Theory Moon and Planetary Nomenclatures

Planetary nomenclature became in 1919 the exclusive domain of the International Astronomical Union (IAU) which had been founded this very year in Brussels. IAU took back previous works of regularization about naming Moon and Mars features. Final works about Moon were published in 1936, (Miss Blagg and Muller) then in the 1965s (Gerard K. Kuiper) as Martian nomenclature was stabilized about 1960 only (Audouin Dollfus), building upon previous nomenclatures by Schiaparelli and Antoniadi. Space exploration produced new needs for nomenclature for Moon and planets of the solar system and their moons (1970s works of Gerard de Vaucouleurs and Donald H. Menzel). Since that time IAU has a Working Group for Planetary System Nomenclature (WGPSN) and diverse task groups. A theme is choosen for each celestial body, names are decided along the theme by the task group as investigators of the body then propose additional names. Craters at Mercury, for example, are named after 'deceased artists, musicians, painters and authors who have made outstanding or fundamental contributions to their field and have been recognized as art historically significant figures for more than 50 years.' Names accepted by a task group and successfully submitted to the WGPSN are considered provisionally approved until they are eventually officially accepted by the IAU's General Assemby meeting each three years. The features named have to be of sufficient scientific importance to be named. see more at the Planetary System Nomenclature (WGPSN)'s page, which is hosted at the U.S. Geological Survey (USGS)

Rules for the naming of satellites of the solar system planets are the following:

• Jupiter's moons are named for Zeus/Jupiter's lovers and descendants. Names of outer satellites with a prograde orbit generally end with the letter "a" -an "o" ending is reserved for some unusual cases. Names of moons with a retrograde orbit end with an "e"
• Saturn's moons are named from Greco-Roman titans, descendants of the titans, those Roman gods of the beginnings, and giants from Greco-Roman and other mythologies. Further, retrograde satellites with an inclination of 90-180° with respect to the ecliptic (no any Saturn's reference) are named from Norse giants (Phoebe is an exception as discovered long ago), prograde satellites with an orbit inclination about 36° are named from Gallic giants, as prograde satellites with an inclination of about 48° are named from Inuit giants
• Uranus' moons are named from characters from Shakespeare's plays and from Pope's "Rape of the Lock"
• Neptune's moons are named from characters of Greek or Roman mythology associated with Neptune, or Poseidon, or the oceans
• as far as objects crossing or approaching the orbit of Neptune, mostly Pluto and its moons, they are given mythological names associated with the underworld. After views sent back by NASA's New Horizons mission, the International Astronomical Union (IAU) approved by 2017 naming themes for Pluto and moons as submitted par the mission's team. Namely, for Pluto, all mythological, folklore and litterature associated with the underworld, scientists and engineers associated with Pluto and the Kuiper Belt, pioneering persons, and space missions and spacecraft. For Charon, all what is fictional and mythological travels, and authors and artists associated with space exploration, especially Pluto and the Kuiper Belt. Themes for Pluto’s smaller moons at last are like follows. Styx: river gods, Nix: deities of the night, Kerberos: dogs from literature, mythology and history, Hydra: legendary serpents and dragons

As far the naming of exoplanets is concerned, the IAU said it would devise an official naming process in 1995, the year the first alien planet was confirmed but has yet to do so. The planet-naming status quo is that exoplanets take the name of their parent star along with a lowercase letter, with the first discovered designated 'b,' the second 'c', etc. and is a informal convention