Thin Air - Cassini Finds Ethereal Atmosphere at Rhea

NASA's Cassini spacecraft has detected a very tenuous atmosphere known as an exosphere, infused with oxygen and carbon dioxide around Saturn's icy moon Rhea. This is the first time a spacecraft has directly captured molecules of an oxygen atmosphere – albeit a very thin one -- at a world other than Earth. /NASA



Wikipedia:
Rhea (pronounced /ˈriːə/,or as Greek Ῥέᾱ) 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.
Rhea is named after the Titan Rhea of Greek mythology, "mother of the gods". It is also designated Saturn V (being the fifth major moon going outward from the planet).


Cassini named the four moons he discovered (Tethys, Dione, Rhea and Iapetus) Sidera Lodoicea (the stars of Louis) to honor King Louis XIV. Astronomers fell into the habit of referring to them and Titan as Saturn I through Saturn V. Once Mimas and Enceladus were discovered, in 1789, the numbering scheme was extended to Saturn VII.


The names of all seven satellites of Saturn then known come from John Herschel (son of William Herschel, discoverer of the planet Uranus, and two other Cronian moons, Mimas and Enceladus) in his 1847 publication Results of Astronomical Observations made at the Cape of Good Hope, wherein he suggested the names of the Titans, sisters and brothers of Cronos (Saturn, in Roman mythology), be used.