NASA’s Mars rover Opportunity has completed a three-year trek to reach the enormous Endeavour crater.
Scientists hope it will find rocks and terrain much older than any other that the itinerant robot has examined during its seven years on the red planet.
The U.S. space agency announced Wednesday that Opportunity arrived at the rim of Endeavour on Tuesday. The golf cart-size rover is expected to remain at the 22-kilometer-wide crater for the next few years.
NASA’s Mars Reconnaissance Orbiter, which has been circling the planet since late 2005, detected clay minerals that form in wet conditions in the crater. Scientists want to find out if the minerals date back to Mars’ distant past, when the planet is believed to have been wetter and warmer than the dry frozen desert it is today.
NASA is searching for signs that Mars had a habitable environment billions of years ago. Knowledge of the Martian climate will be important to future manned missions there, and can shed light on the forces that shaped Earth's climate.
NASA launched the Mars rovers Opportunity and Spirit in 2003 for what were planned to be three-month missions. But both continued operating well beyond that. Spirit stopped communicating in March 2010.