[Visit the USGS Home Page]

Astrogeology Research Program

Gazetteer of Planetary Nomenclature

Descriptor Terms (Feature Types)

Feature Description Designation
Albedo Feature Geographic area distinguished by amount of reflected light AL
Arcus, arcūs Arc-shaped feature AR
Astrum, astra Radial-patterned features on Venus AS
Catena, catenae Chain of craters CA
Cavus, cavi Hollows, irregular steep-sided depressions usually in arrays or clusters CB
Chaos Distinctive area of broken terrain CH
Chasma, chasmata A deep, elongated, steep-sided depression CM
Colles Small hills or knobs CO
Corona, coronae Ovoid-shaped feature CR
Crater, craters A circular depression AA
Dorsum, dorsa Ridge DO
Eruptive center Active volcanic centers on Io ER
Facula, faculae Bright spot FA
Farrum, farra Pancake-like structure, or a row of such structures FR
Flexus, flexūs A very low curvilinear ridge with a scalloped pattern FE
Fluctus, fluctūs Flow terrain FL
Flumen, flumina Channel on Titan that might carry liquid FM
Fossa, fossae Long, narrow depression FO
Insula, insulae Island (islands), an isolated land area (or group of such areas) surrounded by, or nearly surrounded by, a liquid area (sea or lake). IN
Labes, labēs Landslide LA
Labyrinthus, labyrinthi Complex of intersecting valleys or ridges. LB
Lacus "Lake" or small plain; on Titan, a "lake" or small, dark plain with discrete, sharp boundaries LC
Landing site name Lunar features at or near Apollo landing sites LF
Large ringed feature Cryptic ringed features LG
Lenticula, lenticulae Small dark spots on Europa LE
Linea, lineae A dark or bright elongate marking, may be curved or straight LI
Lingula, lingulae Extension of plateau having rounded lobate or tongue-like boundaries LN
Macula, maculae Dark spot, may be irregular MA
Mare, maria "Sea"; large circular plain; on Titan, large expanses of dark materials thought to be liquid hydrocarbons ME
Mensa, mensae A flat-topped prominence with cliff-like edges MN
Mons, montes Mountain MO
Oceanus A very large dark area on the moon OC
Palus, paludes "Swamp"; small plain PA
Patera, paterae An irregular crater, or a complex one with scalloped edges PE
Planitia, planitiae Low plain PL
Planum, plana Plateau or high plain PM
Plume Cryo-volcanic features on Triton PU
Promontorium, promontoria "Cape"; headland promontoria PR
Regio, regiones A large area marked by reflectivity or color distinctions from adjacent areas, or a broad geographic region RE
Reticulum, reticula reticular (netlike) pattern on Venus RT
Rima, rimae Fissure RI
Rupes, rupēs Scarp RU
Satellite Feature A feature that shares the name of an associated feature. For example, on the Moon the craters referred to as "Lettered Craters" are classified in the gazetteer as "Satellite Features." SF
Scopulus, scopuli Lobate or irregular scarp SC
Sinus, sinūs "Bay"; small plain SI
Sulcus, sulci Subparallel furrows and ridges SU
Terra, terrae Extensive land mass TA
Tessera, tesserae Tile-like, polygonal terrain TE
Tholus, tholi Small domical mountain or hill TH
Undae Dunes UN
Vallis, valles Valley VA
Vastitas, vastitates Extensive plain VS
Virga, virgae A streak or stripe of color VI

Return to Gazetteer home page