Craters are the most common surface features on many solid planets and moons—Mercury and our Moon are covered with craters. This portion of the Moon is covered by numerous circular holes. These are impact craters, each of which was formed when an asteroid or comet collided with the Moon's surface.

The moon is a natural satellite of the Earth. It revolves round the earth in a definite regular path. The moon is about one fourth the size of the Earth and its weight is about one eighth of our Earth. Its surface is covered with hard and loose dirt, craters and mountains.

Lunar Sightseeing Smooth-looking patterns of gray and white resolve into craters and large mountain ridges. You'll be able to tell where the Moon is relatively undisturbed and where it's been pockmarked by impacts.

Lunar impact craters come in three basic types: simple craters, complex craters, and basins.

There are three distinct crater types: simple craters, complex craters, and multi-ring basins (Fig. 6.1).

While the craters, highlands and maria are the moon's three main landforms, the moon's surface has a number of other highly visible features.

Moon craters are holes on the surface of the moon caused by the impact of meteoroids. The moon is an easy target for these space rocks because it has no atmosphere to protect it. Some craters have light streaks of debris stretching out from their center called rays.