This month NASA plans to launch its latest and most sophisticated mission ever to the Red Planet: the Mars Science Laboratory. After a dramatic landing in Gale Crater using a skycrane for the final descent, the nuclear-powered rover will drive around one of the richest deposits of clays and sulfates on the planet—the remains of a water-rich era when rivers carved out valley networks.
The size of a small car, the rover (named Curiosity) will spend a Martian year exploring the base of the central peak in the crater, thought to be the oldest section. Then, if NASA approves an extended mission, Curiosity will begin to climb the five-kilometer-high debris pile that fills the center of the crater, moving up the geologic timeline toward deposits made in the modern era, scrutinizing the aqueous minerals layer by layer. A robot arm can retrieve samples and feed them to an onboard chemistry lab through a port on top of the rover. Inside, analyzers will determine the mineral structures and elemental composition. These instruments also can sense organic materials and will attempt to decide whether Mars used to be habitable.