Read this very interesting article that details the history that our Moon and the asteroids share. In particular, the asteroid Vesta, which was recently visited by the Dawn spacecraft, has a significant part to the story.
Scientists studied the rocks returned from the Moon by the Apollo astronauts and the recovered meteorites that are thought to have originated from Vesta.
What a combination - the Moon and meteorites! Read More About It: http://www.jpl.nasa.gov/news/news.php?release=2013-114
Sky Guy in VA