• satellite of Saturn discovered in 1684 by Cassini. Tethys orbits Saturn in a circular 1.9 day orbit 295 000km from the planet and is just over 500km across. With a density close to 1gm/cc, Tethys consists mainly of ice. Its surface is heavily cratered and features deep, wide valleys, the latter being regarded as evidence of past geological activity.

Not what you were looking for?