Mars May Have Had Earth-Like Atmosphere in Past, Study Says : SCIENCE FILE / An exploration of issues and trends affecting science, medicine and the environment

U.S. scientists have come up with more evidence that Mars had an atmosphere similar to Earth’s sometime in the past--and thus may have once supported life. Everett Shock of Washington University in St. Louis and his colleagues examined Martian rock that fell to the earth as a meteorite and said it indicated that rocks may have absorbed some of the gases in the ancient atmosphere.

The researchers compared Mars rock to rocks from Iceland, where extensive hot spring and volcanic activity has dissolved large amounts of carbon dioxide under the surface. “Our results suggest that an extensive reservoir of carbonate materials could have been sequestered beneath the surface by widespread hydrothermal activity in the Martian past,� they wrote in the journal Nature.