LOS ANGELES (AP) Opportunity, NASAs other Mars rover, has tooled around the red planet for so long its easy to forget its still alive.

Some 5,000 miles away from the limelight surrounding Curiositys every move, Opportunity this week quietly embarks on its tenth year of exploration a sweet milestone since it was only tasked to work for three months.

Opportunity is still going. Go figure, said mission deputy principal investigator Ray Arvidson of Washington University in St. Louis.

True, its not as snazzy as Curiosity, the most high-tech interplanetary rover ever designed. It awed the world with its landing near the Martian equator five months ago.

After so many years crater-hopping, Opportunity is showing its age: It has an arthritic joint in its robotic arm and it drives mostly backward due to a balky front wheel more annoyances than show-stoppers.

For the past several months, it has been parked on a clay-rich hill along the western rim of Endeavour Crater thats unlike any scenery it encountered before. It plans to wrap up at its current spot in the next several months and then drive south where the terrain looks even riper for discoveries.

Long before Curiosity became everybodys favorite rover, Opportunity was the darling.

The six-wheel, solar-powered rover parachuted to Eagle Crater in Mars southern hemisphere on Jan. 24, 2004, weeks after its twin Spirit landed on the opposite side of the planet.

During the first three months, there were frequent updates about the twin rovers antics. The world, it seemed, followed every trail, every rock touched and even kept up with Spirits health scare that it eventually recovered from.

Opportunity immediately lived up to its name, touching down in an ancient lakebed brimming with minerals that formed in the presence of water, a key ingredient for life. After grinding into rocks and sifting through dirt, Opportunity made one of the enduring finds on Mars: Signs abound of an ancient environment that was warmer and wetter than todays dusty, cold desert state.

See the original post here:

NASA's older Mars rover notches another milestone