Asteroid ice may be 'living fossil'

ORLANDO, Fla., April 28 (UPI) -- U.S.-led researchers say their discovery of ice and organic molecules on an asteroid suggests such a space object may have brought Earth its water.

University of Central Florida scientists led by Professor Humberto Campins detected a thin layer of water ice and organic molecules on the surface of 24 Themis, the largest in a family of asteroids orbiting between Mars and Jupiter.

"What we've found suggests that an asteroid like this one may have hit Earth and brought our planet its water," Campins said.

Campins and his team said they used NASA's Infrared Telescope Facility in Hawaii to measure the intensity of the reflected sunlight as 24 Themis rotated. They said they found ice and carbon-based compounds evenly distributed on the asteroid.

The discovery, they said, was unexpected because surface ice should be short lived on asteroids, which are thought to be too warm for ice to survive.

Campins said one possibility for the existence of ice is that 24 Themis might have preserved it in its subsoil as a kind of "living fossil" or remnant of an early solar system that was generally considered to have disappeared long ago.

Campins' team includes scientists from the University of La Laguna in Spain, the University of Southern Maine, University of Maryland, the Federal University of Rio de Janeiro, NASA's Ames Research Center and the Arecibo Observatory in Puerto Rico.