Q: Where did the moon come from?A:...

Q: Where did the moon come from?

A: We don’t know for sure, planetary scientist David Stevenson of Caltech said, but the moon probably was formed when a large chunk of the Earth was knocked off by another astronomical body, such as a meteor. Evidence supporting this view includes the following facts: The moon, like the outer layers of the Earth, contains little iron; the moon was once molten; it lacks a dense core; and the angular momentum of the Earth and the moon, taken together, is about what one would expect from such a collision.