Having a radius of about 60,000 kilometers, Saturn is the second largest planet in our Solar System. It is also the remotest planet that can be seen with the naked eye. Until 1781 it was thought to be the outermost planet. From the time when the telescope was invented, a conspicuous system of rings has been observed around Saturn, which is why it is also known as the ‘ringed planet‘. Being about twice as far away from the Sun as Jupiter, Saturn takes nearly 30 years to complete an orbit. Every 20 years, Jupiter and Saturn appear quite close together to observers on Earth as a particularly distinctive bright light in the night sky. This close constellation is occasionally quoted as a plausible explanation for the famous Star of Bethlehem.
Its gravitational force, which is equal to that of 95 Earth masses, enables Saturn – like Jupiter – to divert comets from their paths and entrap them in its ‘family‘. Saturn‘s structure resembles that of Jupiter, although it is assumed that its outer, comparatively lightweight shell of hydrogen and helium extends to a much. Read more...

Saturn is surrounded by 18 moons that have been known for some time: Pan, Atlas, Prometheus, Pandora, Epimetheus, Janus, Mimas, Enceladus, Tethys, Telesto, Calypso, Dione, Helene, Rhea, Titan, Hyperion, Iapetus and Phoebe. Another 42 smaller moons have been discovered so far, either by Cassini or by observers on Earth using a telescope.
Titan, Saturn‘s largest moon, is the only satellite in the Solar System that possesses a dense, extensive atmosphere. Its color is reddish-orange. Titan‘s atmosphere consists mainly of nitrogen augmented by traces of methane, ethane, acetylene, propane, diacetylene, methyl acetylene, hydrogen, cyanide and cyanoacetylene as well as carbon dioxide and monoxide. Titan and Earth are the only bodies in the Solar System whose atmosphere consists mainly of nitrogen. Being opaque, it obscures our view of the surface. Read more...

The exploration of the Saturnian system by the Cassini spacecraft has yielded a collection of new data about the planet and its rings and moons, including the icy satellite Enceladus. Enceladus has been found to be one of the most geologically active objects in the Solar System and has raised major questions in understanding the evolution and dynamics of small and mid-sized icy satellites. It is thus among the priority targets for Cassini''s extended mission.
As already revealed by Voyager data (Smith et al. 1981), its surface is very heterogeneous, displaying young, tectonically modified terrain, as well as old, heavily cratered surface areas. The youngest features, including the "tiger stripes", roughly parallel lineaments about 500m deep, 2 km wide, ~ 130 km in length and flanked by about 100-m-high ridges, are found in the south-pole region (Porco et al., 2006). An outstanding discovery of the Cassini mission was the detection of venting plumes composed of gas and dust, emanating from the south pole region of Enceladus, the sources of which are probably correlated with the location of the tiger stripes. Furthermore, the vigorous activity near the south-pole is associated with strong thermal activity, which is completely unexpected for such a small satellite. Read more....