The solar system is a spirograph!

[Mike]

Very very cool orbital animations below. Check it out! I've always known that Cruithne (usually billed as Earth's "second moon") orbited Earth in a weird kidney bean shaped orbit, but I've always been vague on the how/why of it. This video explains it perfectly. Cruithne doesn't "orbit" Earth at all. It orbits the sun, but it has the same year as Earth so... oh, just watch the video. So much better than words.

[Phoebe]

GOOD Video

[Stan]

Beautiful.

The first part demonstrates why people stuck with a geocentric assumption had such complex formulas for predicting locations.