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
Sol (day on Mars) Mars Sol Date is defined mathematically as MSD = (Julian Date using International Atomic Time - 2451549.5 + "k")/1.02749125 + 44796.0, where "k" is a small correction of approximately 0.00014 d (or 12 s) due to uncertainty in the exact geographical position of the prime meridian at Airy-0 crater. The word "yestersol" was coined by the NASA Mars operations team early during the MER mission to refer to the previous sol (the Mars version of "yesterday"), and came into fairly wide use within that organization during the Mars Exploration Rover Mission of 2003. It was eventually picked up and used