Earth Every human language has its own word for the Earth's
Moon, and these words are the ones normally used in astronomical contexts. However, a number of fanciful or mythological names for the Moon have been used in the context of astronomy (an even larger number of lunar epithets have been used in non-astronomical contexts). In the 17th century, the Moon was sometimes referred to as
Proserpina. More recently, especially in science-fiction content, the Moon has been called
Earth I, analogue to the numbering
of Jovian moons with roman numbers, or by the
Latin name
Luna, presumably on the analogy of the Latin names of the planets, or by association with the adjectival form
lunar, or a need to differentiate it from other moons that may be present in a fictional setting; however, in several Romance languages, such as Spanish, the word "luna" is often used to refer to any natural satellite in the same way as "moon" in English, which is problematic. In technical terminology, the word-stems
seleno- (from
Greek selēnē "moon") and
cynthi- (from
Cynthia, an epithet of the goddess
Artemis or
Diana) are sometimes used to refer to the Moon, as in
selenography,
selenology, and
pericynthion.
Mars The moons of
Mars (
Phobos and
Deimos) were named by
Asaph Hall in 1878, soon after he discovered them. They are named after the sons of the god
Ares (the Greek equivalent of the Roman god
Mars).
Jupiter The
Galilean moons of Jupiter (
Io,
Europa,
Ganymede and
Callisto) were named by
Simon Marius soon after their discovery in 1610. However, by the late 19th century these names had fallen out of favor, and for a long time it was most common to refer to them in the astronomical literature simply as "Jupiter I", "Jupiter II", etc., or as "the first satellite of Jupiter", "Jupiter's second satellite", etc. By the first decade of the 20th century, the names Io, Europa, Ganymede, and Callisto had once again recovered popularity, but the later-discovered moons, numbered, usually in Roman numerals V (5) through XII (12), remained unnamed. By a popular though unofficial convention, Jupiter V, discovered in 1892, was given the name
Amalthea, first used by the French astronomer
Camille Flammarion. The other
irregular satellites (discovered 1904 to 1951) were, in the overwhelming majority of astronomical literature, simply left nameless. No names were proposed until
Brian G. Marsden suggested a nomenclature for these satellites in 1955. Although the 1955 names met with immediate acceptance in some quarters (e.g. in science fiction and popular science articles), they were still rarely if ever met in astronomical literature until the 1970s. Two other proposals for naming the satellites were made between 1955 and 1975, both by Soviet astronomers, E. I. Nesterovich (in 1962) and Yu. A. Karpenko (in 1973). These met no particularly enthusiastic reception. In 1975, following
Charles Kowal's discovery of the satellite Jupiter XIII in 1974, the
IAU Task Group for Outer Solar System Nomenclature granted names to satellites V-XIII, and provided for a formal naming process for future satellites to be discovered. Under the new process, Jupiter V continued as
Amalthea, Jupiter XIII was named
Leda in accordance with a suggestion of Kowal's, and all previous proposals for the seven satellites VI-XII were abandoned in favor of new names, in accordance with a scheme suggested by the German philologist
Jürgen Blunck where
prograde moons received names ending in 'a' and
retrograde moons received names ending in 'e'. The new names met considerable protest from some quarters. Kowal, despite suggesting a name for Jupiter XIII, was of the opinion that Jupiter's irregular satellites should not be named at all.
Carl Sagan noted that the names chosen were extraordinarily obscure (a fact that
Tobias Owen, chair of the Task Group, admitted was intentional in a response to Sagan these preserved some of the names from the 1955 proposal. Karpenko had noted the same in his 1981 book "The Names of the Starry Sky", along with stating that the names chosen for retrograde moons, and therefore the "e" ending, were not always the ones for which it was the more common one. The proposals are summarized in the table below (data from
Icarus unless specified otherwise In the 1840s, better instruments and a more favourable position of Uranus in the sky led to sporadic indications of satellites additional to Titania and Oberon. Publications hesitated between William Herschel's designations (where Titania and Oberon are Uranus II and IV) and William Lassell's (where they are sometimes I and II). With the confirmation of Ariel and Umbriel, Lassell numbered the moons I through IV from Uranus outward, and this finally stuck. The first two Uranian moons, discovered in 1787, did not receive names until 1852, a year after two more moons had been discovered. The responsibility for naming was taken by
John Herschel, son of the discoverer of Uranus. Herschel, instead of assigning names from
Greek mythology, named the moons after magical spirits in
English literature: the fairies
Oberon and
Titania from
William Shakespeare's ''
A Midsummer Night's Dream'', and the sylphs Ariel and Umbriel from
Alexander Pope's
The Rape of the Lock (
Ariel is also a sprite in Shakespeare's
The Tempest). The reasoning was presumably that Uranus, as god of the sky and air, would be attended by spirits of the air. Subsequent names, rather than continuing the "airy spirits" theme (only
Puck and
Mab continuing the trend), have focused on Herschel's source material. In 1949, the fifth moon,
Miranda, was named by its discoverer,
Gerard Kuiper, after a thoroughly mortal character in Shakespeare's
The Tempest. Current IAU practice is to name moons after characters from Shakespeare's plays and
The Rape of the Lock (although at present only Ariel, Umbriel, and Belinda have names drawn from the latter poem, all the rest being from Shakespeare). All the retrograde irregular moons are named after characters from one play,
The Tempest; the only prograde irregular moon,
Margaret, is named from
Much Ado About Nothing.
Neptune The one known moon (at the time) of
Neptune was not named for many decades. Although the name
Triton was suggested in 1880 by
Camille Flammarion, it did not come into general use until the mid 20th-century, and for many years was considered "unofficial". In the astronomical literature it was simply referred to as "the satellite of Neptune". Later, the second known moon,
Nereid, was named by its discoverer in 1949,
Gerard P. Kuiper, soon after its discovery. Current IAU practice for newly discovered Neptunian moons is to accord with these first two choices by naming them after Greek sea deities. For the "normal" irregular satellites, the general convention is to use names ending in "a" for prograde satellites, names ending in "e" for retrograde satellites, and names ending in "o" for exceptionally inclined satellites, exactly like the convention for the
moons of Jupiter.
Pluto The name of
Pluto's moon
Charon was suggested by
James W. Christy, its discoverer, soon after its discovery. The other four moons are named
Hydra,
Nix,
Kerberos, and
Styx. Charon, Hydra, Nix, and Kerberos are all characters in Greek mythology, with ties to Hades (the Greek equivalent of Pluto).
Charon ferries the dead across the River Acheron,
Hydra guards the waters of the underworld, Nix (a respelling of
Nyx) is the mother of Charon and the goddess of darkness and the night, and Kerberos (a respelling of
Cerberus) is a giant three-headed dog who guards the entrance to the underworld. The fifth moon is named for the river
Styx that forms the boundary between the worlds of the living and the dead.
Eris The name of
Eris's moon
Dysnomia was suggested by its discoverer
Michael E. Brown, who also suggested the name of the dwarf planet. The name has two meanings: in mythology
Dysnomia (lawlessness) is the daughter of
Eris (chaos). However, the name is also an intentional reference to the actor
Lucy Lawless who plays the character
Xena. The background for this is that during the long period when Eris had no formal name, the name 'Xena' – originally Brown's nickname for his discovery – spread and became popular. When the name 'Eris' was chosen, Brown suggested Dysnomia (which until then had been referred to as
Gabrielle) as a reference to this. Hence, Dysnomia is the only moon which could be said to be named after an actor. The names Eris and Dysnomia were accepted by the IAU on 14 September 2006.
Haumea The name of
Haumea and its
moons were suggested by
David L. Rabinowitz of
Caltech and refer to the mother goddess and her daughters in
Hawaiian mythology.
Gonggong When the discoverers of Gonggong proposed choices for a public vote on its name, they chose figures that had associates that could provide a name for the satellite. Xiangliu's name was chosen by its discovery team led by Csaba Kiss. The name refers to the
venomous nine-headed snake monster and minister of
Gonggong who brings floods and destruction in
Chinese mythology.
Quaoar Quaoar was named after the creator god of the
Tongva tribe. Brown, who had co-discovered both Quaoar and its moon, left the name of the moon up to the Tongva. The Tongva chose the sky god
Weywot, son of Quaoar.
Orcus On 23 March 2009, Brown asked readers of his weekly column to suggest possible names for the satellite of Orcus which he had codiscovered, with the best one to be submitted to the
International Astronomical Union (IAU) on 5 April. The name
Vanth, the winged
Etruscan psychopomp who guides the souls of the dead to the underworld, was chosen from among a large pool of submissions. Vanth was the only suggestion that was purely Etruscan in origin. It was the most popular submission, first suggested by
Sonya Taaffe. The Etruscan Vanth is frequently portrayed in the company of
Charun (Charon), and so as the name of the moon of Orcus (nicknamed the "anti-Pluto" because resonance with Neptune keeps it on the opposite side of the Sun from Pluto), it is an allusion to the parallels between Orcus and . Brown quoted Taaffe as saying that if Vanth "accompanies dead souls from the moment of death to the underworld itself, then of course her face is turned always toward Orcus", a reference to the likely synchronous orbit of Vanth about Orcus.
Asteroids and other trans-Neptunian objects Unlike the planets and dwarf planets, relatively few moons orbiting asteroids have been named. Among them are the following: == Roman numeral designations ==