Home > Encyclopedia of Science > Saturn

• Saturn's rings
• Saturn's moons
• Cassini mission to Saturn

Saturn, the sixth planet from the Sun, is named for the Roman god of agriculture, who was based on the Greek god Cronus. The second largest planet in the solar system, it measures almost 75,000 miles (120,600 kilometers) in diameter at its equator. Despite its large size, Saturn is the least dense of all the planets. It is almost 30 percent less dense than water; placed in a large-enough body of water, Saturn would float.

Saturn completes one rotation on its axis very quickly, roughly 10.5 Earth hours. As a result of this spinning, the planet has been flattened at its poles. The measurement around its equator is 10 percent greater than the measurement around the planet from pole to pole. In contrast to the length of its day, Saturn has a very long...