These are some cool videos on how our moon may have been made and what makes it look the way it does.
http://www.youtube.com/watch?feature=player_detailpage&v=L8dXIxZzBMk
http://www.youtube.com/watch?feature=player_detailpage&v=2iSZMv64wuU
The Moon is thought to have formed nearly 4.5 billion years ago, not long after the Earth. Although there have been several hypotheses for its origin in the past, the current most widely accepted explanation is that the Moon formed from the debris left over after a giant inpack between Earth and a Mars sized body.