Expert: Ed - 4/22/2006

Question
how was the moon formed

Answer
Patrick,

Astronomers think the moon was formed by the impact of a massive object with the Earth, in primordial times.  This object was probably a HUGE asteroid, or possibly even something that would have formed another planet if it hadn't hit the Earth.

Whatever it was, when it slammed into the Earth (at thousands of miles per hour) it caused gigantic quatities of rock and lava to splash out into outer space.  All this stuff gradually fell into orbit around what was left of the Earth, and eventually cooled off and became the moon.  

Look at these links for more information:
http://www.astrobio.net/news/article178.html
http://www.space.com/scienceastronomy/planetearth/moonwhack_main_000901.html

Keep Looking Up!
--Ed