'Somersault Spider' Backsprings Through the Desert

A newly discovered spider has just entered the animal record books by becoming the only known somersaulting spider.

The new species, Cebrennus rechenbergi, is described in the latest issue of the journal Zootaxa. It’s a nocturnal spider that lives in the Erg Chebbi desert of southeastern Morocco.

Check out its impressive, super fast backsprings!

While somersaulting, the spider moves over 6.5 feet per second, according to a press release issued by the Senckenberg Natural History Museum in Frankfurt. In Germany, the arachnid is known as the “flic-flac spider.” Flic-flac, aka flip-flop in English, also is a term referring to back handsprings.

The spider spends most of its time living in a custom-made home crafted out of sand and silk, according to the study, which was led by spider expert Peter Jäger. The cozy domicile is tube-shaped and sits beneath the desert surface, thereby protecting the spider from the sun and predators.

The spider has to leave to hunt and for other reasons. When it does, somersaulting can permit a speedy getaway should a predator try to pounce. Threats to the spider include scorpions, other spiders like the camel spider, and even humans.

The spider moves faster by somersaulting than it would if it were running. There is less friction to contend with and the vaulting motion creates its own momentum.

The spider is such a good athlete that it can do backsprings both up and down tall sand dunes.

As you might imagine, all of this can be exhausting and uses up a lot of energy, so the spiders can keel over if they have to do a somersault escape anywhere between 5 and 10 times a day.

Even with that limitation, scientist Ingo Rechenberg of the Technical University of Berlin was so impressed by the spider’s gymnastics that he built a tiny robot, called The Tabbot, mimicking the agile spider’s moves. “Tabacha” means “spider” in the Berber language.

Read more at Discovery News

Shipwreck Yields Bonanza of Gold Bars & Coins

In 1857, during the dwindling years of the California Gold Rush, a steamship loaded with some 30,000 pounds (13,600 kilograms) of gold was ensnared in a hurricane and sunk off the coast of South Carolina, banishing gold bars and freshly minted coins to the bottom of the sea. Last month, during a reconnaissance expedition to the wreckage of the so-called "Ship of Gold," more than 60 lbs. (27 kg) of the lost treasure was recovered.

Odyssey Marine Exploration Inc., a company that specializes in deep-ocean exploration, retrieved five gold bars and two gold coins — one from 1850 that was minted in Philadelphia, and the other from 1857 that was minted in San Francisco — from the sunken ship known as the SS Central America.

The precious artifacts were recovered during a reconnaissance dive to the shipwreck site on April 15. Odyssey Marine Exploration researchers are in the process of documenting the underwater site, and they eventually plan to conduct a full archaeological excavation of the shipwreck, according to company officials.

The remains of the SS Central America were first located in 1988 by the Columbus-America Discovery Group. The ship was found at a depth of 7,200 feet (2,200 meters), about 160 miles (257 kilometers) off the coast of South Carolina.

From 1988 to 1991, recovery operations managed to retrieve gold from approximately 5 percent of the total shipwreck site, historians have said. Odyssey Marine Exploration now has an exclusive contract to excavate and recover the rest of the SS Central America's treasure.

Experts say the shipwreck could still contain a commercial shipment of gold that was valued in 1857 at $93,000, company officials said. A "substantial amount of passenger gold," valued in 1857 at between $250,000 and $1.28 million, could also be locked within the ship's sunken remains, according to Odyssey Marine Exploration.

Still, the treasure's true worth remains to be seen. "The ultimate value of the recovery can only be determined once the total quantity, quality and form of the recovered gold is known," company officials said in a statement.

Last month, the Odyssey Marine Exploration's remotely operated underwater vehicle (ROV), named Zeus, became the first to visit the famous shipwreck in decades.

"This dive confirms for me that the site has not been disturbed since 1991, when I was last there," Bob Evans, chief scientist and historian for the Recovery Limited Partnership, which legally owns the shipwreck, said in a statement.

Besides the gold bars and coins, the two-hour expedition also uncovered a bottle, a piece of pottery, a sample of the shipwreck's wooden structure and part of a scientific experiment that had been left at the site 20 years ago, company officials said.

"The skill exhibited and results achieved during the initial reconnaissance dive reinforces our belief that the Odyssey team was the absolute best choice for this project," Craig Mullen, director of operations for the Recovery Limited Partnership, said in a statement.

Read more at Discovery News

Space Telescope Spies Galaxy's Magnetic 'Fingerprint'

If you live in or have ever visited a place with clear, dark skies, you have likely seen the hazy band of the Milky Way stretching across the night sky. Now a European space telescope has looked deeper into the Milky Way’s light, revealing our galaxy’s unique ‘fingerprint’ created by vast magnetic fields.

The Milky Way’s faint glow comes from the light of billions of distant stars inside the plane of our disk-shaped galaxy. But that’s only the visible light that our eyes can detect — the Milky Way shines brightly in many other parts of the electromagnetic spectrum, as does the entire universe. And it’s in these hidden wavelengths that European Space Agency’s Planck spacecraft observes our galaxy — and beyond — mapping the leftover light from the birth of the cosmos, before even the very first stars formed.

In order to best determine which light originates from the Big Bang and which is from  much closer and younger sources, like the stars and dust in our own home galaxy, scientists have to know how to filter out one from the other. Using Planck, the Milky Way is observed across a wide range of the electromagnetic spectrum and its specific pattern emerges, revealing not just light but also its magnetic “fingerprint,” created by polarized light from tiny interstellar dust grains aligned with magnetic fields.

The dust grains, part of the interstellar medium that pervades the entire galaxy, are very, very cold but still emit light in the infrared and microwave portion of the spectrum, light Planck is designed to detect. As these tiny grains spin they tend to emit more radiation along their longest axis, creating a preferential direction to the light — an effect known as polarization.

If you have polarized sunglasses you can easily appreciate this effect, as film inside the lenses specifically blocks reflected horizontally-aligned light and remove distracting glare.

In the new Planck visualization above, made with a technique called line integral convolution (LIC), polarized light emitted by dust particles traces out swirling linear patterns, not unlike the unique pattern of loops and whorls in a human fingerprint. The wavy lines are created by complex magnetic fields weaving throughout the Milky Way, which align the rotations of the interstellar dust particles and thus shape the net polarization of their radiation.

Darker regions correspond to stronger polarized emissions, and where there’s just a dark line running through the center is the densest part of the plane of the Milky Way, and strong parallel patterns have overlapped in three dimensions.

Read more at Discovery News

Could We Soon Detect Alien 'Plant' Life on Exoplanets?

Now we’re detecting dozens of exoplanets within the habitable zones of their stars — and even one world that has similar characteristics as Earth — the next big question will be: do any of these promising worlds host life?

Unfortunately, the answer will remain elusive for some time to come, but that hasn’t stopped scientists from formulating plans to seek out alien biomarkers that could be ripe for detection.

In a new paper submitted to the arXiv preprint service, astrophysicists Timothy Brandt and David Spiegel of the Institute for Advanced Study at Princeton University, New Jersey, focused on the hunt for the chemical signature of oxygen, water and chlorophyll in the atmospheres of Earth-like exoplanetary atmospheres. Oxygen and water are essential for life as we know it, and chlorophyll is a biomolecule vital for photosynthesis on Earth. Photosynthesis is the extraction of energy from sunlight, a process employed by plants and some microbes, such as cyanobacteria.

So the logic goes: If we can detect these molecules on an Earth-sized alien world, there could be some not-so-unfamiliar form of extraterrestrial life that has evolved to produce chlorophyll to extract energy from their star.

But the challenges to detect such signals are overwhelming, at least for the technology we have today. So the researchers have constructed some computer models in an effort to create hypothetical “second Earths” and the chemical signatures we may detect from afar.

The key issue facing any future space telescope set up to search for “Earth 2.0″ is that of contrast. Although analyzing the spectroscopic signature of large exoplanets has been done, often these worlds have wide orbits (well outside the habitable zone) or they are very large (like “hot-Jupiters”). Extracting a spectroscopic signal from a small world within the habitable zone of their star is tough, as the light from the star will overwhelm any reflected starlight signal from the exoplanet. The signal-to-noise ratio will be, basically, horrible.

This is where sophisticated models come in handy; if you can model an exoplanetary atmosphere with components similar to that of Earth, we know what chemical fingerprints to look for in observational data.

Brandt and Spiegel’s models created an ice world, a desert world and a world not so dissimilar to Earth (including oceans and vegetation). All their models assumed cloud cover of 50 percent. Then they simulated what chemical fingerprints could be detected in the spectroscopic signal. By far the easiest signal to detect would be that of water, a goal that could be achieved with technology we have today. But the detection of oxygen would be hard. But what of chlorophyll?

“Finally, we show that the ‘red edge’ of chlorophyll absorption … will be extremely difficult to detect, unless the cloud cover is much lower and/or the vegetation fraction is much higher than on Earth,” the researchers write. “Assuming extraterrestrial chlorophyll to have the same optical properties as the terrestrial pigments, and assuming Earth-like cloud and vegetation coverings, detecting chlorophyll will require a SNR (signal-to-noise ratio) 6 times higher than for diatomic oxygen…”

They point out that chlorophyll will only have as strong a signal as oxygen if the cloud cover is zero or if the planet has a higher proportion of its landmass covered in vegetation.

Although we may be waiting for some time until we can overcome the technological challenges to detect chlorophyll on an alien planet’s surface, it’s fascinating to think that the first hint of alien life could be through the detection of the signature of something that resembles terrestrial flora.

Read more at Discovery News

History to blame for slow crop taming, study shows

It's been about 10,000 years since our ancestors began farming, but crop domestication has taken much longer than expected -- a delay caused less by genetics and more by culture and history, according to a new study co-authored by University of Guelph researchers.

The new paper digs at the roots not just of crop domestication but of civilization itself, says plant agriculture professor Lewis Lukens. "How did humans get food? Without domestication -- without food -- it's hard for populations to settle down," he said. "Domestication was the key for all subsequent human civilization."

The study appears this the current issue of the Proceedings of the National Academy of Sciences.

Lukens and Guelph PhD student Ann Meyer worked on the study with biologists at Oklahoma State University and Washington State University.

Examining crop domestication tells us how our ancestors developed food, feed and fiber leading to today's crops and products. Examining crop genetics might also help breeders and farmers looking to further refine and grow more crops for an expanding human population.

"This work is largely historical, but there are increasing demands for food production, and understanding the genetic basis of past plant improvement should help future efforts," he said.

The Guelph team analyzed data from earlier studies of domesticated cereal crop species, and the American scientists also performed field tests.

To study the historical effects of interactions between genes and between genes and the environment, they looked at genes controlling several crop plant traits.

Domestication has yielded modern crops whose seeds resist shattering, such as corn whose kernels stay on the cob instead of falling off. Early agriculturalists also shortened flowering time for crops, necessary in shorter growing seasons as in Canada.

Domestication traits are known to have developed more slowly than expected over the past 10,000 years. The researchers wondered whether genetic factors hindered transmission of genes controlling such traits. Instead, they found that domestication traits are often faithfully passed from parent to progeny, and often more so than ancestral traits, said Lukens.

Read more at Science Daily

Infusion of young blood recharges brains of old mice

Something -- or some things -- in the blood of young mice has the ability to restore mental capabilities in old mice, a new study by Stanford University School of Medicine investigators has found.

If the same goes for humans, it could spell a new paradigm for recharging our aging brains, and it might mean new therapeutic approaches for treating dementias such as Alzheimer's disease.

In the study, to be published online May 4 in Nature Medicine, the researchers used sophisticated techniques to pin down numerous important molecular, neuroanatomical and neurophysiological changes in the brains of old mice that shared the blood of young mice.

But they also conducted a critical experiment that was far from sophisticated, said Tony Wyss-Coray, PhD, the senior author of the study and a professor of neurology and neurological sciences. The scientists simply compared older mice's performance on standard laboratory tests of spatial memory after these mice had received infusions of plasma (the cell-free part of blood) from young versus old mice, or no plasma at all.

"This could have been done 20 years ago," said Wyss-Coray, who is also senior research career scientist at the Veterans Affairs Palo Alto Health Care System. "You don't need to know anything about how the brain works. You just give an old mouse young blood and see if the animal is smarter than before. It's just that nobody did it."

Wyss-Coray has co-founded a biotechnology company, Alkahest, to explore the therapeutic implications of the new study's findings. He serves as the director of Alkahest's scientific advisory board.

The study's lead author, Saul Villeda, PhD, now has an active lab of his own as a faculty fellow in anatomy at the University of California-San Francisco. Villeda was a graduate student at Stanford and, briefly, a postdoctoral scholar under Wyss-Coray's direction when the bulk of the work was performed.

"We've shown that at least some age-related impairments in brain function are reversible. They're not final," Villeda said.

Previous experiments by Wyss-Coray, Villeda and their colleagues, described in a paper published in 2011 in Nature, had revealed that key regions in the brains of old mice exposed to blood from young mice produced more new nerve cells than did the brains of old mice similarly exposed to blood from old mice. Conversely, exposing young mice to blood from old mice had the opposite effect with respect to new nerve-cell production, and also reduced the young mice's ability to navigate their environments.

But that earlier work didn't directly assess the impact of young mouse blood on older mice's behavior. This time, the researchers checked both for changes within nerve circuits and individual nerve cells and for demonstrable improvements in learning and memory. First, they examined pairs of mice whose circulatory systems had been surgically conjoined. Members of such pairs, known as parabiotic mice, share a pooled blood supply.

Wyss-Coray's group paid special attention, in these parabiotic mice, to a brain structure called the hippocampus. In both mice and humans, this structure is critical for forming certain types of memories, notably the recollection and recognition of spatial patterns. "That's what you need to use when, for example, you try to find your car in a parking lot or navigate around a city without using your GPS system," Wyss-Coray said.

Experience alters hippocampal activity and anatomy. Studies have found, for instance, that a veteran London cabdriver's hippocampus is larger than it was when the driver was first hired, and larger than the average person's. The hippocampus is also extremely vulnerable to the normal aging process, showing early erosion in function as people grow older. In dementias such as Alzheimer's disease, this hippocampal deterioration is accelerated, leading to an inability to form new memories.

"We know that detrimental anatomical and functional changes occur in the hippocampus as mice and people get older," said Villeda. "This is just from natural aging. We're all heading in that direction."

When the investigators compared hippocampi from old mice whose circulatory systems had been conjoined with those of young mice to hippocampi from old mice that had been paired with other old mice, they found consistent differences in a number of biochemical, anatomical and electrophysiological measures known to be important to nerve-cell circuits' encoding of new experiences for retention in the cerebral cortex.

The hippocampi of older mice that had been conjoined to younger mice more closely resembled those of younger mice than did the hippocampi of older mice similarly paired with old mice. The old mice paired with young mice made greater amounts of certain substances that hippocampal cells are known to produce when learning is taking place, for example. Hippocampal nerve cells from older members of old-young parabiotic pairs also showed an enhanced ability to strengthen the connections between one nerve cell and another -- essential to learning and memory.

"It was as if these old brains were recharged by young blood," Wyss-Coray said.

Villeda, Wyss-Coray and their associates next subjected regular older mice to a test in which the mice were trained to quickly locate a submerged platform in a water-filled container. The mice had to speedily orient themselves using memory cues provided by their surroundings. The investigators injected old mice intravenously with plasma from young or old mice and ran them through the test. Typically, untreated older mice did poorly compared to young mice, as they did when injected with plasma from old mice. But if they were infused with young mice's plasma they did much better.

This was likewise the case on another test in which mice were trained to freeze in fear when plunked into a particular environment. The better they recognized that environment, the longer they would freeze. Older mice typically freeze for a shorter period of time than younger ones do. Again, "freezing" times for older mice given young plasma, but not old plasma, increased significantly.

Read more at Science Daily

Is the 'Gospel of Jesus's Wife' a Fake After All?

The "Gospel of Jesus's Wife," a papyrus written in Coptic and containing text that refers to Jesus being married, is looking more and more like it is not authentic, research is revealing.

A growing number of scholars have denounced the business card-sized papyrus as a fake, with recent op-eds appearing in The Wall Street Journal and on CNN. Meanwhile, Harvard University, which announced the papyrus' discovery, has fallen silent on the artifact, not responding to requests for comment on new developments suggesting the find is a forgery.

The discovery of the Gospel of Jesus's Wife was first announced by Karen King, of Harvard University, in September 2012. Its owner, who reportedly gave the papyrus to King, has insisted on remaining anonymous, and King has not disclosed the person's identity.

The fragment contains the translated line, "Jesus said to them, 'My wife …'" and also refers to a "Mary," possibly Mary Magdalene. If authentic, the papyrus suggests some people in ancient times believed that Jesus and Mary Magdalene were married.

At the time of the discovery, King tentatively dated the papyrus to the fourth century A.D., saying it may be a copy of a gospel written in the second century in Greek. Recent radiocarbon dating suggests that the papyrus may date to between the sixth and ninth centuries A.D.

Documents provided by the anonymous owner published in an essay by King recently in Harvard Theological Review say that the Gospel of Jesus's Wife was purchased from Hans-Ulrich Laukamp in 1999 and he, in turn, obtained it in Potsdam, in what was East Germany, in 1963.

A Live Science investigation published last week revealed that Laukamp was co-owner of ACMB-American Corporation for Milling and Boreworks in Venice, Florida. The man listed as representative of Laukamp's estate in Sarasota County, Florida, Rene Ernest, said that Laukamp didn't own this papyrus, didn't collect antiquities, didn't have an interest in old things and was living in West Berlin in 1963 — as such, Laukamp couldn't have reached Potsdam across the Berlin Wall to purchase this papyrus. Laukamp died in 2002.

Axel Herzsprung, who was another co-owner of ACMB-American Corporation for Milling and Boreworks, also said Laukamp didn't own this papyrus and didn't collect antiquities.

Additionally, since the investigation was published, Live Science has been in contact with an agency in Berlin that issues permits for the exportation of antiquities. Representatives of that agency said they could find no record that a papyrus like this had been exported from their office. It's possible that the Gospel of Jesus's Wife papyrus was exported from elsewhere in Germany or from the European Union.

Just recently, Christian Askeland, a research associate with the Institut für Septuaginta-und biblische Textforschung in Wuppertal Germany, revealed new information that casts further doubt on the papyrus' authenticity. His work is set to be published in the journal Tyndale Bulletin and is currently posted on a blog.

Askeland analyzed a second papyrus that, according to documents published in the Harvard Theological Review, was also purchased by the anonymous owner from Laukamp. It was presented to Harvard as a papyrus believed to be genuine.

This second papyrus, which has writing on two sides, includes text from the Gospel of John — and is a fake, writes Askeland, its lines being copied from a papyrus published in 1924. In addition, the researcher notes this papyrus has similar handwriting and ink to the Gospel of Jesus's Wife, making it likely that the Jesus's wife papyrus is also fake.

This second papyrus, which was carbon dated to between the seventh and ninth centuries A.D., is very similar to a Gospel of John papyrus, written and published by Egyptologist Sir Herbert Thompson in 1924, Askeland noted. In fact, the line breaks (the places where the text begins) are identical to those from Thompson's text. This is illustrated in an image of one side of the papyrus alongside Thompson’s 1924 text posted by Mark Goodacre of Duke University on his blog and republished on Live Science.

"Seventeen of 17 line breaks are the same. This defies coincidence," writes Askeland.

The John fragment is written in a dialect of Coptic called Lycopolitan, which had died out by the seventh century A.D., which would seem to confirm the fragment's inauthenticity, Askeland said.

Tests carried out by James Yardley and Alexis Hagadorn of Columbia University found that the ink from the Gospel of Jesus's Wife and the John fragment are similar but not quite the same. The handwriting style, however, from the John fragment is similar to that of the Gospel of Jesus's Wife, Askeland noted.

Given the similar handwriting and ink, and the identical owner, Askeland, and a large number of other scholars who have written online about Askeland's finds, argue that the Gospel of Jesus's Wife is likely also fake.

Live Science contacted two Egyptologists who have examined the Gospel of Jesus's Wife firsthand to get their opinions. Malcolm Choat, of Macquarie University, who published an analysis of the writing of the Gospel of Jesus's Wife recently in Harvard Theological Review, says that he needs time to investigate Askeland's findings before he can comment. Similarly, Roger Bagnall, the director of the Institute for the Study of the Ancient World at New York University (the Gospel of Jesus's Wife was examined there at one point) said that he needs time to analyze Askeland's findings and those of other scholars before he can comment.

If Laukamp did own both the Gospel of Jesus's Wife and the John papyrus, as the documents from the anonymous owner indicate, then this makes him an even more interesting and daring man.

He would have had to cross the Berlin Wall in 1963, at the height of the Cold War, to obtain the Jesus' wife papyrus from Potsdam (and if caught, he would have to explain to East German police that the Jesus' wife papyrus was just an ancient manuscript and not a coded message). He also would, at some point, have obtained a fake Coptic papyrus of the Gospel of John that had very similar handwriting and ink to the Jesus' wife papyrus.

He then would have hidden his collecting habits from Ernest (his estate representative in Sarasota County, Florida) and Axel Herzsprung, his closest business partner.

The two Egyptologists who can verify any part of this story, Gerhard Fecht and Peter Munro, died in 2006 and 2009, respectively. Additionally, Laukamp didn't have any children and doesn't appear to have any relatives still alive. And if the papyrus was exported from Berlin at some point, antiquities officials there have no record of it.

Biblical scholars have made numerous comments arguing that the Gospel of Jesus's Wife is a fake.

"If the Gospel of Jesus's Wife fragment is genuine, this already involves a pile-on of unusual and suspicious features that amounts to us having won the lottery," writes James Davila, a professor at the University of St. Andrews, on his blog. "Now another manuscript from the same cache written in the same hand again presents us with another pile-on of similarly suspicious features. At what point do we stop claiming another lottery win and just accept that the whole thing is a forgery?"

Read more at Discovery News

Eye to Eye With Michelangelo's Moses Creates Emotional Peak

They are stony eyes, but they can arouse a rush of emotions in those staring at them.

An eye-to-eye meeting with Michelangelo's Moses triggers the highest emotional responses, says a study which measured the emotional and cognitive engagement during the observation of a sculpture masterpiece.

Previous researchers have investigated the emotional impact produced by great works of art, but such studies were all based on surveys and lab experiments.

"Our research is the first ever that collects brain activity during the observation of a sculpture in its original setting," Fabio Babiloni, professor of physiology at the University of Rome Sapienza, told Discovery News.

To assess the cerebral and emotional reactions a sculpture can trigger, Babiloni and colleagues examined a group of 20 healthy subjects. For each onlooker, the researchers, in collaboration with the university spin-off Brainsigns, simultaneously collected the neuroelectrical brain activity (through EEG), heart rate (HR) and galvanic skin response (GSR), which basically measures the skin's sweat gland activity.

"While the emotional engage is described by mixing the HR and GSR, the cognitive factors are indexed by the estimation of the EEG asymmetry over the prefrontal cortex," the researchers wrote in a paper which will be presented in August at the International Conference of the IEEE Engineering in Medicine and Biology Society in Chicago.

Basically, relatively greater left frontal activity indicates a propensity to engage a stimulus, while relatively greater right frontal activity shows disposition to withdraw from it.

It emerged that cognitive and emotional responses triggered by the contemplation of Moses vary in relation to the different points from which the sculpture is viewed.

"Emotions raise to very high levels when observers meet the statue's eyes," Babiloni said.

Part of Pope Julius II's tomb in the basilica of St. Peter in Chains in Rome, Moses is an imposing marble statue carved in a niche. Michelangelo, who worked on the tomb project for 40 years, between 1505 and 1545, considered it his most accomplished, life-like creation.

Legend has it that the sculpture produced deep emotions in the artist himself.

As he finished it, Michelangelo is said to have struck the right knee with a hammer and said, "Now speak!"

The sculpture was particularly suitable for Babiloni's experiments as Moses's face is not oriented toward the observer, but looks to the left.

The subjects, half of whom had never seen the masterpiece before, were asked to contemplate the statue from three different points of view, each one revealing different details.

"Interestingly, we observed a dissociation between cognitive and emotional responses," Babiloni said.

The highest cognitive appreciation was achieved when the subjects were placed in front of the sculpture, with Moses not meeting their eyes, at a distance of about 32 feet. The strongest emotions were aroused when the observers stood on the right of the statue at a distance of about 16 feet, directly toward Moses's face.

No significant cognitive and emotional responses were collected when the subjects were positioned in front of Moses, at a distance of about 16 feet.

"An eye-to-eye interaction with Moses triggers the highest emotional response. On the other hand, cortical appreciation is achieved when the subject stands in a position which allows a full view of the sculpture, albeit not fully showing Mose's face," Babiloni said.

Artworks are known to produce intense reactions. Previous studies even suggested that David, another Michelangelo's masterpiece, may cause mind-bending symptoms in overly sensitive onlookers.

The condition is similar to a dizzying and disorientating state known as "Stendhal Syndrome." Named after the French writer, its most famous victim, after he was overwhelmed by the frescoes in Florence's Church of Santa Croce in 1817, the phenomenon causes symptoms ranging from heavy perspiration, rapid heartbeat and dizziness to even exaggerated reactions such as temporary panic attacks, aggressive feelings and hallucinations.

Read more at Discovery News

Jupiter's moon Ganymede may harbor 'club sandwich' of oceans and ice

The largest moon in our solar system, a companion to Jupiter named Ganymede, might have ice and oceans stacked up in several layers like a club sandwich, according to new NASA-funded research that models the moon's makeup.

Previously, the moon was thought to harbor a thick ocean sandwiched between just two layers of ice, one on top and one on bottom.

"Ganymede's ocean might be organized like a Dagwood sandwich," said Steve Vance of NASA's Jet Propulsion Laboratory in Pasadena, Calif., explaining the moon's resemblance to the "Blondie" cartoon character's multi-tiered sandwiches. The study, led by Vance, provides new theoretical evidence for the team's "club sandwich" model, first proposed last year. The research appears in the journal Planetary and Space Science.

The results support the idea that primitive life might have possibly arisen on the icy moon. Scientists say that places where water and rock interact are important for the development of life; for example, it's possible life began on Earth in bubbling vents on our sea floor. Prior to the new study, Ganymede's rocky sea bottom was thought to be coated with ice, not liquid -- a problem for the emergence of life. The "club sandwich" findings suggest otherwise: the first layer on top of the rocky core might be salty water.

"This is good news for Ganymede," said Vance. "Its ocean is huge, with enormous pressures, so it was thought that dense ice had to form at the bottom of the ocean. When we added salts to our models, we came up with liquids dense enough to sink to the sea floor."

NASA scientists first suspected an ocean in Ganymede in the 1970s, based on models of the large moon, which is bigger than Mercury. In the 1990s, NASA's Galileo mission flew by Ganymede, confirming the moon's ocean, and showing it extends to depths of hundreds of miles. The spacecraft also found evidence for salty seas, likely containing the salt magnesium sulfate.

Previous models of Ganymede's oceans assumed that salt didn't change the properties of liquid very much with pressure. Vance and his team showed, through laboratory experiments, how much salt really increases the density of liquids under the extreme conditions inside Ganymede and similar moons. It may seem strange that salt can make the ocean denser, but you can see for yourself how this works by adding plain old table salt to a glass of water. Rather than increasing in volume, the liquid shrinks and becomes denser. This is because the salt ions attract water molecules.

The models get more complicated when the different forms of ice are taken into account. The ice that floats in your drinks is called "Ice I." It's the least dense form of ice and lighter than water. But at high pressures, like those in crushingly deep oceans like Ganymede's, the ice crystal structures become more compact. "It's like finding a better arrangement of shoes in your luggage -- the ice molecules become packed together more tightly," said Vance. The ice can become so dense that it is heavier than water and falls to the bottom of the sea. The densest and heaviest ice thought to persist in Ganymede is called "Ice VI."

By modeling these processes using computers, the team came up with an ocean sandwiched between up to three ice layers, in addition to the rocky seafloor. The lightest ice is on top, and the saltiest liquid is heavy enough to sink to the bottom. What's more, the results demonstrate a possible bizarre phenomenon that causes the oceans to "snow upwards." As the oceans churn and cold plumes snake around, ice in the uppermost ocean layer, called "Ice III," could form in the seawater. When ice forms, salts precipitate out. The heavier salts would thus fall downward, and the lighter ice, or "snow," would float upward. This "snow" melts again before reaching the top of the ocean, possibly leaving slush in the middle of the moon sandwich.

"We don't know how long the Dagwood-sandwich structure would exist," said Christophe Sotin of JPL. "This structure represents a stable state, but various factors could mean the moon doesn't reach this stable state.

Sotin and Vance are both members of the Icy Worlds team at JPL, part of the multi-institutional NASA Astrobiology Institute based at the Ames Research Center in Moffett Field, Calif.

The results can be applied to exoplanets too, planets that circle stars beyond our sun. Some super-Earths, rocky planets more massive than Earth, have been proposed as "water worlds" covered in oceans. Could they have life? Vance and his team think laboratory experiments and more detailed modeling of exotic oceans might help find answers.

Read more at Science Daily

Two Suns Could Boost Odds of Habitable 'Exomoons'

Moons in close binary solar systems have a better chance of hosting life than those in single-star systems, new research has shown.

Binary stars dampen each other's solar radiation and stellar winds, thereby creating a more hospitable environment for life and increasing the habitable zone around such solar systems, according to research presented at the 223rd American Astronomical Society meeting in January.

"The two stars calm each other down in terms of activity," said Paul Mason, an astrophysicist at the University of Texas at El Paso in an interview with Astrobiology Magazine.

Mason presented the results of a study, which used data collected by NASA's Kepler spacecraft mission to discover potentially habitable exoplanets in our region of the Milky Way galaxy.

Stretching the habitable zone

Although more than a thousand planets have been found outside of the solar system, as well as a host of candidates waiting for follow-up observations, no moons have yet been confirmed. Scientists like Mason are performing theoretical calculations to determine which solar systems might be better for hosting potentially habitable moons.

Violent and active young stars spin rapidly, emitting radiation and stellar winds that could interfere with the habitability of planets and moons nearby. A close binary system of stars can help to dampen these effects, as the two stars synchronize their spins.

Binary stars exist in a range of configurations. Some are widely separated, so that a planet in orbit around one functions much like a planet around a single sun, while the companion is so distant that it appears as point-like as any other star. Others may be extremely close together, synching together to keep each other rapidly spinning for billions of years.

Mason's research focuses on pairs of stars that orbit each other between 10 and 60 Earth-days, with a planet in orbit around both suns. These are known as circumbinary systems. The paired stars exert tidal forces on one another that cause a slowdown in spin, weakening the radiation and stellar wind of the pair faster than they would suffer as single stars. Fast-moving stellar winds can strip a moon or planet of its atmosphere, leaving it open to heavy radiation bombardment that can interfere with the development of life.

At the same time, the combined light from the duo pushes the edge of the region where water can exist, commonly termed the "habitable zone," farther back than it would lie around a single star. Moving the entire zone a greater distance from its sun further reduces the negative effects from the stars.

"The habitable zone in a binary system is a little bit farther away, simply because you have the light from two stars rather than the light from one," Mason said.

This distance is important because, if a planet orbits too close to its parent star, its moon can be stripped away completely.

"The closer a planet is to the star, the smaller its gravitational sphere of influence," said David Kipping and astronomer at the Harvard-Smithsonian Center for Astrophysics in an interview with Astrobiology Magazine.

"Essentially, the star will rip off the moon if it gets too close," he said.

Kipping, who was not involved in the research, searches for exomoons and is the principle investigator of The Hunt for Exomoons with Kepler project.

Pushing exomoons farther away also has ramifications for red dwarfs, the most populous stellar type in the galaxy. The habitable zone around these smaller, long-lived stars is so close to its parent star that stellar activity made many astronomers consider habitable planets around them unlikely to even exist, though recent research has increased the potential. In a binary system, the pushed-back habitable zone would decrease many of the negative effects that limit habitability around the plentiful stars.

According to Mason, if the sun had a companion star, the makeup of the solar system would change significantly. The water stripped from the atmosphere of Venus would likely still be present, making it potentially habitable. Earth itself could have been a very different environment.

"Earth would be a wetter planet if we were orbiting a binary star," Mason said.

Twin suns

When it comes to potentially habitable exomoons, sun-like stars are always better.

"The ideal circumstance is solar twins," Mason said.

Simply adding a sun-like star to the mix improves the chances for life.

"Solar-type stars with companions work really well," Mason said. "They work better than our own solar-type star without a companion."

Still, in a circumbinary system, it is not the type of star that matters nearly as much as how often they orbit one another. As long as the pair of stars dance around between once every 10 and 60 Earth-days, they increase the chances of the habitability of their moons and planets. (The exception is massive, giant stars, which burn through their fuel and die quickly, giving life little to no chance to evolve.)

Still, if at least one of the two stars in a binary system is sun-like, it provides a very wide habitable zone with plenty of room for water, a situation that Mason says he's most excited about.

A wider habitable zone means a better chance of hosting planets capable of sustaining life, as well as exomoons that could support it.

"There's plenty of room for several habitable planets," Mason said. "These may be places where many worlds in system could be habitable."

Unfortunately, systems with multiple planets make finding exomoons more challenging at the moment.

The hunt for exomoons

Astronomers hunt for distant moons essentially the same ways that they hunt for distant planets. They might watch for the planet and its moon to cross between their sun and the Earth. As a single planet crosses, it causes a dip in brightness; if a moon precedes or follows it, that dip is preceded or followed by a smaller dip as just the moon blocks the stellar light.

They can also watch a planet for a small wobble as the moon gravitationally tugs its host ever-so-slightly. A moon might also slightly change how quickly a planet orbits its sun.

In a multi-planet system, however, other planets can also cause the wobbles and velocity changes, making them "kind of a pain for looking for exomoons," according to Kipping.

Kipping and his team have pared down the list of almost 5,000 planetary candidates detected by NASA's Kepler spacecraft to approximately 250 bodies considered the best targets for hosting an exomoon.

Originally, he hoped to target Jupiter-size and larger planets. In the solar system, the only moons considered potentially habitable orbit gas giants. Earth-sized moons could lay outside of the habitable zone of a star but still hold liquid water due to tidal heating from their planet. Such moons would be minimally affected by their orbit around a binary star system instead of a single star.

But it was not to be.

"One of the most staggering discoveries from Kepler is that Jupiter-like planets are rare," Kipping said. "This is kind of a shame for the exomoon hunt, because those are the planets easiest to find a moon around."

Instead, Kipping and his team have turned to the slightly less massive sub-Neptunes, which abound in Kepler's field of view.

Although moons around Earth-sized planets may not be habitable by themselves, they could have an enormous impact on their parent body. Born of a collision early in the life of the solar system, Earth's moon is far larger by comparison to its planet than other moons in the solar system. The collision might have kicked off volcanism and plate tectonics on the early Earth, while the moon stabilizes the planet's tilt and controls the tides. Biologists consider all four actions important to the evolution of life.

"There are many beneficial qualities to having a big moon nearby," Kipping said. "If we find Earth 2.0, one of the first things we'll be asking is if it has a Moon 2.0."

Because our moon is unique in the solar system, scientists don't yet understand whether its formation was what Kipping called "a freak event" or something that's very common. Detecting different kinds of moons in a variety of orbits will help scientists narrow down how unique the solar system and the Earth-moon system are.

As scientists have used Kepler to hunt for exoplanets, they have learned a great deal about the variety of planetary systems in the galaxy. According to Kipping, circumbinary systems were once thought to be "the more exotic type" of binary systems. But Kepler revealed several cases, showing them to be fairly common.

Though the mission goal is to detect planets, Kepler is an important tool when it comes to looking for moons outside of the solar system.

"Kepler is really the ideal instrument for detecting exomoons," Kipping said.

He pointed out that while NASA's upcoming James Webb Space Telescope, to be launched in October 2018, will be ideal for follow-up observations, it will be in too high of a demand by the astronomical community to stare at a patch of sky for years on end the way Kepler did. If Kepler's second run, K2, is funded, it will stare at a different region of the sky than the original Kepler mission, and will provide greater insight into planet populations.

Though he expressed excitement about the exoplanet discoveries that will come from both upcoming missions, he said, "My feeling is that Kepler is still probably the best resource for discovering exomoons."

As to how long it might be before the first exomoon is confirmed around a distant planet, Kipping said that it depends on how common larger moons are.

"If Nature builds big moons—Earth-sized moons—very frequently throughout the cosmos, then they're in the Kepler data," he said. "They're lurking there, and we will find them in the next year or two."

Read more at Discovery News