Saturn

    Saturn is the sixth planet from the Sun and is the second largest. Its diameter is 120,563km and the mass is 5.68e26kg. Saturn is the least dense of the planets. 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 has a very complex ring system in addition with 31 moons.

The Core

    Saturn's interior is hot (12000 K at the core) and Saturn radiates more energy into space than it receives from the sun. Saturn's interior consists of a rocky core, a liquid metallic hydrogen layer and a molecular hydrogen layer. Traces of various ices are also present.

The Rings

      Saturn's rings are extraordinarily thin: though they're 250,000 km or more in diameter they're less than one kilometer thick. Despite their impressive appearance, there's really very little material in the rings, if the rings were compressed into a single body it would be no more than 100 km across. The ring particles seem to be composed primarily of water ice, but they may also include rocky particles with icy coatings. Two prominent rings and one faint ring can be seen from the Earth. The gap between the two prominent rings is known as the Cassini division. The much fainter gap in the outer part of those rings is known as the Encke Division. Saturn's rings, unlike the rings of the other planets, are very bright.

    Saturn's outermost ring is a complex structure made up of several smaller rings along which "knots" are visible. Scientists think that the knots may be clumps of ring material, or mini moons. The origin of the rings of Saturn 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's Moons

Saturn has many moons up to 31, some of them are: Pan, Atlas, Prometheus, Pandora, Epimetheus, Janus, Mimas, Enceladus, Tethys, Telesto, Calypso, Dione, Helene, Rhea, Titan, Hyperion, and Iapetus. Most of its moons are very small but only few are big. Some moons orbit around the planet's rings which helps to keep the rings in place. These are called Shepard Moons.

Tethys

    Tethys has an enormous trench named Ithaca Chasma that is about 65 kilometers (40 miles) wide and several kilometers deep. It covers three-fourths of Tethys' circumference. The fissure is about the size scientists would predict if Tethys were once fluid and its crust hardened before the interior. Another prominent feature is an enormous 400-kilometer impact basin named Odysseus. The impact scar spans more than two-fifths of the satellite with a diameter slightly larger than Saturn's moon Mimas. When Odysseus was first created, the crater must have been deep with a high mountainous rim and towering central peak. Over time the crater floor relaxed to the spherical shape of the Tethys's surface, and the crater's rim and central peak collapsed. Tethys' surface temperature is -187° C (-305° F).

    Early in the history of Tethys, an impact occurred forming an enormous 400-kilometer impact basin named Odysseus.  When Odysseus was first created, the crater must have been deep with a high mountainous rim and towering central peak. Over time the crater floor relaxed to the spherical shape of the Tethys' surface, and the crater's rim and central peak collapsed. Tethys' interior may have even been liquid. If Tethys had been colder and more brittle at the time of impact, the moon may have been shattered.

Titan

     Titan is the largest moon orbiting Saturn, and the second largest moon in the Solar System. It is bigger in diameter then both the planets Mercury and Pluto. Titan's surface temperature appears to be about -178°C (-289°F). It contains an atmosphere far thicker than that of Earth. The atmospheric pressure near the surface is about 1.6 bars, 60 percent greater than Earth's. Titan's air is predominantly made up of nitrogen with other hydrocarbon elements which give Titan its orange hue. These hydrocarbon rich elements are the building blocks for amino acids necessary for the formation of life.

Iapetus

    Iapetus is made up of entire water ice. Most of Saturn's moons orbit the planet in the same way, the way of the equator but Iapetus does not follow the same path as the other moons. Instead, it orbits Saturn from top to bottom.

    Iapetus is one of the stranger moons of Saturn. Its leading side is dark with a slight reddish color while its trailing side is bright. The dark surface might be composed of matter that was either swept up from space or oozed from the moon's interior. The dark material might be a thin layer of organic material perhaps similar to the complex substances found in the most primitive meteorites. The dark material may have originated from Phoebe (another of Saturn's moons), which has a very low albedo. Micrometeor impacts could kick dark matter off Phoebe which is then swept up by Iapetus. The fact that the material is on the leading hemisphere seems to support this theory. On the other hand, the dark material seems to be concentrated in crater floors. This would indicate an internal origin. Since Iapetus is so far from Saturn, it may have formed with methane or ammonia ice in its interior. The dark material could be explained by eruptions of methane from its interior. This theory is supported by a dark ring of material about 100 kilometers (62 miles) in diameter that straddles the border between the leading and trailing hemispheres of Iapetus. Such rings formed on the Moon and on Mars when dark volcanic material flowed into impact craters and filled around the central peak.

Mercury         Venus         Earth         Mars         Jupiter         Saturn         Uranus         Neptune         Pluto