The adjectival forms of the names of astronomical bodies are not always easily predictable. Attested adjectival forms of the larger bodies are listed below, along with the two small Martian moons; in some cases they are accompanied by their demonymic equivalents, which denote hypothetical inhabitants of these bodies.
For Classical (Greco-Roman) names, the adjectival and demonym forms normally derive from the oblique stem, which may differ from the nominative form used in English for the noun form. For instance, for a large portion of names ending in -s, the oblique stem and therefore the English adjective changes the -s to a -d, -t, or -r, as in Mars–Martian, Pallas–Palladian and Ceres–Cererian;This is reflected in Russian Паллада Pallada 'Pallas' and Церера Tserera 'Ceres', as well as in Italian Pallade 'Pallas' and Cerere 'Ceres', as in these (and several other) languages the nominal forms of the names often also reflect the oblique. This is not always the case, however – for Mars, Italian Marte parallels the English adjective but Russian Марс Mars parallels the English noun. occasionally an -n has been lost historically from the nominative form, and reappears in the oblique and therefore in the English adjective, as in Pluto–Plutonian and Atlas–Atlantean.
Many of the more recent or more obscure names are only attested in mythological or literary contexts, rather than in specifically astronomical contexts. Forms ending in -ish or -ine, such as "Puckish", are not included below if a derivation in -an is also attested. Rare forms, or forms only attested with spellings not in keeping with the IAU-approved spelling (such as c for k), are shown in italics.
Note on pronunciation The suffix -ian is always unstressed: that is, . The related ending -ean, from an e in the root plus a suffix -an, has traditionally been stressed (that is, ) if the e is long ē in Latin (or is from ē in Greek); but if the e is short in Latin, the suffix is pronounced the same as -ian. In practice forms ending in -ean may be pronounced as if they were spelled -ian even if the e is long in Latin. This dichotomy should be familiar from the dual pronunciations of Caribbean as and .
Generic bodies Name Adjective Demonym asteroid asteroidal, asteroidic Asterite comet cometary cosmos, universe cosmic, cosmian, universal ecliptic ecliptical, zodiacal galaxy galactic, galactian meteoroid meteoroidal nebula nebular planet planetary, planetic planetoid planetoidal quasar quasaric, quasarian sky celestial star astral, sidereal, siderean, stellar supernova supernovan space Spacer
Constellations Derivative forms of constellations are used primarily for meteor showers. The genitive forms of the constellations are used to name stars. (See List of constellations.) Other adjectival forms are less common.
Name Adjective Derivative Andromeda Andromedan Andromedid Aquarius Aquarian Aquariid Aries Arian Arietid Auriga Aurigal Aurigid Boötes Bootid Cancer Cancerian Cancrid Carina Carinal Carinid Capricorn Capricornian Capricornid Centaurus Centaurean, Centaurian Centaurid Cetus Cetid Coma Berenices Comal Coma Berenicid Corona Austrina Coronal Corona Austrinid Crux Crucial Crucid Cygnus Cygnean Cygnid Dorado Doradid Draco Draconic Draconid Eridanus Eridanid Gemini Geminian Geminid Hydra, Hydrus Hydrid Leo Leonic, Leonian, Leonean Leonid Leo Minor Leo Minorid Libra Libran Librid Lyra Lyrid Monoceros Monocerotid Norma Normid Ophiuchus Ophiuchid Orion Orionid Pavo Pavonid Pegasus Pegasean, Pegasarian Pegasid Perseus Perseid Phoenix Phoenicean Phoenicid Pisces Piscean, Piscian Piscid Piscis Austrinus Piscis Austrinid Puppis Puppid Sagittarius Sagittarian Sagittariid Scorpius Scorpian, Scorpionic Scorpiid Taurus Taurean, Taurian Taurid Ursa Major, Ursa Minor Ursal Ursid Vela Velar, Velic Velid Virgo Virginal, Virginian Virginid zodiac zodiacal
Sun Name Adjective Demonym Prefix Sun, Sol, Helios Solar, Heliacal, Phoebean, Phebean Solarian helio-
Planets Name Adjective Demonym Prefix MercuryHermes (in the evening),Apollo (in the morning) Mercurian, Mercurial, Hermean/Hermeian, Cyllenian,Lewis (1888) A Latin dictionary for schools Cyllenean Mercurian, Hermean hermeo- VenusHesperus, Vesper (in the evening),Eosphorus, Phosphorus, Phosphor (in the morning),Lucifer (in the day) Venerian, Venusian, Cytherean,Raitala (1993) "Crustal tectonic zone on Venus", Earth, Moon, and Planets, v. 64, no. 2 Cytherian,"A theoretical study of the martian and cytherian ionospheres", NASA Technical Reports Server, JPL-TR-32-398 Hesperian,Goodsell Observatory (1909) Popular astronomy, v. 17 Luciferian,Duffy (2009) The Constitution of Shelley's Poetry Phosphorian,Boardman (2001) The poems of Francis Thompson AphroditanPatricia Brace (2011) The Broadview Anthology of Sixteenth-Century Poetry and Prose, p. 607 Venusian, Cytherean cythero- EarthTerra, Tellus, Gaia, Gaea Earthly, Terran, Terrestrial, Terrene, Tellurian, Telluric, Gaian, Gaean Earthling, Terran, Tellurian, Earthian, Earther, Earthican, Gaian, Gaean geo- Mars Martian, Martial, Arean"Schiaparelli on Mars" (1895 ) Nature, v. 51 Martian areo- Jupiter Jovian, Jupiterian, Zeusian Jovian zeno- Saturn Saturnian, Saturnine, Cronian, Kronian,Müller et al. (2010) Azimuthal plasma flow in the Kronian magnetosphere, J. Geophys. Res. 115, A08203 SaturnialPennsylvania school journal, v. 29 (1880) Saturnian crono- Uranus Uranian, Caelian Uranian urano- Neptune Neptunian, Neptunial, Poseidean Neptunian poseido-
Minor planets Name Adjective Demonym Cererian,Rüpke (2007) A companion to Roman religion CerereanBooth (1923) Flowers of Roman poesy Cererian Eridian HaumeanE.g. Giovanni Vulpetti (2013) Fast Solar Sailing, p. 333. Makemakean Orcean,Angley (1847) De Clifford, the philosopher Orcan Pallas Palladian Pluto Plutonic, Plutonian Plutonian Sednian (named for Sedna Planitia). Vesta Vestian,Jet Propulsion Laboratory (2010) Dawn Journal, March 28Tsiolkovsky (1960) The call of the cosmos Vestan,Meteoritics & planetary science, Volume 42, Issues 6–8, 2007Origin and evolution of Earth, National Research Council et al., 2008 Vestalian Vestan, Vestian
Moons Earth and Mars Name Adjective Demonym Prefix Moon (Luna, Selene) Lunar, Selenian, Cynthian Lunarian, Selenite seleno- Deimos DeimianHarry Shipman (2013) Humans in Space: 21st Century Frontiers, p. 317 Phobos PhobianThe Century Dictionary and Cyclopedia (1911)
Jupiter Name Adjective, demonym Callisto Callistoan,Harland (2000) Jupiter odyssey: the story of NASA's Galileo mission CallistonianMonthly Notices of the Royal Astronomical Society, v.71, 1911 Europa EuropanGreenberg (2005) Europa: the ocean moon Ganymede Ganymedean,Journal of Geophysical Research, v. 95 (1990) Ganymedian Io Ionian"Electron Beams and Ion Composition Measured at Io and in Its Torus", Science, 1996 October 18
Saturn Name Adjective, demonym Dione DioneanAnthon (1849) The Aeneïd of Virgil Enceladus Enceladean,JBIS: journal of the British Interplanetary Society, v. 36 (1983) EnceladanLebowitz (1970) Progress into silence: a study of Melville's heroes Hyperion Hyperionian Iapetus Iapetian, Japetian Mimas Mimantean, MimantianHarrison (1908) Prolegomena to the study of Greek religion, ed. 2 Rhea RheanThe Westminster review, v. 140 (1893) Tethys TethyanŞengör & Atayman (2009) The Permian extinction and the Tethys Titan Titanian ,JPL (ca. 2008) Cassini Equinox Mission: Huygens Landed with a Splat TitaneanMilton, Hughes (2003) Complete poems and major prose
Uranus Name Adjective, demonym Ariel ArielianDeKoven (1991) Rich and strange: gender, history, modernism Miranda Mirandan,Journal of Geophysical Research, v. 93 (1988) MirandianRobertson (1929) The life of Miranda Oberon OberonianNormand (1970) Nathaniel Hawthorne Titania Titanian Umbriel UmbrielianJames Hall III (2015) Moons of the Solar System, p. 150
Neptune, Pluto and Eris Name Adjective, demonym Triton TritonianBunbury (1883) A history of ancient geography Charon CharonianKathryn Bosher (2012) Theater outside Athens: Drama in Greek Sicily and South Italy, pp 100, 104–105 Dysnomia Dysnomian
Galaxies Name Adjective Milky Way Galaxy Galactic,When capitalized, "Galactic" refers specifically to the Milky Way galaxy. LactealThe Independent, v. 55, p. 964 (1903) Andromeda Galaxy Andromedan Magellanic Clouds Magellanic
Notes
References
External links Wordorigins.org: Naming The Planets, Part I