Laser identification

Different elements, such as aluminum and copper, and rock types, like basalt, give off their own color of light when zapped by a laser.

Unlike previous missions to Mars, which required the rather laborious and time-consuming task of approaching a rock, brushing away dust, and grinding away outer layers to take a measurement of the composition, ChemCam’s laser removes the need to physically touch the rock. It allows ChemCam to determine a rock’s composition from a distance of up to 7 meters On average, the ChemCam team expects to take approximately one dozen compositional measurements of rocks per day.