NASA's Opportunity rover on Mars has now boldly gone farther than any vehicle has before on the surface of another world.
As of Sunday, the Opportunity rover has driven 25.01 miles (40.2 kilometers) on the Red Planet, NASA officials said. The distance record had been held by the Soviet Union's Lunokhod 2 rover, which covered 24.2 miles (39 km) on the moon in 1973.
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"Opportunity has driven farther than any other wheeled vehicle on another world," Opportunity project manager John Callas of NASA's Jet Propulsion Laboratory said Monday in a statement. "This is so remarkable, considering Opportunity was intended to drive about one kilometer and was never designed for distance. But what is really important is not how many miles the rover has racked up, but how much exploration and discovery we have accomplished over that distance." [Infographic: Distances Driven on Other Worlds]
There has been some uncertainty regarding how far Lunokhod 2 actually went on the moon. The lunar rover's record was initially set at 23 miles (37 kilometers), then upped last year to 26 miles (42 kilometers) by a Russian team that analyzed photos of Lunokhod 2 tracks taken by NASA's Lunar Reconnaissance Orbiter.
That estimate was revised downward recently, and NASA is confident that Opportunity is now the record holder. An international team has confirmed that the methods used to calculate the two rovers' odometry is consistent and comparable from the moon to Mars.
Opportunity and its twin, Spirit, landed in different parts of Mars in 2004 to search for evidence of past water activity. Both rovers found plenty of such evidence. Spirit ceased communicating with Earth in 2010, while Opportunity is still going strong today. Meanwhile, NASA's other operational Mars rover, the 1-ton Curiosity, has gone 5.5 miles (8.9 kilometers) since its landing in August 2012.