This Demonstration shows the kinematic equivalence of three world systems: geocentric (Ptolemaic system), heliocentric (Copernican system), and "areocentric" (with Mars at the center). Select the orbital center by clicking the astronomical symbol under "stationary", and then let time flow to see the orbits of other celestial bodies from the chosen viewpoint. Adjust the perspective by zooming toward the center of the celestial sphere and changing the viewing angle to obtain a realistic night sky vision of planetary motion. The "Earth-Sun-Mars relative positions" box down/left (not a control) lets you check that the relative positions of the three bodies are the same regardless of the viewpoint.
The stars chosen in the zodiacal constellations and the way they are connected is taken from "Advanced Celestial Sphere" from the Wolfram Demonstrations Project, contributed by Jim Arlow and based on a program by Jeff Bryant.