The vocabulary of planetary surfaces
Every kind of place there is
The IAU does not call a mountain a mountain. It classifies every named surface feature in the Solar System with one of 53 Latin descriptor terms — a mons is a mountain, a patera an irregular volcanic crater, a chasma a deep canyon. Those 53 terms sort the 8,079 named places on 14 mapped worlds. Each one has its own page, with the full census and the largest examples anywhere.
Cratersa circular depression, almost always an impact scar13 worlds4,787Coronaean oval feature raised by rising material beneath the crust1 world341Montesa mountain7 worlds284Pateraean irregular or scalloped-edged crater, usually volcanic5 worlds280Vallesa valley5 worlds249Dorsaa ridge8 worlds184Albedo featuresa region named for how bright or dark it appears from a distance4 worlds172Fossaea long, narrow depression9 worlds117Lacusa small dark plain2 worlds114Rupesa scarp or cliff7 worlds113Rimaea fissure — a collapsed lava channel or a crack in the crust1 world112Tholia small domical mountain or hill5 worlds109Chasmataa deep, steep-sided canyon2 worlds88Planitiaea low plain9 worlds83Fluctusa flow of erupted material4 worlds81Astronaut-named featuressmall craters near the Apollo landing sites, named for the crews1 world81Lineaea long, dark or bright marking2 worlds71Sulcia set of parallel grooves and ridges4 worlds70Tesseraeterrain deformed into a tile-like pattern of ridges and grooves1 world65Faculaea bright spot5 worlds61Catenaea chain of craters7 worlds59Regionesa large area distinguished by its brightness or colour7 worlds51Mensaea flat-topped elevation with cliff-like edges3 worlds50Planaa high plain or plateau5 worlds49Collesa small hill or knob3 worlds44Sinusa bay-shaped dark plain2 worlds40Chaosterrain broken into a jumble of blocks and hollows2 worlds39Labyrinthia complex of intersecting valleys or ridges4 worlds33Cavia hollow or irregular steep-sided depression2 worlds30Mariaa large dark plain — an ancient lava flood, not a sea2 worlds25Terraean extensive landmass4 worlds20Undaea dune field3 worlds14Eruptive centersthe active source of an eruption1 world14Scopulian irregular scarp1 world13Maculaea dark spot3 worlds13Lacunaean irregular depression, read as the bed of a lake that has dried1 world13Insulaean island1 world13Fluminaa channel that carries, or once carried, a liquid1 world11Labesa landslide2 worlds10Large ringed featuresa multi-ring impact basin, the largest class of impact structure there is3 worlds10Farraa pancake-like structure, or a row of them1 world9Paludesa small dark plain2 worlds9Promontoriaa cape, where a highland juts into a plain1 world9Virgaea coloured streak1 world8Stationesa landing site — the only class named after a human arrival1 world6Lingulaea tongue-shaped extension of a plateau1 world5Serpentesa sinuous feature with segments of alternating rise and fall1 world5Flexusa low curved ridge with a scalloped pattern1 world5Fretaa strait — a narrow channel connecting two larger bodies of liquid1 world4Saxaa boulder or rock1 world3Oceanithe largest of the dark lava plains1 world1Vastitatesan extensive plain — the term is used for exactly one feature1 world1Arcusan arc-shaped feature1 world1