Methane on Mars
January 16, 2009
Scientists don't yet know enough to say with certainty what the source of the Martian methane is, but this artist's concept depicts a possibility. In this illustration, subsurface water, carbon dioxide and the planet's internal heat combine to release methane. Although we don't have evidence on Mars of active volcanoes today, ancient methane trapped in ice "cages" might now be released.