PASADENA, Calif. -- The odometer of NASA's Mars rover Opportunity has hit 25.01 miles (40.25 kilometres), breaking the record for off-Earth distance travelled.

NASA officials said Monday that Opportunity drove 47.8 metres over the weekend, which was enough to surpass the record held by the Soviet Union's Lunokhod 2 rover.

NASA project manager John Callas says Opportunity was only intended to drive about 1 kilometre and was not designed for distance. He says the rover has driven farther than any other wheeled vehicle on another world.

NASA says if the rover hits 42.1 kilometres, it will reach the next major investigation site that scientists refer to as "Marathon Valley" -- because it will have travelled the distance of a marathon.

The Russian Lunokhod 2 rover landed on Earth's moon in 1973 and drove 38.9 kilometres.