Tethys is one of Saturn's larger inner moons with a diameter of 1050 km. The moon lies at a distance of 295,000 km from Saturn. It orbits the planet in 1.8 days. The density is 1.3 much the same as with the other moons.

     The surface of Tethys is covered with cracks and craters. The cracks are probably from cooling and shrinking of the surface or meteoritic impacts. The largest impact, which is 2/3 the diameter of the moon, is Odysseus.

     Another prominent surface feature on Tethys is a large canyon called Ithaca Chasma. It is probably associated with the Odysseus impact crater. This great canyon stretches 3/4 the way around Tethys.

     Some areas on Tethys are much less heavily cratered and this could mean that at some point there was geologic activity on the surface.