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It's surface is the most reflective of all Saturn's satellites (around 100 %), and therefore very cold (72 K). It seems to be very uniform on the snapshots of Voyager 2 in 1981. With some regions hailed by craters, there are essentially wide plains striked by fractures, that seem to be a sign of geological activity that periodically reshapes the surface due to ice fusion in the core under tidal effects of Saturn and Dionea.

It's consituted essentially of ice, with rocky material that could be a source of internal heat. Its surface, revealed by Voyager 1 in 1980 presents a certain variety of dark and light teints. Big bright trails could be long fractures with young ice within it. Darker regions are certainly more ancient and craterized with some craters more than 100 km wide.

Fractures and riddles appear lightly visible on the surface of this Saturn's satellite, that is very craterized. There could be a small icy core, since the satellite's gravity is sufficient for that, and it could undergo light phase changes of the ice due to temperature variations.Ozone has been discovered in craterized zones where it is protected from the dissociation of the solar ultraviolet light.(Nature, 3 july 1997)

The biggest Saturn's satellites and the first discovered, in 1655, by Huygens. His diameter of 5150 km puts it as one of the biggest moons in the solar system, bigger than Mercury, smaller than Mars. It looks like telluric planets. With the Neptune's satellite Titan, it's one of the only moon of the solar system to own an atmosphere, that was detected for the first time in 1944 by spectroscopy.The most information were given by the probe Voyager 1, that flew to less than 5000 km from its surface on 12 november 1980. But the thick orange atmosphere hid completely the surface. The latter consists esssentially of azote and methan. Under the action of the radiance of the Sun, the photodissociation of methane and azote leads to the formation of hydrocarbonates (ethane, ethylene, acetylene ...). The so formed molecules condense above 200 km of altitude and fall slowly to the soil and create a thick and uniform haze, that is orange. The surface temperature, revealed by infrared spectrometry, is -178° C. There should be stretches of liquid methane on the surface. There are certainly droplets of hydrocarbonates and there even could be rains of methan in the atmosphere. With an average density of 1.92, Titan is considered as a melting of rocks, icy ices, methan and perhaps ammoniac. There would be a core of silicates.

Galilean Satellites

S indicates synchronous rotation - the rotation period is the same as the orbital period

Lesser Satellites

New satellites have been observed.

The count of Jupiter's satellites

Major Satellites

Lesser Satellites

New satellites have been observed. There are 60 satellites around Saturn.

The Saturn's satellites that are known

More on the satellites in the Solar System