Curiosity finds evidence for a habitable lake…on Mars

The report in SCIENCE is here. News story here. Short version: the Curiosity Mars Rover has found very strong evidence for a water-filled lake that lasted a minimum of thousands of years in Gale Crater (the landing site). Importantly, the lake’s PH (acidity) would have supported life. Even more exciting, there appears to be evidence for organic material–money quote from the news story:

When SAM heated the samples, the lakebed samples emitted more carbon dioxide than equal-size dust samples did, and their carbon dioxide came off at lower temperatures. Those observations suggested that heating the dust had simply decomposed naturally occurring, inorganic carbonate minerals, but that heating the lakebed samples had burned organic matter. Most telling, as carbon dioxide from the lakebed surged, the level of oxygen gas from decomposing perchlorates dropped. On seeing those data, one SAM team member reportedly declared, “This is combustion of organic carbon, folks.”