Timeline of Mars Science Laboratory microorganisms, as well as ancient water, including fluvio-lacustrine environments (plains related to ancient rivers or lakes) that may have been habitable. The search for evidence of habitability, taphonomy (related to fossils), and organic carbon on the planet Mars is now a primary NASA objective. On September 11, 2014 (Sol 746), "Curiosity" reached the slopes of Aeolis Mons (or Mount Sharp), the rover mission's long-term prime destination and where the rover is expected to learn more about the history of Mars. "Curiosity" had traveled an estimated linear distance of to the mountain slopes since leaving its ""start"" point in Yellowknife Bay
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