These albedo features were first named by Giovanni Schiaparelli. Schiaparelli was not the first to give names to these features; Richard Anthony Proctor had drawn up an earlier map in 1867, based in part on the observations of William Rutter Dawes, in which several features were given the names of astronomers who had been involved in mapping Mars; in some cases, several times over. These names competed with the Schiaparellian names for several decades, and were used in notable early maps drawn by Camille Flammarion in 1876 and Nathaniel Green in 1877. The Proctorian names are now, however, regarded as totally obsolete. Schiaparelli's observations differed from those of Proctor et al., and he used this difference to justify drawing up an entirely new scheme of nomenclature in Latin. This nomenclature, drawn from the myths and history of classical antiquity with a mixture of other sources, is still used – with subsequent adjustments and elaborations by Schiaparelli and other astronomers – in some circumstances. The names are not, for the most part, used to describe the features now observed as part of the topography of Mars such as craters, volcanoes, and canyons. However, many of the names used for topographic features on Mars are based on the albedo nomenclature; for instance, the albedo feature Ascraeus Lacus ("lake of Ascra") provides the basis of the name of the Tharsis volcano Ascraeus Mons. The observations of the early telescopic astronomers, observing from a great distance through what can now be regarded as somewhat primitive instruments (though they were advanced for their day), were limited to albedo contrasts on the surface of the planet. These albedo contrasts rarely correspond to topographic features, and in many cases obscure them. The origins of the albedo contrasts were a mystery. The lighter patches at the poles were correctly believed to be a frozen substance, either water or carbon dioxide, but the nature of the dark patches seen against the general reddish tint of Mars was obscure for a century. When Schiaparelli began observing, he believed that the darker features were seas or lakes, and named them accordingly (mare, lacus, palus, etc.). Within a few decades Mars was agreed to be devoid of surface water. The dark features were then thought by some to be indications of some kind of vegetation, since they changed shape and intensity over the course of the Martian year. They are now known to be areas where a darker surface dust is deposited; their borders change in response to windstorms on the Martian surface that pick up the dust, widening or narrowing the features. Since most Earth-based amateur telescopes are not powerful enough to resolve the topographic surface features of Mars, amateur astronomers still use many of the old feature-names to orient and record their observations. Not listed here are the "canals" also observed and named by Schiaparelli, for which see the article Martian canals.
Common feature names
Several Latin words involved here are common nouns. These are generally, but not always, second in the name, but are usually ignored in alphabetizing below:
Fons (ˈfɑnz) – fountain
Fretum (ˈfri.təm) – strait
Insula (ˈɪn.sjə.lə) – island
Lacus (ˈleɪ.kəs) - lake
Lucus (ˈlu.kəs) - grove
Mare (ˈme.ɹi) – sea
Nix (ˈnɪks) – snow
Palus (ˈpeɪ.ləs) - marsh
Pons (ˈpɑnz) – bridge
Promontorium (ˌpɹɑ.mənˈto.ɹi.əm) – cape
Silva (ˈsɪl.və) - wood
Sinus (ˈsaɪ.nəs) – bay
Regio (ˈɹi.dʒi.oʊ) - region
List of features
A
Name
Pronunciation
Meaning
Abalos
ˈæ.bə.lɑs
A no-longer existent island in the North Sea, east of Heligoland.
