Saturn, the sixth planet from the Sun, has beautiful rings composed of ice particles. It is the second largest planet in the Solar System, yet it is the least dense - it would float in water if there were a bathtub large enough to hold it.
Saturn is mainly composed of hydrogen and helium and does not have a solid surface. It has 25 satellites that measure at least 10km in diameter - the largest, Titan, is the only moon in the Solar System with a substantial atmosphere.
Saturn's interior is thought to contain fluid metallic hydrogen - a substance that cannot be studied directly because it is not possible to recreate the very high temperatures and pressures at which it is predicted to form.
Photo: Saturn taken by the Cassini probe (NASA/JPL/Space Science Institute)
The ringed planet is a complex world.
The early Solar System was a shooting gallery.
Professor Brian Cox explains how the orbiting gas giants may have caused an enormous asteroid and comet bombardment in the inner Solar System 3.6 billion years ago. Earth and the other planets were peppered by asteroids and comets.
Spectacular ice fountains on one of Saturn's moons blast up into space.
Professor Brian Cox explores geysers in Iceland and discovers how the ice fountains on Saturn's moon Enceladus get their power.
Learn how to remember all the planets of the Solar System in order.
Here’s an animated guide to remembering all the planets of the Solar System in order, using an easy mnemonic trick.
The world sees Saturn's intricate rings up-close for the first time.
Voyager 2 showed the world Saturn's intricate rings up-close for the first time. Strange features like shepherd moons and spokes gave researchers plenty to think about. The Voyager probes were launched in 1977.
Enjoy Astronomer Marek Kukula's guide to the Solar System.
If Jupiter were much larger it would be a star in its own right! Enjoy Astronomer Marek Kukula's eloquent guide to the Sun, the planets and the outer reaches of the Solar System.
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Named after the Roman god of agriculture, its astronomical symbol (♄) represents the god's sickle. Saturn is a gas giant with an average radius about nine times that of Earth. While only one-eighth the average density of Earth, with its larger volume Saturn is just over 95 times more massive.
Saturn's interior is probably composed of a core of iron, nickel and rock (silicon and oxygen compounds), surrounded by a deep layer of metallic hydrogen, an intermediate layer of liquid hydrogen and liquid helium and an outer gaseous layer. The planet exhibits a pale yellow hue due to ammonia crystals in its upper atmosphere. Electrical current within the metallic hydrogen layer is thought to give rise to Saturn's planetary magnetic field, which is weaker than Earth's magnetic field but has a magnetic moment 580 times that of the Earth due to Saturn's larger body radius. Saturn's magnetic field strength is around one-twentieth the strength of Jupiter's. The outer atmosphere is generally bland and lacking in contrast, although long-lived features can appear. Wind speeds on Saturn can reach 1,800 km/h (1,100 mph), faster than on Jupiter, but not as fast as those on Neptune.
Saturn has a prominent ring system that consists of nine continuous main rings and three discontinuous arcs, composed mostly of ice particles with a smaller amount of rocky debris and dust. Sixty-two known moons orbit the planet; fifty-three are officially named. This does not include the hundreds of "moonlets" comprising the rings. Titan, Saturn's largest and the Solar System's second largest moon, is larger than the planet Mercury and is the only moon in the Solar System to retain a substantial atmosphere.