The naming of
moons
A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body (or sometimes another natural satellite). Natural satellites are often colloquially referred to as ''moons'' ...
has been the responsibility of the
International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
's committee for Planetary System Nomenclature since 1973. That committee is known today as the
Working Group for Planetary System Nomenclature
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...
(WGPSN).
Prior to its formation, the names of satellites have had varying histories. The choice of names is often determined by a satellite's discoverer; however, historically some satellites were not given names for many years after their discovery; for instance,
Titan was discovered by
Huygens in 1655, but was not named until 1847, almost two centuries later.
Before the IAU assumed responsibility for astronomical nomenclature, only twenty-five satellites had been given names that were in wide use and are still used: 1 of Earth, 2 of Mars, 5 of Jupiter, 10 of Saturn, 5 of Uranus, and 2 of Neptune. Since then, names have been given to 137 additional planetary and dwarf planetary satellites: 52 satellites of
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...
, 53 of
Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...
, 22 of
Uranus
Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus (mythology), Uranus (Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars (mythology), Mars), grandfather ...
, 12 of
Neptune
Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...
, 5 of
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...
, 2 of
Haumea
Haumea (minor-planet designation 136108 Haumea) is a dwarf planet located trans-Neptunian object, beyond Neptune's orbit. It was discovered in 2004 by a team headed by Michael E. Brown, Mike Brown of Caltech at the Palomar Observatory in the United ...
, and 1 each of , , , and . Names have also been given to some satellites of minor planets, including the dwarf planet candidates and which have one satellite each. The number will continue to rise as current satellite discoveries are documented and new satellites are discovered.
At the IAU General Assembly in July 2004,
the WGPSN suggested it may become advisable to not name small satellites, as
CCD technology makes it possible to discover satellites as small as 1 km in diameter. Until 2014, names were applied to all planetary moons discovered, regardless of size. From 2015, some small moons have not received names.
Naming of moons by Solar System object
Earth
Every human language has its own word for the Earth's
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
, 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-fictional contexts, the Moon has been called by the
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
name ''Luna'', presumably on the analogy of the Latin names of the planets, or by association with the adjectival form ''lunar''. In technical terminology, the word-stems ''seleno-'' (from
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
''selēnē'' "moon") and ''cynthi-'' (from ''Cynthia'', an epithet of the goddess
Artemis
In ancient Greek mythology and religion, Artemis (; grc-gre, Ἄρτεμις) is the goddess of the hunt, the wilderness, wild animals, nature, vegetation, childbirth, care of children, and chastity. She was heavily identified wit ...
) are sometimes used to refer to the Moon, as in ''selenography, selenology,'' and ''pericynthion.''
Mars
The moons of
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
(
Phobos and
Deimos Deimos, a Greek word for ''dread'', may refer to:
* Deimos (deity), one of the sons of Ares and Aphrodite in Greek mythology
* Deimos (moon), the smaller and outermost of Mars' two natural satellites
* Elecnor Deimos, a Spanish aerospace company
* ...
) were named by
Asaph Hall
Asaph Hall III (October 15, 1829 – November 22, 1907) was an American astronomer who is best known for having discovered the two moons of Mars, Deimos and Phobos, in 1877. He determined the orbits of satellites of other planets and of double ...
in 1878, soon after he discovered them. They are named after the sons of the god
Ares
Ares (; grc, Ἄρης, ''Árēs'' ) is the Greek god of war and courage. He is one of the Twelve Olympians, and the son of Zeus and Hera. The Greeks were ambivalent towards him. He embodies the physical valor necessary for success in war b ...
(the Greek equivalent of the Roman god
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
).
Jupiter
The Galilean moons of Jupiter (
Io,
Europa
Europa may refer to:
Places
* Europe
* Europa (Roman province), a province within the Diocese of Thrace
* Europa (Seville Metro), Seville, Spain; a station on the Seville Metro
* Europa City, Paris, France; a planned development
* Europa Cliff ...
,
Ganymede and
Callisto Callisto most commonly refers to:
*Callisto (mythology), a nymph
*Callisto (moon), a moon of Jupiter
Callisto may also refer to:
Art and entertainment
*''Callisto series'', a sequence of novels by Lin Carter
*''Callisto'', a novel by Torsten Kro ...
) were named by
Simon Marius
Simon Marius ( latinized form of Simon Mayr; 10 January 1573 – 5 January 1625) was a German astronomer. He was born in Gunzenhausen, near Nuremberg, but spent most of his life in the city of Ansbach. He is most known for being among the first ...
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
Nicolas Camille Flammarion FRAS (; 26 February 1842 – 3 June 1925) was a French astronomer and author. He was a prolific author of more than fifty titles, including popular science works about astronomy, several notable early science fiction ...
.
The other
irregular satellite
In astronomy, an irregular moon, irregular satellite or irregular natural satellite is a natural satellite following a distant, orbital inclination, inclined, and often orbital eccentricity, eccentric and Retrograde and prograde motion, retrograd ...
s (discovered 1904 to 1951) were, in the overwhelming majority of astronomical literature, simply left nameless. No names were proposed until
Brian G. Marsden
Brian Geoffrey Marsden (5 August 1937 – 18 November 2010) was a British astronomer and the longtime director of the Minor Planet Center (MPC) at the Center for Astrophysics Harvard & Smithsonian (director emeritus from 2006 to 2010).
...
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).
[Журнал "Земля и Вселенная" №6 1973 г](_blank)
/ref> These met no particularly enthusiastic reception.
In 1975, following Charles Kowal
Charles Thomas Kowal (November 8, 1940 – November 28, 2011) was an American astronomer known for his observations and discoveries in the Solar System. As a staff astronomer at Caltech's Mount Wilson and Palomar Mountain observatories between ...
's discovery of the satellite Jupiter XIII in 1974 the IAU
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...
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
Leda may refer to:
Mythology
* Leda (mythology), queen of Sparta and mother of Helen of Troy in Greek mythology
Places
* Leda, Western Australia, a suburb of Perth, Western Australia
* Leda makeshift settlement, Bangladesh, a refugee camp ...
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
Jürgen or Jurgen is a popular masculine given name in Germany, Estonia, Belgium and the Netherlands. It is cognate with George (given name), George. Notable people named Jürgen include:
A
*Jürgen Ahrend (born 1930), German organ builder
*J ...
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
Carl Edward Sagan (; ; November 9, 1934December 20, 1996) was an American astronomer, planetary scientist, cosmologist, astrophysicist, astrobiologist, author, and science communicator. His best known scientific contribution is research on ext ...
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) and suggested his own names in 1976; 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):
Current practice is that newly discovered moons of Jupiter must be named after lovers or descendants of the mythological Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...
(Zeus
Zeus or , , ; grc, Δῐός, ''Diós'', label=Genitive case, genitive Aeolic Greek, Boeotian Aeolic and Doric Greek#Laconian, Laconian grc-dor, Δεύς, Deús ; grc, Δέος, ''Déos'', label=Genitive case, genitive el, Δίας, ''D ...
). Blunck's scheme for the outer moons was retained, with the addition that names ending in 'o' could also be used for prograde moons. At the IAU General Assembly in July 2004, the WGPSN allowed Jovian satellites to be named for Zeus
Zeus or , , ; grc, Δῐός, ''Diós'', label=Genitive case, genitive Aeolic Greek, Boeotian Aeolic and Doric Greek#Laconian, Laconian grc-dor, Δεύς, Deús ; grc, Δέος, ''Déos'', label=Genitive case, genitive el, Δίας, ''D ...
' descendants in addition to his lovers and favorites which were the previous source of names, due to the large number of new Jovian satellites that had then recently been discovered. All of Jupiter's satellites from XXXIV (Euporie
In Greek mythology, Euporie or Euporia is the goddess of abundance. She is one of the third generation of Horae.
Sources
* Gaius Julius Hyginus, ''Fabulae
Gaius Julius Hyginus (; 64 BC – AD 17) was a Latin author, a pupil of the scholar ...
) on were named for descendants of Zeus, until Jupiter LIII ( Dia), named after another one of his lovers.
Saturn
In 1847 the seven then known moons of Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...
were named by John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint and did botanical wor ...
. Herschel named Saturn's two innermost moons (Mimas and Enceladus) after the mythological Greek Giants
A giant is a being of human appearance, sometimes of prodigious size and strength, common in folklore.
Giant(s) or The Giant(s) may also refer to:
Mythology and religion
*Giants (Greek mythology)
*Jötunn, a Germanic term often translated as 'gi ...
, and the outer five after the Titans (Titan, Iapetus) and Titanesses (Tethys, Dione, Rhea) of the same mythology. Until then, Titan was known as the "Huygenian (or Huyghenian) satellite of Saturn" and the other moons had Roman numeral designations in order of their distance from Saturn. Subsequent discoverers of Saturnian moons followed Herschel's scheme: Hyperion was discovered soon after in 1848, and the ninth moon, Phoebe, was named by its discoverer in 1899 soon after its discovery; they were named for a Titan and a Titaness respectively. The name of Janus
In ancient Roman religion and myth, Janus ( ; la, Ianvs ) is the god of beginnings, gates, transitions, time, duality, doorways, passages, frames, and endings. He is usually depicted as having two faces. The month of January is named for Janu ...
was suggested by its discoverer, Audouin Dollfus
Audouin Charles Dollfus (12 November 1924 – 1 October 2010) was a French astronomer and aeronaut, specialist in studies of the Solar System and discoverer of Janus, a moon of Saturn.
Life and career
Dollfus was born in Paris to aeronaut Charl ...
.
Current IAU practice for newly discovered inner moons is to continue with Herschel's system, naming them after Titans or their descendants. However, the increasing number of moons that were being discovered in the 21st century caused the IAU to draw up a new scheme for the outer moons. At the IAU General Assembly in July 2004, the WGPSN allowed satellites of Saturn to have names of giants and monsters in mythologies other than the Greco-Roman. Since the outer moons fall naturally into three groups, one group is named after Norse giants, one after Gallic giants, and one after Inuit
Inuit (; iu, ᐃᓄᐃᑦ 'the people', singular: Inuk, , dual: Inuuk, ) are a group of culturally similar indigenous peoples inhabiting the Arctic and subarctic regions of Greenland, Labrador, Quebec, Nunavut, the Northwest Territories ...
giants. The only moon that fails to fit this scheme is the Greek-named Phoebe, which is in the Norse group.
Uranus
The Roman numbering scheme of Uranus
Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus (mythology), Uranus (Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars (mythology), Mars), grandfather ...
' moons was in a state of flux for a considerable time. Sir William Herschel thought he had discovered up to six moons and maybe even a ring. For nearly fifty years, Herschel's instrument was the only one the moons had been seen with. 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
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint and did botanical wor ...
, son of the discoverer of Uranus. Herschel, instead of assigning names from Greek mythology
A major branch of classical mythology, Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the Cosmogony, origin and Cosmology#Metaphysical co ...
, named the moons after magical spirits in English literature
English literature is literature written in the English language from United Kingdom, its crown dependencies, the Republic of Ireland, the United States, and the countries of the former British Empire. ''The Encyclopaedia Britannica'' defines E ...
: the fairies Oberon
Oberon () is a king of the fairies in medieval and Renaissance literature. He is best known as a character in William Shakespeare's play ''A Midsummer Night's Dream'', in which he is King of the Fairies and spouse of Titania, Queen of the Fair ...
and Titania from William Shakespeare
William Shakespeare ( 26 April 1564 – 23 April 1616) was an English playwright, poet and actor. He is widely regarded as the greatest writer in the English language and the world's pre-eminent dramatist. He is often called England's nation ...
's ''A Midsummer Night's Dream
''A Midsummer Night's Dream'' is a comedy written by William Shakespeare 1595 or 1596. The play is set in Athens, and consists of several subplots that revolve around the marriage of Theseus and Hippolyta. One subplot involves a conflict amon ...
'', and the sylphs Ariel and Umbriel from Alexander Pope
Alexander Pope (21 May 1688 O.S. – 30 May 1744) was an English poet, translator, and satirist of the Enlightenment era who is considered one of the most prominent English poets of the early 18th century. An exponent of Augustan literature, ...
's ''The Rape of the Lock
''The Rape of the Lock'' is a mock-heroic narrative poem written by Alexander Pope. One of the most commonly cited examples of high burlesque, it was first published anonymously in Lintot's ''Miscellaneous Poems and Translations'' (May 1712) ...
'' (Ariel
Ariel may refer to:
Film and television
*Ariel Award, a Mexican Academy of Film award
* ''Ariel'' (film), a 1988 Finnish film by Aki Kaurismäki
* ''ARIEL Visual'' and ''ARIEL Deluxe'', 1989 and 1991 anime video series based on the novel series ...
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
A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a cell Lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell.
Monoclonal antibodies ca ...
continuing the trend), have focused on Herschel's source material. In 1949, the fifth moon, Miranda, was named by its discoverer, Gerard Kuiper
Gerard Peter Kuiper (; ; born Gerrit Pieter Kuiper; 7 December 1905 – 23 December 1973) was a Dutch astronomer, planetary scientist, selenographer, author and professor. He is the eponymous namesake of the Kuiper belt.
Kuiper is c ...
, 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
Margaret is a female first name, derived via French () and Latin () from grc, μαργαρίτης () meaning "pearl". The Greek is borrowed from Persian.
Margaret has been an English name since the 11th century, and remained popular througho ...
, is named from ''Much Ado About Nothing
''Much Ado About Nothing'' is a comedy by William Shakespeare thought to have been written in 1598 and 1599.See textual notes to ''Much Ado About Nothing'' in ''The Norton Shakespeare'' ( W. W. Norton & Company, 1997 ) p. 1387 The play ...
''.
Neptune
The one known moon (at the time) of Neptune
Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...
was not named for many decades. Although the name Triton
Triton commonly refers to:
* Triton (mythology), a Greek god
* Triton (moon), a satellite of Neptune
Triton may also refer to:
Biology
* Triton cockatoo, a parrot
* Triton (gastropod), a group of sea snails
* ''Triton'', a synonym of ''Triturus' ...
was suggested in 1880 by Camille Flammarion
Nicolas Camille Flammarion FRAS (; 26 February 1842 – 3 June 1925) was a French astronomer and author. He was a prolific author of more than fifty titles, including popular science works about astronomy, several notable early science fiction ...
, 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
In Greek mythology, the Nereids or Nereides ( ; grc, Νηρηΐδες, Nērēḯdes; , also Νημερτές) are sea nymphs (female spirits of sea waters), the 50 daughters of the 'Old Man of the Sea' Nereus and the Oceanids, Oceanid Doris ...
, was named by its discoverer in 1949, Gerard P. Kuiper
Gerard Peter Kuiper (; ; born Gerrit Pieter Kuiper; 7 December 1905 – 23 December 1973) was a Dutch astronomer, planetary scientist, selenographer, author and professor. He is the eponymous namesake of the Kuiper belt.
Kuiper is co ...
, 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
There are 82 known moons of Jupiter, not counting a number of moonlets likely shed from the inner moons. All together, they form a satellite system which is called the Jovian system. The most massive of the moons are the four Galilean moons: ...
.
Pluto
The name of Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...
's moon Charon
In Greek mythology, Charon or Kharon (; grc, Χάρων) is a psychopomp, the ferryman of Hades, the Greek underworld. He carries the souls of those who have been given funeral rites across the rivers Acheron and Styx, which separate the wo ...
was suggested by James W. Christy
James Walter "Jim" Christy (born September 15, 1938) is an American astronomer known for discovering Charon, the largest moon of the dwarf planet Pluto.
Early years
Christy was born in 1938 in Milwaukee, Wisconsin. He attended the University of ...
, its discoverer, soon after its discovery.
The other four moons are named Hydra
Hydra generally refers to:
* Lernaean Hydra, a many-headed serpent in Greek mythology
* ''Hydra'' (genus), a genus of simple freshwater animals belonging to the phylum Cnidaria
Hydra or The Hydra may also refer to:
Astronomy
* Hydra (constel ...
, Nix
Nix or NIX may refer to:
Places
* Nix, Alabama, an unincorporated community, United States
* Nix, Texas, a ghost town in southwestern Lampasas County, Texas, United States
* Nix (moon), a moon of Pluto
People
* Nix (surname), listing people with ...
, Kerberos, and Styx
In Greek mythology, Styx (; grc, Στύξ ) is a river that forms the boundary between Earth (Gaia) and the Underworld. The rivers Acheron, Cocytus, Lethe, Phlegethon, and Styx all converge at the centre of the underworld on a great marsh, whic ...
.
Charon, Hydra, Nix, and Kerberos are all characters in Greek mythology, with ties to Hades (the Greek equivalent of Pluto). Charon
In Greek mythology, Charon or Kharon (; grc, Χάρων) is a psychopomp, the ferryman of Hades, the Greek underworld. He carries the souls of those who have been given funeral rites across the rivers Acheron and Styx, which separate the wo ...
ferries the dead across the River Acheron, Hydra
Hydra generally refers to:
* Lernaean Hydra, a many-headed serpent in Greek mythology
* ''Hydra'' (genus), a genus of simple freshwater animals belonging to the phylum Cnidaria
Hydra or The Hydra may also refer to:
Astronomy
* Hydra (constel ...
guards the waters of the underworld, and Nix (a respelling of Nyx), mother of Charon, is the goddess of darkness and the night. Kerberos is a giant three-headed dog who guards the entrance to the underworld. The fifth moon is named for the river Styx
In Greek mythology, Styx (; grc, Στύξ ) is a river that forms the boundary between Earth (Gaia) and the Underworld. The rivers Acheron, Cocytus, Lethe, Phlegethon, and Styx all converge at the centre of the underworld on a great marsh, whic ...
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
Michael E. Brown (born June 5, 1965) is an American astronomer, who has been professor of planetary astronomy at the California Institute of Technology (Caltech) since 2003. His team has discovered many trans-Neptunian objects (TNOs), including ...
, 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
Lucille Frances Lawless (; born 29 March 1968) is a New Zealand actress and singer. She is best known for her roles as Xena in the television series '' Xena: Warrior Princess'', as D'Anna Biers on the re-imagined '' Battlestar Galactica'' seri ...
who plays the character Xena
Xena is a fictional character from Robert Tapert's '' Xena: Warrior Princess'' franchise. Co-created by Tapert and John Schulian, she first appeared in the 1995–1999 television series ''Hercules: The Legendary Journeys'', before going on to ...
. 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
Haumea (minor-planet designation 136108 Haumea) is a dwarf planet located trans-Neptunian object, beyond Neptune's orbit. It was discovered in 2004 by a team headed by Michael E. Brown, Mike Brown of Caltech at the Palomar Observatory in the United ...
and its moons
A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body (or sometimes another natural satellite). Natural satellites are often colloquially referred to as ''moons'' ...
were suggested by David L. Rabinowitz
David Lincoln Rabinowitz (born 1960) is an American astronomer, discoverer of minor planets and researcher at Yale University.
Career
David Rabinowitz has built CCD cameras and software for the detection of near-Earth and Kuiper belt obje ...
of Caltech
The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...
and refer to the mother goddess and her daughters in Hawaiian mythology
Hawaiian religion refers to the indigenous religious beliefs and practices of native Hawaiians, also known as the kapu system. Hawaiian religion is based largely on the tapu religion common in Polynesia and likely originated among the Tahitians ...
.
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.
Quaoar
Quaoar was named after the creator god of the Tongva
The Tongva ( ) are an Indigenous people of California from the Los Angeles Basin and the Southern Channel Islands, an area covering approximately . Some descendants of the people prefer Kizh as an endonym that, they argue, is more historically ...
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
Weywot, officially (50000) Quaoar I Weywot, is the only known moon of the trans-Neptunian planetoid 50000 Quaoar. Discovered by Michael Brown and T.A. Suer using images acquired by the Hubble Space Telescope on 14 February 2006, its existence w ...
, son of Quaoar.["Heavenly Bodies and the People of the Earth"]
, Nick Street, ''Search Magazine,'' July/August 2008
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
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
(IAU) on 5 April.[
] The name Vanth
Vanth is a chthonic figure in Etruscan mythology shown in a variety of forms of funerary art, such as in tomb paintings and on sarcophagi.
Vanth is a female demon in the Etruscan underworld that is often accompanied either by additional Vanth fi ...
, the winged Etruscan __NOTOC__
Etruscan may refer to:
Ancient civilization
*The Etruscan language, an extinct language in ancient Italy
*Something derived from or related to the Etruscan civilization
**Etruscan architecture
**Etruscan art
**Etruscan cities
** Etrusca ...
psychopomp
Psychopomps (from the Greek word , , literally meaning the 'guide of souls') are supernatural creatures, spirits, entities, angels, demons or deities in many religions whose responsibility is to escort newly deceased souls from Earth to the afte ...
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
Sonya Taaffe is an American author of short fiction and poetry based out of Massachusetts. She grew up in Arlington and Lexington, Massachusetts and graduated from Brandeis University in 2003 where she received a B.A. and M.A. in Classical Studi ...
.[
]
The Etruscan Vanth is frequently portrayed in the company of Charun
In Etruscan mythology, Charun (also spelled Charu, or Karun) acted as one of the psychopompoi of the underworld (not to be confused with the god of the underworld, known to the Etruscans as Aita). He is often portrayed with Vanth, a winged figu ...
(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
The Roman numbering system for satellites arose with the very first discovery of natural satellites other than Earth's Moon: Galileo
Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642) was an Italian astronomer, physicist and engineer, sometimes described as a polymath. Commonly referred to as Galileo, his name was pronounced (, ). He was ...
referred to the Galilean moons
The Galilean moons (), or Galilean satellites, are the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto. They were first seen by Galileo Galilei in December 1609 or January 1610, and recognized by him as satellites of Jupiter ...
as I through IV (counting from Jupiter outward), refusing to adopt the names proposed by his rival Simon Marius
Simon Marius ( latinized form of Simon Mayr; 10 January 1573 – 5 January 1625) was a German astronomer. He was born in Gunzenhausen, near Nuremberg, but spent most of his life in the city of Ansbach. He is most known for being among the first ...
. Similar numbering schemes naturally arose with the discovery of multiple moons around Saturn, Uranus, and Mars. The numbers initially designated the moons in orbital sequence, and were re-numbered after each new discovery; for instance, before the discovery of Mimas and Enceladus in 1789, Tethys was Saturn I, Dione Saturn II, etc., but after the new moons were discovered, Mimas became Saturn I, Enceladus Saturn II, Tethys Saturn III and Dione Saturn IV.
In the middle of the 19th century, however, the numeration became fixed, and later discoveries failed to conform with the orbital sequence scheme. Amalthea, discovered in 1892, was labelled "Jupiter V" although it orbits more closely to Jupiter than does Io (Jupiter I). The unstated convention then became, at the close of the 19th century, that the numbers more or less reflected the order of discovery, except for prior historical exceptions (see Timeline of discovery of Solar System planets and their natural satellites); though if a large number of satellites were discovered in a short span of time, the group could be numbered in orbital sequence, or according to other principles than strictly by order of discovery. The convention has been extended to natural satellites of minor planets, such as (87) Sylvia I Romulus. The outer irregular satellites of Jupiter (VI through XII) were left officially unnamed throughout this period, although as stated above some unofficial names were used in some contexts.
From 1975 to 2009, the International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
was assigning names to all planetary satellites, and Roman numerals were usually not assigned to satellites until they are named. (An exception is Saturn's moon Helene, which received the Roman numeral XII in 1982, but was not named until 1988.) During this period, the use of Roman numeral designations diminished, and some are very rarely used; Phobos and Deimos Deimos, a Greek word for ''dread'', may refer to:
* Deimos (deity), one of the sons of Ares and Aphrodite in Greek mythology
* Deimos (moon), the smaller and outermost of Mars' two natural satellites
* Elecnor Deimos, a Spanish aerospace company
* ...
are rarely referred to as Mars I and Mars II, and the Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
is never referred to as "Earth I". However, since 2015 some moons have again been numbered without being named, starting from Jupiter LI
Jupiter LI, provisionally known as , is a natural satellite of Jupiter. It was discovered by R. Jacobson, M. Brozović, B. Gladman, and M. Alexandersen in 2010. It received its permanent number in March 2015. CBET 4075: 20150307 : SATELLITES OF JU ...
.
The thirteen named satellites of Saturn from Aegir to Surtur were named in alphabetical order
Alphabetical order is a system whereby character strings are placed in order based on the position of the characters in the conventional ordering of an alphabet. It is one of the methods of collation. In mathematics, a lexicographical order is t ...
corresponding to their Roman numerals.
Provisional designations
When satellites are first discovered, they are given provisional designations such as " S/2010 J 2" (the 2nd new satellite of Jupiter discovered in 2010) or " S/2003 S 1" (the 1st new satellite of Saturn discovered in 2003). The initial "S/" stands for "satellite", and distinguishes from such prefixes as "D/", "C/", and "P/", used for comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...
s. The designation "R/" is used for planetary rings. These designations are sometimes written like "S/2003 S1", dropping the second space. The letter following the category and year identifies the planet (Jupiter, Saturn, Uranus, Neptune; although no occurrence of the other planets is expected, Mars and Mercury are disambiguated through the use of Hermes for the latter). Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...
was designated by P prior to its recategorization as a dwarf planet
A dwarf planet is a small planetary-mass object that is in direct orbit of the Sun, smaller than any of the eight classical planets but still a world in its own right. The prototypical dwarf planet is Pluto. The interest of dwarf planets to p ...
. When the object is found around a minor planet, the identifier used is the latter's number in parentheses. Thus, Dactyl
Dactyl may refer to:
* Dactyl (mythology), a legendary being
* Dactyl (poetry), a metrical unit of verse
* Dactyl Foundation, an arts organization
* Finger, a part of the hand
* Dactylus, part of a decapod crustacean
* "-dactyl", a suffix used ...
, the moon of 243 Ida
Ida, minor planet designation 243 Ida, is an asteroid in the Koronis family of the asteroid belt. It was discovered on 29 September 1884 by Austrian astronomer Johann Palisa at Vienna Observatory and named after a nymph from Greek mythology. ...
, was at first designated " S/1993 (243) 1". Once confirmed and named, it became (243) Ida I Dactyl
Ida, minor planet designation 243 Ida, is an asteroid in the Koronis family of the asteroid belt. It was discovered on 29 September 1884 by Austrian astronomer Johann Palisa at Vienna Observatory and named after a nymph from Greek mytholo ...
. Similarly, the fourth satellite of Pluto, Kerberos, discovered after Pluto was categorized as a dwarf planet and assigned a minor planet number, was designated S/2011 (134340) 1 rather than S/2011 P 1, though the ''New Horizons
''New Horizons'' is an Interplanetary spaceflight, interplanetary space probe that was launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research ...
'' team, who maintained that dwarf planets were planets, used the latter.
* H = Mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
(Hermes)
* V = Venus
Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...
* E = Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
* M = Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
* J = Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...
* S = Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...
* U = Uranus
Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus (mythology), Uranus (Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars (mythology), Mars), grandfather ...
* N = Neptune
Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...
Note: The assignation of "H" for Mercury is specified by th
USGS Gazetteer of Planetary Nomenclature
since they usually follow IAU guidelines closely, this is very likely the IAU convention, but confirmation is needed: there have been no moons found to be orbiting Mercury as of yet.
After a few months or years, when a newly discovered satellite's existence has been confirmed and its orbit computed, a permanent name is chosen, which replaces the "S/" provisional designation. However, in the past, some satellites remained unnamed for surprisingly long periods after their discovery.
Timeline
The timeline only includes moons of the planets and the more likely dwarf planets. (no moons), , , , , , , , and (no moons) are generally agreed among astronomers to be dwarf planets. and are more controversial.
Pre-IAU names
The following names were adopted by informal processes preceding the assumption by the IAU
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...
of control over the assignment of satellite nomenclature in 1973.
IAU names
The following names were selected through a formal process controlled by the IAU. Only in a few cases is the person who chose the name identified.
20th century
21st century
For completeness, moons that were left unnamed upon their official numbering have also been included.
Other references
Astronomical Headlines
See also
* Timeline of discovery of Solar System planets and their moons
The timeline of discovery of Solar System planets and their natural satellites charts the progress of the discovery of new bodies over history. Each object is listed in chronological order of its discovery (multiple dates occur when the moments ...
* Astronomical naming conventions
In ancient times, only the Sun and Moon, a few stars, and the most easily visible planets had names. Over the last few hundred years, the number of identified astronomical objects has risen from hundreds to over a billion, and more are discovered ...
* Provisional designation in astronomy
Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calcu ...
* Planetary nomenclature
Planetary nomenclature, like terrestrial nomenclature, is a system of uniquely identifying features on the surface of a planet or natural satellite so that the features can be easily located, described, and discussed. Since the invention of the tel ...
* Name conflicts of solar system objects
Notes
{{DEFAULTSORT:Naming Of Moons
Moons
*
Moons
A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body (or sometimes another natural satellite). Natural satellites are often colloquially referred to as ''moons'' ...