Space and Time
Size: Diameter 120,536km
Mass: 5.68x10(exp26)kg
Composition: Small rocky iron core
Mean temperature: -180 °c
Distance from Sun: 1429.39 million km
Atmosphere/weather: Mainly hydrogen and helium
Moon/satellites: At least 30
Orbital length: 10,749.2 days
Length of day: 10 hours 14 minutes
Distance from Earth: Max 1579 million km, min 1279 million km
Saturn is the sixth planet from our Sun. It is called the 'jewel of the solar system' because of its beautiful rings. It is the second largest planet in the solar system.
In 1610, Italian Galileo Galilei was the first astronomer to gaze at Saturn through a telescope. To his surprise, he saw a pair of objects on either side of the planet, which he later drew as 'cup handles' attached to the planet on each side. In 1659, Dutch astronomer Christiaan Huygens announced that this was a ring encircling the planet. In 1675, Italian-born astronomer Jean Dominique Cassini discovered a gap between what are now called the A and B rings. |
A storm, seen as a pale area, raging on Saturn
Like the other giant planets - Jupiter, Uranus and Neptune - Saturn is a gas giant made mostly of hydrogen and helium. Its volume is 755 times greater than Earth's. Winds in the upper atmosphere reach 500 meters per second in the equatorial region. (In contrast, the strongest hurricane-force winds on Earth top out at about 110 meters per second.) These super-fast winds, combined with heat rising from within the planet's interior, cause the yellow and gold bands visible in its atmosphere.
Saturn's ring system is the most extensive and complex in our solar system. It extends hundreds of thousands of kilometres from the planet. In fact, Saturn and its rings would just fit in the distance between Earth and the Moon.
A false-colour image of Saturn's rings.
In the early 1980s, NASA's two Voyager spacecraft revealed that Saturn's rings are made mostly of water ice. They found 'braided' rings, ringlets, and 'spokes' - dark features in the rings that seem to circle the planet at a different rate from that of the surrounding ring material. Some of the small moons orbit within the ring system as well. Material in the rings ranges in size from a few micrometers to several tens of meters.
Montage of Saturn and several of its satellites, Dione, Tethys, Mimas, Enceladus, Rhea, and Titan.
Saturn has at least 30 satellites. The largest, Titan, is a bit bigger than the planet Mercury. Titan is shrouded in a thick nitrogen-rich atmosphere that might be similar to what Earth's was like long ago. Further study of this moon promises to reveal much about planetary formation and, perhaps, about the early days of Earth as well.
In addition to Titan, Saturn has many smaller 'icy' satellites. From Enceladus, which shows evidence of surface changes, to Iapetus, with one hemisphere darker than asphalt and the other as bright as snow, each of Saturn's satellites is unique.
NASA's Cassini-Huygens spacecraft is currently studying Saturn, after a seven-year journey. Find out more at the NASA project web-pages [opens new window].
Iapetus, with its highly contrasted hemispheres
In Roman mythology, Saturn is the god of agriculture. The associated Greek god, Cronus, was the son of Uranus and Gaia and the father of Zeus (Jupiter). Saturn is the root of the English word 'Saturday'.
Titan, Saturn's largest moon.
Images, information and videos courtesy of NASA.