This moon of Saturn has a diameter of approximately 1,120 kilometers and is covered with impact craters, valleys, and canyons. For unknown reasons, one side of Dione is much darker than the other. Dione shares its orbit around Saturn with another unnamed small moon (Tethys also shares its orbit with companion satellites). Before observing SaturnΓÇÖs moons, natural satellites had never been observed in shared orbits.
