Galatea, a moon of Neptune
38,309 miles
109 miles
Galatea is a small moon of Neptune. It is one of Neptune's inner moons and is the third closest moon to orbit the planet. Galatea has a diameter of approximately 175 kilometres (109 miles). It orbits Neptune at a distance of just over 61,500 kilometres (38,300 miles). A length of an orbit takes only 10 hours which means that it orbits Neptune faster than the planet spins.
Galatea was discovered in 1989 through images taken by the Voyager 2 spacecraft. Voyager 2 flew past Neptune in 1989 and also discovered most of the planet's other inner moons.
Galatea orbits about 1,000 kilometres (620 miles) from one of Neptune's rings, its Adams ring. It is considered to be a shepherd moon, a moon which holds the materials in the Adams ring in place.
Galatea is believed to be the fragments of an earlier moon that was destroyed when Neptune captured its largest moon Triton. Parts of that destroyed moon joined back together to form Galatea and some of Neptune's other inner moons.
Galatea is classed as a regular prograde moon. Regular moons are moons that formed out of materials spinning around a planet. Irregular moons are ones that were captured by a planet. A prograde moon is one which orbits in the same direction of the rotation of its host planet.
In Greek mythology, Galatea is one of the fifty Nereids, or sea nymphs. Each Nereid represented a different aspect of the sea or those that sailed on it. Galatea either represents calm seas or milky white sea foam. Galatea would often visit the coast of Sicily, where she caught the eye of a giant Cyclops called Polyphemos. Despite the attempts of Polyphemos to attract her, Galatea was more interested in a river god called Akis. It a moment of jealous anger, Polyphemos crushed Akis under a rock. Galatea turned Akis into a stream.
As Neptune is the Roman god of the sea, all of its moons have water-related names.
Before it received its official name by the International Astronomical Union on 16th September 1991, Galatea was identified as S/1989 N 4. It can also be referred to as Neptune VI.
