Free Republic

Comet Hartley 2 contains water more like that found on Earth than prior comets seem to have, researchers say. A study using the Herschel space telescope aimed to measure the quantity of deuterium, a rare type of hydrogen, present in the comet's water. The comet had just half the amount of deuterium seen in comets. The result, published in Nature, hints at the idea that much of the Earth's water could have initially came from cometary impacts. Just a few million years after its formation, the early Earth was rocky and dry; something must have brought the water that covers...

Given the reality of the dark spots, which soon became known as "atmospheric holes" because of their appearance in the images, there is only one explanation which has endured over all these years to present. That is, the holes are due to the shadowing of the atmospheric light by an object above the atmosphere. This object simply cannot be a stony or iron meteor because the holes are very large, tens of miles in diameter. A rock of this size would provide a disastrous impact on the Earth's surface. As it turns out, water vapor is very good at absorbing...

While investigating the chemical make-up of comets, Prof. Akiva Bar-Nun of the Department of Geophysics and Planetary Sciences at Tel Aviv University found they were the source of missing ingredients needed for life in Earth's ancient primordial soup. "When comets slammed into the Earth through the atmosphere about four billion years ago, they delivered a payload of organic materials to the young Earth, adding materials that combined with Earth's own large reservoir of organics and led to the emergence of life," says Prof. Bar-Nun.

Clandestine comets found in main asteroid belt 19:00 23 March 2006 NewScientist.com news service Kimm Groshong You do not have to look to the outer edges of the solar system, or even out beyond Neptune to observe a reservoir of comets. A bevy of the ice-containing bodies lies disguised as main-belt asteroids between Mars and Jupiter, claim astronomers from the University of Hawaii, US. David Jewitt and Henry Hsieh have dubbed the new population "main belt comets". They describe three objects with near circular, flat orbits in the asteroid belt that stream volatile materials, producing an observable tail for weeks...

An investigation by the University of Kansas' Adrian Melott and colleagues reveals a promising new method of detecting past comet strikes upon Earth and gauging their frequencyLAWRENCE, Kan. — It's the stuff of a Hollywood disaster epic: A comet plunges from outer space into the Earth's atmosphere, splitting the sky with a devastating shock wave that flattens forests and shakes the countryside. But this isn't a disaster movie plotline. "Comet impacts might be much more frequent than we expect," said Adrian Melott, professor of physics and astronomy at the University of Kansas. "There's a lot of interest in the rate...

On 26 May, JPL's unique orbital calculation software determined that Comet Catalina was on what could possibly be a collision course with Earth, though the odds of such an impact were small: just 1 chance in 300,000 of a strike on June 11, 2085. Based on the 980-metre size estimate, that would produce a 6-gigaton impact - equivalent to 6 billion tonnes of TNT. Astronomers expected the addition of further observations to the calculations to rule out any possibility of a collision, as happens with most newly-seen objects. But that did not quite happen. The comet's predicted pathway actually drew...

Man owes a lot to chunks of rock and ice floating through space. From ancient jewellery to water and possibly even the beginnings of life itself, scientists are discovering that comets have contributed in many ways to the development of life on the planet, Robert Matthews writes Since their discovery in an Egyptian cemetery more than a century ago, a handful of metal beads have perplexed archaeologists. As jewellery, the beads seem decidedly downmarket, being made of nothing more glamorous than iron. Yet clearly their owner, dead for more than 5,000 years, held them in great esteem - as do...

“It is dangerous to assume life is common across the Universe.” These were the words of Charles Cockell at a Royal Society event on March 11 this year. While many people have freely debated the existence of extraterrestrial life, Cockell’s words carry a bit more weight than most. He happens to be the director of the U.K. Center for Astrobiology, based at the University of Edinburgh. Bringing to mind the argument made by Fermi’s paradox — if the universe is teeming with life, where exactly is everyone? — this may seem at first to be a slightly pessimistic outlook. Evidently,...

A fireball that appeared over the Sri Lankan province of Polonnaruwa on December 29, 2012 was a meteorite containing algae fossils, according to a paper published in the Journal of Cosmology. A team of researchers, led by Jamie Wallis of Cardiff University, believes that these fossils provide evidence of cometary panspermia, the hypothesis that life originated in outer space and comets brought it to Earth. Scientists at the Sri Lankan Medical Research Institute in Colombo forwarded 628 stone fragments that allegedly fell from the fireball to Cardiff University, where Wallis' team indentified three as originating from a carbonaceous chondrite. The...

NASA is reporting that an analysis of a rock powder sample collected by the Curiosity rover suggests that ancient Mars could have supported living microbes. The sample contained traces of sulfur, nitrogen, hydrogen, oxygen, phosphorus, and carbon -- key chemical ingredients for life. For astronomers, the news constitutes the latest clue in their pursuit of a scientific holy grail: Answering the big question about whether life ever existed on the Red Planet. Their challenge until now has been to confirm whether the Martian atmosphere could have supported a habitable environment. The preliminary evidence now suggests the answer is yes...

Last year, the team drilled through almost 4km (2.34 miles) of ice to reach the lake and retrieve samples. Vostok is thought to have been cut off from the surface for millions of years. This has raised the possibility that such isolated bodies of water might host microbial life forms new to science. "After putting aside all possible elements of contamination, DNA was found that did not coincide with any of the well-known types in the global database," said Sergei Bulat, of the genetics laboratory at the St Petersburg Institute of Nuclear Physics. "We are calling this life form unclassified...

Explanation: Is this an alien? Probably not, but of all the animals on Earth, the tardigrade might be the best candidate. That's because tardigrades are known to be able to go for decades without food or water, to survive temperatures from near absolute zero to well above the boiling point of water, to survive pressures from near zero to well above that on ocean floors, and to survive direct exposure to dangerous radiations. The far-ranging survivability of these extremophiles was tested in 2011 outside an orbiting space shuttle. Tardigrades are so durable partly because they can repair their own DNA...

Canadian geologists have found more evidence that impact craters may, in fact, be the best places to look for signs of past life on Mars and other worlds, and could even have been the place life began on Earth... It was during some field work on the 15-mile (24 kilometer) wide Haughton crater that he and his colleagues recognized what appeared to be the remains of hydrothermal structures. These would have been steaming vents at one time, releasing heat for millennia that had been generated by the impact event.

 Two potential signatures of life on Saturn's moon Titan have been found by the Cassini spacecraft. But scientists are quick to point out that non-biological chemical reactions could also be behind the observations.Titan is much too cold to support liquid water on its surface, but some scientists have suggested that exotic life-forms could live in the lakes of liquid methane or ethane that dot the moon's surface.In 2005, Chris McKay of NASA's Ames Research Center in Moffett Field and Heather R Smith of the International Space University in Strasbourg, France, calculated that such microbes could eke out an existence by breathing in hydrogen...

Physicists of the University of Granada and the University of Valencia (Spain) have developed a proceeding to analyse specific data sent by the Huygens probe from Titan, the largest moon of Saturn, proving "in an unequivocal way" that there is natural electric activity in its atmosphere. The scientific community thinks that there is a higher probability that organic molecules precursors to life could form in those planets or satellites which have an atmosphere with electric storms. Researcher Juan Antonio Morente, from the Department of Applied Physics of the University of Granada, has informed the SINC that Titan is considered to...

The potential discovery of water on one of Saturn's moons would add a new environment in the solar system where life could exist, according to scientists. NASA's Cassini spacecraft made the surprising find on Enceladus during its mission around Saturn and the ringed planet's natural satellites. The probe may have found evidence of liquid water that erupts like geysers from Yellowstone park in the western United States, NASA said Thursday. "The rare occurrence of liquid water so near the surface raises many new questions about the mysterious moon," NASA said. "We realize that this is a radical conclusion -- that...

On Aug. 28, 2012, during the 22nd Martian day, or sol, after landing on Mars, NASA's Curiosity rover drove about 52 feet (16 meters) eastward. The drive imprinted the wheel tracks visible in this image. Credit: NASA/JPL-Caltech After decades of following the water, the reality that “life as we know it” may never have gotten a foothold on Mars’ surface, at least, has arguably taken root within the planetary science community. If life ever was or is lurking on the Red planet, it’s been extremely coy about revealing itself. The recent news that the Mars Curiosity rover has thus far...

Transport proteins show 4,000-fold preference for phosphate over arsenate.A bacterium that some scientists thought could use arsenic in place of phosphorus in its DNA actually goes to extreme lengths to grab any traces of phosphorus it can find.The finding clears up a lingering question sparked by a controversial study1, published in Science in 2010, which claimed that the GFAJ-1 microbe could thrive in the high-arsenic conditions of Mono Lake in California without metabolizing phosphorus — an element that is essential for all forms of life.Although this and other key claims of the paper were later undermined (see 'Study challenges existence...

SETI and Intelligent Design By Seth ShostakSETI Instituteposted: 01 December 200506:37 am ET If you’re an inveterate tube-o-phile, you may remember the episode of "Cheers" in which Cliff, the postman who’s stayed by neither snow, nor rain, nor gloom of night from his appointed rounds of beer, exclaims to Norm that he’s found a potato that looks like Richard Nixon’s head.This could be an astonishing attempt by taters to express their political views, but Norm is unimpressed. Finding evidence of complexity (the Nixon physiognomy) in a natural setting (the spud), and inferring some deliberate, magical mechanism behind it all,...

We are not alone in the universe -- and alien life forms may have a lot more in common with life on Earth than we had previously thought. That's the stunning conclusion one NASA scientist has come to, releasing his groundbreaking revelations in a new study in the March edition of the Journal of Cosmology. Dr. Richard B. Hoover, an astrobiologist with NASA’s Marshall Space Flight Center, has traveled to remote areas in Antarctica, Siberia, and Alaska, amongst others, for over ten years now, collecting and studying meteorites. He gave FoxNews.com early access to the out-of-this-world research, published late...