NASA GSFC Scientific Visualization Studio created this animation of the Moon, showing how its phases will wax and wane over the course of 2012. Time resolution is down to the hour. The tipping and rocking are a manifestation of the Moon’s elliptical orbit coupled with its tilt. The video is captioned with more detailed explanations of what you’re seeing. But, just watch, ignore the captions and the music. (Then watch again and read the captions).