This artist's concept features NASA's Mars Science Laboratory Curiosity rover, a mobile robot for investigating Mars' past or present ability to sustain microbial life.

In this picture, the rover examines a rock on Mars with a set of tools at the end of the rover's arm, which extends about 7 feet (2 meters). Two instruments on the arm can study rocks up close. A drill can collect sample material from inside of rocks and a scoop can pick up samples of soil. The arm can sieve the samples and deliver fine powder to instruments inside the rover for thorough analysis.