This is the LEGO orrery (a mechanical model of the solar system, or just the earth, moon and sun) built by LEGOManiac Jason Allemann (of LEGO labyrinth fame). It's surprisingly accurate too, considering its size and the fact it was made out of plastic LEGO bits. I probably couldn't built a more accurate orrery even if I was given free reign of a watchmaker's shop and wasn't just tempted to build myself a mechanical son.
The Earth spins on it's axis, mimicking each day. The moon orbits the Earth once every 28 "days", and the Earth-Moon system makes a full rotation around the sun once every 375 days, slightly more than the 365 (or 366) day years we normally have.
Most impressive. I've never built an orrery before but I did make a model of our solar system out of painted Styrofoam balls and hang it from a coathanger. I got a purple participation ribbon in the science fair. I had this plan where I would get the judges to judge my project first then I'd set off a stink bomb so they wouldn't be able to judge any of the other projects and I'd win by default but I accidentally set off the stink bomb in my pocket on the ride to the fair and my mom grounded me for a month and my pants smelled so bad nobody would sit with me at lunch and I lost all my friends, the end.
Keep going for a video of the orrery in action.
Thanks to Pop, who should get hopped on like in the Dr. Seuss book.