quote:The moon formed after a nasty planetary collision with young Earth, yet it looks odd next to its watery orbital neighbor. Turns out it really is odd: Only about one in every 10 to 20 solar systems may harbor a similar moon.
There is also a good video link on how the moon was formed. I find it interesting that the authors support the planetary impact theory as the origin of the Earth's moon; I know of many scientists who are not yet convinced of the origin of our moon, even after 6 lunar landings and numerous remote sensing satellite missions.