On July 27, 2014, which corresponds to the Sol – as in Martian day – 3,735 of its mission, the Mars Rover Opportunity has set the record for the driving distance covered by a human vehicle on another world, reaching 40.25 km (25.01 miles). The previous record belonged to the Soviet Lunokhod 2 rover, which in 1973 covered 39 km (24.2 miles) on the Moon.