Planet Saturn 3D Screensaver - Version 1.0 Saturn is a large gas planet with an atmosphere composed of hydrogen and helium. It has the lowest density of any planet in our solar system. In fact its density is so low that it would float if it was placed in water! Visually, Saturn is flattened at the poles, due to the quick rotation on its axis. The winds in its atmosphere reach speeds up to 1700 kilometers per hour! Saturn is known for its extensive ring system which is formed by a thousand individual rings. They are mainly composed of water ice and dust. Planet Saturn 3D Screensaver is an extraordinary 3D representation of this fascinating ringed planet.