Saturn
Planet
Facts
- Diameter
- 120,536 km
- Mean distance from the Sun
- 1.43 billion km
- Orbital period
- 29.4 years
- Rotation
- 10.7 hours
- Rings
- up to 282,000 km from the planet
- Thickness of the main rings
- about 10 m
Saturn is the sixth planet from the Sun, famous for its system of rings made of billions of pieces of ice and rock. It is the only planet with an average density lower than water's. It is named after the Roman god of farming and wealth, the father of Jupiter.
At the north pole a jet stream traces a hexagon, and at the equator the winds of the upper atmosphere reach 500 m/s. Its moon Titan, wrapped in haze, has lakes of methane.
In 1610 Galileo saw the rings through his telescope but took them for a “triple planet”. In 1655 Christiaan Huygens discovered the rings and Titan, and in 1675 Giovanni Domenico Cassini the division between what are now called the A and B rings.
Pioneer 11 was the first probe to reach Saturn, in 1979, followed by Voyager 1 and 2. Cassini was the first to orbit it: it arrived in 2004 and ended its mission on 15 September 2017 by diving into the planet's atmosphere.