Ancient mud cracks on Mars point to conditions favorable for life

Did life once exist on Mars? Today, the planet is frigid, dry, and inhospitable. But billions of years ago, water flowed through rivers and filled lakes. Now, the discovery of distinctive mud cracks on the planet’s surface suggest ancient Mars cycled through sustained wet and dry seasons for millions of years. Not only would the climate have been habitable, scientists say, but the cycling might have also given the basic chemistry of life a boost. The discovery, reported today in Nature , is compelling evidence for an Earth-like climate on early Mars and presents “thought-provoking” theories about the origin of life on the Red Planet, says Amy Williams, a geologist at the University of Florida who was not involved in the study. In the 1990s, NASA satellites orbiting Mars first began to capture gullies, dried-out river deltas, and layered sedimentary deposits, all of which require liquid water to form. These geological features suggest the ancient martian climate was much warmer and wetter than it is today, says Ashwin Vasavada, project scientist for the Curiosity rover at NASA’s Jet Propulsion Laboratory. The question is how the early martian climate could have allowed these warm and wet conditions to persist for enough time for life to take hold. Today, the planet’s cold and thin atmosphere means what little water it has is locked up in frozen ice caps or minerals in the crust. According to Vasavada, conditions would have been e...
Source: ScienceNOW - Category: Science Source Type: news