The term 'satellite of Saturn' refers to a natural satellite that orbits the planet Saturn. The most well-known of these satellites is RHEA, which is the second-largest moon of Saturn and the ninth-largest moon in the Solar System. It was discovered in 1672 by Giovanni Domenico Cassini and is named after the Titan RHEA of Greek mythology. RHEA has an icy surface with numerous craters and is composed mostly of water ice.