2THE “EGYPTIAN” SYSTEM. The orbits are not to scale, of course, but the rotational periods are proportionally accurate. The Earth completes one “year” in 20 seconds, while Mercury revolves in 4.8 seconds and Saturn in 590 seconds.

The “Egyptian System”: Geocentric. Mercury and Venus orbit the Sun, which, together with Mars, Jupiter, and Saturn, orbits the Earth.

This demo uses the rotation.css stylesheet to position the “fixed stars” around the solar system; no other elements require it.

1. Ptolemaic System • “Egyptian” System • 3. Tychonic System • 4. Copernican System