Spirit and Opportunity
Artist rendering of the Mars rover
Spirit landed in Gusev Crater, a large impact crater in the southern highlands of Mars. Finding only ancient lava on the crater floor, Spirit drove a mile and a half to the base of the Columbia Hills, a mountain range near the landing site. There Spirit ascended Husband Hill, the highest summit in the range, finding strong evidence that the rocks were modified long ago by water. Recently, Spirit has found strong evidence for ancient hot springs on Mars.
Opportunity landed on Meridiani Planum, a smooth plateau near the martian equator. In the first few weeks after landing, Opportunity found compelling evidence for long-ago water on Mars. This evidence included thick deposits of sulfate salts, concretions that precipitated from liquid water, and rocks that preserve ancient ripples formed when water flowed over sand. Opportunity has driven nearly 12 kilometers across the martian surface, and has recently explored Victoria Crater, a spectacular impact crater half a mile in diameter.
