When we look at the moon, either through a pair of binoculars, a telescope, or past footage from the Apollo missions, we see a landscape that's riddled with what appear to be massive sinkholes. But these "sinkholes" aren't just on the moon, as they are evident on nearly every planetary body throughout the solar system, from planets, to other moons, to asteroids. They are called impact craters and can range in size from cities to small countries.