Water found in unlikeliest of places in solar system

WASHINGTON — Scientists have found lots of life-essential water — frozen as ice — in an unexpected place in our solar system: an asteroid between Mars and Jupiter.

The discovery of significant asteroid ice has several consequences. It could help explain where early Earth first got its water. It makes asteroids more attractive to explore, dovetailing with President Obama's announcement earlier this month that astronauts should visit an asteroid. And it even muddies the definition between comets and asteroids, potentially triggering a Pluto-like scientific spat over what to call these solar system bodies.

This asteroid has an extensive but thin frosty coating. It is likely replenished by an extensive reservoir of frozen water deep inside rock once thought to be dry and desolate, scientists report in two studies in today's issue of the journal Nature.

Two teams of scientists used a NASA telescope in Hawaii to look at an asteroid called 24 Themis, a rock more than 100 miles wide in the asteroid belt between Mars and Jupiter.

Scientists didn't just find ice; they found organic molecules, similar to what may have started life on Earth, said University of Central Florida astronomy professor Humberto Campins, lead author of one of the studies.