.

Nearly 60 percent of Republicans consider the ability of terrorists to attack as greater than at the time of 9/11, Pew finds, while 34 percent of independents and 31 percent of Democrats felt the same.

"Opinions about terrorists' capabilities to attack the U.S. have long been divided along partisan lines," the center writes. "During George W. Bush's presidency, Democrats were often more likely than Republicans to say the ability to terrorists to launch a major strike was greater than at the time of 9/11, while the reverse has been true during Barack Obama's administration."

"But this marks the first time in the past 14 years that a majority in either party has expressed this view," the report continues.

From Discovery News