Saturn (astronomy)

Sixth planet from the Sun, and the second-largest in the Solar System, encircled by bright and easily visible equatorial rings. Viewed through a telescope it is ochre. Its polar diameter is 12,000 km/7,450 mi smaller than its equatorial diameter, a result of its fast rotation and low density, the lowest of any planet. Its mass is 95 times that of the Earth and its magnetic field 1,000 times stronger.

Mean distance from the Sun
1.427 billion km/0.886 billion mi

Equatorial diameter
120,000 km/75,000 mi

Rotational period
10 hours 14 minutes at equator, 10 hours 40 minutes at higher latitudes

Year
29.46 Earth years

Atmosphere
visible surface consists of swirling clouds, probably made of frozen ammonia at a temperature of -170°C/-274°F, although the markings in the clouds are not as prominent as Jupiter's. The Voyager probes, visiting in 1980 and 1981, found winds reaching 1,800 kph/1,100 mph

Surface
Saturn is believed to have a small core of rock and iron, encased in ice and topped by a deep layer of liquid hydrogen

Satellites
as of 2005, 49 moons were known, more than for any other planet. The largest moon, Titan, has a dense atmosphere

Rings
the rings visible from Earth begin about 14,000 km/9,000 mi from the planet's cloudtops and extend out to about 76,000 km/47,000 mi. Made of small chunks of ice and rock (averaging 1 m/3.3 ft across), they are 275,000 km/170,000 mi rim to rim, but only 100 m/300 ft thick. The Voyager probes showed that the rings actually consist of thousands of closely spaced ringlets, looking like the grooves in a gramophone record. In 2004 a new ring around Saturn was reported by astronomers. They detected a 300-km/186-mi-wide dust ring located 1,200 km/746 mi beyond the main ring system of Saturn, between the A and the F rings.