Mars rover Mars rover A Mars rover is a motor vehicle that propels itself across the surface of the planet Mars upon arrival. Rovers have several advantages over stationary landers: they examine more territory, and they can be directed to interesting features, they can place themselves in sunny positions to weather winter months, and they can advance the knowledge of how to perform very remote robotic vehicle control. There have been four successful robotically operated Mars rovers. The Jet Propulsion Laboratory managed the "Sojourner" rover, the "Opportunity" rover, "Spirit" rover, and, now the "Curiosity" rover. On January 24, 2016 NASA reported that
Scientific information from the Mars Exploration Rover mission made during a press conference, where mission scientists listed a number of observations that strongly support this view: Detailed analysis of environmental, chemical, and mineralogical data taken from the Opportunity rover led to the elimination of the competing hypotheses, and the confirmation of the conclusion that the spherules were formed in place as post-depositional sedimentary concretions from an aqueous source On March 23, 2004, NASA announced that they believe that "Opportunity" had not landed in a location merely "drenched in water", but on what was once a coastal area. "We think "Opportunity" is parked on what was once the shoreline