Aeolis Palus December 9, 2013, NASA reported that, based on evidence from "Curiosity" studying Aeolis Palus, Gale Crater contained an ancient freshwater lake which could have been a hospitable environment for microbial life. On December 16, 2014, NASA reported detecting, based on measurements by the "Curiosity" rover, an unusual increase, then decrease, in the amounts of methane in the atmosphere of the planet Mars; in addition, organic chemicals were detected in powder drilled from a rock by the "Curiosity" rover. Also, based on deuterium to hydrogen ratio studies, much of the water at Gale Crater on Mars was found to have been
Mars Exploration Rover one Martian year anniversary (669 sols or 687 Earth days) on November 20, 2005. "Opportunity" celebrated its anniversary on December 12, 2005. At the beginning of the mission, it was expected that the rovers would not survive much longer than 90 Martian days. The Columbia Hills were "just a dream", according to rover driver Chris Leger. "Spirit" explored the semicircular rock formation known as Home Plate. It is a layered rock outcrop that puzzles and excites scientists. It is thought that its rocks are explosive volcanic deposits, though other possibilities exist, including impact deposits or sediment borne by wind or