By Steve Gorman
LOS ANGELES (Reuters) - NASA's decade-old Mars rover Opportunity has set a new off-Earth, off-road distance record, logging just over 25 miles (40 km) on the surface of the Red Planet to surpass the benchmark set in 1973 by a Russian probe on the moon.
Opportunity, which arrived on Mars in January 2004, a few weeks after its now-defunct rover twin Spirit, was built to drive only about a single kilometer but has continued to operate far beyond its design capabilities.
Earlier this year, the aging but intrepid rover, a six-wheeled vehicle about the size of a golf cart, found evidence that fresh water once pooled on the surface of Mars, reinforcing similar discoveries made by a newer, larger probe Curiosity, on the other side of the planet.
On Sunday, the robot rover advanced another 157 feet (48 meters) as it continued along the rim of a Martian crater, putting Opportunity's total odometer at 25.01 miles (40.25 km), according to NASA's Jet Propulsion Laboratory near Pasadena, California.
By comparison, the Soviet Union's Lunokhod 2 rover drove about 24.2 miles (39 km) in less than five months after landing on Earth's moon on Jan. 15, 1973, JPL said. The manned lunar rover driven by astronauts of the Apollo 17 mission logged 22.2 miles (35.7 km) in 1972.
"Opportunity has driven farther than any other wheeled vehicle on another world," JPL's Mars Exploration Rover Project Manager John Callas said in a statement.
Opportunity still has miles to go. Scientists said they plan next to direct the rover to a nearby Martian valley that would extend its accumulated operating distance to 26.2 miles, the traditional length of a marathon.
(Reporting by Steve Gorman; Editing by Nick Zieminski)