Saturn is the most visually striking planet in the Solar System. It is the second largest gas giant behind Jupiter and is surrounded by a spectacular series of rings. Saturn is the sixth furthest planet from the Sun at 1,400 million km away and is named after the Roman God Saturnus. The rings are made from icy particles and dust, Saturn has around 60 moons as well as the only moon with a stable atmosphere, Titan.

Saturn has a small core made from ice and rock with the rest of the planet being chiefly hydrogen and helium. There are thought to be liquid metallic hydrogen and liquid hydrogen and helium layers surrounding the core before the gaseous outer layers.

The inside of Saturn can reach extremely hot temperatures, with the interior temperature of 11,700 degrees C thought to be due to the Kelvin-Helmholtz mechanism of gravitational compression. The atmosphere of Saturn is not as strikingly active as the one on Jupiter, but it does display some of the same characteristics. The gases have a banded appearance and there is evidence of cloud layers and storms.

The rings of Saturn initially were a great source of confusion for early astronomers, lacking the high-powered telescopes to identify them. Galileo thought that Saturn was three bodies, but was lost for an explanation as to why the outer two would disappear only to reappear again later. It took until 1655 for Christiaan Huygens to correctly identify Saturn's rings. The rings are mainly composed of water ice and they extend from 6,630km to 120,700km from the surface.

The origin of the rings is not known for certain, with theories that they are the remnants of a moon ripped apart by tidal forces or a leftover material from Saturn's formation both being considered.

Saturn has been visited by probes during the 80s and more recently in 2004. In 1980 and 1981 the Voyager probes, 1 and 2, both performed fly-bys of the gas giant on their way out of the Solar System. They provided high quality images of the planet and its rings.

Voyager 1 flew close to Titan, obtaining more data about the atmosphere on the moon. The main probe to gather data about Saturn and its satellites was the Cassini-Huygens probe which reached the planet in July 2004. The probe gathered a lot of data on Titan including details of its lakes, coastlines and other geographical features.

The craft then released the Huygens lander which became the first craft to land on a moon other than our own. Cassini would also go on to discover liquid water erupting from geysers on the surface of Enceladus, another of Saturn's moons.

Titan dominates Saturn's moons, making up 96% of their mass. Titan is unique among the moons of the Solar System as it has an extremely thick atmosphere, not dissimilar to the one found on Venus. The atmosphere of Titan, however, has a reverse effect of Venus as it has an anti-greenhouse effect which cools the surface where Venus's atmosphere has heated the surface to scorching effect.

The Cassini-Huygens probe discovered the liquid methane lakes on Titan, the first stable bodies of liquid found on any extra-terrestrial body. There are weather systems similar to Earth in effect on Titan with rain and high winds all present. The average surface temperature is between -179 and -290 degrees C, with atmospheric pressure higher than Earth and much lower gravity.

Despite its low temperatures Titan is compared to early Earth with its high amount of organic chemical activity. The moon is thought to be one of the most likely places in the Solar System to find alien life.

The nature of gas giants means that they don't lend themselves well for direct colonisation or human visits. However in Saturn's case it may prove that Titan is an excellent place for a future colony if the low temperature and high pressures can be overcome.

Any human landing on the planet-facing side of the moon would also be treated to some of the most spectacular views in the Solar System, with Saturn and its rings taking up a large portion of the sky.