Helene is a moon of Saturn. It was discovered by Pierre Laques and Jean Lecacheux in 1980 from ground-based observations at Pic du Midi Observatory, and was designated S/1980 S 6. In 1988 it was officially named after Helen of Troy, who was the granddaughter of Cronus (Saturn) in Greek mythology. Helene is also designated Saturn XII (12), which it was given in 1982, and Dione B, because it is co-orbital with Dione and located in its leading Lagrangian point (L4). It is one of four known trojan moons.
High-resolution view of leading hemisphere, showing gullies and apparent dust (regolith) flows (Cassini, June 2011)
Flow-like features on Helene's leading hemisphere (Cassini, January 2011)
Image of Helene against the backdrop of Saturn's clouds (Cassini, March 3, 2010)
Helene's Saturn-facing side, lit by saturnshine (Cassini, March 2010)
A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body. Natural satellites are colloquially referred to as moons, a derivation from the Moon of Earth.
Size comparison of Earth and the Moon
Artist impression of Rhea's proposed rings