Fish Genital Shape Linked to Predation

When predators lurk nearby, male Bahamas mosquitofish (Gambusia hubbsi) change mating strategies, rejecting elaborate courting rituals for more frequent and sometimes forceful encounters with females.

But as a recent North Carolina State University study shows, mating strategies aren't the only things changing for G. hubbsi when predators abound. The shape and size of the male fish's genitalia are also linked to the presence or absence of predators.

NC State Ph.D. student Justa Heinen-Kay and assistant professor of biological sciences R. Brian Langerhans show, in a paper published in the Journal of Evolutionary Biology, that fish coexisting with predators have longer, bonier and more elongated gonopodium tips than fish living without threat of predation. The gonopodium is the sperm-transferring organ in these livebearing fish.

Longer, bonier and more elongated gonopodium tips are, of course, relative; in small fish, these organ tips are generally only 1 millimeter long. Yet the findings suggest that male fish under constant threat of serving as a predator's snack have evolved better ways to impregnate females under these conditions.

"When predators are around, G. hubbsi males spend a lot of time attempting to mate with females because of the high mortality rate," Heinen-Kay said. "We hypothesize that G. hubbsi have evolved these bonier and more elongated gonopodium tips as a way to copulate even when females don't cooperate."

"Essentially, males need to transfer as much sperm as possible as quickly as possible, and this shape difference could help facilitate that," Langerhans said.

The researchers conducted the study in so-called "blue holes" in the Bahamas. These "big test tubes" are caves that have filled with water in the past 17,000 years; Langerhans calls them aquatic islands in a sea of land. Some of these aquatic islands contain Gambusia predators, while others do not.

Read more at Science Daily

Scholar Claims Jesus Was a Roman Hoax

A historical scholar claims to have found evidence proving that the story of Jesus as described in the New Testament is a fiction, and that historical claims about Jesus were actually created by Roman aristocrats to control the poor.

According to a news story in The Independent:

“Joseph Atwill, who is the author of a book entitled ‘Caesar’s Messiah: The Roman Conspiracy to Invent Jesus’, asserts that Christianity did not begin as a religion, but was actually a sophisticated government propaganda exercise used to pacify the subjects of the Roman Empire.”

Atwill’s take on Jesus is of course not new. In 1844 Karl Marx famously declared religion as the opiate of the masses. History is filled with skeptics, freethinkers, atheists, agnostics and other doubters who have questioned religious doctrine and dogma.

Atwill’s claims are based on what he described as important and revealing parallels between a first-person account of first-century Judea (an ancient Roman province now part of Israel and Palestine) and the New Testament.

“What seems to have eluded many scholars is that the sequence of events and locations of Jesus ministry are more or less the same as the sequence of events and locations of the military campaign of (Emperor) Titus Flavius as described by Josephus,” Atwill wrote in a blog on his web site.

Atwill believes that the story of Jesus was actually copied and created from the biography of the Roman emperor.

Evidence for a Historical Jesus?

While Atwill’s thesis is intriguing, there are reasons to be skeptical.

“The reality is we are unlikely ever to know the ‘facts’ about Jesus,” says Ronald A. Lindsay, a Senior Research Fellow at the Center for Inquiry, a non-profit educational organization. Lindsay authored an essay on the evidence for Jesus in the book “Sources of the Jesus Tradition.”

“There are too many different stories about him, all of which have some serious credibility problems and which are inconsistent with one another,” Lindsay told Discovery News. “For the objective historian, he will always remain a shadowy figure, with little substantive biographical content. On the one hand, we have many who will take things on faith, accepting some subset of the stories as unquestionably true. On the other hand, there are those who insist that Jesus is an invented figure, a myth or a hoax. I think both of these extremes are almost equally implausible.”

Biblical scholars, as well as lay Christians, have long sought hard evidence of events and miracles described in the Bible, ranging from Noah’s Ark to the Shroud of Turin, with little success. New claims about proof of Jesus surface every few years.

For example, in 2003 a relics dealer claimed to have discovered a limestone mortuary box that held the remains of Jesus’ brother. The inscription read, “James, son of Joseph, brother of Jesus.”

The find made international news and spawned several documentaries, including one titled “The Lost Tomb of Jesus,” which aired on the Discovery Channel. Further investigation by the Israeli Antiquities Authority concluded that though the ossuary box was authentic, the inscription on it had been faked.

And just last year an historian at Harvard Divinity School claimed to have found documentary evidence in the form of a fragment of Coptic writing on papyrus that Jesus was married; a later analysis by Biblical scholars suggested the writing was hoaxed.

Read more at Discovery News

Hunter-Gatherers and Immigrant Farmers Lived Together for 2,000 Years in Central Europe

Indigenous hunter-gatherers and immigrant farmers lived side-by-side for more than 2,000 years in Central Europe, before the hunter-gatherer communities died out or adopted the agricultural lifestyle. The results come from a study undertaken by the Institute of Anthropology at Johannes Gutenberg University Mainz (JGU) that has just been published in the journal Science.

A team led by Mainz anthropologist Professor Joachim Burger studied bones from the 'Blätterhöhle' cave near Hagen in Germany, where both hunter-gatherers and farmers were buried. "It is commonly assumed that the Central European hunter-gatherers disappeared soon after the arrival of farmers," said Dr. Ruth Bollongino, lead author of the study. "But our study shows that the descendants of Mesolithic Europeans maintained their hunter-gatherer way of life and lived in parallel with the immigrant farmers, for at least 2,000 years. The hunter-gathering lifestyle thus only died out in Central Europe around 5,000 years ago, much later than previously thought."

Until around 7,500 years ago all central Europeans were hunter-gatherers. They were the descendants of the first anatomically modern humans to arrive in Europe, around 45,000 years ago, who survived the last Ice Age and the warming that started around 10,000 years ago. But previous genetic studies by Professor Burger's group indicated that agriculture and a sedentary lifestyle were brought to Central Europe around 7,500 years ago by immigrant farmers. From that time on, little trace of hunter-gathering can be seen in the archaeological record, and it was widely assumed that the hunter-gatherers died out or were absorbed into the farming populations.

The relationship between these immigrant agriculturalists and local hunter-gatherers has been poorly researched to date. The Mainz anthropologists have now determined that the foragers stayed in close proximity to farmers, had contact with them for thousands of years, and buried their dead in the same cave. This contact was not without consequences, because hunter-gatherer women sometimes married into the farming communities, while no genetic lines of farmer women have been found in hunter-gatherers. "This pattern of marriage is known from many studies of human populations in the modern world. Farmer women regarded marrying into hunter-gatherer groups as social anathema, maybe because of the higher birthrate among the farmers," explains Burger.

For the study published in Science, the team examined the DNA from the bones from the 'Blätterhöhle' cave in Westphalia, which is being excavated by the Berlin archaeologist Jörg Orschiedt. It is one of the rare pieces of evidence of the continuing presence of foragers over a period of about 5,000 years.

For a long time the Mainz researchers were unable to make sense of the findings. "It was only through the analysis of isotopes in the human remains, performed by our Canadian colleagues, that the pieces of the puzzle began to fit," states Bollongino. "This showed that the hunter-gatherers sustained themselves in Central and Northern Europe on a very specialized diet that included fish, among other things, until 5,000 years ago.

The team also pursued the question of what impact both groups had on the gene pool of modern Europeans. Dr. Adam Powell, population geneticist at the JGU Institute of Anthropology, explains: "Neither hunter-gatherers nor farmers can be regarded as the sole ancestors of modern-day Central Europeans. European ancestry will reflect a mixture of both populations, and the ongoing question is how and to what extent this admixture happened."

Read more at Science Dialy

Stellar Graveyard Shows Signs of Possible (Past) Life

The next time you gaze up at the night sky, remember that you’re looking at a graveyard. The Milky Way is studded with dead stars, from black holes to neutron stars to dim white dwarfs. Often, these stellar corpses reveal little about their past. But once in a while, they provide clues to how they—and any planets they once hosted—lived and died. Now, scientists have discovered evidence that a white dwarf known as GD 61 was once orbited by a rocky, water-rich asteroid—just the kind of thing you’d need to build a habitable alien world.

Most stars (including, in about 4 billion years, our sun) end their lives as white dwarfs, after they have burned all their nuclear fuel. These super dense stellar embers exert such strong gravity that any element heavier than helium will immediately sink to the dwarf’s core. So imagine astronomers’ surprise when they discovered that some white dwarfs are cloaked in layers of “pollution” made up of silicon, oxygen, and other elements much higher up on the periodic table.

This pollution is made up of “pieces of planetary systems that are falling into their central stars,” explains Jay Farihi, an astronomer at the University of Cambridge in the United Kingdom. By measuring the pollution’s constituent elements, scientists can peer back in time and discover what the original solar system’s asteroids, comets, and planets were made of. “It’s a wonderful technique for doing planetary forensics,” says Michael Jura, a white dwarf expert at the University of California, Los Angeles, who wasn’t involved in the current research.

In GD 61’s pollution, Farihi and his colleagues noticed a curious abundance of oxygen. Their first thought was that the original asteroid must have been encrusted with carbon dioxide in the form of dry ice. Trouble is, there was no carbon anywhere to be found around GD 61. So in order to account for the extra oxygen, “the only chemically viable substance left is water,” Farihi says.

Online today in Science, the team proposes that GD 61 has “shredded” a rocky asteroid that was 26% to 28% water. About the same size as Vesta in our solar system’s asteroid belt, the asteroid likely orbited the white dwarf’s precursor, an A-type star slightly bigger than the sun. After that star died, the white dwarf’s stronger gravity probably dragged in the asteroid and tore it apart.

Water-rich asteroids are considered to be important for the formation of habitable planets, crashing into them and supplying them with life-giving liquid water. Although “we certainly can’t rewind the clock completely” to discover what GD 61’s original solar system looked like, Farihi says, the discovery of the asteroid reveals “the building blocks of Earth-like planets were there.” In the future, he hopes to look at the system with a powerful telescope like the Atacama Large Millimeter/submillimeter Array radio array in Chile to see if any of the original planets survived the death of their star, or whether anything remains of the asteroid belt where the water-rich planetesimal was born.

Read more at Wired Science

Clues to Lost Prehistoric Code Found in Mesopotamia

Researchers studying clay balls from Mesopotamia have discovered clues to a lost code that was used for record-keeping about 200 years before writing was invented.

The clay balls may represent the world's "very first data storage system," at least the first that scientists know of, said Christopher Woods, a professor at the University of Chicago's Oriental Institute, in a lecture at Toronto's Royal Ontario Museum, where he presented initial findings.

The balls, often called "envelopes" by researchers, were sealed and contain tokens in a variety of geometric shapes — the balls varying from golf ball-size to baseball-size. Only about 150 intact examples survive worldwide today.

The researchers used high-resolution CT scans and 3D modeling to look inside more than 20 examples that were excavated at the site of Choga Mish, in western Iran, in the late 1960s. They were created about 5,500 years ago at a time when early cities were flourishing in Mesopotamia.

Researchers have long believed these clay balls were used to record economic transactions. That interpretation is based on an analysis of a 3,300-year-old clay ball found at a site in Mesopotamia named Nuzi that had 49 pebbles and a cuneiform text containing a contract commanding a shepherd to care for 49 sheep and goats.

How these devices would have worked in prehistoric times, before the invention of writing, is a mystery. Researchers now face the question of how people recorded the number and type of a commodity being exchanged without the help of writing.

Peering inside

The CT scans revealed that some of the balls have tiny channels, 1-2 millimeters (less than one-tenth of an inch) across, crisscrossing them. Woods said he's not certain what they were used for, but speculates the balls contained fine threads that connected together on the outside. These threads could have held labels, perhaps made out of wax, which reflected the tokens within the clay balls.

The tokens within the balls come in 14 different shapes, including spheres, pyramids, ovoids, lenses and cones, the researchers found. Rather than representing whole words, these shapes would have conveyed numbers connected to a variety of metrological systems used in counting different types of commodities, Woods suggested. One ovoid, for instance, might mean a certain unit, say 10, which was used while counting a certain type of commodity.

The researchers, however, were perplexed when their CT scans found one clay ball containing tokens made of a low-density material, likely bitumen, a petroleum substance. "When we make a three-dimensional model of the cavity you get this very strange amoeba like-looking shape," Woods said during the lecture.

The tokens, in this instance, had air bubbles around them, suggesting they were wrapped in cloth before being put in the ball, the cloth disintegrating over time. In addition, it appears that a liquid, likely liquid bitumen, was poured over the tokens after they were inserted into the balls. What someone was trying to communicate by creating such tokens is unknown.

"That's a mystery," Woods told LiveScience in an interview. "I don't really have a good answer for that," he said, adding that the bitumen tokens may represent a divergent accounting practice, or, perhaps even, that the transaction recorded involved bitumen.

In ancient Mesopotamia bitumen was used as an adhesive and to waterproof things like baskets, boats and the foundations of buildings, Woods said.

Cracking the prehistoric code

All of the clay balls contain, on the outside, one "equatorial" seal (running through the middle) and quite often two "polar" seals, running above and below.

The equatorial seals tend to be unique and more complex containing what appear to be mythological motifs; for instance a ball from the Louvre Museum shows human figures fighting what appear to be serpents. The polar seals, on the other hand, are repeated more often and tend to have simpler geometric motifs.

Based on this evidence, Woods hypothesizes the seal in the middle represents the "buyer" or recipient; the polar seals would represent the "seller" or distributor and perhaps third parties who would have participated in the transaction or acted as witnesses.

Many people would have acted as the buyers, but only a limited number of sellers or distributors would have been around to transact business with, explaining why the polar seals are repeated more often.

After a transaction of some importance was complete, one of these clay devices was created to serve as a "receipt" of sorts for the seller, as a record of what was expended. "There's a greater necessity to keep track of things that have been expended than things that are on hand," Woods said in the lecture.

Deciphering what transaction each clay ball represented is a trickier problem. Woods suspects the tokens represent numbers and metrical units. It's possible that, through the different token shapes, people in prehistoric times communicated numbers and units in a way similar to how the first scribes did 200 years later when writing was invented. If that's the case, Woods and other scientists may be able, in time, to crack the code by uncovering how token types cluster and vary.

"If they are, then there is at least some hope of deciphering the envelopes and with it uncovering the earliest evidence for complex numerical literacy," Woods said.

Technological achievement

The amount of detail the scientists gleaned from the CT scans and 3D modeling was extraordinary, Woods said during the lecture. "We can learn more about these artifacts by non-destructive testing than we could by physically opening the envelopes," he said.

Woods will publish the full research results in the future and plans to put the images and 3D models online.

Read more at Discovery News

Shutdown Wasting Years of Antarctic Research

More than 10 years of planning, $10 million of government funding and tireless work from the team that discovered life in a lake buried beneath an Antarctic glacier earlier this year may largely go to waste due to the government shutdown.

The WISSARD drilling program — a collaborative effort of 14 principal investigators including glaciologists, geophysicists, microbiologists and others from nine institutions across the country — is one of the largest programs ever fielded by the U.S. Antarctic Program.

The team consists of more than 50 scientists, graduate students and support staff members, who aim to explore the underbelly of the West Antarctic Ice Sheet— a flowing mass of ice about the size of France — in order to study its dynamics and improve models that predict its melting rate. If it were to melt completely, the ice sheet would increase average global sea level by between 10 to 16 feet (3 to 5 meters).

The National Science Foundation funded WISSARD in 2009 with stimulus money, providing enough resources to complete two field seasons during the Southern Hemisphere summers of 2012-2013 and 2013-2014.

Last year, the team drilled the first ever hole into a lake buried under roughly half a mile (0.8 kilometers) of ice. Researchers discovered microbial life within this remote environment, and deployed a series of environmental sensors that would measure temperature and other conditions through the following year.

For the second and final field season, scheduled for this December through early February, the team planned to collect those data loggers and drill a new hole into the grounding zone of the glacier, where the glacier's base meets the sea. This would be the first hole ever drilled into a glacial grounding zone, a region that largely controls the stability of the ice sheet and the rate at which it flows into the sea and increases sea level.

Science in jeopardy

But the National Science Foundation announced this week that it would cancel its entire U.S. Antarctic research program until the shutdown ends, jeopardizing the entire second half of the WISSARD program.

"It's heartbreaking," said Slawek Tulaczyk, a glaciologist at the University of California, Santa Cruz, and a principal investigator with WISSARD. "So many people put in their time, their passion into making sure that this happens. It takes a lot of professional, dedicated work."

Tulaczyk's team has worked through many weekends over the past three months preparing to ship scientific equipment — some of which they spent years designing specifically for this year's work — down to Antarctica to ensure that it arrives in time for their field season.

Those shipments have now stopped en route, and likely won't arrive in Antarctica by mid-November as had been scheduled.

"If we can't get stuff into the field on time, then there is no reason to see it forward," Tulaczyk told LiveScience.

The team cannot postpone the season and push it forward, because they need a full two-and-a-half months to achieve their goals, and because pushing the season further into February would pose serious safety risks: By late summer, temperatures drop well below 10 degrees Fahrenheit (12 degrees below zero Celsius), winds pick up, the sun sets earlier and search and rescue teams do not have enough visibility in the featureless white expanse of the continent to safely access emergencies.

"There is a hard deadline after which we cannot delay, because it just becomes unsafe for the personnel," Tulaczyk said.

Uncertain future

The funding for the project ends in 2014, so the team would need special permission from the government to extend the project through 2015, which Tulaczyk said might be possible but seems unlikely.

Graduate students whose dissertations depend on this year's data are considering discontinuing their graduate programs, said John Priscu, a researcher at Montana State University and the principal investigator studying the newly discovered microbial life underneath the glacier.

"The loss of graduate student field work will diminish our efforts to train the next generation of polar scientists," Priscu said.

Read more at Discovery News

Elephants Instictively Get Human Pointing

Elephants require zero instruction to understand human pointing, according to a new study that demonstrates just how smart these large mammals are.

To put this into perspective, many great apes fail to understand human pointing, and they are genetically closer to us.

The study, published in the latest Current Biology, not only demonstrates how smart elephants are, but it also indicates that pointing is in their visual “vocabulary” too.

“By showing that African elephants spontaneously understand human pointing, without any training to do so, we have shown that the ability to understand pointing is not uniquely human but has also evolved in a lineage of animal very remote from the primates,” Richard Byrne of the University of St Andrews, who worked on the study, said in a press release.

He noted that elephants are part of an ancient African radiation of animals, including the hyrax, golden mole, aardvark and manatee.

Byrne continued, “What elephants share with humans is that they live in an elaborate and complex network in which support, empathy, and help for others are critical for survival. It may be only in such a society that the ability to follow pointing has adaptive value, or, more generally, elephant society may have selected for an ability to understand when others are trying to communicate with them, and they are thus able to work out what pointing is about when they see it.”

Byrne and co-author Anna Smet made the discovery while studying elephants whose “day job” is taking tourists on elephant-back rides near Victoria Falls, southern Africa. The elephants did receive training on some basic vocal commands, but didn’t have any lessons on pointing.

“Of course, we always hoped that our elephants would be able to learn to follow human pointing, or we’d not have carried out the experiments,” Smet said. “What really surprised us is that they did not apparently need to learn anything. Their understanding was as good on the first trial as the last, and we could find no sign of learning over the experiment.”

The researchers had seen elephants gesturing around with their trunks, but no one has yet placed any meaning to those movements. Now you have to wonder that the elephants are telling each other, “Hey, look over there,” “Look here,” and so on, all with this simple yet important gesture.

Elephants are hardly house pet material, but people who regularly interact with them are blown away by their intelligence.

Read more at Discovery News

First Evidence of Comet Striking Earth Found

A team of scientists claims to have found the first-ever definitive evidence of a comet striking Earth.

After conducting a series of analyses, the researchers determined that a mysterious black pebble discovered years ago in the Egyptian desert is a piece of a comet nucleus — the first ever discovered.

"It’s a typical scientific euphoria when you eliminate all other options and come to the realization of what it must be," study lead author Jan Kramers, of the University of Johannesburg in South Africa, said in a statement.

The pebble, which the team has named "Hypatia" in honor of the ancient female mathematician, astronomer and philosopher Hypatia of Alexandria, is also studded with diamonds, which makes sense considering its cometary origin, researchers said.

"Diamonds are produced from carbon-bearing material," Kramers said. "Normally they form deep in the Earth, where the pressure is high, but you can also generate very high pressure with shock. Part of the comet impacted, and the shock of the impact produced the diamonds."

This impact occurred about 28 million years ago over Egypt, study team members say. The comet exploded in the atmosphere, heating the sand below to a temperature of 3,630 degrees Fahrenheit (2,000 degrees Celsius) and generating huge amounts of yellow silica glass across 2,317 square miles (6,000 square kilometers) of the Sahara Desert.

One piece of this silica glass even found its way into a brooch that belonged to the famous Egyptian pharaoh Tutankhamen, researchers said.

Comets have almost certainly struck the Earth many times over the planet's long history. But before the Hypatia pebble's origin was determined, tiny dust particles in the upper atmosphere and carbon-rich dust in Antarctic ice were the only cometary material known on Earth, researchers said.

Comets are leftover pieces from the formation of the solar system 4.5 billion years ago, so the new discovery could have valuable scientific applications as well as gee-whiz appeal.

"NASA and ESA (European Space Agency) spend billions of dollars collecting a few micrograms of comet material and bringing it back to Earth, and now we’ve got a radical new approach of studying this material, without spending billions of dollars collecting it," Kramers said.

Read more at Discovery News

Water Discovered In Shredded Planetary Debris

Astronomers have made the first direct detection of water in a rocky body that once orbited a sun-like star.

The object is the remnant of a rocky planet or a large asteroid that was shredded by its burned-out star, a white dwarf known as GD 61 and located about 150 light-years from Earth.

The fingerprints of water emerged after a tally of oxygen molecules littering the star’s otherwise pristine hydrogen and helium surface. (Heavier elements like silicon and carbon sink into the dead star’s core.)

Astronomers determined the object was about 25 percent water, similar to Ceres, the largest object in our solar system’s main asteroid belt.

Earth, by comparison, is a paltry 0.02 percent water -- essentially a dry planet. Scientists believe Earth was too warm to retain any water it had during its formation and that water-rich asteroids later crashed into the planet, delivering its oceans.

“The Earth was mostly finished and then you hit it with a couple of water-rich guys and then you’re done. That’s the final bit in the recipe,” astronomer Jay Farihi, with the University of Cambridge, told Discovery News.

“Because this object had a lot of water, we know it formed in a region that is pretty similar to our main asteroid belt’s outer region,” Farihi said.

Whether the object was a large asteroid or a piece of a planet is immaterial, he added.

“Because we have rocks this big, we know that (this system) had rocky planets. You just simply cannot get to something that big without going all the way to planets. It’s a runaway process,” Farihi said.

“This is the first time we’ve seen the kind of building blocks and puzzle pieces that are necessary for habitable, water-rich planets,” he added.

Farihi and colleagues used a light-splitting spectrograph on the Hubble Space Telescope to chemically analyze GD 61 after other astronomers discovered it contained huge amounts of oxygen.

“Where the oxygen will go will determine if you’ve got water,” said Torrence Johnson, a senior scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

Johnson presented a separate study this week about how carbon-rich systems could deprive otherwise habitable planets of water, which is believed to be a key ingredient for life.

After accounting for GD 61 oxygen molecules chemically tied with silicon, magnesium, iron, calcium, aluminum and other elements, Farihi and colleagues realized there were far too many oxygen molecules left over.

The excess oxygen could have been chemically bonded with carbon to make carbon dioxide gas, but GD 61 turned out to be very carbon-poor.

“The only other chemically viable candidate is water,” Farihi said. “Water is very abundant in the universe. Oxygen combines with hydrogen pretty much wherever it can. Chemically speaking, there’s just no other alternative for this much oxygen.”

Read more at Discovery News

'Rock Snow' May Fall From Exoplanet Skies

Eight years ago, astronomers announced the discovery of 51 Pegasi b (51 Peg b), the first planet found circling a sun-like star beyond our solar system.

The planet is about the size of Jupiter, but it orbits far closer to its parent star than Mercury orbits the sun. A year on 51 Peg b lasts just four Earth days.

That got Brian Jackson, a researcher at the Carnegie Institution for Science in Washington DC, and colleagues curious if there were planets located even closer to their host stars. So they began sifting through nearly three years of data collected by NASA’s Kepler space telescope.

The observatory, now sidelined by a positioning system failure, looked for slight dips in the amount of light coming from target stars, potential telltale signs of planets passing by, or transiting, relative to the telescope’s line of sight.

Kepler was designed to seek out Earth-like worlds fortuitously positioned from their parent stars for liquid surface water, the so-called “Goldlilocks” zone believed to be favorable for life.

But staring at 150,000 stars for four years turned up thousands of other potential planets, including four candidate planets with orbits 20 times closer than Mercury circles the sun.

Surface temperatures on these planets would soar past 3,000 degrees Fahrenheit -- hot enough to melt rock.

One suspected planet, referred to as KOI-1843, circles its host star in 4.2 hours -- an orbit that brings it 40 times closer to its star than Mercury orbits the sun -- with a surface temperatures of about 4,200 degrees Fahrenheit.

Conditions on these planets would be extreme. Surfaces on their day-sides are likely molten rock, setting up the bizarre prospect of rocky vapor atmospheres that transform into “rock snow” falling on their relatively cooler night-sides.

“That could be very interesting,” Jackson told reporters during a webcast press conference at the American Astronomical Society meeting in Denver this week.

“These molten rock lakes could shed a rocky vapor atmosphere that could go screaming around to the night side of the planet and then be deposited as sort of a rock snow as the rock vapor cools,” Jackson said.

While life on these worlds is highly doubtful, finding extrasolar planets that skim their parent stars is helping scientists figure out how planets form and evolve.

“They didn’t form there, almost definitely,” Jackson told Discovery News.

For starters, temperatures in the original gas disks from which the planets formed would have been too high at the planets' current locations for them to form, Jackson pointed out.

Read more at Discovery News