< * >
Montage of Saturn and several of its satellites, Dione, Tethys, Mimas, Enceladus, Rhea, and Titan.

Saturn and its satellites
Saturn has 18 officially recognized and named satellites. In addition, there are other unconfirmed satellites. One circles in the orbit of Dione, a second is located between the orbits of Tethys and Dione, and a third is located between Dione and Rhea. The unconfirmed satellites were found in Voyager photographs, but were not confirmed by more than one sighting. Recently, the Hubble Space Telescope imaged four objects that might be new moons. Several generalizations can be made about the satellites of Saturn. Only Titan has an appreciable atmosphere. Most of the satellites have a synchronous rotation. The exceptions are Hyperion, which has a chaotic orbit, and Phoebe. Saturn has a regular system of satellites. That is, the satellites have nearly circular orbits and lie in the equatorial plane. The two exceptions are Iapetus and Phoebe. All of the satellites have a density of < 2 gm/cm3. This indicates they are composed of 30 to 40% rock and 60 to 70% water ice. Most of the satellites reflect 60 to 90% of the light that strikes them. The outer four satellites reflect less than this and Phoebe reflects only 2% of the light that strikes it. The following table summarizes the radius, mass, distance from the planet center, discoverer and the date of discovery of each of the confirmed satellites of Saturn:
                 Radius       Mass         Distance
Moon       #     (km)         (kg)           (km)     Discoverer       Date
--------------------------------------------------------------------------
Pan        XVIII 9.655          ?          133,583    M. Showalter     1990
Atlas      XV    20x15          ?          137,640    R. Terrile       1980
Prometheus XVI   72.5x42.5x32.5 2.7e+17    139,350    S. Collins       1980
Pandora    XVII  57x42x31       2.2e+17    141,700    S. Collins       1980
Epimetheus XI    72x54x49       5.6e+17    151,422    R. Walker        1966
Janus      X     98x96x75       2.01e+18   151,472    A. Dollfus       1966
Mimas      I     196            3.80e+19   185,520    W. Herschel      1789
Enceladus  II    250            8.40e+19   238,020    W. Herschel      1789
Tethys     III   530            7.55e+20   294,660    G. Cassini       1684
Telesto    XIII  17x14x13       ?          294,660    B. Smith         1980
Calypso    XIV   17x11x11       ?          294,660    B. Smith         1980
Dione      IV    560            1.05e+21   377,400    G. Cassini       1684
Helene     XII   18x16x15       ?          377,400    Laques-Lecacheux 1980
Rhea       V     765            2.49e+21   527,040    G. Cassini       1672
Titan      VI    2,575          1.35e+23   1,221,850  C. Huygens       1655
Hyperion   VII   205x130x110    1.77e+19   1,481,000  W. Bond          1848
Iapetus    VIII  730            1.88e+21   3,561,300  G. Cassini       1671
Phoebe     IX    110            4.0e+18    12,952,000 W. Pickering     1898
Possible New Satellites of Saturn