InSight's Mars landing team deliberately chose a landing region in Elysium Planitia that is relatively free of rocks. Even so, the landing spot turned out even better than they hoped. The spacecraft sits in what appears to be a nearly rock-free "hollow" — a depression created by a meteor impact that later filled with sand. That should make it easier for one of InSight's instruments, the heat-flow probe, to bore down to its goal of 16 feet (5 meters) below the surface.