Descriptor terms

These are the Latin descriptor terms of the feature names, in the singular and the plural. The singular is used for a single feature. The plural is used when a feature has several parts or occurs in a group. The definitions are the official ones of the IAU Working Group for Planetary System Nomenclature.

Astrum, astra

Radial-patterned features on Venus

Chasma, chasmata

A deep, elongated, steep-sided depression

Collis, colles

Small hills or knobs

Corona, coronae

Ovoid-shaped feature See: Corona

Dorsum, dorsa

Ridge See: Wrinkle ridge plains

Facula, faculae

Bright spot

Farrum, farra

Pancake-like structure, or a row of such structures See: Steep-sided dome, Pancake dome

Fluctus, fluctūs

Flow terrain See: Lava flow, Festoon

Fossa, fossae

Long, narrow depression See: Graben system, Rift zone · Fracture belt, Groove belt

Labes, labēs

Landslide See: Slide

Linea, lineae

A dark or bright elongate marking, may be curved or straight

Macula, maculae

Dark spot, may be irregular

Mons, montes

Mountain See: Large volcano

Patera, paterae

An irregular crater, or a complex one with scalloped edges

Planitia, planitiae

Low plain

Planum, plana

Plateau or high plain See: Crustal plateau

Regio, regiones

A large area marked by reflectivity or color distinctions from adjacent areas, or a broad geographic region

Reticulum, reticula

reticular (netlike) pattern on Venus

Rima, rimae

Fissure

Rupes, rupēs

Scarp

Terra, terrae

Extensive land mass

Tessera, tesserae

Tile-like, polygonal terrain See: Tessera

Tholus, tholi

Small domical mountain or hill

Unda, undae

Dunes See: Dune field

Vallis, valles

Valley See: Valley network

Virga, virgae

A streak or stripe of color

Impact crater names have no descriptor term.

Source of the definitions: Gazetteer of Planetary Nomenclature, Descriptor Terms (Feature Types). IAU Working Group for Planetary System Nomenclature and USGS Astrogeology Science Center. https://planetarynames.wr.usgs.gov/DescriptorTerms