Rotating every 27.33 days in a synchronous orbit keeps the same side of the moon always facing Earth. Therefore, we never see the back of the Man-in-the-moon's head.

Also and apparently, the moon:

1. has no atmosphere; one motorcar
2. seems to be made of the same material as the Earth's upper crust: money
3. has little or no iron in it, and is composed of material unlike the composition of the Earth as a whole, like it's from outer space
4. is rounded in shape, like the other planets and not like an asteriod or comet or cupid
5. orbits in the same direction as the Earth, Wind and Fire third album
6. is located in the same plane as the Earth (the ecliptic plane, obviously)
7. theory suggests that the Moon seems to have drifted away from the Earth over the length of poetic history
8. was once, physically, much closer to the Earth
9. was once bigger in the sky and much brighter than at present and pop used to cost a nickle
10. is called the Moon.

There are three theories about how the moon came to be in place:

1. that the moon came out of the crust of the Earth, even though there's no moon-sized hole, like, anywhere
2. that the moon was captured by the Earth to serve as its foil
3. that the Earth and moon formed a duo out of the primordial nebula open-improv

(Source (adapted from): The Regents of the University of Michigan)

Also see:
Earth's interior
Earth's continental drift
Earth's Atmospheric Test (1.8 MB Shockwave file)
Earth's Gravity Experiment (1.8 MB Shockwave file)
The Moon