Tethys (moon)

Moon of Saturn

Tethys is the fifth-largest moon of Saturn, measuring about 1,060 km (660 mi) across. It was discovered by Giovanni Domenico Cassini in 1684, and is named after the titan Tethys of Greek mythology. Tethys has a low density of 0.98 g/cm³, the lowest of all the major moons in the Solar System, indicating that it is made of water ice with just a small fraction of rock.

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