Associated Press - October 7, 2009 12:54 PM ET
ST. LOUIS (AP) - Researchers at Washington University in St. Louis believe a planet outside our solar system rains not water, but rocks.
They studied the atmosphere of Corot-7b (kuh-ROH'), an extrasolar planet that orbits a star other than our sun.
European scientists who announced the discovery of the "exoplanet" earlier this year asked Washington University planetary researchers to create models of its atmosphere.
They found the planet's blazing heat would lead rock to vaporize. Instead of water clouds, they think rock clouds would form and rain small pebbles.
Their research appears this month in The Astrophysical Journal.