Los Angeles - The rover Opportunity may not be sleek like a brand new car, but it shows no signs of braking even after a decade on Mars.
Scientists and engineers gathered at the Nasa Jet Propulsion Laboratory on Thursday to celebrate the plucky rover, which has logged 39km since landing.
Opportunity has been exploring the rim of Endeavour Crater, its fifth crater destination. A new study of rocks examined by Opportunity and published in the journal Science found they're the oldest yet - about 4 billion years old.
The rocks interacted with water during a time when environmental conditions were favourable for microbes.
The solar-powered rover is in a good spot to ride out the Martian winter.
Opportunity outlasted its twin Spirit, which stopped communicating in 2010 after getting stuck in sand.