Moon Craters Craters are the scars leftover when something hits an object in space.

There is a lot of “stuff” floating around in space, and gravity pulls everything together. The primary things floating around are comets, made of ice and dirt, and rocks made of stone and iron.

On the Moon we see tons of craters, yet on Earth we see few. You would expect Earth to be hit by more things, because the bigger Earth has 6 times the gravity of the Moon.

Two factors can explain this lack of craters on Earth. First, the Earth has an atmosphere, where the Moon has none. Small rocks falling towards us heat up, and burn up due to friction with our air. These same rocks would hit the Moon and leave a crater.

The second reason you see so many craters on the Moon and few on Earth is we have wind, liquid water and plate tectonics which erode and change the surface of the Earth, erasing craters.

Different terms apply to different things falling toward Earth. Meteor: any small object burning up in our atmosphere. A shooting star is the same thing.

A meteoroid is a small rock floating around in space. An asteroid is a big one.

A meteorite is a rock on Earth that came from space.

A comet is a big chunk of ice and dirt orbiting the Sun.

Mare

Crater Features Crater wall Central Peak

Rays

You can tell the relative age of craters by how they overlap