As the Earth flies through space in its celestial dance around the sun, it's accompanied by its perpetual partner, the moon.

Scientists have proposed a shocking new theory for the origin of the moon, and their calculations suggest Earth once had a secret world hiding right next door. Astronomers believe that the moon was ...

It’s a general rule in science that the more you know about some aspect of the natural world, the better you understand it. But rules are sometimes broken, and the question of how Earth got its Moon ...