NASA is celebrating the fact that its Opportunity rover on Mars has completed a journey comparable to a marathon run - though it took the tiny, wheeled robot 11 years and 2 months to complete the course.

During its time on the Red Planet, Opportunity has covered 26.219 miles, the space agency says.

"This is the first time any human enterprise has exceeded the distance of a marathon on the surface of another world," John Callas, Opportunity project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said. "A first time happens only once."

Originally expected to carry out just a 3-month mission on Mars, Opportunity has now been operating for 45 times longer than that original planned mission duration.

Although wear and tear will eventually bring it to a halt, as happened to its twin rover Spirit in 2010, Opportunity probably has a few miles left in it, NASA says.

Launched in July 2013, Opportunity landed on the Red Planet on Jan. 25, 2004, three weeks after Spirit landed on the opposite side of the planet.

Opportunity is currently exploring a valley that scientists have named Monument Valley, in honor of the rover's long-distance achievements.

The valley overlooks Endeavour Crater, which Opportunity has been slowly working its way around for the last 4 years.

Last year, it broke the previous record for the longest distance traveled by an earthly land vehicle on another world, beating the 1973 mark of 24 miles achieved by the Soviet Union's moon rover Lunokhod 2.

It passed the marathon distance in a recent drive of 153 feet.

"This mission isn't about setting distance records, of course; it's about making scientific discoveries on Mars and inspiring future explorers to achieve even more," says Opportunity principal investigator Steve Squyres at Cornell University in Ithaca, N.Y. "Still, running a marathon on Mars feels pretty cool."

After it landed in 2004, Opportunity found signs of ancient water soaking the planet's surface and flowing in channels.

At the Endeavour crater, is has continued that search, finding evidence of prehistoric water less acidic than what it found in 2004, a fact which would have made it more hospitable to the possible existence of microbial life.

The team behind Opportunity says if the rover can run a marathon then they can, too, so members are planning a marathon-length relay race next week at their Pasadena facility.

Although none would claim to be expert marathoners, it is entirely possible they'll beat Opportunity's time.

For more information on the rovers, check out NASA's rover page.