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Saturn

Saturn during Equinox

Color image of Saturn created from images taken by Cassini in 2008. Image credit: NASA/JPL/Space Science Institute

Saturn is the 6th planet from the Sun with an average distance of 9.572 AU or 1.432 x 109 km. It takes 29.37 Earth years to orbit the Sun, and rotates very quickly at a rate of 1 rotation every 10 hours 13 minutes and 59 seconds. It is the second largest planet in the Solar System with a mass of 5.685 x 1026 kg or 95.16 Earth masses. It has 63 confirmed and named moons, and a further 20 moons awaiting confirmation of discovery. The average temperature of Saturn at the cloudtops is about 93 K (−180 °C or −292 °F).

Saturn is the most distant of the planets that can easily be seen with the naked eye. It is famous for its prominent ring system, discovered by Galileo. The rings of Saturn are 250,000 km wide, but only a few tens of meters thick and are comprised of individual particles of mostly water ice. When Galileo first observed them in 1610, he believed them to be two moons on either side of Saturn. Saturn is the most oblate (flattened sphere) of all the gas giants, with a nearly 10% difference between its equatorial and polar radii. Titan is the only moon in the Solar System known to have a dense atmosphere and the only place other than Earth to have liquid on its surface. It is believed to be similar to what a very young Earth was like, and one of the very few places that has the potential for life. Saturn has a magnetic field slightly weaker than Earth's.

Saturn has been visited by several spacecraft including Pioneer 11, Voyager 1, Voyager 2, and Cassini

Saturn Factbox
Average distance from Sun 9.572 AU = 1.432 x 109 km = 3,725 Earth - Moon distances
Number of moons 63
Average orbital speed 9.64 km/s
Orbital period 29.37 years
Rotation period 10h 13m 59s
Inclination of equator to orbit 26.73°
Diameter 120,536 km = 9.449 Earth diameter
Mass 5.685 x 1026 kg = 95.16 Earth masses
Average density 687 kg/m3
Surface gravity (Earth = 1) 0.92
Albedo 0.46
Average temperature at cloudtops -180°C = -292°F = 93 K
Atmosphere 96.3% hydrogen, 3.3% helium, 0.4% methane, ammonia, water vapor and other gases