The

surface A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space. It is the portion or region of the object that can first be perceived by an observer using the senses of sight and touch, and is ...

of the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

has many features, including mountains and valleys, craters, and ''maria''—wide flat areas that look like seas from a distance but are probably solidified molten rock. Some of these features are listed.

Maria features

Lunar maria The lunar maria (; singular: mare ) are large, dark, basaltic plains on Earth's Moon, formed by ancient asteroid impacts on the far side on the Moon that triggered volcanic activity on the opposite (near) side. They were dubbed , Latin for 'seas' ...

'' (singular ''mare'') are large, dark, regions of the Moon. They do not contain any water, but are believed to have been formed from molten rock from the Moon's mantle coming out onto the surface of the Moon. This list also includes the one ''oceanus'' and the features known by the names ''lacus'', ''palus'' and ''sinus''. The modern system of lunar nomenclature was introduced in 1651 by Riccioli. Riccioli's map of the Moon was drawn by Francesco Maria Grimaldi, who has a crater named after him.

''Maria'' and ''Oceanus''

There is also a region on the Lunar farside that was briefly misidentified as a mare and named '' Mare Desiderii'' (Sea of Dreams). It is no longer recognized. Other former maria include: * Mare Parvum ("Small Sea"), immediately to the east of Inghirami * Mare Incognitum ("Unknown Sea") *

Mare Novum A mare is an adult female horse or other equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more than four y ...

("New Sea"), northeast of

Plutarch Plutarch (; grc-gre, Πλούταρχος, ''Ploútarchos''; ; – after AD 119) was a Greek Middle Platonist philosopher, historian, biographer, essayist, and priest at the Temple of Apollo in Delphi. He is known primarily for hi ...

* Mare Struve ("Struve's Sea"), near Messala

''Lacus''

A related set of features are the Lunar ''lacus'' (singular ''lacus'', Latin for "

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

"), which are smaller basaltic plains of similar origin:

''Sinus'' and ''Paludes''

A related set of features are the ''sinus'' (singular ''sinus'', Latin for "bay") and ''paludes'' (singular ''palus'', Latin for "marsh"): Some sources also list a ''Palus Nebularum'' ("Marsh of Mists") at 38.0° N, 1.0° E, but the designation for this feature has not been officially recognized by the IAU.

Craters

The large majority of these features are

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...

s. The crater nomenclature is governed by the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

, and this list only includes features that are officially recognized by that scientific society. The lunar craters are listed in the following subsections. Where a formation has associated satellite craters (smaller associated craters), these are detailed on the main crater description pages.

''Catenae''

A '' catena'' is a chain of craters.

Valleys

Several large lunar

valley A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams ove ...

s have been given names. Most of them are named after a nearby crater; see the

list of craters on the Moon This is a list of named lunar craters. The large majority of these features are impact craters. The crater nomenclature is governed by the International Astronomical Union, and this listing only includes features that are officially recognized b ...

for more information.

Mountains

The heights of the isolated mountains or

massif In geology, a massif ( or ) is a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole. The term also refers to a ...

s listed here are not consistently reported across sources. In the 1960s, the US Army Mapping Service used elevation relative to 1,737,988 meters from the center of the Moon. In the 1970s, the US Defense Mapping Agency used 1,730,000 meters. The ''

Clementine A clementine (''Citrus × clementina'') is a tangor, a citrus fruit hybrid between a willowleaf mandarin orange ( ''C.'' × ''deliciosa'') and a sweet orange (''C. × sinensis''), named in honor of Clément Rodier, a French missionary who fir ...

'' topographic data published in the 1990s uses 1,737,400 meters. This list is not comprehensive, and does not list the highest places on the Moon. ''Clementine'' data show a range of about 18,100 meters from lowest to highest point on the Moon. The highest point, located on the far side of the Moon, is approximately 6500 meters higher than Mons Huygens (usually listed as the tallest mountain). Mountains are referred to using the Latin word ''mons'' (plural ''montes'').

Mountain ranges

Other features

The

's surface exhibits many other geological features. In addition to mountains, valleys, and impact craters, the following surface features have received names in the Lunar nomenclature, many of them named after a nearby crater or mountain. The listed

diameter In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid fo ...

for these features is the longest dimension that contains the entire geological formation. The

latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...

s and

longitude Longitude (, ) is a geographic coordinate that specifies the east– west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lette ...

s are in

selenographic coordinates The selenographic coordinate system is used to refer to locations on the surface of Earth's moon. Any position on the lunar surface can be referenced by specifying two numerical values, which are comparable to the latitude and longitude of Earth. ...

Albedo

These features have a high

albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ...

compared to the surrounding terrain. On the far side of the

there are unnamed albedo features on

Mare Ingenii Mare Ingenii (Latin ''ingeniī'', the "Sea of Cleverness") is one of the few lunar mare features on the far side of the Moon. The mare sits in the Ingenii basin, which is of the Pre-Nectarian epoch, which lies in turn in the outer part of the ol ...

and

Mare Marginis Mare Marginis (Latin ''marginis'', the "Sea of the Edge") is a lunar mare that lies on the very edge of the lunar nearside. The selenographic coordinates of this feature are 13.3° N, 86.1° E, and the diameter is 358 km. The name is Latin ...

. These are located antipodal to the Mare Imbrium and

Mare Orientale Mare Orientale (Latin ''orientāle'', the "eastern sea") is a lunar mare. It is located on the western border of the near side and far side of the Moon, and is difficult to see from an Earthbound perspective. Images from spacecraft have reveal ...

impact basins.

''Dorsa''

A ''dorsum'' (plural ''dorsa'', meaning back or ridge) is a wrinkle-ridge system commonly found on

lunar maria The lunar maria (; singular: mare ) are large, dark, basaltic plains on Earth's Moon, formed by ancient asteroid impacts on the far side on the Moon that triggered volcanic activity on the opposite (near) side. They were dubbed , Latin for 'seas' ...

''Promontoria''

These features form a cape or headland on a

mare A mare is an adult female horse or other equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more than fo ...

''Rimae''

''Rimae'' (singular ''rima'') are lunar

rille Rille (German for 'groove') is typically used to describe any of the long, narrow depressions in the surface of the Moon that resemble channels. The Latin term is ''rima'', plural ''rimae''. Typically, a rille can be several kilometers wi ...

''Rupes''

These are

escarpment An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''esca ...

s in the surface.

''Terrae''

The continental areas between the seas were given comparable names by

Giovanni Battista Riccioli Giovanni Battista Riccioli, SJ (17 April 1598 – 25 June 1671) was an Italian astronomer and a Catholic priest in the Jesuit order. He is known, among other things, for his experiments with pendulums and with falling bodies, for his discussion ...

, but were opposite the names used for the seas. Thus there were the lands of sterility (Terra Sterilitatis), heat (Terra Caloris), and liveliness (Terra Vitae). However these names for the highland regions are no longer used on recent maps, and ''Terrae'' are not officially recognized as standard lunar nomenclature by the

References

These were used for references in the Water Features section. * , no ISBN. * Ben Bussey and

Paul Spudis Paul D. Spudis (1952–2018) was an American geologist and lunar scientist. His specialty was the study of volcanism and impact processes on the planets, including Mercury and Mars. Spudis was well known as a leading advocate of a return to ...

, ''The Clementine Atlas of the Moon'', Cambridge University Press, 2004, . * Antonín Rükl, ''Atlas of the Moon'', Kalmbach Books,

1990 File:1990 Events Collage.png, From left, clockwise: The 1990 FIFA World Cup is played in Italy; The Human Genome Project is launched; Voyager I takes the famous Pale Blue Dot image- speaking on the fragility of humanity on Earth, astrophysicist ...

, . * Ewen A. Whitaker, ''Mapping and Naming the Moon'', Cambridge University Press, 1999, . The following sources were used as references on the individual crater pages. * * * * * * * * * * * * *

External links

NASA lunar AtlasIAU, USGS: Moon nomenclatureIAU, USGS: Moon nomenclature: mountains

Astronomica Langrenus
— Italian Lunar Web Site
Gazetteer of Planetary Nomenclature

Lunar Atlases
at the Lunar & Planetary Institute *
Digital Lunar Orbiter Photographic Atlas of the Moon

Lunar Nomenclature

Lunar Photo of the Day
by Charles A. Wood ''et al.'' {{DEFAULTSORT:Lunar features

* * Features