Moon Craters

Craters appear on most bodies on the Solar system and primarily stem from the period of bombardment from between 3 and 4 billion years ago. Only very few of the Moon's craters are candidates for a volcanic origin.

Tycho and Copernicus are the 'source' for bright rays.The longest ray from Tycho can be seen more than halfway across the disk. These rays are best seen at Full Moon.

Copernicus wa formed 900 million years ago, probably by a small body about 5 km in diamtere stiking at between 10-30 km/sec. The crater was probably formed within less than two minutes.