Opportunity's 10-year Martian Marathon

NASA scientists are celebrating the 10th anniversary of a robotic rover's touchdown on Mars's Meridiani Planum. Opportunity is still healthy, still rolling, and returning valuable insights about the Red Planet.

This weekend, NASA managers and planetary scientists everywhere are celebrating a remarkable, almost unthinkable achievement: the Opportunity rover has been operating on Mars since dropped to the surface on January 25, 2004. These numbers bear witness to the little rover's accomplishments:

Intended lifetime: 90 sols (Martian days)
Lifetime to date: 3,557 sols

Intended mobility: at least 200 meters
Mobility to date: 38,730 meters (24.07 miles)

These days the rover is far from its original landing site on Meridiani Planum. It's perched on "Solander Point" at the rim of Endeavour, a relatively fresh crater 14 miles (23 km) across, which has been "home" for the past 2½ years. The walls of Enveavour's rim have exposed outcrops that orbital observations suggest might contain small amounts of clay minerals.

The rover isn't moving much these days — it's winter there now, and the weak sunlight falling on its solar-cell arrays isn't providing enough electricity. A recent "selfie" shows that Opportunity is hardly the spiffy, ready-to-roll robot that arrived back in 2004. It's covered from mast to wheels in the ruddy, superfine dust that coats everything on the Martian surface. Mission engineers' most recent update notes that the dust has reduced the solar cells' output to only 60% of what they'd be if completely clean.

But that hasn't stopped Opportunity from continuing its scientific mission. The rover is studying a curious rock, dubbed "Pinnacle Island," that apparently got churned to the surface by one of the wheels during a recent traverse. Indeed, Opportunity's findings while at Endeavour are highlighted in this week's edition of Science, which has recently brimmed with results from Opportunity's much-bigger sibling, Curiosity.

"These rocks are older than any we examined earlier in the mission," says Ray Arvidson (Washington University), lead author for the report about Endeavour, "and they reveal more favorable conditions for microbial life than any evidence previously examined by investigations with Opportunity." Arvidson's remarks appear in a JPL press release celebrating the rover's accomplishments.

Members of the Mars Exploration Rover team (as the mission is formally known) have assembled some great highlights from the explorations of both Opportunity and its twin, Spirit, over the past 10 years.

Sometimes the light's all shinin' on me;
Other times I can barely see.
Lately it occurs to me
What a long, strange trip it's been.

— "Truckin" (Grateful Dead, 1970)