Planetary nomenclature

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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 telescope, astronomers have given names to the surface features they have discerned, especially on the Moon and Mars. To found an authority on planetary nomenclature, the International Astronomical Union (IAU) was organized in 1919 to designate and standardize names for features on Solar System bodies. [1]

Contents

The heart-shaped Tombaugh Regio, on Pluto, is named after the planet's discoverer Clyde Tombaugh. Pluto-01 Stern 03 Pluto Color TXT.jpg
The heart-shaped Tombaugh Regio, on Pluto, is named after the planet's discoverer Clyde Tombaugh.
A map of the Moon from Andrees Allgemeiner Handatlas, 1st edition (1881), predating IAU conventions MoonMap1.jpg
A map of the Moon from Andrees Allgemeiner Handatlas, 1st edition (1881), predating IAU conventions

IAU approval procedure

When images are first obtained of the surface of a planet or satellite, a theme for naming features is chosen and a few important features are named, usually by members of the appropriate IAU task group (a commonly accepted planet-naming group). Later, as higher resolution images and maps become available, additional features are named at the request of investigators mapping or describing specific surfaces, features, or geologic formations. Anyone may suggest that a specific name be considered by a task group. If the members of the task group agree that the name is appropriate, it can be retained for use when there is a request from a member of the scientific community for a name of a specific feature. Names that pass review by a task group are submitted to the IAU Working Group for Planetary System Nomenclature (WGPSN). Once approved by the WGPSN, names are considered official and can be used on maps and in publications. They are also listed in the Gazetteer of Planetary Nomenclature. [2]

IAU rules and conventions

Names adopted by the IAU must follow various rules and conventions established and amended through the years by the Union. These include: [3]

  1. Nomenclature is a tool and the first consideration should be to make it simple, clear, and unambiguous.
  2. In general, official names will not be given to features whose longest dimensions are less than 100 meters, although exceptions may be made for smaller features having exceptional scientific interest.
  3. The number of names chosen for each body should be kept to a minimum. Features should be named only when they have special scientific interest, and when the naming of such features is useful to the scientific and cartographic communities at large.
  4. Duplication of the same surface feature name on two or more bodies, and of the same name for satellites and minor planets, is discouraged. Duplications may be allowed when names are especially appropriate and the chances for confusion are very small.
  5. Individual names chosen for each body should be expressed in the language of origin. Transliteration for various alphabets should be given, but there will be no translation from one language to another.
  6. Where possible, the themes established in early solar system nomenclature should be used and expanded on.
  7. Solar system nomenclature should be international in its choice of names. Recommendations submitted to the IAU national committees will be considered, but final selection of the names is the responsibility of the International Astronomical Union. Where appropriate, the WGPSN strongly supports an equitable selection of names from ethnic groups, countries, and gender on each map; however, a higher percentage of names from the country planning a landing is allowed on landing site maps.
  8. No names having political, military or (modern) religious significance may be used, except for names of political figures prior to the 19th century.
  9. Commemoration of persons on planetary bodies should not normally be a goal in itself, but may be employed in special circumstances and is reserved for persons of high and enduring international standing. Persons being so honored must have been deceased for at least three years.
  10. When more than one spelling of a name is extant, the spelling preferred by the person, or used in an authoritative reference, should be used. Diacritical marks are a necessary part of a name and will be used.
  11. Ring and ring-gap nomenclature and names for newly discovered satellites are developed in joint deliberation between WGPSN and IAU Commission 20. Names will not be assigned to satellites until their orbital elements are reasonably well known or definite features have been identified on them.
  12. Accessible and authoritative sources, including Internet sources, are required for adopted names. Wikipedia is not sufficient as a source, but may be useful for identifying appropriate sources.

In addition to these general rules, each task group develops additional conventions as it formulates an interesting and meaningful nomenclature for individual planetary bodies.

Naming conventions

Names for all planetary features include a descriptor term, with the exception of two feature types. For craters, the descriptor term is implicit. Some features named on Io and Triton do not carry a descriptor term because they are ephemeral.

In general, the naming convention for a feature type remains the same regardless of its size. Exceptions to this rule are valleys and craters on Mars and Venus; naming conventions for these features differ according to size.

One feature classification, regio, was originally used on early maps of the Moon and Mercury (drawn from telescopic observations) to describe vague albedo features. It is now used to delineate a broad geographic region.

Named features on bodies so small that coordinates have not yet been determined are identified on drawings of the body that are included in the IAU Transactions volume of the year when the names were adopted. Satellite rings and gaps in the rings are named for scientists who have studied these features; drawings that show these names are also included in the pertinent Transactions volume. Names for atmospheric features are informal at present; a formal system will be chosen in the future.

The boundaries of many large features (such as terrae, regiones, planitiae and plana) are not topographically or geomorphically distinct; the coordinates of these features are identified from an arbitrarily chosen center point. Boundaries (and thus coordinates) may be determined more accurately from geochemical and geophysical data obtained by future missions.

During active missions, small surface features are often given informal names. These may include landing sites, spacecraft impact sites, and small topographic features, such as craters, hills, and rocks. Such names will not be given official status by the IAU, except as provided for by Rule 2 above. As for the larger objects, official names for any such small features would have to conform to established IAU rules and categories.

Descriptor terms (feature types)

FeaturePronunciation [note 1] DescriptionDesignation
Albedo feature /ælˈbd/ An area which shows a contrast in brightness or darkness (albedo) with adjacent areas. This term is implicit.AL
Arcus, arcūs /ˈɑːrkəs/ Arc: curved featureAR
Astrum, astra /ˈæstrəm/ , /ˈæstrə/ Radial-patterned features on Venus AS
Catena, catenae /kəˈtnə/ , /kəˈtn/ A chain of craters e.g. Enki Catena.CA
Cavus, cavi /ˈkvəs/ , /ˈkv/ Hollows, irregular steep-sided depressions usually in arrays or clustersCB
Chaos /ˈkɒs/ A distinctive area of broken or jumbled terrain e.g. Iani Chaos.CH
Chasma, chasmata /ˈkæzmə/ , /ˈkæzmətə/ Deep, elongated, steep-sided depression e.g. Eos Chasma.CM
Collis, colles /ˈkɒlɪs/ , /ˈkɒlz/ A small hill or knob.CO
Corona, coronae /kɒˈrnə/ , /kɒˈrn/ An oval feature. Used only on Venus and Miranda.CR
Crater, craters /ˈkrtər/ A circular depression (in most cases created by impact event). This term is implicit.AA
Dorsum, dorsa /ˈdɔːrsəm/ , /ˈdɔːrsə/ Ridge, sometimes called a wrinkle ridge e.g. Dorsum Buckland.DO
Eruptive centerAn active volcano on Io. This term is implicit.ER
Facula, faculae /ˈfækjʊlə/ , /ˈfækjʊl/ Bright spotFA
Farrum, farra /ˈfærəm/ , /ˈfærə/ Pancake-like structure, or a row of such structures. Used only on Venus.FR
Flexus, flexūs /ˈflɛksəs/ Very low curvilinear ridge with a scalloped patternFE
Fluctus, fluctūs /ˈflʌktəs/ , /flʌkˈts/ Terrain covered by outflow of liquid. Used on Venus, Io, Titan, and Mars.FL
Flumen, flumina /ˈflmɪn/ , /ˈflmɪnə/ Channel on Titan that might carry liquidFM
Fossa, fossae /ˈfɒsə/ , /ˈfɒs/ Long, narrow, shallow depressionFO
Fretum, freta /ˈfrtəm/ , /ˈfrtə/ Strait of liquid connecting two larger areas of liquid. Used only on Titan.FT
Insula, insulae /ˈɪnsjlə/ , /ˈɪnsjl/ Island (islands), an isolated land area (or group of such areas) surrounded by, or nearly surrounded by, a liquid area (sea or lake). Used only on Titan.IN
Labes, labēs /ˈlbɪs/ , /ˈlbz/ Landslide debris. Used only on Mars and 1 Ceres.LA
Labyrinthus, labyrinthi /læbɪˈrɪnθəs/ , /læbɪˈrɪnθ/ Complex of intersecting valleys or ridges.LB
Lacuna, lacunae /ləˈkjuːnə/ , /ləˈkjuːn/ Irregularly shaped depression having the appearance of a dry lake bed. Used only on Titan.LU
Lacus, lacūs /ˈlkəs/ A "lake" or small plain on Moon and Mars; on Titan, a "true lake" of dark liquid hydrocarbons or a small, dark plain with discrete, sharp boundaries; on Pluto, a small isolated glacierLC
Landing site nameLunar features at or near Apollo landing sitesLF
Large ringed featureCryptic ringed featuresLG
Lenticula, lenticulae /lɛnˈtɪkjʊlə/ , /lɛnˈtɪkjʊl/ Small dark spots on Europa LE
Linea, lineae /ˈlɪnə/ , /ˈlɪn/ Dark or bright elongate marking, may be curved or straightLI
Lingula, lingulae /ˈlɪŋɡjʊlə/ , /ˈlɪŋɡjʊl/ Extension of plateau having rounded lobate or tongue-like boundariesLN
LobusLobes of contact binaries. Currently used only on Arrokoth.LO
Macula, maculae /ˈmækjʊlə/ , /ˈmækjʊl/ Dark spot, may be irregularMA
Mare, maria /ˈmɑːr,-/ , /ˈmɑːriə/ A "sea": on the Moon, a low albedo, relatively smooth plain, generally of large extent; on Mars, dark albedo area, e.g. Mare Erythraeum; on Titan, large expanses of dark materials thought to be liquid hydrocarbons, e.g. Ligeia Mare.ME
Mensa, mensae /ˈmɛnsə/ , /ˈmɛns/ A flat-topped prominence with cliff-like edges, i.e. a mesa.MN
Mons, montes /ˈmɒnz/ , /ˈmɒntz/ Mons refers to a mountain. Montes refers to a mountain range.MO
Oceanus /ˈsənəs/ Very large dark area. The only feature with this designation is Oceanus Procellarum.OC
Palus, paludes /ˈpləs/ , /pəˈljdz/ "Swamp"; small plain. Used on the Moon and Mars.PA
Patera, paterae /ˈpætərə/ , /ˈpætər/ Irregular crater, or a complex one with scalloped edges e.g. Ah Peku Patera. Usually refers to the dish-shaped depression atop a volcano.PE
Planitia, planitiae /pləˈnɪʃə/ , /pləˈnɪʃ/ Low plain e.g. Amazonis Planitia.PL
Planum, plana /ˈplnəm/ , /ˈplnə/ A plateau or high plain e.g. Planum Boreum.PM
Plume, plumes /ˈplm/ A cryovolcanic feature on Triton. This term is currently unused.PU
Promontorium, promontoria /prɒmənˈtɔːriəm/ , /prɒmənˈtɔːriə/ "Cape"; headland. Used only on the Moon.PR
Regio, regiones /ˈri/ , /rɛiˈnz/ Large area marked by reflectivity or color distinctions from adjacent areas, or a broad geographic regionRE
Reticulum, reticula /rɪˈtɪkjʊləm/ , /rɪˈtɪkjʊlə/ reticular (netlike) pattern on VenusRT
Rima, rimae /ˈrmə/ , /ˈrm/ Fissure. Used only on the Moon and 21 Lutetia.RI
Rupes, rupēs /ˈrpɪs/ , /ˈrpz/ ScarpRU
Saxum, saxa /ˈsæksəm/ , /ˈsæksə/ Boulder or rockSA
Satellite featureA feature that shares the name of an associated feature, for example Hertzsprung D.SF
Scopulus, scopuli /ˈskɒpjʊlə/ , /ˈskɒpjʊl/ Lobate or irregular scarpSC
Serpens, serpentes /ˈsɜːrpənz/ , /sərˈpɛntz/ Sinuous feature with segments of positive and negative relief along its lengthSE
Sinus, sinūs /ˈsnəs/ "Bay"; small plain on Moon or Mars, e.g. Sinus Meridiani; On Titan, bay within bodies of liquid.SI
Sulcus, sulci /ˈsʌlkəs/ , /ˈsʌls/ Subparallel furrows and ridgesSU
Terra, terrae /ˈtɛrə/ , /ˈtɛr/ Extensive land mass e.g. Arabia Terra, Aphrodite Terra.TA
Tessera, tesserae /ˈtɛsərə/ , /ˈtɛsər/ An area of tile-like, polygonal terrain. This term is used only on Venus.TE
Tholus, tholi /ˈθləs/ , /ˈθl/ Small domical mountain or hill e.g. Hecates Tholus.TH
Undae, undae /ˈʌnd/ A field of dunes. Used on Venus, Mars and Titan.UN
Vallis, valles /ˈvælɪs/ , /ˈvælz/ A valley e.g. Valles Marineris.VA
Vastitas, vastitates /ˈvæstɪtəs/ , /væstɪˈttz/ An extensive plain. The only feature with this designation is Vastitas Borealis.VS
Virga, virgae /ˈvɜːrɡə/ , /ˈvɜːr/ A streak or stripe of color. This term is currently used only on Titan.VI

Categories for naming features on planets and satellites

Mercury

Examples of Mercurian nomenclature from the Kuiper quadrangle. Mercury h06 Kuiper quadrangle.png
Examples of Mercurian nomenclature from the Kuiper quadrangle.
Feature typeCurrent listNaming convention
Catenae list Radio telescope facilities
Craters list Famous deceased artists, musicians, painters, authors
Dorsa list Astronomers who made detailed studies of the planet
Facula list The word 'snake' in various languages
Fossae list Significant works of architecture
Montes list Words for "hot" in various languages. Only one mountain range is currently named: Caloris Montes, from Latin word for "heat"
Planitiae list Names for Mercury (either planet or god) in various languages. Two exceptions exist.
Rupēs list Ships of discovery or scientific expeditions
Valles list Abandoned cities, towns or settlements of antiquity

Venus

All but three features on Venus are named after female personages (goddesses and historical or mythological women). These three exceptions were named before the convention was adopted, being respectively Alpha Regio, Beta Regio, and Maxwell Montes which is named after James Clerk Maxwell.

Feature typeCurrent listNaming convention
Astranone Goddesses, miscellaneous
Chasmata list Goddesses of hunt; moon goddesses
Colles list Sea goddesses
Coronae list Fertility and earth goddesses
Craters list Over 20 km, famous women; under 20 km, common female first names
Dorsa list Sky goddesses
Farra list Water goddesses
Fluctūs list Goddesses, miscellaneous
Fossae list Goddesses of war
Labyrinthi list Goddesses, miscellaneous
Lineae list Goddesses of war
Montes list Goddesses, miscellaneous (also one radar scientist)
Paterae list Famous women
Planitiae list Mythological heroines
Plana list Goddesses of prosperity
Regiones list Giantesses and Titanesses (also two Greek alphanumeric)
Rupēs list Goddesses of hearth and home
Terrae list Goddesses of love
Tesserae list Goddesses of fate and fortune
Tholi list Goddesses, miscellaneous
Undae list Desert goddesses
Valles list Word for planet Venus in various world languages (400 km and longer); river goddesses (less than 400 km in length)

The Moon

Feature typeNaming convention
CratersCraters are generally named after deceased scientists, scholars, artists and explorers who have made outstanding or fundamental contributions to their field. Additionally, craters in or around Mare Moscoviense are named after deceased Russian cosmonauts and craters in and around Apollo crater are named after deceased American astronauts (see Space accidents and incidents). This convention may be extended if other space-faring countries suffer fatalities in spaceflight.
Lacūs, Maria, Paludes, SinūsThese features are assigned names which are Latin terms describing weather and other abstract concepts.
MontesMontes are named after terrestrial mountain ranges or nearby craters.
RupēsRupēs are named after nearby mountain ranges (see above).
VallesValles are named after nearby features.
OthersFeatures that don't fall into any of the above categories are named after nearby craters.

Mars and martian satellites

Mars

Early map of Mars by Giovanni Schiaparelli, which depicts classical albedo features Karte Mars Schiaparelli MKL1888.png
Early map of Mars by Giovanni Schiaparelli, which depicts classical albedo features
Feature typeNaming convention
Large cratersDeceased scientists who have contributed to the study of Mars; writers and others who have contributed to the lore of Mars
Small cratersVillages of the world with a population of less than 100,000.
Large vallesName for Mars/star in various languages
Small vallesClassical or modern names of rivers
Other featuresFrom nearest named albedo feature on Schiaparelli or Antoniadi maps. See Classical albedo features on Mars for a list.

When space probes have landed on Mars, individual small features such as rocks, dunes, and hollows have often been given informal names. Many of these are frivolous: features have been named after ice cream (such as Cookies N Cream); cartoon characters (such as SpongeBob SquarePants and Patrick); and 1970s music acts (such as ABBA and the Bee Gees). [4]

Deimos

The two named craters on Deimos SwiftCrater.gif
The two named craters on Deimos

Features on Deimos are named after authors who wrote about Martian satellites. There are currently two named features on Deimos  Swift crater and Voltaire crater   after Jonathan Swift and Voltaire who predicted the presence of Martian moons.

Phobos

All features on Phobos are named after scientists involved with the discovery, dynamics, or properties of the Martian satellites or people and places from Jonathan Swift's Gulliver's Travels .

Satellites of Jupiter

Amalthea

People and places associated with the Amalthea myth.

Thebe

Features on Thebe are named after people and places associated with the Thebe myth. There is only one named feature on Thebe  Zethus Crater.

Io

Feature typeNaming convention
Active eruptive centersActive volcanoes on Io are named after fire, sun or thunder gods or heroes.
CatenaeCrater chains are named after Sun gods.
FluctūsNames of fluctūs are derived from a nearby named feature, fire, sun, thunder or volcano gods, goddesses and heroes or mythical blacksmiths.
Mensae, Montes, Plana, Regiones and TholiThese features can be named after places associated with Io mythology, derived from nearby named features, or places from Dante's Inferno
PateraePaterae on Io are named after fire, sun, thunder or volcano gods, heroes or goddesses or mythical blacksmiths.
VallesNames of valleys are derived from nearby named features.

Europa

Feature typeNaming convention
ChaosPlaces associated with Celtic myths
CratersCeltic gods and heroes
FlexūsPlaces associated with the Europa myth
Large ringed featuresCeltic stone circles
LenticulaeCeltic gods and heroes
LineaePeople associated with the Europa myth
MaculaePlaces associated with the Europa myth
RegionesPlaces associated with Celtic myths

Ganymede

Feature typeNaming convention
Catenae, cratersGods and heroes of ancient Middle Eastern civilizations
FaculaePlaces associated with Egyptian myths
FossaeGods (or principals) of ancient Fertile Crescent people
PateraePaterae on Ganymede are named after wadis in the Middle East.
RegionesAstronomers who discovered Jovian satellites
SulciPlaces associated with myths of ancient people

Callisto

Feature typeNaming convention
Large ringed featuresHomes of the gods and of heroes
CratersHeroes and heroines from northern myths
CatenaeMythological places in high latitudes

Satellites of Saturn

Janus

People from myth of Castor and Pollux (twins)

Epimetheus

People from myth of Castor and Pollux (twins)

Mimas

People and places from Malory's Le Morte d'Arthur legends (Baines translation)

Enceladus

People and places from Burton's Arabian Nights

Tethys

People and places from Homer's Odyssey

Dione

Locations from Roman mythology, or people and places from Virgil's Aeneid

Rhea

People and places from creation myths

Titan

Feature typeNaming convention
Albedo features, terraeSacred or enchanted places, paradise, or celestial realms from legends, myths, stories, and poems of cultures from around the world
CollesNames of characters from Middle-earth, the fictional setting in fantasy novels by English author J.R.R. Tolkien (1892–1973)
Craters and ringed featuresGods and goddesses of wisdom
Facula and faculaeFacula: Names of islands on Earth that are not politically independent, Faculae: Names of archipelagos
FluctūsGods and goddesses of beauty
FluminaNames of mythical or imaginary rivers
FretaNames of characters from the Foundation series of science fiction novels by American author Isaac Asimov (1920–1992)
InsulaeNames of islands from legends and myths
Lacūs and lacunaeLakes on Earth, preferably with a shape similar to the lacus or lacuna on Titan
Mare and mariaSea creatures from myth and literature
MontesNames of mountains and peaks from Middle-earth, the fictional setting in fantasy novels by English author J.R.R. Tolkien (1892–1973)
Planitiae and labyrinthiNames of planets from the Dune series of science fiction novels by American author Frank Herbert (1920–1986)
SinūsNames of terrestrial bays, coves, fjords or other inlets
UndaeGods and goddesses of wind
VirgaeGods and goddesses of rain

Hyperion

Sun and Moon deities

Iapetus

People and places from Sayers' translation of Chanson de Roland; the only exception is Cassini Regio, which is named after its discoverer, Giovanni Cassini.

Phoebe

Examples of crater nomenclature on Phoebe Cratersofphoebe.jpg
Examples of crater nomenclature on Phoebe
Feature typeNaming convention
CratersCraters of Phoebe are named after people associated with Phoebe or people from Argonautica by Apollonius Rhodius or Gaius Valerius Flaccus.
OtherNon-crater features on Phoebe are named after places from Argonautica.

Satellites of Uranus

Satellites of Uranus are named for characters from the works of William Shakespeare or from The Rape of the Lock .

Puck

Mischievous (Pucklike) spirits (class)

Miranda

Characters, places from Shakespeare's plays

Ariel

Light spirits (individual and class)

Umbriel

Dark spirits (individual)

Titania

Female Shakespearean characters, places

Oberon

Shakespearean tragic heroes and places

Small satellites

There are currently no named features on Uranian small satellites, however the naming convention is heroines from plays by Shakespeare and Pope.

Satellites of Neptune

Proteus

Features on Proteus are to be named after water-related spirits, gods or goddesses who are neither Greek nor Roman. The only named feature on Proteus is crater Pharos.

Triton

Geological features on Triton should be assigned aquatic names, excluding those which are Roman and Greek in origin. Possible themes for individual descriptor terms include worldwide aquatic spirits, famous terrestrial fountains or fountain locations, terrestrial aquatic features, famous terrestrial geysers or geyser locations and terrestrial islands.

Nereid

There are currently no named features on Nereid. When features are discovered, they are to be named after individual nereids.

Small satellites

Features on other satellites of Neptune, once discovered, should be named after gods and goddesses associated with Neptune/Poseidon mythology or generic mythological aquatic beings.

Pluto and satellites

Informally named geographic features on Pluto Pluto-Map-Annotated.jpg
Informally named geographic features on Pluto

In February 2017, the IAU approved the following themes for surface features on Pluto and its satellites: [5] [6]

Pluto

  • Gods, goddesses, and other beings associated with the Underworld from mythology, folklore and literature.
  • Names for the Underworld and for Underworld locales from mythology, folklore and literature.
  • Heroes and other explorers of the Underworld.
  • Scientists and engineers associated with Pluto and the Kuiper Belt.
  • Pioneering space missions and spacecraft.
  • Historic pioneers who crossed new horizons in the exploration of the Earth, sea and sky.

Charon

  • Destinations and milestones of fictional space and other exploration.
  • Fictional and mythological vessels of space and other exploration.
  • Fictional and mythological voyagers, travellers and explorers.
  • Authors and artists associated with space exploration, especially Pluto and the Kuiper Belt.

Nix

  • Deities of the night.

Hydra

  • Legendary serpents and dragons.

Kerberos

  • Dogs from literature, mythology, and history.

Styx

  • River gods.

Asteroids

1 Ceres

Feature typeNaming convention
CratersAgricultural deities
otherAgricultural festivals

4 Vesta

Feature typeNaming convention
CratersHistorical and mythological women of Ancient Rome (in one case, Angioletta, a modern-day female scientist who lived in Rome)
otherFestivals of Ancient Rome

243 Ida

Feature typeNaming convention
CratersCaverns and grottos of the world
Dorsa Galileo project participants
RegionesDiscoverer of Ida and places associated with the discoverer

(243) Ida I Dactyl

Feature typeNaming convention
CratersIdaean dactyls

951 Gaspra

Feature typeNaming convention
CratersSpas of the world
RegionesDiscoverer of Gaspra, and Galileo project participants

253 Mathilde

Feature typeNaming convention
CratersCoal fields and basins of the world

433 Eros

Feature typeNaming convention
CratersMythological, literary, and historical names of lovers
RegionesDiscoverers of Eros
DorsaScientists who have contributed to the exploration and study of Eros

25143 Itokawa

See also

Notes

  1. Listed pronunciations are conventional or follow the traditional English pronunciation of Latin words. However, some speakers use different (often variable) pronunciations that are closer to the Latin or Greek.

Related Research Articles

This is a directory of lists of geological features on planets excepting Earth, moons and asteroids ordered by increasing distance from the Sun.

The naming of moons has been the responsibility of the International Astronomical Union's committee for Planetary System Nomenclature since 1973. That committee is known today as the Working Group for Planetary System Nomenclature (WGPSN).

<span class="mw-page-title-main">Planetary geology</span> Geology of astronomical objects apparently in orbit around stellar objects

Planetary geology, alternatively known as astrogeology or exogeology, is a planetary science discipline concerned with the geology of celestial bodies such as planets and their moons, asteroids, comets, and meteorites. Although the geo- prefix typically indicates topics of or relating to Earth, planetary geology is named as such for historical and convenience reasons; due to the types of investigations involved, it is closely linked with Earth-based geology. These investigations are centered around the composition, structure, processes, and history of a celestial body.

<span class="mw-page-title-main">Patsaev</span> Lunar impact crater

Patsaev is a lunar impact crater that lies on the far side of the Moon, to the northeast of the prominent crater Tsiolkovskiy. To the northwest is the smaller crater Lander.

<span class="mw-page-title-main">Tholus</span> Small domical mountain or hill

In planetary nomenclature, a tholus is a small domical mountain or hill. The word is from the Greek θόλος, tholos, which means a circular building with a conical or vaulted roof. The Romans transliterated the word into the Latin tholus, which means cupola or dome. In 1973, the International Astronomical Union (IAU) adopted tholus as one of a number of official descriptor terms for topographic features on Mars and other planets and satellites. One justification for using neutral Latin or Greek descriptors was that it allowed features to be named and described before their geology or geomorphology could be determined. For example, many tholi appear to be volcanic in origin, but the term does not imply a specific geologic origin. Currently, the IAU recognizes 56 descriptor terms. Tholi are present on Venus, Mars, asteroid 4 Vesta, dwarf planet Ceres, and on Jupiter's moon Io.

<span class="mw-page-title-main">Mons (planetary nomenclature)</span>

Mons is a mountain on a celestial body. The term is used in planetary nomenclature: it is a part of the international names of such features. It is capitalized and usually stands after the proper given name, but stands before it in the case of lunar mountains.

<span class="mw-page-title-main">Collis (planetary nomenclature)</span>

Collis is a small hill or knob on a celestial body. The term is used in planetary nomenclature: it is a part of international proper names of such features. Like other generic terms, it is capitalized and stands after the proper name. As of 2015, only groups of the hills have names, and the term is used only in plural.

<span class="mw-page-title-main">Patera (planetary nomenclature)</span> Irregular type of crater

PateraPAT-ər-ə is an irregular crater, or a complex crater with scalloped edges on a celestial body. Paterae can have any origin, although the majority of them were created by volcanism. The term comes from Latin, where it refers to a shallow bowl used in antique cultures.

References

Citations

  1. "History of Planetary Nomenclature". United States Geological Survey. May 17, 2008.
  2. "How Names Are Approved". Gazetteer of Planetary Nomenclature. United States Geological Survey. International Astronomical Union . Retrieved May 6, 2021.
  3. "Planetary Names: IAU Rules and Conventions". United States Geological Survey. International Astronomical Union. Retrieved September 18, 2022.
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Sources

Further reading