Nasa Probe Indicates Asteroid Vesta Once Had Flowing Water

One of the largest asteroids in our solar system - Vesta - may once have had flowing water which formed gullies and other erosion features on its surface, according to data from Nasa's Dawn spacecraft.

Vesta, visited by Dawn from 2011 to 2013, was once thought to be completely dry, incapable of retaining water because of the low temperatures and pressures at its surface. However, a new study shows evidence that Vesta may have had short-lived flows of water-mobilised material on 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," said Jennifer Scully, postgraduate researcher at the University of California, Los Angeles.

"However, Vesta is proving to be a very interesting and complex planetary body," said Scully.

"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," said UCLA's Christopher Russell, principal investigator for the Dawn mission. Scully and colleagues identified a small number of young craters on Vesta with curved gullies and fan-shaped deposits.

"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 mobilises the sandy and rocky particles into a flow," Scully said.