Saturn is the sixth planet from the sun and is the second largest in this solar system and is the root of the English word 'Saturday'.

Saturn's orbit is 1,429,400,000 km from the sun and it has a diameter of 120,536 km (equatorial) and mass of 5.68e26 kg.

Saturn has been known since prehistoric times. It was first observed by Galileo with a telescope in 1610. Early observations of Saturn were complicated by the fact that the Earth passes through the plane of Saturn's rings every few years as Saturn moves in its orbit.

It was not until 1659 that Christiaan Huygens correctly inferred the geometry of the rings. Saturn's rings remained unique in the known solar system until 1977 when very faint rings were discovered around three other planets Uranus, Jupiter and Nepture.

Like Jupiter, Saturn is about 75% hydrogen and 25% helium with traces of water, methane, ammonia and 'rock', similar to the composition of the primordial Solar Nebula from which the solar system was formed.

Saturn's interior is similar to Jupiter's consisting of a rocky core, a liquid metallic hydrogen layer and a molecular hydrogen layer. Traces of various ices are also present.

Saturn's interior is hot (12000 K at the core) and Saturn radiates more energy into space than it receives from the Sun.

The bands so prominent on Jupiter are  much fainter on Saturn. They are also much wider near the equator. Saturn also exhibits long-lived ovals (red spot at center of image at right) and other features common on Jupiter.

Two prominent rings and one faint ring can be seen from the Earth. The gap between the A and B rings is known as the Cassini division. The much fainter gap in the outer part of the A ring is known as the Encke Gap. There are also four additional faint rings. Saturn's rings, unlike the rings of the other planets, are very bright.

Saturn's rings are extraordinarily thin: though they're 250,000 km or more in diameter they're no more than 1.5 kilometers thick. Despite their impressive appearance, there's really very little material in the rings.

The ring particles seem to be composed primarily of water ice, but they may also include rocky particles with icy coatings.

Saturn also has some puzzling radial inhomogeneities in the rings called 'spokes' which were first reported by amateur astronomers. Their nature remains a mystery, but may have something to do with Saturn's magnetic field.

Saturn's outermost ring, the F-ring, is a complex structure made up of several smaller rings along which 'knots' are visible. Some scientists speculate that the knots may be clumps of ring material, or mini moons.

The origin of the rings of Saturn (and the other jovian planets) is unknown. Though they may have had rings since their formation, the ring systems are not stable and must be regenerated by ongoing processes, probably the breakup of larger satellites.

Saturn has a significant magnetic field.

When it is in the nighttime sky, Saturn is easily visible to the naked eye. Though it is not nearly as bright as Jupiter, it is easy to identify as a planet because it doesn't "twinkle" like the stars do. The rings and the larger satellites are visible with a small astronomical telescope.