Complete with a rock-identifying infrared sensor, Spirit is the first space-venturing robot to cut into stone, inspect the inside of a rock, and perform microscopic examinations of soil and rock on a planet other than Earth.
The rover uses its spectrometers and a rock abrasion tool to detect minerals and elements in rocks and soils. Soil deposits are especially good markers of recent environmental conditions. Planetary scientist Ray Arvidson, one of the rover researchers, describes the geology that Spirit investigates: “The caprock on the plains is volcanic basalt. It has been broken up by impact cratering, and then wind-blown materials have accumulated into a mantle of soil.” Spirit’s first target is Adirondack (pictured), a football-sized rock that scientists deem a “time capsule,” since probing it has brought to light past geological conditions of the Martian surface.