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Themis

1. Minor planet 24. A C-class asteroid with a diameter of 220 km, discovered in 1853 by A. de Gasparis. It orbits in the main body of the asteroid family that bears its name (see Themis family); semimajor axis 3.13 AU, perihelion 2.71 AU, aphelion 3.55 AU, inclination 0.8°. In 2008 and 2009, two teams of scientists independently announced the discovery of water-ice on the surface of Themis, lending credence to the idea that colliding asteroids (as well as comets) delivered large quantities of water to Earth in the remote past.


2. A satellite of Saturn reported by William Pickering in 1898 to be in orbit between Titan and Hyperion, but subsequently not seen again.