Mars surface seen during the descent of the Mars Exploration Rover Spirit's lander to the planet's surface on 4 January 2004. The large crater at far right is the Gusev Crater, a 145- kilometre-wide crater, in which the rover landed. Numerous other smaller craters are also seen. This image was taken by the Descent Image Motion Estimation System (DIMES) camera on the bottom of the lander at an altitude of 1690 metres. Images taken by this camera aided onboard software as it decreased the lander's speed during its descent to Mars.