(See the Tethys Gallery)
Tethys is a Greek titan and daughter of Uranus and Gaia. She gave birth to and oversaw the major rivers in the world. Discovered in 1684, Tethys was one of four moons discovered by Cassini (Dione, Rhea & Iapetus).
Similar to Dione and Rhea, Tethys is made mostly of water ice and has a low density (~0.973g/cm3). There is a huge crater on the western hemisphere named Odysseus. With a 400km diameter it covers 40% of the moon. Ithaca Chasma is a chasm that stretches three quarters the way around Tethys called. It is 3-5km deep, 100km wide and 2000km long.