Mimas, also designated Saturn I, is a moon of Saturn which was discovered in 1789 by William Herschel. It is named after Mimas, a son of Gaia in Greek mythology.
With a diameter of 396 kilometres (246 mi) it is the smallest astronomical body that is known to still be rounded in shape because of self-gravitation. However, Mimas is not actually in hydrostatic equilibrium for its current rotation.
Mimas was discovered by the astronomer William Herschel on 17 September 1789. He recorded his discov...