Tethys (moon)

Tethys (pronounced TEE-this) is a large moon of the planet Saturn.

 Discovery 
It was discovered by Giovanni Domenico Cassini in 1684. It was one of the first Saturnian moons discovered.

 Physical characteristics 
 Mass, density and volume 
Tethys' mass is 617,551,805,221,061,000,000 kg, its density is 0.973 g/cm3 and its volume is 634,264,255 km3.

 Craters and valleys 
It has a very large crater on its surface, called Odysseus. It is named after a Greek warrior king in Homer's two great works, The Iliad and The Odyssey. There is also a very long valley called Ithaca Chasma. It is 100 km wide and 2000 km long.

 Orbit and rotation 
Tethys takes 45.3 hours to orbit (go around) Saturn and orbits Saturn 294,660 km away. Tethys is tidally locked in phase with its parent planet - one side always faces toward Saturn.

 References 

Category:Saturn's moons