Fly us to the moon! And drive us back till midnight. Do you know why the Earth's only natural satellite has so many craters on its surface? It is due to a long history of being bombarded by meteoroids, asteroids, and comets. These objects collide with the moon's surface at high speeds, creating impact craters different in size from a few millimeters to hundreds of kilometers across. The moon does not have an atmosphere to protect it from such impacts as our planet - so it has been exposed to this constant bombardment for billions of years.