The second largest moon of Saturn Rhea was discovered on December 23rd 1672 by Giovanni Cassini. In Greek mythology Rhea was the ‘mother of gods’.
It is a rocky body with a radius of around 760 km, Rhea takes about 4.5 days to orbit Saturn once.
Cassini would also discover the moons Dione, Iapetus and Tethys which also orbit Saturn.
The space craft Cassini which has been orbiting Saturn is named after the famous astronomer.