Planetary Nomenclature - Descriptor Terms (feature Types)

Descriptor Terms (feature Types)

Feature	Description	Designation
Albedo feature	An area which shows a contrast in brightness or darkness (albedo) with adjacent areas. This term is implicit.	AL
Arcus, arcūs	Arc: curved feature	AR
Astrum, astra	Radial-patterned features on Venus	AS
Catena, catenae	A chain of craters e.g. Enki Catena.	CA
Cavus, cavi	Hollows, irregular steep-sided depressions usually in arrays or clusters	CB
Chaos	A distinctive area of broken or jumbled terrain e.g. Iani Chaos.	CH
Chasma, chasmata	Deep, elongated, steep-sided depression e.g. Eos Chasma.	CM
Colles	A collection of small hills or knobs.	CO
Corona, coronae	An oval feature. Used only on Venus and Miranda.	CR
Crater, craters	A circular depression likely created by impact event. This term is implicit.	AA
Dorsum, dorsa	Ridge, sometimes called a wrinkle ridge e.g. Dorsum Buckland.	DO
Eruptive center	An active volcano on Io. This term is implicit.	ER
Facula, faculae	Bright spot	FA
Farrum, farra	Pancake-like structure, or a row of such structures	FR
Flexus, flexūs	Very low curvilinear ridge with a scalloped pattern	FE
Fluctus, fluctūs	Terrain covered by outflow from a volcano.	FL
Flumen, flumina	Channel on Titan that might carry liquid	FM
Fossa, fossae	Long, narrow, shallow 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). The only feature with this designation is Mayda Insula.	IN
Labes, labēs	Landslide debris. Used only on Mars.	LA
Labyrinthus, labyrinthi	Complex of intersecting valleys or ridges.	LB
Lacus	A "lake" or small plain. Used on the Moon, Mars and Titan.	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	Dark or bright elongate marking, may be curved or straight	LI
Macula, maculae	Dark spot, may be irregular	MA
Mare, maria	A "sea" or large circular plain e.g. Mare Erythraeum. Used on the Moon, Mars and Titan.	ME
Mensa, mensae	A flat-topped prominence with cliff-like edges, i.e. a mesa.	MN
Mons, montes	Mons refers to a mountain. Montes refers to a mountain range.	MO
Oceanus	Very large dark area. Used only on the Moon.	OC
Palus, paludes	"Swamp"; small plain. Used on the Moon and Mars.	PA
Patera, paterae	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	Low plain e.g. Amazonis Planitia.	PL
Planum, plana	A plateau or high plain e.g. Planum Boreum.	PM
Plume	A cryovolcanic feature on Triton. This term is currently unused.	PU
Promontorium, promontoria	"Cape"; headland. Used only on the Moon.	PR
Regio, regiones	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. Used only on the Moon.	RI
Rupes, rupēes	Scarp	RU
Satellite feature	A feature that shares the name of an associated feature, for example Hertzsprung D.	SF
Scopulus, scopuli	Lobate or irregular scarp	SC
Sinus	"Bay"; small plain e.g. Sinus Meridiani.	SI
Sulcus, sulci	Subparallel furrows and ridges	SU
Terra, terrae	Extensive land mass e.g. Arabia Terra.	TA
Tessera, tesserae	An area of tile-like, polygonal terrain. This term is used only on Venus.	TE
Tholus, tholi	Small domical mountain or hill e.g. Hecates Tholus.	TH
Undae	A field of dunes.	UN
Vallis, valles	A valley e.g. Valles Marineris.	VA
Vastitas, vastitates	An extensive plain. The only feature with this designation is Vastitas Borealis.	VS
Virga, virgae	A streak or stripe of color	VI