Hippopede of Eudoxos

This is the final part of the solarsystem book. It shows a model for the solar system from the ancient greeks, published by the not so famous Eudoxos of Knidos. He tried to simulate the opposition loops by constructing 3 rotating spheres with different orientation and spin direction. The stationary loop is a so called hippopede and can also be constructed by the intersection of a sphere and a cylinder, as illustrated in this applet. Thank you for going through the whole series!