Opportunity (rover) Opportunity (rover) Opportunity, also known as MER-B (Mars Exploration Rover – B) or MER-1, is a robotic rover active on Mars since 2004. Launched on July 7, 2003 as part of NASA's Mars Exploration Rover program, it landed in Meridiani Planum on January 25, 2004, three weeks after its twin "Spirit" (MER-A) touched down on the other side of the planet. With a planned 90 sol duration of activity (slightly more than 90 earth days), "Spirit" functioned until getting stuck in 2009 and ceased communications in 2010, while "Opportunity" was active as of June 10, 2018 when a dust storm
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