Impact Crater

space · geology · asteroids · moon

Smashed by space rocks. Impact craters form when asteroids or meteorites slam into a planet or moon at incredibly fast speeds. The force of the crash creates a depression in the ground, kind of like dropping a ball into mud.

Different from volcanoes. Impact craters are not the same as volcanic craters. While volcanic craters happen when a volcano explodes or collapses from inside, impact craters are made by something hitting from above and always have raised rims around the edge.

Mostly round (but not always). Most impact craters are circular in shape, but sometimes they end up elliptical or lumpy and irregular because of landslides or the angle the space rock hit at.

Huge size range. Impact craters can be microscopic tiny spots on moon rocks or enormous multi-ringed basins bigger than entire states. Meteor Crater in Arizona is a famous smaller example you can actually visit on Earth.

Moon rocks tell the story. Scientists learned about impact craters by studying rocks that astronauts brought back from the Apollo missions to the moon, which showed lots of tiny crater marks from billions of years of cosmic impacts.