LOS ANGELES (January 21, 2013)—Opportunity, NASA’s older Mars rover, is quietly embarking on its tenth year of exploration.

Since landing in January 2004, it has made many discoveries including that Mars was once warmer and wetter than it is today.

Opportunity and its twin Spirit were only supposed to explore for three months, but both outlasted their original mission.

Opportunity remains operational and is studying interesting rocks in a massive crater.

Spirit lost communication with Earth in 2010 shortly after getting stuck in Martian sand.