Gullies suggest comet Vesta once had flowing water on its surface

This image of the giant asteroid Vesta was taken by NASA’s Dawn spacecraft, as part

of a rotation characterization sequence on July 24, 2011

NASA’s Dawn spacecraft is currently approaching the dwarf planet

Ceres, the largest object in the asteroid belt that lies between Mars

and Jupiter. However, from 2011 to 2013 Dawn collected extensive data on

Vesta, the second largest object in the asteroid belt and one of the

largest known comets in our solar system.

The data collected from Vesta is still being analyzed and will

continue to be for years to come. As the data is examined interesting

new information about the giant asteroid is coming to light. Vesta which

is very cold and has no atmosphere has long thought to be dry. A new

study published in the journal Earth and Planetary Science Letters casts doubt on that assumption.

While there are certainly no rivers and lakes on Vesta, photographs

taken by Dawn show evidence of short lived flows of water mobilized

material on the surface.

“Nobody expected to find evidence of water on Vesta. The surface is

very cold and there is no atmosphere, so any water on the surface

evaporates. However, Vesta is proving to be a very interesting and

complex planetary body,” said Jennifer Scully, postgraduate researcher

at the University of California, Los Angeles in a statement.

The research could change some basic assumptions in planetary science.

“These results, and many others from the Dawn mission, show that

Vesta is home to many processes that were previously thought to be

exclusive to planets. We look forward to uncovering even more insights

and mysteries when Dawn studies Ceres,” said UCLA’s Christopher Russell,

principal investigator for the Dawn mission.

The curved gullies on vesta are very different from what would be expected from dry material flows, say the researchers.

“We’re not suggesting that there was a river-like flow of water.

We’re suggesting a process similar to debris flows, where a small amount

of water mobilizes the sandy and rocky particles into a flow. These

features on Vesta share many characteristics with those formed by debris

flows on Earth and Mars,“ said Scully.

The leading theory so far is that Vesta has small patches of ice

beneath the surface, possibly deposited by impacts from other comets.

Later impacts could have heated the ice enough to thaw some of the

water, releasing it into the crater.

Source Article from http://feedproxy.google.com/~r/AscensionEarth2012/~3/zIvjFy58tZU/gullies-suggest-comet-vesta-once-had.html

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Gullies suggest comet Vesta once had flowing water on its surface