The Moon!

Visualize the phases of the moon with this video.



Why do we always see the same side of the moon even though it rotates? Watch this video to find out.



If you have trouble grasping the concept do this: Take an object (I used a styrofoam cup because it was close at hand)and place a mark on it. Hold it out to the side with the mark facing you. Orbit it around in front of you keeping the mark always facing the same direction. The mark needs to always face the same place. You will see different sides of the object. Do it again but rotate it enough to keep the mark always facing you. Yolu will find that the object will spin once in one rotation.