NASA/JPL-Caltech

The Mars rover Opportunity has outdone itself by driving further than any other off-Earth vehicle in history. NASA announced Monday that the 10-year-old rover hit 25 miles, which breaks the previous record set by the Soviet Union's Lunokhod 2 rover.

"Opportunity has driven farther than any other wheeled vehicle on another world," said John Callas, Mars Exploration Rover project manager at NASA's Jet Propulsion Laboratory, in a statement. "This is so remarkable considering Opportunity was intended to drive about one kilometer and was never designed for distance."

While often in the shadow of its popular sibling Curiosity, Opportunity has exceeded expectations by living on the inhospitable planet for more than 10 years. The rover landed on Mars in 2004 and has since been hard at work exploring the surface of the planet, collecting Martian rock samples, and beaming information back to Earth.

On Saturday, Opportunity drove 157 feet along the western rim of the Endeavour Crater putting its total distance traveled at 25.01 miles. At this location, the rover has examined outcrops with clay and sulfate-bearing minerals, which may point to evidence of ancient environments with less acidic water than the area where Opportunity first landed.

"What is really important is not how many miles the rover has racked up," Callas said, "but how much exploration and discovery we have accomplished over that distance."

The previous record for miles traveled by an off-Earth vehicle was set more than 40 years ago by the Soviet Union's remote-controlled Lunokhod 2 rover, which rolled about 24.2 miles across the moon in 1973.

"The Lunokhod missions still stand as two signature accomplishments of what I think of as the first golden age of planetary exploration, the 1960s and 1970s," said Steve Squyres, principal investigator for NASA's twin Mars rovers, in a statement. "We're in a second golden age now, and what we've tried to do on Mars with Spirit and Opportunity has been very much inspired by the accomplishments of the Lunokhod team on the moon so many years ago. It has been a real honor to follow in their historical wheel tracks."

Opportunity's next goal is to roll the distance of a marathon -- 26.2 miles -- which would get it to "Marathon Valley." This spot is believed to have clay mineral deposits close together, which show various layers and could help scientists learn more about Mars.