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{{Short description|Hemisphere of the Moon facing the Earth}}
{{redirect|Nearside|the usage in road vehicles|Right- and left-hand traffic#Road vehicle configurations}}
[[File:Moon names.svg|thumb|upright=1.35|The names of the major [[lunar mare|maria]] and some [[lunar craters|craters]] on the near side of the Moon]]

The '''near side of the Moon''' is the lunar hemisphere that always faces towards [[Earth]], opposite to the [[far side of the Moon|far side]]. Only one side of the [[Moon]] is visible from Earth because the Moon rotates on its axis at the same rate that the Moon orbits the Earth—a situation known as [[tidal locking]].

The Moon is directly illuminated by the [[Sun]], and the cyclically varying viewing conditions cause the [[lunar phase]]s. Sometimes the dark portion of the Moon is faintly visible due to [[earthlight (astronomy)|earthshine]], which is indirect [[sunlight]] reflected from the surface of Earth and onto the Moon.

Since the [[orbit of the Moon|Moon's orbit]] is both somewhat [[elliptic orbit|elliptical]] and [[orbital inclination|inclined]] to its [[equator|equatorial plane]], [[libration]] allows up to 59% of the Moon's surface to be viewed from Earth (though only half at any moment from any point).

[[File:Lunar libration with phase Oct 2007 (continuous loop).gif|right|thumb|thumbtime=0:02|alt=Over one lunar month more than half of the Moon's surface can be seen from the surface of the Earth.|The near side as observed (from Earth's [[Northern Hemisphere]]) over the course of one [[lunar month|month]], showing the [[libration]] effects]]

==Orientation==
[[File:Moon nearside LRO.jpg|right|thumb|Detailed view by NASA's [[Lunar Reconnaissance Orbiter]] ]]
The image of the Moon here is drawn as is normally shown on maps, that is with north on top and west to the left. Astronomers traditionally turn the map to have south on top to correspond with the northern-hemisphere view in astronomical telescopes, which typically show the image upside down.

West and east on the Moon are where they would be expected, when standing on the Moon. But when the Moon is seen from Earth, then the east–west direction is reversed. When specifying coordinates on the Moon it should therefore always be mentioned whether [[geographic]] (or rather [[selenographic coordinates|selenographic]]) coordinates are used or [[astronomical]] coordinates.

The Moon's actual orientation in Earth's sky or on the horizon depends on the viewers geographic [[latitude]] on Earth. In the following description a few typical cases will be considered.

*On the north pole, if the Moon is visible, it stands low above the horizon with [[Lunar north pole|its north pole]] up.
*In mid northern latitudes (North America, Europe, Asia) the Moon rises in the east with its northeastern limb up (Mare Crisium), it reaches its highest point in the south with its north on top, and sets in the west with its northwestern limb (Mare Imbrium) on top.
*On the equator, when the Moon rises in the east, its N — S axis appears horizontal and Mare Foecunditatis is on top. When it sets in the west, about 12.5 hours later, the axis is still horizontal, and Oceanus Procellarum is the last area to dip below the horizon. In between these events, the Moon reached its highest point in the [[zenith]] and then its selenographic directions are lined up with those on Earth.
*In mid southern latitudes (South America, South Pacific, Australia, South Africa) the Moon rises in the east with its southeastern limb up (Mare Nectaris), it reaches its highest point in the north with its south on top, and sets in the west with its southwestern limb (Mare Humorum) on top.
*On the south pole the Moon behaves as on the north pole, but there it appears with [[Lunar south pole|its south pole]] up.
[[Image:Diurnal motion by latitude.svg|752px|thumb|center|Schematics of moonrise on different Earth latitudes]]
{{multiple image
|header=Moon – [[Oceanus Procellarum]] ("Ocean of Storms") | align = center | total_width=600 |width1=614 |height1=228 |image1=14-236-LunarGrailMission-OceanusProcellarum-Rifts-Overall-20141001.jpg|caption1=Ancient [[rift valley]]s – rectangular structure (visible – topography – [[Gravity Recovery and Interior Laboratory|GRAIL gravity gradients]]) (October 1, 2014).|width2=1500 |height2=1500 |image2=PIA18822-LunarGrailMission-OceanusProcellarum-Rifts-Overall-20141001.jpg|caption2=Ancient [[rift valley]]s – context.|width3=1546 |height3=905 |image3=PIA18821-LunarGrailMission-OceanusProcellarum-Rifts-Closeup-20141001.jpg|caption3=Ancient [[rift valley]]s – closeup (artist's concept).}}

==Differences==
{{see also|Geology of the Moon}}
[[File:Wac643 4globes 800p.png|thumb|Changing landscape between the hemispheres]]
The two hemispheres have distinctly different appearances, with the near side covered in multiple, large [[Lunar mare|''maria'']] (Latin for 'seas'). These lowlands were believed to be seas of [[lunar water]] by the astronomers who first mapped them, in the 17th century (notably, [[Giovanni Battista Riccioli]] and [[Francesco Maria Grimaldi]]). Although no bodies of [[liquid]] exist on the Moon, the term "''mare''" (plural: ''maria'') is still used. [[Far side of the Moon|The far side]] has a battered, densely cratered appearance with few maria. Only 1% of the surface of the far side is covered by maria,<ref>{{cite journal | author=J. J. Gillis | author2=P. D. Spudis | title=The Composition and Geologic Setting of Lunar Far Side Maria | journal=Lunar and Planetary Science | date=1996 | volume=27 | pages=413| bibcode=1996LPI....27..413G }}</ref> compared to 31.2% on the near side. According to research analyzed by NASA's [[Gravity Recovery and Interior Laboratory]] (GRAIL) mission, the reason for the difference is because the Moon's [[crust (geology)|crust]] is thinner on the near side compared to the far side.<ref>{{Cite web|date=2013-11-13|title=Moon's Blotchy Near Side Has Bigger Craters Than Expected|url=https://www.universetoday.com/106378/moons-blotchy-near-side-has-bigger-craters-than-expected/|access-date=2021-10-06|website=Universe Today|language=en-US}}</ref> The dark splotches that make up the large lunar maria are [[lava]]-filled [[impact basin]]s that were created by asteroid impacts about four billion years ago. Though both sides of the Moon were bombarded by similarly large impactors, the near side hemisphere crust and upper mantle was hotter than that of the far side, resulting in the larger impact craters.<ref>[https://www.science.org/doi/10.1126/science.1243224 Science Magazine]</ref> These larger impact craters make up the [[Man in the Moon]] references from popular mythology.

==See also==
* [[Giant impact hypothesis]]
* [[Lists of astronomical objects]]
* [[Moon rabbit]]

==References==
{{Reflist}}

==Further reading==
*{{cite book|author=John Moore|title=Craters of the Near Side Moon|url=https://books.google.com/books?id=skP9nwEACAAJ|date=2014|publisher=Createspace Independent Pub|isbn=978-1-4973-2444-2}}

==External links==
*[http://www.lpi.usra.edu/expmoon/ Lunar and Planetary Institute: Exploring the Moon]
*[https://web.archive.org/web/20111218085633/http://www.lpi.usra.edu/resources/lunar_atlases/ Lunar and Planetary Institute: Lunar Atlases] (archived 18 December 2011)
*[https://web.archive.org/web/20040206052233/http://ralphaeschliman.com/id26.htm Ralph Aeschliman Planetary Cartography and Graphics: Lunar Maps] (archived 6 February 2004)
*[http://www.nasa.gov/mission_pages/grail/main/index.html NASA's Gravity Recovery and Interior Laboratory (GRAIL) Mission]

{{The Moon}}
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[[Category:Lunar science]]
[[Category:Hemispheres of Moon]]

Near side of the Moon - Revision history

Ajay Kumar: Created a new article