It’s well known that comets are made primarily of ice. But the recent discovery of frost on an asteroid–the first ever–has scientists looking for clues that icy rocks could have been the source of the Earth’s oceans, Scientific American reports.
Two studies in the journal Nature detail how scientists have used an infrared telescope to spectroscopically examine asteroid 24 Themis’s surface, the report said. The resulting chemical signature looked like a match for water ice.
Previously, asteroids were thought to be free of ice. 24 Themis first attracted attention because all of its neighbors are icy comets.
The asteroid is one of the largest in the belt just outside Mars, with a diameter of 129 miles. Let’s hope that one stays away from Earth. (Artist concept credit: NASA/JPL-Caltech/T. Pyle)