May 7, 2016

Spotty Star Reveals Magnetic Weirdness

Our sun’s magnetism waxes and wanes over cycles lasting approximately 11 years, producing a rash of dark sunspots that drift around the sun’s equator at “solar maximum” and then all but disappear during “solar minimum.” Astronomers have tracked sunspot numbers for centuries, but only now are we beginning to understand what drives them and how the underlying magnetic field is generated.

But as we get up-close and personal with our nearest star, solar physicists are curious as to whether our sun is typical — do other stars exhibit similar cycles? Do they have sunspots or, more accurately, starspots? If so, are they driven by the same mechanisms?

Of course this answer is hard to come by; zooming in on a distant point of light to decipher surface features on other stars, let alone resolve starspots, has been asking a little too much of astronomical techniques. But we are reaching a point where we can see small stars, particularly red dwarfs, exhibiting huge regions, covered with large spots, which cause the star’s brightness to dim as they rotate.

Now astronomers have gone one better: they’ve mapped the photosphere of a large old star 180 light-years away and resolved individual spots as the star rotates. And it looks weird.

But “weird” is a very relative term. Just because other stars behave differently from our sun, it’s just as likely that our sun is weird when compared with other stars in the universe. Or perhaps every star is unique in some way; countless physical variables all amounting to a rich and varied stellar family.

And in this particular case, zeta Andromedae, a star 15 times the size of the sun, has starspots dotted all over in an apparently random fashion, even at high latitudes (i.e. near the poles).

This is very different to our sun where the majority of sunspots tend to erupt around the equator and we have a pretty good idea as to why this is. The sun experiences differential rotation, in other words it rotates faster at the equator than it does at the poles. This has a dragging effect on the internal magnetic field, pulling it more around the equator. This is thought to “wind up” the magnetic field, making magnetic field lines pop through the photosphere as coronal loops, creating a rash of darkened regions — sunspots — in an equatorial pattern.

Read more at Discovery News

'Very Strange Animal' Was First Marine Plant Eater

An animal described as part Dr. Seuss, part dinosaur has been identified as being the first known plant-eating marine reptile.

The reptile, which lived 242 million years ago in southern China, arose after the planet's largest mass extinction, revealing that dire times can result in animals with seemingly improbable features.

The crocodile-sized plant eater, named Atopodentatus unicus, aka "Uniquely Strangely Toothed," is described in the journal Science Advances.

Senior author Nicholas Fraser of National Museums Scotland told Discovery News, "To me, it is very much in keeping with a Dr. Seuss creation!" said Senior author Nicholas Fraser of National Museums Scotland, adding that the Seuss tale, "The Things You Can Think" comes to mind.

Fraser and his team studied the fossils for the reptile, with a particular focus on what was previously thought to be a flamingo-like beak. The new analysis instead found that the "beak" was part of a hammerhead-shaped jaw apparatus that the reptile used to feed on plants on the ocean floor. Peg-like front teeth lined the jaw, which also had needle-shaped teeth. None of the teeth were suitable for eating meat.

Some sharks today have hammerheads, but their sharp teeth are definitely ready to sink into moving prey such as octopus and even other sharks.

Co-author Olivier Rieppel of Chicago's The Field Museum said that the marine reptile's peg teeth were used "to scrape plants off rocks on the seafloor, and then it opened its mouth and sucked in the bits of plant material. Then it used its needle-like teeth as a sieve, trapping the plants and letting the water back out, like how whales filter-feed with their baleen."

The teeth are reminiscent of those of certain dinosaurs, such as plant-eating Nigersaurus. The body of A. unicus seemed to be dinosaur-like as well, given the creature's long neck and rather chunky mid section.

While the lineage of A. unicus is a mystery for now, the researchers speculate that it was an "aberrant sauropterygian." These were aquatic reptiles that developed from terrestrial ancestors at around the time of the Permian-Triassic extinction event 252 million years ago. Sauropterygians include plesiosaurs that, like A. unicus, breathed air, had flippers and often long necks.

As for A. unicus looking somewhat like an underwater dinosaur, Fraser said, "Maybe all these large extinct animals seem so far-removed from anything we know today that we automatically try to group them together."

He said that after the big extinction event, there was a major breakdown in the food chain. Over a period of 6–7 million years, a large range of different feeding strategies had become established among marine reptiles. Some of these animals became suction feeders, while others feasted only on mollusks or fish. Still other strategies emerged, including A. unicus taking advantage of seafloor plant life.

Michael Benton, a professor of vertebrate paleontology at the University of Bristol, told Discovery News that A. unicus "adds to the amazing explosion of marine reptiles during the massive recovery of life from the Permian-Triassic mass extinction."

Xiao-Chun Wu of the Canadian Museum of Nature said, "The research is important not only for revealing the oldest record of herbivory with a bizarre head within marine reptiles, but also for us to understand the recovery mechanism of marine vertebrates, especially reptiles after the global extinction at the Permian-Triassic Transition."

Wu believes that further examination of the reptile's teeth using a highly magnified electronic microscope might reveal wear surfaces that could provide additional clues concerning what the animal was eating. He wonders if, instead of scraping off plants, A. unicus was "grabbing muddy piles with organisms, including algae and plant matter, which were shoveled together" in the mouth.

Read more at Discovery News

Pluto Behaves More Like a Planet Than Thought

Apologies to all of the Pluto-isn't-a-real-planet folks out there but researchers have found a way in which this ever-surprising world acts more planet-like than dwarf-like: how it interacts with the solar wind.

During New Horizons’ flyby through the Plutonian system in July 2015, the spacecraft’s Solar Wind Around Pluto (SWAP) instrument measured what happens when charged particles streaming out from the sun interact with Pluto’s atmosphere.

What was observed was a much less subtle comet-like interaction (as had been previously suspected) and more a hybrid comet/planet behavior, with the solar wind being deflected abruptly but relatively close to its upwind-facing surface.

“This is a type of interaction we’ve never seen before anywhere in our solar system,” said David J. McComas, professor of astrophysical sciences at Princeton University and lead author of the study. “The results are astonishing.”

Surprisingly, Pluto is able to maintain a gravitational grasp on much of its thin atmosphere even as ions are being stripped away by the solar wind into a long tail (which, by the way, is also found on other planets like Earth.)

“These results speak to the power of exploration,” said Alan Stern, New Horizons principal investigator. ”Once again we’ve gone to a new kind of place and found ourselves discovering entirely new kinds of expressions in nature.”

The findings were published on May 4, 2016 in the Journal of Geophysical Research – Space Physics.

From Discovey News

May 5, 2016

China Bug Declared World's Longest Insect

A bug over half a meter (1.6 feet) long discovered in southern China has been declared the world’s longest insect, state media said Thursday.

A stick insect measuring 62.4 centimeters (24.6 inches) found two years ago in the southern province of Guangxi has broken the record for length among the world’s 807,625 known insects, the official Xinhua agency said, citing the Insect Museum of West China.

The previous record-holder was a Malaysian 56.7-centimeter-long (22.3 inches) stick insect discovered in 2008 and now on display in London’s Natural History Museum.

Tipped off by locals about a huge beast half a meter long but as thick as a human index finger, scientist Zhao Li had been on the hunt for the bug for six years before he finally glimpsed and captured one.

“I was collecting insects on a 1,200-meter-tall (3,397-foot) mountain in Guangxi’s Liuzhou City on the night of Aug. 16, 2014, when a dark shadow appeared in the distance, which looked like a tree twig,” Zhao said, according to Xinhua.

“As I went near, I was shocked to find the huge insect’s legs were as long as its body,” he added.

The bug has been dubbed Phryganistria chinensis Zhao in his honour, and a paper about it will soon be published.

More than 3,000 varieties of stick insects have been discovered so far, Xinhua said.

From Discovery News

Primate Fossil 'Mother Lode' Shows Our Ancestors' Rough Past

A “mother lode” of newly found fossil primates in southern China strengthens evidence that primates first emerged in Asia, with climate change later shifting the evolution of monkeys, apes and even our own species to Africa.

The findings, published in the journal Science, help explain the Asia-Africa story of primate evolution and also demonstrate how sensitive humans and other primates are to climate change.

“Primates like it warm and wet, so they faced hard times around the world — to the extent that they went extinct in North America and Europe,” co-author K. Christopher Beard, senior curator at the University of Kansas’ Biodiversity Institute, said in a press release.

“Of course,” he added, “primates somehow survived in Africa and Southern Asia, because we’re still around to talk about it.”

Beard and his colleagues discovered six new species of fossil primates dating to 34 million years ago from southern China. All that’s left of the primates now are jaw and tooth fragments, which survived so long due to their tough enamel surfaces.

“The fossil record usually gives you a snapshot here or there of what ancient life was like. You typically don’t get a movie,” Beard said.

He continued: “We have so many primates from the Oligocene (approximately 34–23 million years ago) at this particular site because it was located far enough to the south that it remained warm enough during that cold, dry time that primates could still survive there. They crowded into the limited space that remained available to them.”

Some primates had previously migrated to North America, Europe and other parts of Asia. As Beard mentioned, those early populations eventually died out. This was due to a drastic cooling that took place around 34 million years ago. The dramatic change in climate made much of Asia inhospitable to primates, slashed their populations and rendered discoveries of such fossils especially rare, making the new fossil finds all the more important.

Like most of today’s primates, the ancient Chinese ones were tropical tree-dwellers, according to the researchers. One of the species, named Oligotarsius rarus, was “incredibly similar” to the modern tarsier found today only in the Philippine and Indonesian islands, they wrote.

“If you look back at the fossil record, we know that tarsiers once lived on mainland Asia, as far north as central China,” Beard said. “The fossil teeth described in this paper are nearly identical to those of modern tarsiers. Research shows that modern tarsiers are pretty much living fossils — those things have been doing what they do ever since time immemorial, as far as we can tell.”

If the global intense cooling had not occurred 34 million years ago, the main stage of primate evolution may have continued to be in Asia, rather than transitioning to Africa, where it is believed our species eventually emerged.

Read more at Discovery News

Cinco de Mayo: NOT Mexico's Independence Day

With a history steeped in battles and rebuilding, Mexico has earned every right to be proud. Today marks a Mexican holiday that more and more people celebrate every year in the United States, many not knowing the reason for the festivities: the "Batalla de Puebla" (Battle of Puebla) or "Cinco de Mayo" (Fifth of May).

While it may all seem like a huge fiesta now, the history of this holiday is covered in bloodshed and remembrance.

Contrary to popular belief, Cinco de Mayo is not the celebration of Mexico's independence day. El Grito de la Indepedencia (The Cry of Independence) is held annually on Sept. 16 in honor of Mexico's independence from Spanish rule in 1810.

Cinco de Mayo celebrates the country's freedom from a different oppressive European empire: France.

French occupation viciously swept across Mexico after the Mexican-American War of 1846-48. Mexico was left ripped to shreds and bankrupt after having suffered incredible defeat against the Americans. By the 1850s, the country was in a state of crisis.

Newly elected President Benito Juarez issued a moratorium on July 17, 1861, to help get a handle on his country’s wrecked economy, according to UCLA’s Chicano and Latino issues resource center.

The moratorium stipulated a hold on all foreign debt payments for the next two years so that Mexico could get out of financial ruin. Payments could resume after the two-year mark, but in the meantime Mexico was forced to default on debts abroad.

England, Spain and France — all of which Mexico owed money to — were furious. According to, all three sent naval ships to Veracruz to demand reimbursement. British and Spanish forces eventually negotiated with Mexico and withdrew, but it was France that decided to take severe action.

Seeing an opportunity to take advantage of a fallen nation, French ruler Napoleon III had hoped to be victorious over the weakened Mexican army and carve out an independent empire for France.

According to UCLA, there is some speculation that the United States’ enactment of the Monroe Doctrine in 1823, which stated that any European attempts to re-colonize any part of the Americas would be considered an act of war, may have sparked the French invasion frenzy. At the time, the United States’ quick and immense expansion was seen as a threat to other world powers.

In 1862, French Gen. Charles Latrille de Lorencez was ordered to march his forces into Veracruz and attack with 6,000 troops and 2,000 French loyalists headed for Puebla de Los Angeles, just east of Mexico City — Napoleon’s ultimate goal. In response, Juarez gathered up any Mexican loyalists he could find and put together a 4,000-strong, but hackneyed, force against the French. Many were farmers armed with hunting rifles and machetes, according to a PBS report.

For nearly 50 years, the French army had remained undefeated, until they clashed with the Mexican army on May 5, 1862, in Puebla. Led by Texas-born Gen. Ignacio Zaragoza, the outnumbered and poorly supplied Mexican army defeated French forces in what became known as the "Batalla de Puebla."

Read more at Discovery News

Highlighting the Hazards of Herbal Remedies

An estimated 40 million Americans take herbal supplements assuming that they are safe and effective. They often are, but a new journal article highlights the very real dangers of herbal remedies.

In their new article “Global hazards of herbal remedies: Lessons from Aristolochia,” published this month in “EMBO Reports” Arthur Grollman and Donald Marcus note that “the history of herbal use shows that not all herbs are benign and sometimes are deadly. Moreover, we cannot know whether all herbal medicines are safe because only a few have been tested systematically for toxicity or carcinogenicity.”

The authors highlight a widely-used herb called Aristolochia, also known as birthwort or pipevine. Various species of the herb are used in alternative and Chinese medicines, where it is claimed to treat edema and arthritis and used as a disinfectant. As Grollman and Marcus note, “The recognition of Aristolochia’s profound toxicity and carcinogenicity in humans began in the early 1990s, when about 100 otherwise healthy Belgian women developed a rapidly progressing chronic kidney disease that ultimately required dialysis or renal transplantation.”

If the plant can be toxic, why weren’t the health dangers known earlier? As an article on “Science Daily” notes, “Almost all carcinogens and many toxins require a long period of time before symptoms appear. This makes it very difficult for a layman or a professional to identify a particular compound as the cause of an illness when it was taken months or years earlier.”

Though most people think of poisoning as being a sudden event (such as by an accidental ingestion or single serving of contaminated food), people can unknowingly poison themselves over the course of several years. Residents of Flint, Mich., for example, drank lead-poisoned water for years without being aware of the problem. Similarly, a person may unknowingly consume small doses of a toxic—but seemingly harmless or even beneficial—herb that builds up in the body and causes disease months or years later.

Herbal supplements are not regulated by the Food and Drug Administration because they are not marketed as drugs. According to the Dietary Supplement Health and Education Act of 1994 herbal supplement manufacturers are entirely responsible for ensuring the safety and effectiveness of their products. Health officials typically only intervene when illnesses or deaths are reported, and of course by then the damage has been done.

An investigation into the herbal supplement industry led by the New York Attorney General discovered that four out of five bottles of herbal pills sold in national drugstore chains didn’t in fact contain any of the herbs indicated on their labels. In other cases they existed in dosages so small as to be ineffective, and were often diluted with cheap filler including powdered rice.

Read more at Discovery News

ALMA 'Weighs' Monster Black Hole to Highest Precision

Though we know black holes are kinda big, how do astronomers measure their mass? It’s not as if we can go out there and simply “weigh” them. Fortunately, astronomers have many tricky ways to work out the mass of objects in the universe and black holes are no exception.

Using the biggest and most powerful observatory on the planet, astronomers have been able to zoom in on the central region of an elliptical galaxy called NGC 1332, around 75 million light-years away, to get a high-precision view of the swirling gases around the central supermassive black hole. Although most known galaxies are now known to contain these black hole behemoths in their cores, this particular beast is quite the specimen: it’s 660 million times the mass of our sun.

The Atacama Large Millimeter/submillimeter Array (ALMA) in Chile was used to achieve this high-precision feat, but it didn’t look at the black hole directly, it measured the furious storm of galactic gases stuck inside the deep gravitational well of the black hole.

“To calculate the mass of a black hole in a galaxy’s center, we need to measure the speed of something orbiting around it,” said Aaron Barth, of the University of California, Irvine, and lead author of a study published in the Astrophysical Journal Letters. “For a precise measurement, we need to zoom in to the very center of a galaxy where the black hole’s gravitational pull is the dominant force.

“ALMA is a fantastic new tool for carrying out these observations.”

As we all know, black holes are, well, black. Their mass has such an immense gravitational pull that nothing, not event light, can escape. As we can’t see them (as there’s nothing to see as there’s no escaping light), astronomers have to look for black holes’ presence through other, indirect, means. One way is to measure the emissions of the hot gas trapped in a black hole’s accretion disk, for example. Another is to see how a black hole’s mass will warp spacetime, bending (or lensing) light around it.

But in this case, cold molecular gas could be seen in the vicinity of NGC 1332′s black hole. Knowing the distance of the gas cloud from the black hole and using ALMA to clock its speed, a highly precise measurement of the black hole’s mass could be made. And this one is certainly in the heavyweight division of supermassive black holes.

In the case of this galaxy, the gas has flattened out into a vast disk of spinning matter about the black hole with a radius of 800 light-years. Keep in mind that the distance from our solar system to the nearest star system, Alpha Centauri, is a little over 4 light-years, the radius of this structure is a whopping 200 times wider. At visible wavelengths, this disk cannot be resolved and just appears as a silhouette against a background of densely-packed stars (as can be seen in the image, top). ALMA, however, observes the cosmos in radio wavelengths and the cold gas disk generates radio emissions, allowing the astronomers to resolve small structures, only 16 light-years wide, inside the disk.

This stunning precision allowed measurements of the spinning gas within the black hole’s “sphere of influence” — a region within 80 light-years of the black hole — that is dominated by the black hole’s gravity, and its speed could be found. The gases in this region are whipping around the black hole as an awesome speed of over 300 miles per second.

Read more at Discovery News

May 4, 2016

Comet craters: literal melting pots for life on Earth

Geochemists from Trinity College Dublin's School of Natural Sciences may have found a solution to a long-debated problem as to where -- and how -- life first formed on Earth.

In a paper just published in the journal Geochimica et Cosmochimica Acta, the team proposes that large meteorite and comet impacts into the sea created structures that provided conditions favourable for life. Water then interacted with impact-heated rock to enable synthesis of complex organic molecules, and the enclosed crater itself was a microhabitat within which life could flourish.

It has long been suggested that the meteoritic and cometary material that bombarded the early Earth delivered the raw materials -- complex organic molecules, such as glycine, β-alanine, γ-amino-n-butyric acid, and water -- and the energy that was required for synthesis. The Trinity group's work has provided the new hypothesis that impact craters were ideal environments to facilitate the reactions that saw the first 'seeds of life' take root.

First author Edel O'Sullivan, now a PhD candidate in Switzerland, said: "Previous studies investigating the origin of life have focused on synthesis in hydrothermal environments. Today these are found at mid-ocean ridges -- hallmark features of plate tectonics, which likely did not exist on the early Earth. By contrast, the findings of this new study suggest that extensive hydrothermal systems operated in an enclosed impact crater at Sudbury, Ontario, Canada."

The research was part of a wider project funded by Science Foundation Ireland and led by senior author, Professor of Geology and Mineralogy at Trinity, Balz Kamber.

Although no very ancient terrestrial impact structures are preserved, the Sudbury basin provides a unique opportunity to study the sediment that filled the basin as a guide to what the earlier impact craters would have looked like. The Sudbury structure is distinctive among the known terrestrial impact craters. It has an unusually thick (nearly 2.5 km) basin fill, and much of this is almost black in colour (due to carbon) containing also hydrothermal metal deposits.

Professor Kamber said: "Due to later tectonic forces, all the rocks of the once ~200 km-wide structure are now exposed at the surface rather than being buried. This makes it possible to take a traverse from the shocked footwall through the melt sheet and then across the entire basin fill. To a geologist, this is like a time journey from the impact event through its aftermath."

Representative samples across the basin fill were analysed for their chemistry and for carbon isotopes, and they revealed an interesting sequence of events.

The first thing that became evident was that the crater was filled with seawater at an early stage, and remained sub-marine throughout deposition. Importantly, the water in the basin was isolated from the open ocean for long enough to deposit more than 1.5 km of volcanic rock and sediment. The lower fill is made up of rocks that formed when the water entered the crater whose floor was covered by hot impact melt. Fuel-coolant reactions deposited volcanic rocks and promoted hydrothermal activity. Above these deposits, reduced carbon starts to appear within the basin fill and the volcanic products become more basaltic.

Previously the puzzling presence of carbon in these rocks was explained by washing in from outside the crater basin. However, the new data show that it was microbial life within the crater basin that was responsible for the build-up of carbon and also for the depletion in vital nutrients, such as sulphate.

"There is clear evidence for exhaustion of molybdenum in the water column, and this strongly indicates a closed environment, shut off from the surrounding ocean," added Edel O'Sullivan.

Read more at Science Daily

Second strongest shock wave found in merging galaxy clusters

The discovery by a physics doctoral student at The University of Alabama in Huntsville (UAH) of the second-strongest merger shock in clusters of galaxies ever observed has generated excitement that is opening doors to further scientific exploration.

Sarthak Dasadia, who is advised by assistant physics professor Dr. Ming Sun, discovered the very strong shock in the merging galaxy cluster Abell 655 using observations from the Chandra X-ray Observatory.

The shock to the north of this cluster is second in strength only to the Bullet Cluster shock.

The shock is traveling with an astonishing speed of 2,700 kilometers per second, about three times the local speed of sound in the cluster. By comparison, NASA's Juno spacecraft in 2013 became the fastest human-made object when it was slingshot around Earth toward Jupiter at a relatively pedantic 40 kilometers a second.

"Studying mergers of galaxy clusters has proven to be crucial to our understanding of how such large scale objects form and evolve," says Dasadia. Shocks provide unique opportunities to study high-energy phenomena in the intra-cluster medium -- the hot plasma between galaxies.

"This could open a door, where people can do a number of different studies based on what I have found," Dasadia says. Already, scientists are targeting shocks in galaxy clusters to study dark matter, the magnetic field in the intracluster space, particle acceleration and energy transfer in the intracluster medium.

In only 10 days, Dasadia's research was accepted for publication by The Astrophysical Journal Letters. Dasadia recently received one year of research support from the Alabama EPSCoR Graduate Research Scholars Program (ALEPSCoR). He also gave an oral presentation on his research in August at the International Astronomical Union (IAU) General Assembly in Honolulu, Hawaii.

The universe is populated with galaxy clusters that are relaxed and unrelaxed, Dasadia says. The relaxed ones are mellow -- they've been around a lot longer, have seen lots of past mergers and really aren't dynamically active. It's the unrelaxed clusters like Abell 665 that are good candidates to study merger features such as shocks and turbulence.

"These galaxy clusters are not boundary objects," he says. "They do not have a very well-defined boundary around them."

When the undefined boundaries of massive clusters of galaxies 3 million light-years across are drawn together in a slow-motion collision, their cold cores and surrounding hot gases are disrupted into shock waves and gas fronts of various temperatures.

"When two cold cores collide, they may create a shock of heated gas," Dasadia says. "Such mergers are actually among the most energetic events in the universe, other than the Big Bang itself."

If talking about fronts and shock waves and temperature differentials sounds lot like the weather on Earth, Dasadia says that's because there is not much difference as far as the physics involved.

"Technically, we observe the same features in space that we do on Earth," he says. "This area has been studied extensively before at small scales, but few had done the work to discover what I found here at such big scales."

Read more at Science Daily

The Hunt for Da Vinci's Descendants

The face of Leonardo Da Vinci has always been a mystery, with experts never totally certain what Leonardo looked like.

Now research into Da Vinci’s family tree has revealed an amazing resemblance between one of the descendants of the Renaissance genius and the amiable old man depicted in the famous red chalk drawing kept in Turin's Royal Library, which is the only work largely agreed to be a self-portrait by da Vinci.

“It is certainly a surprising likeness, but we are not drawing any conclusion from it,” Alessandro Vezzosi, director of the Museo Ideale in the Tuscan town of Vinci, where the artist was born on April 15, 1452, told Discovery News.

Last month, Vezzosi and historian Agnese Sabato presented the results of a decades-long genealogical study into Leonardo’s family at a crowded conference in Vinci. Their findings will be published later this week in the journal Human Evolution.

At the conference, Vezzosi and Sabato announced the existence of 35 living relatives of Leonardo Da Vinci, with some of them attending the event. The descendants come from Leonardo’s father, a Florentine legal notary named Ser Piero Da Vinci.

“They have grown into 41 by now,” Sabato told Discovery News.

It was believed that no traces were left of the painter, engineer, mathematician, philosopher and naturalist. The remains of Leonardo, who died in 1519 in Amboise, France, were dispersed before the 19th century. However, around 1863, a skeleton claimed to be Da Vinci’s was buried in a chapel of the Amboise Castle.

To reconstruct Da Vinci’s family tree, Sabato and Vezzosi had to rely on documents such as parish records, contracts, manuscripts, historical maps and other archival data.

We know from a document written by Antonio, Leonardo’s grandfather, that Leonardo was born on April 15, 1452 “at 3 o'clock at night.”

In another document Antonio also stated that five-year old Leonardo was the illegitimate son of Ser Piero and “Chaterina, who at present is the wife of Achattabriga di Piero del Vaccha da Vinci.”

Leonardo’s illegitimate status and his complex family of four step-mothers and 21 or even 24 half-brothers and half sisters made it rather difficult to update the official Da Vinci family tree.

Vezzosi and Sabato had to deal with repeating names and confusing surnames. Indeed, Da Vinci had become a surname while “da Vinci” simply meant “from Vinci.”

“We know the surname Da Vinci was kept at least until 1803, since we have found it in the tomb of Ser Anton Giuseppe, an important descendant,” Sabato said.

“The surname Da Vinci was then simplified to Vinci,” she added.

During their research Vezzosi and Sabato made some intriguing findings. They found more details on Lucia, Leonardo’s paternal grandmother. Her family owned a kiln for artistic ceramic ware at Toia di Bacchereto, near Carmignano in the Vinci surroundings. The kiln was then owned by Ser Piero, Leonardo’s father.

“It is more than likely that Leonardo began his artistic activity between the age of 8 and 10, not only in Florence, but also at the family kiln,” Vezzosi said.

The researchers also shed some light on the mysterious figure of Caterina, Leonardo’s mother.

It was known that she lived with her husband Accattabriga in the village of San Pantaleo near Vinci. The most likely reconstruction identifies her as a female slave coming from the Middle East. It is believed she moved to Milan in 1493 to stay with Leonardo and that she died there.

Caterina and Accattabriga had five children. The only male, Francesco, died at 26 “killed by a springald in Pisa." Little is known of Piera, Maria, Lisabetta and Sandra, Leonardo’s half-sisters.

“We know that Lisabetta had three daughters and now we are investigating her genealogy,” Vezzosi said.

Finding Caterina’s descendants would be crucial to possibly retrieving mitochondrial DNA, which is passed down through the maternal line.

The most interesting branch of the Da Vinci’s family tree turned out to be connected to one of Ser Piero’s sons -- Domenico Matteo, who was born in 1483 from Ser Piero’s third wife.

From there, Vezzosi and Sabato were able to trace a direct and uninterrupted line up to today’s living descendants.

Dina, who appears to bear a striking resemblance to Leonardo’s self-portrait, was indeed a descendant of Leonardo’s half-brother Domenico Matteo.

“Her son Giovanni has helped us out finding important connections,” Vezzosi said.

He noted that their research added more than 150 names to the Da Vinci’s tree.

Read more at Discovery News

Fla. Keys Coral Reefs Dissolving Faster Than Thought

Ocean acidification due to climate change is dissolving coral along the Florida Reef Tract much faster than previously thought, reports a new study.

As the ocean absorbs carbon dioxide from the atmosphere, the oceans become more acidic. But lab studies hadn’t predicted a pH low enough to make reefs dissolve until 2050 or later, according to researchers at the University of Miami's Rosensteil School of Marine & Atmospheric Science.

It was widely believed that the reefs would reach a point where they lost more limestone than they were gaining. But the study, published in the in the journal Global Biogeochemical Cycles, reports that the limestone forming the foundation for the coral reefs is already dissolving.

“We don’t have as much time as we previously thought,” said Chris Langdon, professor of marine biology and ecology at the University of Miami and a senior author of the study. “The reefs are beginning to dissolve away.”

The damage to the reefs is expected to reduce habitat for fish species important for recreation and commercially. The Florida Keys reefs have an estimated worth of $7.6 billion, the researchers report.

Two years of collecting samples suggests reefs to the south are reaching the point where their growth cycle doesn't create more limestone than is dissolving during fall and winter.

“Only the two southern-most reefs were net depositional year-round,” the researchers wrote in the study. “These results indicate that parts of the (Florida Reef Tract) have already crossed the tipping point for carbonate production and other parts are getting close.”

“This is one more reason why we need to get serious about reducing carbon dioxide emission sooner rather than later,” Langdon said.

From Discovery News

Was 'Star Wars' Right? Can We Walk On Most Exoplanets?

When you saw ”Star Wars: The Force Awakens” for the fourth time in theaters, did you see any niggling issues with gravity? Or the fact that alien worlds had breathable atmospheres? The characters were conveniently zipping from planet to planet and walking on each surface with no apparent problem.

Is this actually true for most exoplanets we know of? After all, several of the planets in our solar system aren’t that friendly for a stroll. Jupiter’s pressure would crush you long before you reached the surface — if there is a “surface” buried beneath the gas layers. Venus-landing spacecraft had to be reinforced against the immense surface pressure from its thick clouds. The moon and Mars — past and future destinations for astronauts — are both possible for astronauts to walk on, however, though those gravitational fields would take some getting used to.

A new paper in the journal Astrobiology (also available in preprint version on Arxiv) says the “Star Wars” problem is understandable because “filming is done on Earth, and an accurate representation of other gravity fields would be technically difficult and expensive.” But is it representative of exoplanets generally? Led by the University of Valencia’s Fernando Ballesteros, the authors say reality may actually be not too far off.

The authors say more than 2,000 extrasolar worlds (both confirmed and plausible) have been found, at a rate of about three per week since 2011. That’s mostly thanks to NASA’s prolific Kepler space telescope. While Kepler finds planets by looking at the dip in light they produce when passing across a star, other telescopes measure the gravitational wobble these planets create in the star instead. That wobble gives an estimate of how massive the planet is.

The authors classify found exoplanets into three categories: 1) masses below Earth (like Mars), 2) a transition zone with super-Earths, Neptunes and some solar system planets, 3) gas giants with masses hundreds of times that of Earth. Surprisingly, that “transition zone” has several planet analogs in our own solar system with surface gravities similar to Earth: Venus, Uranus, Neptune, and Saturn. (Note again that the gravity of Venus is similar to Earth, but its atmosphere can quickly crush unprotected spacecraft.)

But it’s still unclear what the precise relationship is between planetary masses and their diameters. “For a given mass one could expect a diversity of sizes depending on the planetary composition and atmospheric size,” the authors write, “and we do not even know whether all that we call super-Earths have a solid surface.”

The authors add that in theory, you could have a huge rocky planet with no natural atmosphere, but that is challenged by current planetary formation models. Generally it is believed that planets assembled with bits of rock and gas attracting each other over time.

“One could in principle propose a rocky planet as big and massive as one would wish, with no atmosphere at all, but no natural process produces it. The accretion process and the competition for materials during planetary formation impose severe constraints on feasible planets,” the authors wrote.

Read more at Discovery News

May 3, 2016

Lab Retrievers Hardwired to Crave Food

New research confirms what a lot of pet owners have suspected for ages: Labrador retrievers tend to be more food-obsessed than other breeds.

The reason is that Labrador retrievers sometimes have a mutation of a gene called POMC that leads to greater food-motivated behaviors, according to a study in the journal Cell Metabolism. It is the first gene ever discovered that is associated with canine obesity.

“Whenever there’s something more common in one breed than another, we think genetics are involved,” co-author Eleanor Raffan, a veterinary surgeon and geneticist at the University of Cambridge, said in a press release. She previously studied human obesity before investigating the canine angle.

Raffan and her team first looked at the genes of 15 obese and 18 lean Labrador retrievers. The researchers noted a variation of POMC in many of the overweight dogs. For these canines, the POMC gene looked “scrambled at the end,” they said, hindering the dog’s ability to produce compounds that are usually involved in switching off hunger after a meal.

In humans, common variations in the POMC gene have been associated with weight gain and reduced feelings of satiation.

Senior author Stephen O’Rahilly, co-director of the Wellcome Trust-Medical Research Council Institute of Metabolic Science, said, “There are even some rare obese people who lack a very similar part of the POMC gene to that which is missing in the dogs.”

The researchers next analyzed a much larger number of dogs: 310 Labrador retrievers. Not all of the dogs with the DNA variation were obese, and some were obese without having the mutation, but the POMC deletion was nonetheless associated with greater weight.

According to an owner survey, these same dogs were also more food-motivated, meaning they frequently begged their owners for food, paid greater attention at mealtimes, and scavenged for scraps more often. On average, the genetic mutation was associated with about a 4.5-pound weight increase in the dogs.

“We’ve found something in about a quarter of pet Labradors that fits with a hardwired biological reason for the food-obsessed behavior reported by owners,” Raffan said.

She added that there were plenty of food-motivated dogs in the study that didn’t have the mutation, “but there’s still quite a striking effect.”

The team looked at yet another group of Labs, totaling 411, and found that roughly 23 percent of them have the noted genetic mutation. The mutation might not be all bad news, though. It might even make dogs easier to train, since they respond so well to food rewards.

The researchers determined that the mutation was markedly more common in 81 assistance Labrador retrievers that were included in the study. The POMC deletion occurred in 76 percent of these dogs.

Read more at Discovery News

Captain Cook's Lost Ship Endeavour Believed Found

Researchers said they believe they have located the wreckage of the Endeavour, a ship sailed by the famous British explorer James Cook, which was sunk off the United States during the Revolutionary War.

The ship was scuttled in 1778 leading up to the Battle of Rhode Island between American colonists and the British, and was as part of a blockade during the Revolutionary War.

It now appears to have been located by the Rhode Island Marine Archaeology Project (RIMAP) at one of nine sites containing 13 ships.

The ship, which Cook sailed in the Pacific Ocean, passed through a number of hands before eventually being renamed the Lord Sandwich and used in the Revolutionary War blockade.

RIMAP said it had pinpointed the wreckage at a site that included five other vessel, off the state of Rhode Island in Newport Harbor.

The association is launching a campaign to finance the construction of a storage facility to accommodate the objects that are likely to be found during excavation.

During his famous 1768-1771 voyage, Cook helped map the southwest Pacific Ocean and took possession of Australia in the name of the Crown.

From Discovery News

New Nazca Geoglyph Found in Peru

A new Nazca geoglyph has been uncovered by Japanese scientists in Peru, and it could be linked to a major ceremonial center.

Measuring 98-feet long, the geoglyph is located within the central area of the Nazca pampa, a large, flat, arid region of Peru between the Andes and the coast. The line drawing is of an animal, with many legs and spotted markings, sticking out its tongue.

“It certainly represents an imaginary or mythical creature,” Masato Sakai at the Yamagata University in Japan, said.

Last year a team lead by Sakai discovered dozens of new geoglyphs of animals in the same area using to 3-D scans of the ground.

This time, the researchers just spotted the new lines when walking on the Nazca plateau.

“Because the geoglyph is located on the slopes, it can easily be identified on the ground level,” Sakai told Discovery News.

Mostly known for their massive desert images of animals and birds, the Nazca flourished in Peru between the first century B.C. and the seventh century A.D. and slid into oblivion by the time the Inca Empire rose to dominate the Andes.

The new geoglyph is estimated to date back to the Late Paracas Period (400 B.C. to 200 B.C.). The dating comes from earlier versions of the motifs previously found on the pampa, which are believed to have been created at the Late Paracas period.

The geoglyph features a different technique than most famous Nazca lines. Typical of the Late Paracas Period, the technique relies on the white ground which lies underneath the black oxidized pebbles of the pampa.

“This new animal drawing was created by removing dark surface stones and exposing the underlying whitish ground,” Sakai said. ”The removed stones were then piled up to shape the animal image like a relief.”

He believes the animal drawing might be linked to the vast ceremonial center of Cahuachi, which contains about 40 mounds topped with adobe structures.

“We discovered another geoglyph in 2011, not far from the newly found one,” Sakai said. “It was created using the same technique and showed a pair of anthropomorphic figures in a scene of decapitation.” Decapitation was a popular activity within the Nazca civilization, which was obsessed over trophy heads. They seem to have used the human heads for their ceremonial activity.

Read more at Discovery News

'Impossibly Rare' Violet Diamond Found

A rare violet diamond, the largest of its kind ever found at Australia’s remote Argyle mine, will be the centerpiece of Rio Tinto’s annual pink diamonds showcase, the company said Tuesday.

The rough gem, discovered in August 2015 at a mine where more than 90 percent of the world’s pink and red jewels are produced, originally weighed 9.17 carats and had etchings, pits and crevices.

After weeks of assessment, the Argyle Violet was polished down to a 2.83 carat, oval-shaped diamond.

“Impossibly rare and limited by nature, the Argyle Violet will be highly sought after for its beauty, size and provenance,” Rio Tinto Diamonds general manager of sales, Patrick Coppens, said in a statement.

Rio Tinto did not put a figure on its worth, but said it had been assessed by the Gemological Institute of America as a notable diamond with the color grade of Fancy Deep Greyish Bluish Violet.

It is not known how diamonds acquire their colored tinge but it is thought to come from a molecular structure distortion as the jewel forms in the earth’s crust or makes its way to the surface.

Diamonds for sale as part of the annual Argyle pink diamonds tender can fetch $1-2 million a carat. As a basic rule of thumb, pink and red diamonds are worth about 50 times more than white diamonds.

Rio Tinto said violet diamonds were extremely rare with only 12 carats of polished stone produced for the tender in 32 years.

“This stunning violet diamond will capture the imagination of the world’s leading collectors and connoisseurs,” Argyle pink diamonds manager Josephine Johnson said.

The 2016 tender will begin private trade viewings in June and travel to Copenhagen, Hong Kong and New York, Rio Tinto said.

From Discovery News

Three Planets Found Orbiting Nearby Star

Astronomers have discovered three planets orbiting the habitable zone of an ultra-cool dwarf star just 40 light-years from Earth.

The discovery, reported today in Nature, is the first evidence supporting the hypothesis that these very low-mass and low-temperature stars should have Earth-sized or smaller planets orbiting them.

The planets, which are the size of Venus and Earth, are currently the best places to look for life outside our solar system, said the team of researchers led by astronomer Michaël Gillon, from the University of Liege in Belgium.

“Systems around these tiny stars are the only places where we can detect life on an Earth-sized exoplanet with our current technology,” Gillon said. “So if we want to find life elsewhere in the universe, this is where we should start to look.”

The planets were found almost by accident, as an international group of astronomers were conducting a test survey of an ultra-cool dwarf star labelled TRAPPIST-1, which lies in the constellation of Aquarius.

“We were preparing a much more ambitious project that will start this year, which will use a bigger telescope operating from Chile, and this prototype was meant to assess the feasibility of the project, but it worked so well that it detected an amazing system around a nearby ultra-cool dwarf,” Gillon said.

Planets could be habitable

The star, TRAPPIST-1, is about the size of Jupiter but is one thousand times dimmer than our Sun and shines in the much cooler infrared part of the light spectrum.

Orbiting it are three planets; two orbiting within 1.1 to 1.5 per cent of the distance between the Earth and the Sun and passing in front of the star every one to two days.

“Because the star is so faint, so small and cold, it emits much less photons so these planets should have temperatures which are quite similar to Venus,” Gillon said.

A third planet was found further out from the star but its orbit is less well-characterised, with researchers estimating that it passes in front of the star anywhere from every four to 72 days.

This distance puts the third planet in the middle of the so-called “Goldilocks Zone” of habitability, which means it could have a temperature range similar to that found on Earth, Gillon said.

Discovery ‘pushes limits’ of equipment

While astronomical theory suggests these ultra-cool, low mass stars would have Earth-sized planets orbiting them, astronomer Simon O’Toole from the Australian Astronomical Observatory said finding them was far from easy.

“That’s one of the neat parts of the project; that they basically stare at all the stars like this for as long as they can, then trying to find the transits, the dimming in brightness, and then try to find it periodically,” O’Toole, who was not involved in the study, said.

The researchers used a small 60-centimeter telescope to monitor the brightness of TRAPPIST-1 every 1.2 minutes for 245 hours over 62 nights.

The small telescope picked up the periodic dimming of the star, which suggested planets were passing in front of it and blocking some of its light.

The research team then used three much larger telescopes in India, Chile and Hawaii to confirm that these were indeed planets orbiting the star.

“It’s a phenomenal measurement … it’s really, really challenging, they’re pushing the limits of their equipment,” O’Toole said.

Read more at Discovery News

May 2, 2016

New Jellyfish Looks Like an Alien Spacecraft

With red and yellow lights seeming to glow inside its bulbous body, a newfound jellyfish looks more alien spaceship than deep-sea cnidarian.

Using a remotely operated vehicle (ROV), marine scientists dove to the deepest part of the world’s oceans, called the Mariana Trench, east of the Mariana Islands near Guam in the western Pacific Ocean; they were exploring the so-called Enigma Seamount (named for the lack of information scientists have on it) when they came upon this surreal-looking creature.

Video captured of the jellyfish reveals a stunning sight: The organism sports two sets of tentacles, long and short, that extend from its pulsating bell. When the long tentacles are extended outward, the jellyfish’s bell remains still. That feature, the researchers noted in a statement by the National Oceanic and Atmospheric Administration (NOAA), suggests the jellyfish is an ambush predator.

Inside the bell, which resembles a flying saucer of sorts, are red canals that seem to connect bright-yellow gonads, according to the scientists. From the looks of the jellyfish, the researchers identified it as belonging to the genus Crossota.

Scientists operating the ROV Deep Discoverer from aboard the research vessel Okeanos Explorer found the jellyfish on April 24 at a depth of 12,140 feet (3,700 meters). This was the fourth dive for the ROV for the first leg of a mission called the 2016 Deepwater Exploration of the Marianas, a three-cruise expedition run by NOAA and partners with the goal of understanding the deep-water habitats in and around the Mariana Trench. During the dive, the scientists found other fascinating features of this underwater mountain they call Enigma Seamount.

“Its morphology is quite different from other seamounts in the region, which generally have a flat top with steep, smooth sides radiating out into narrow ridges,” they wrote in a daily log of the expedition. “By contrast, this one is more circular in form and the sides are much less smooth.”

Throughout the ROV dive, the researchers also noticed “small, rounded balls that looked like they had been constructed from sediment,” they wrote. The balls could be a large species of single-celled amoeba or they could be marine sponges, the researchers said. Though deep-sea animals were scarce, the researchers said they did observe some wacky creatures, including “stalked crinoids and primnoid corals, swimming polychaete worms, a cusk eel, Caulophacus sponges, cladhorizid sponges, a Munidopsis squat lobster, a beautiful hydrozoan jellyfish and at least two Nematocarcinus shrimp.”

Read more at Discovery News

Hungry Polar Bears Decimating Seabird Colonies

While the iconic images of polar bears in a warming world are arguably of starving bears shivering on ice floes, or of bears swimming great distances as those floes disappear, a different scene may be a more accurate portrayal of the animal’s near future: hungry polar bears decimating colonies of nesting seabirds.

“Picture instead,” writes Daniel Grossman in a post for Yale Climate Connections, “a cream-colored bear loping on land, across tundra, and along the pebbled shores.” Forced to venture ashore in search of sustenance, this hypothetical bear is fighting off hunger by snacking on bird eggs.

The image is fully grounded in fact. As Grossman notes, polar bears have increasingly been observed marauding through colonies of seabirds as they seek alternate sources of sustenance in the absence of sea ice.

A 2010 study, for example, documented four cases of polar bears eating snow goose eggs, and the chicks and eggs of thick-billed murres, in Arctic Canada – with the bears in some instances even clambering up cliff faces to reach the nests.

And just last year, a team of European researchers reported that, in Greenland and the Svalbard Archipelago, bear raids on colonies of common eiders, glaucous gulls and barnacle geese, rarely if ever seen before 2000, are now commonplace.

Some scientists have argued this shows that concern over polar bears’ future is overstated and that the species may be able to survive the absence of their usual sea-ice-dwelling seal prey by switching to birds and to coastal Arctic land mammals such as caribou.

Theirs, however, is very much a minority position; others have calculated that such terrestrial food intake is “insufficient to offset lost ice-based hunting opportunities,” although they warn that it “can have ecological consequences for other species.”

This is what concerns Jouke Prop, a Dutch ornithologist who was one of the team that reported its findings from Greenland and Svalbard. He has observed polar bears eating more than 200 eggs in two hours; in 2014, no chicks or eggs of any of the three species species at his study sites survived.

According to a 2012 study, the combined effects of polar bear predation and parasitism by mosquitoes (itself likely also increasing as a result of higher temperatures) reduced the overall productivity of a thick-billed murre colony in Canada’s Hudson Bay by 20 percent in one year, and also increased adult mortality by 20 percent.

Read more at Discovery News

Turning Fog into Beer in World's Driest Desert

Every morning at dawn, a thick mist known as "The Darkness" blows in from the Pacific to the edge of the Atacama Desert, the most arid place in the world.

After tantalizing the northern Chilean desert with the promise of moisture, the mist evaporates in the sun, leaving the heat to bake the stark lunar landscape.

But the South American country is researching how to use a technique called "fog harvesting" to collect this mist in large quantities and deliver it to communities that currently depend on water shipped in from the city in tanker trucks.

Chilean researchers have patented a device resembling a large window screen to turn the mist into usable water.

These fog harvesters are set up facing the wind, which blows the mist into myriad tiny black threads that crisscross them.

Instead of passing through, the mist condenses on the polypropylene threads, slowly gathering into drops that eventually seep down into an awaiting container.

The technique is basic but efficient: each window-sized device can collect 14 liters (3.7 gallons) of water a day, said Camilo Del Rio, a researcher at the geography institute of Catholic University in Santiago.

The university runs a research center on fog harvesting in the northern city of Alto Patache.

The technology has been exported to Spain, Nepal, Namibia and several other Latin American nations. Other countries collect water with the same principle, but using trees to gather the condensed moisture.

The water tastes like rain, but must be treated for drinking because it contains minerals from the ocean and can harbor bacteria.

"Transforming it into potable water isn't complicated or expensive," and it can be used as is for bathing or irrigation, said Del Rio.

Old Idea

The research center in Alto Patache comprises six white domes with a weather station, a kitchen, bedrooms and bathrooms -- all of which run completely on harvested fog, which provides the facility with more than 200 liters of water a day on average.

The first fog harvester was installed in the desert in 1992. Around 150 have been deployed since then, though only 40 or so are currently in operation.

The Atacama Desert's dawn mist is produced by the intense solar radiation that hits the nearby Pacific, evaporating large volumes of water that is then carried inland by the region's strong winds.

When this moist air mass reaches the snowy peaks of the Andes mountains west of the desert, it cools and turns to a thick mist.

The indigenous people native to the region call the mist "Camanchaca," which means "The Darkness" in the Aymara language.

Using it for water is an old idea.

The Aymara have long collected condensed mist as it dripped from the rocks.

Today, researchers say, fog harvesting could enable entire communities in Chile's parched northern reaches to be self-sufficient for water, despite the near-total absence of rain.

Misty Beer

"This mist is a blessing," said Del Rio.

"We live in an extremely arid, desert climate... but we have this moisture from the ocean."

The lone drawback? Inconsistency. The amount of water collected by a single fog harvester can range from 14 liters a day or more in winter to zero in the summertime.

Read more at Discovery News

Boiling Water May Be Cause of Martian Streaks

The results of Earth-bound lab experiments appear to back up the theory that dark lines on Martian slopes are created by water — though in an otherworldly manner, scientists said Monday.

A team from France, Britain and the United States constructed models and simulated Mars conditions to follow up on a 2015 study which proffered “the strongest evidence yet” for liquid water — a prerequisite for life — on the Red Planet.

That finding had left many scientists scratching their heads as the low pressure of Mars’ atmosphere means that water does not survive long in liquid form. It either boils or freezes.

Identifying water on the Red Planet is complicated by our limited understanding of natural processes under conditions so different to those on Earth.

In September last year, a team reported in the journal Nature Geoscience that curious lines running down slopes on the Martian surface in “summer” may be streaks of super-salty brine.

They said they had found evidence in the lines of “hydrated” salt minerals, which require water for their creation.

The lines, up to a few hundred meters in length and typically under five meters (16 feet) wide, appear on slopes during warm seasons, lengthen, then fade as they cool.

“Under certain circumstances, liquid water has been found on Mars,” NASA concluded at the time.

For the latest study, also published in Nature Geoscience, researchers took to the lab to try and explain how water could have made the lines.

The team, led by Marion Masse of the University of Nantes in France, included several of the authors of last year’s headline-making study.

They placed a block of ice on a 30-degree plastic slope covered with loose fine-grained sand, and allowed it to melt in a chamber in which Martian pressure and summer temperature was recreated.

They repeated the experiment under Earth conditions to compare the processes.

Read more at Discovery News

May 1, 2016

At last: Non-toxic and cheap thin-film solar cells for 'zero-energy' buildings

'Zero-energy' buildings -- which generate as much power as they consume -- are now much closer after a team at Australia's University of New South Wales achieved the world's highest efficiency using flexible solar cells that are non-toxic and cheap to make.

Until now, the promise of 'zero-energy' buildings been held back by two hurdles: the cost of the thin-film solar cells (used in façades, roofs and windows), and the fact they're made from scarce, and highly toxic, materials.

That's about to change: the UNSW team, led by Dr Xiaojing Hao of the Australian Centre for Advanced Photovoltaics at the UNSW School of Photovoltaic and Renewable Energy Engineering, have achieved the world's highest efficiency rating for a full-sized thin-film solar cell using a competing thin-film technology, known as CZTS.

NREL, the USA's National Renewable Energy Laboratory, confirmed this world leading 7.6% efficiency in a 1cm2 area CZTS cell this month.

Unlike its thin-film competitors, CZTS cells are made from abundant materials: copper, zinc, tin and sulphur.

And CZTS has none of the toxicity problems of its two thin-film rivals, known as CdTe (cadmium-telluride) and CIGS (copper-indium-gallium-selenide). Cadmium and selenium are toxic at even tiny doses, while tellurium and indium are extremely rare.

"This is the first step on CZTS's road to beyond 20% efficiency, and marks a milestone in its journey from the lab to commercial product," said Hao, named one of UNSW's 20 rising stars last year. "There is still a lot of work needed to catch up with CdTe and CIGS, in both efficiency and cell size, but we are well on the way."

"In addition to its elements being more commonplace and environmentally benign, we're interested in these higher bandgap CZTS cells for two reasons," said Professor Martin Green, a mentor of Dr Hao and a global pioneer of photovoltaic research stretching back 40 years.

"They can be deposited directly onto materials as thin layers that are 50 times thinner than a human hair, so there's no need to manufacture silicon 'wafer' cells and interconnect them separately," he added. "They also respond better than silicon to blue wavelengths of light, and can be stacked as a thin-film on top of silicon cells to ultimately improve the overall performance."

By being able to deposit CZTS solar cells on various surfaces, Hao's team believe this puts them firmly on the road to making thin-film photovoltaic cells that can be rigid or flexible, and durable and cheap enough to be widely integrated into buildings to generate electricity from the sunlight that strikes structures such as glazing, façades, roof tiles and windows.

However, because CZTS is cheaper -- and easier to bring from lab to commercialisation than other thin-film solar cells, given already available commercialised manufacturing method -- applications are likely even sooner. UNSW is collaborating with a number of large companies keen to develop applications well before it reaches 20% efficiency -- probably, Hao says, within the next few years.

"I'm quietly confident we can overcome the technical challenges to further boosting the efficiency of CZTS cells, because there are a lot of tricks we've learned over the past 30 years in boosting CdTe and CIGS and even silicon cells, but which haven't been applied to CZTS," said Hao.

Currently, thin-film photovoltaic cells like CdTe are used mainly in large solar power farms, as the cadmium toxicity makes them unsuitable for residential systems, while CIGS cells is more commonly used in Japan on rooftops.

First Solar, a US$5 billion behemoth that specialises in large-scale photovoltaic systems, relies entirely on CdTe; while CIGS is the preferred technology of China's Hanergy, the world's largest thin-film solar power company.

Thin-film technologies such as CdTe and CIGS are also attractive because they are physically flexible, which increases the number of potential applications, such as curved surfaces, roofing membranes, or transparent and translucent structures like windows and skylights.

But their toxicity has made the construction industry -- mindful of its history with asbestos -- wary of using them. Scarcity of the elements also renders them unattractive, as price spikes are likely as demand rises. Despite this, the global market for so-called Building-Integrated Photovoltaics (BIPV) is already valued at US$1.6 billion.

Read more at Science Daily

Possible extragalactic source of high-energy neutrinos

Nearly 10 billion years ago in a galaxy known as PKS B1424-418, a dramatic explosion occurred. Light from this blast began arriving at Earth in 2012. Now, an international team of astronomers, led by Prof. Matthias Kadler, professor for astrophysics at the university of Würzburg, and including other scientists from the new research cluster for astronomy and astroparticle physics at the universities of Würzburg and Erlangen-Nürnberg, have shown that a record-breaking neutrino seen around the same time likely was born in the same event. The results are published in Nature Physics.

Neutrinos are the fastest, lightest, most unsociable and least understood fundamental particles, and scientists are just now capable of detecting high-energy ones arriving from deep space. The present work provides the first plausible association between a single extragalactic object and one of these cosmic neutrinos.

Although neutrinos far outnumber all the atoms in the universe, they rarely interact with matter, which makes detecting them quite a challenge. But this same property lets neutrinos make a fast exit from places where light cannot easily escape such as the core of a collapsing star and zip across the universe almost completely unimpeded. Neutrinos can provide information about processes and environments that simply aren't available through a study of light alone.

Recently, the IceCube Neutrino Observatory at the South Pole found first evidence for a flux of extraterrestrial neutrinos, which was named the Physics World breakthrough of the year 2013. To date, the science team of IceCube Neutrino has announced about a hundred very high-energy neutrinos and nicknamed the most extreme events after characters on the children's TV series "Sesame Street." On Dec. 4, 2012, IceCube detected an event known as Big Bird, a neutrino with an energy exceeding 2 quadrillion electron volts (PeV). To put that in perspective, it's more than a million million times greater than the energy of a dental X-ray packed into a single particle thought to possess less than a millionth the mass of an electron. Big Bird was the highest-energy neutrino ever detected at the time and still ranks second.

Where did it come from? The best IceCube position only narrowed the source to a patch of the southern sky about 32 degrees across, equivalent to the apparent size of 64 full moons. "It's like a crime scene investigation," says lead author Matthias Kadler, a professor of astrophysics at the University of Würzburg in Germany, "The case involves an explosion, a suspect, and various pieces of circumstantial evidence."

Starting in the summer of 2012, NASA's Fermi satellite witnessed a dramatic brightening of PKS B1424-418, an active galaxy classified as a gamma-ray blazar. An active galaxy is an otherwise typical galaxy with a compact and unusually bright core. The excess luminosity of the central region is produced by matter falling toward a supermassive black hole weighing millions of times the mass of our sun. As it approaches the black hole, some of the material becomes channeled into particle jets moving outward in opposite directions at nearly the speed of light. In blazars one of these jets happens to point almost directly toward Earth.

During the year-long outburst, PKS B1424-418 shone between 15 and 30 times brighter in gamma rays than its average before the eruption. The blazar is located within the Big Bird source region, but then so are many other active galaxies detected by Fermi.

The scientists searching for the neutrino source then turned to data from a long-term observing program named TANAMI. Since 2007, TANAMI has routinely monitored nearly 100 active galaxies in the southern sky, including many flaring sources detected by Fermi. Three radio observations between 2011 and 2013 cover the period of the Fermi outburst. They reveal that the core of the galaxy's jet had been brightening by about four times. No other galaxy observed by TANAMI over the life of the program has exhibited such a dramatic change.

"Within their jets, blazars are capable of accelerating protons to relativistic energies. Interactions of these protons with light in the central regions of the blazar can create pions. When these pions decay, both gamma rays and neutrinos are produced," explains Karl Mannheim, a coauthor of the study and astronomy professor in Würzburg, Germany. "We combed through the field where Big Bird must have originated looking for astrophysical objects capable of producing high-energy particles and light," adds coauthor Felicia Krauß, a doctoral student at the University of Erlangen-Nürnberg in Germany. "There was a moment of wonder and awe when we realized that the most dramatic outburst we had ever seen in a blazar happened in just the right place at just the right time."

In a paper published Monday, April 18, in Nature Physics, the team suggests the PKS B1424-418 outburst and Big Bird are linked, calculating only a 5-percent probability the two events occurred by chance alone. Using data from Fermi, NASA's Swift and WISE satellites, the LBA and other facilities, the researchers determined how the energy of the eruption was distributed across the electromagnetic spectrum and showed that it was sufficiently powerful to produce a neutrino at PeV energies.

Read more at Science Daily