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“If true, the stirring provided by migrating planets may have been essential to bringing those asteroids,” the astronomers stated in a press release. “This raises the question of whether an Earth-like exoplanet would also require a rain of asteroids to bring water and make it habitable. If so, then Earth-like worlds might be rarer than we thought.” To take this example further, the researchers found that the asteroid belt comes from a mix of locations around the solar system. Well, a model the astronomers cite shows that Jupiter once migrated much closer to the sun, basically at the same distance...

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.

On the morning of June 30, 1908, the sky exploded over a remote region of central Siberia. A fireball powerful as hundreds of Hiroshima atomic blasts scorched through the upper atmosphere "as if there was a second sun," according to one eyewitness. Scientists today think a small fragment of a comet or asteroid caused the "Tunguska event," so named for the Tunguska river nearby. No one knows for certain, however, because no fragment of the meteoroid has ever been found. The explosion was so vast—flattening and incinerating over an 800 square-mile swath of trees—that generations of amateur sleuths have put...

A picture of the gun used in the experiments. The big white box at the left end of the gun is where the target is stored. Credit: Impact Laboratory, University of Kent Bullets of ice shot at high speeds can deposit organic compounds on surfaces they strike. New findings suggest that comets might, indeed, have helped deliver key ingredients of life to Earth and perhaps elsewhere, researchers say. The scientists detailed their findings in the June 13 issue of the journal Astrobiology.Craters on the moon are evidence that the Inner Solar System was prone to giant impacts from asteroids...

Mars Express was able to accomplish what so many other spacecraft have tried and failed by using a SPICAM(2) spectrometer The search for water on Mars has been ongoing for quite some time now, with Mars rovers like NASA's Spirit and Opportunity being two examples of those who have found clues that point to a once-tropical past on the dusty red planet billions of years ago. Now, the European Space Agency's Mars Express spacecraft has discovered that Mars' atmosphere holds water vapor in a supersaturated state. Mars Express was able to accomplish what so many other spacecraft have tried and...

A recently discovered comet will make an uncomfortably-close planetary flyby next year — but this time it’s not Earth that’s in the cosmic crosshairs. According to preliminary orbital prediction models, comet C/2013 A1 will buzz Mars on Oct. 19, 2014. According to calculations by NASA’s Jet Propulsion Laboratory (JPL), close approach data suggests the comet is most likely to make a close pass of 0.0007 AU (that’s approximately 63,000 miles from the Martian surface). However, there’s one huge caveat. Due to uncertainties in the observations — the comet has only been observed for 74 days (so far), so it’s difficult...

This year seems to be one for comets. In addition to the two projectiles that will zoom near Earth, a third one has recently been discovered. The newest one, though, won't fly by our planet. Instead, it will pass uncomfortably close to Mars in 2014. Named C/2013 A1, the comet will fly near the Red Planet on Oct. 19, 2014 according to preliminary orbital prediction models. The icy missile is thought to have first originated from the Oort Cloud, which is a hypothetical region containing billions of cometary nuclei located around our solar system. Comets have struck planets in the...

Impactor ejects mighty water mass By Jonathan Amos BBC News science reporter, in Leicester Comets hold materials unchanged since the Solar System's formation The Nasa projectile that slammed into Comet Tempel 1 last year kicked out at least 250,000 tonnes of water. The figure comes from UK/US scientists on the Swift telescope, one of many observatories called on to study the US space agency's Deep Impact event. Swift's X-ray data shows more water was released and over a longer time scale than had previously been thought. Researchers hope the new information will help them understand better the nature and construction...

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...

Basically, there is a gap between what is thought to have existed in the past, and what is observed today in the form of water ice. The findings made by Tomohiro and the international research team help to account for this. “The total inventory of “observable” current surface water (that mostly occurs as polar ice, ~10E6 km3) is more than one order magnitude smaller than the estimated volume of ancient surface water (~10E7 to 10E8 km3) that is thought to have covered the northern lowlands,” said Tomohiro. “The lack of water at the surface today was problematic for advocates of...

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...

The question about the origin of oceans on Earth is one of the most important questions with respect to the formation of our planet and the origin of life. The most popular theory is that water was brought by impacts of comets and asteroids. Data from the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument aboard the European Space Agency’s Rosetta spacecraft indicate that terrestrial water did not come from comets like 67P/Churyumov-Gerasimenko. The findings were published today in the journal Science. Researchers agree that water must have been delivered to Earth by small bodies at a later...

The Mars rover Opportunity's examination of Martian rocks last week provided the first convincing evidence that our neighbour world was once "awash" in water, as one NASA scientist described it. But where did the water come from? And why does Mars have no liquid water now, while Earth apparently has been covered with the stuff for 4 billion years? Scientists are just beginning to piece the story together, and it goes right back to the beginning. Mars, like Earth, was formed from dusty and rocky debris left over after the sun was born 4.57 billion years ago. Initially, there were...

Scientists have long believed that comets and, or a type of very primitive meteorite called carbonaceous chondrites were the sources of early Earth's volatile elements -- which include hydrogen, nitrogen, and carbon -- and possibly organic material, too. Understanding where these volatiles came from is crucial for determining the origins of both water and life on the planet. New research led by Carnegie's Conel Alexander focuses on frozen water that was distributed throughout much of the early Solar System, but probably not in the materials that aggregated to initially form Earth... It has been suggested that both comets and carbonaceous...

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...

"We were looking to measure a certain particle called dueterium," said Alexander. It is this element that would confirm or scuttle the theory of comets hydrating Earth. And, as it turned out, Rosetta's data cast a strong doubt that comets were our aquatic benefactors.

Did comets flood Earth’s oceans? Did comets flood Earth's oceans? 16 June 2004 Did the Earth form with water locked into its rocks, which then gradually leaked out over millions of years? Or did the occasional impacting comet provide the Earth’s oceans? The Ptolemy experiment on Rosetta may just find out… The Earth needed a supply of water for its oceans, and the comets are large celestial icebergs - frozen reservoirs of water orbiting the Sun. Did the impact of a number of comets, thousands of millions of years ago, provide the Earth with its supply of water? Finding hard...

Scientists scanning the deep interior of Earth have found evidence of a vast water reservoir beneath eastern Asia that is at least the volume of the Arctic Ocean. The discovery marks the first time such a large body of water has found in the planet’s deep mantle. The finding, made by Michael Wysession, a seismologist at Washington State University in St. Louis, and his former graduate student Jesse Lawrence, now at the University of California, San Diego, will be detailed in a forthcoming monograph to be published by the American Geophysical Union. Looking down deep The pair analyzed more than...

Scientists at the University of Liverpool have shown that deep sea fault zones could transport much larger amounts of water from the Earth’s oceans to the upper mantle than previously thought.Water is carried mantle by deep sea fault zones which penetrate the oceanic plate as it bends into the subduction zone.  Subduction, where an oceanic tectonic plate is forced beneath another plate, causes large earthquakes such as the recent Tohoku earthquake, as well as many earthquakes that occur hundreds of kilometers below the Earth’s surface.Seismic modellingSeismologists at Liverpool have estimated that over the age of the Earth, the Japan subduction...

Researchers at Northwestern University have found evidence for a massive reservoir of water deep within the Earth's mantle. The reservoir, which is said to be three times the volume of the oceans on the surface, is contained within highly-pressurized rock known as ringwoodite. The scientists hope that their findings, recently published in the journal Science, can shed light on where Earth's oceans came from. THREE TIMES THE VOLUME OF THE OCEANS ON EARTH'S SURFACE The team, led by mineralogist Steven Jacobsen, used an array of 2000 seismometers to study how seismic waves generated by earthquakes move through the Earth's interior....