MARS RESEARCH Two new studies heap on yet more data indicating that Mars was once wet

Abstract

Two new reports weigh in on the climate of early Mars. One concludes that the early planet was warm, the other that it was cold, but both suggest the planet was wet. An international team of scientists led by Cornell University’s Stephen W. Squyres reports that during two years of exploration, NASA’s Mars rover Opportunity found that compositional features, apparently altered by liquid water in the exposed walls of Mars’s Victoria impact crater, match those of two other impact craters—Eagle and Endurance—several miles away. This suggests, the researchers say, that the same groundwater processes affected large regions of terrain on a warm planet ( Science 2009, 324 , 1058). For example, the craters all show, among other things, sulfate salts, which likely were produced by the interaction of basalt with acidic water. In the second report, NASA Ames Research Center astrobiologist Christopher P. McKay and colleagues take aim at recent work that suggests Mars has ...