Eight years after landing on Mars for what was planned as a three-month mission, NASA’s enduring Mars Exploration Rover Opportunity is working on what essentially became a new mission five months ago.
Opportunity reached a multi-year driving destination, Endeavour Crater, in August 2011. At Endeavour’s rim, it has gained access to geological deposits from an earlier period of Martian history than anything it examined during its first seven years. It also has begun an investigation of the planet’s deep interior that takes advantage of staying in one place for the Martian winter.
Mars years last nearly twice as long as Earth years. Entering its ninth Earth year on Mars, Opportunity is also heading into its fifth Martian winter. Its solar panels have accumulated so much dust since Martian winds last cleaned them — more than in previous winters — the rover needs to stay on a Sun-facing slope to have enough energy to keep active through the winter.
All six of Opportunity’s wheels are still useful for driving, but the rover will stay on an outcrop called “Greeley Haven” until mid-2012 to take advantage of the outcrop’s favorable slope and targets of scientific interest during the Martian winter. After the winter, or earlier if wind cleans dust off the solar panels, researchers plan to drive Opportunity in search of clay minerals that a Mars orbiter’s observations indicate lie on Endeavour’s rim.
Observations for the campaign to monitor wind-caused changes range in scale from dunes in the distance to individual grains seen with the rover’s microscopic imager. “Wind is the most active process on Mars today,” a NASA spokesperson said. “It is harder to watch for changes when the rover is driving every day. We are taking advantage of staying at one place for a while.”