WASHINGTON, July 28 (Xinhua) -- U.S. space agency NASA said Monday that its Opportunity rover, working on Mars since January 2004, passed 25 miles (40 kilometers) of total driving Sunday, setting a distance record for driving on another planet.
The six-wheeled Opportunity rover drove 157 feet (48 meters) on July 27, bringing its total odometry on the Red Planet to 25.01 miles (40.25 kilometers), NASA said in a statement.
The previous record was held by the Soviet Union's Lunokhod 2 rover, which drove about 24.2 miles (39 kilometers) on the moon in less than five months in 1973, according to calculations recently made using images from NASA's lunar orbiter cameras that reveal Lunokhod 2's tracks.
"Opportunity has driven farther than any other wheeled vehicle on another world," said Mars Exploration Rover Project Manager John Callas of NASA's Jet Propulsion Laboratory (JPL).
"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."
Opportunity landed on Mars in January 2004 on what was a three- month mission, but instead the rover has worked on the planet for more than 10 years. It has found evidence of past water activity on the Red Planet.
This month's driving brought the rover southward along the western rim of Endeavour Crater, NASA said.
If the rover can continue to operate the distance of a marathon, or 26.2 miles (about 42.2 kilometers), it will approach the next major investigation site mission scientists have dubbed "Marathon Valley".
Observations from spacecraft orbiting Mars suggest several clay minerals are exposed close together at this valley site, surrounded by steep slopes where the relationships among different layers may be evident, the space agency said.