Saturn
Gas Giant
Distance from Sun
1.434 B km
Orbital Period
29.46 years
About Saturn
Saturn is the sixth planet from the Sun and the second-largest in our solar system. Adorned with a dazzling system of icy rings, Saturn is arguably the most visually spectacular planet. Like Jupiter, it is a gas giant composed mainly of hydrogen and helium, but it is notably less dense. In fact, Saturn is the only planet in our solar system whose average density is less than water.
Saturn's atmosphere exhibits a banded pattern similar to Jupiter's, though with more muted colors in shades of gold, cream, and tan. Beneath the visible cloud deck, pressures and temperatures increase dramatically. Deep inside, hydrogen is compressed into a metallic liquid state, surrounding a dense core of rock, ice, and heavier elements estimated to be 9 to 22 times the mass of Earth.
The planet's magnificent ring system extends from about 6,630 km to 120,700 km above Saturn's equator. The rings are composed of countless particles of ice and rock ranging in size from tiny grains to chunks as large as houses, all orbiting Saturn in an incredibly thin plane relative to their enormous breadth.
Key Facts
- Saturn's rings, while extending up to 282,000 km in diameter, are remarkably thin, averaging only about 10 meters thick.
- Saturn could float in water if you found a bathtub big enough; its average density is 0.687 g/cm³, less than water.
- Winds on Saturn can reach up to 1,800 km/h near the equator, among the fastest in the solar system.
- Saturn has a bizarre hexagonal storm pattern at its north pole, each side spanning about 13,800 km, wider than Earth's diameter.
- Titan, Saturn's largest moon, is the only moon in the solar system with a dense atmosphere and surface liquid (methane and ethane lakes).
- Enceladus, another moon of Saturn, has geysers shooting water ice into space from a subsurface ocean, making it a prime candidate for extraterrestrial life.
- Saturn's ring system includes the Cassini Division, a 4,800 km wide gap between the A and B rings caused by the gravitational influence of the moon Mimas.
Exploration History
Pioneer 11 (1979)
First spacecraft to fly past Saturn, passing within 20,000 km and discovering the F ring and a new moon.
Voyager 1 (1980)
Provided detailed images of Saturn's rings and moons, discovering complex ring structures and several new moons.
Voyager 2 (1981)
Studied Saturn's atmosphere temperature and density profiles and returned detailed images of the ring system.
Cassini-Huygens (2004-2017)
Orbited Saturn for 13 years. The Huygens probe landed on Titan in 2005. Cassini discovered ocean worlds (Enceladus), mapped the rings, and ended with a Grand Finale plunge into Saturn.
Dragonfly (planned ~2034)
NASA rotorcraft lander that will explore Titan's surface, flying to dozens of locations to study prebiotic chemistry and habitability.
Saturn's moon Titan is so cold (-179 °C) that water ice behaves like rock, and liquid methane carves rivers, fills lakes, and falls as rain. If you could stand on Titan's surface, the atmosphere is dense enough and gravity low enough that you could strap on wings and fly by flapping your arms.