Editing Pluto (section)

=== Surface ===
[[File:Pluto’s Heart - Like a Cosmic Lava Lamp.jpg|thumb|Sputnik Planitia is covered with churning nitrogen ice "cells" that are geologically young and turning over due to [[Convection cell|convection]].]]
The plains on Pluto's surface are composed of more than 98 percent [[nitrogen ice]], with traces of methane and [[carbon monoxide]].<ref name="tobias" /> [[Nitrogen]] and carbon monoxide are most abundant on the anti-Charon face of Pluto (around 180° longitude, where [[Tombaugh Regio]]'s western lobe, [[Sputnik Planitia]], is located), whereas methane is most abundant near 300° east.<ref name=Grundy_2013 /> The mountains are made of water ice.<ref name="drake-natgeo">{{cite magazine | url = http://news.nationalgeographic.com/2015/11/151109-astronomy-pluto-nasa-new-horizons-volcano-moons-science/| archive-url = https://web.archive.org/web/20151113013310/http://news.nationalgeographic.com/2015/11/151109-astronomy-pluto-nasa-new-horizons-volcano-moons-science/| url-status = dead| archive-date = November 13, 2015| title = Floating Mountains on Pluto – You Can't Make This Stuff Up| last = Drake| first = Nadia| author-link = Nadia Drake | date = November 9, 2015| magazine = [[National Geographic]]| access-date = December 23, 2016}}</ref> Pluto's surface is quite varied, with large differences in both brightness and color.<ref name="Buie_2010 light curve" /> Pluto is one of the most contrastive bodies in the Solar System, with as much contrast as [[Saturn]]'s moon [[Iapetus (moon)|Iapetus]].<ref name="Buie_web_map" /> The color varies from charcoal black, to dark orange and white.<ref name="Hubble2010" /> Pluto's color is more similar to that of [[Io (moon)|Io]] with slightly more orange and significantly less red than [[Mars]].<ref name="Buie_2010 surface-maps" /> [[Geography of Pluto|Notable geographical features]] include Tombaugh Regio, or the "Heart" (a large bright area on the side opposite Charon), [[Belton Regio]],<ref name = "Pluto System after New Horizons"/> or the "Whale" (a large dark area on the trailing hemisphere), and the "[[Brass Knuckles (Pluto)|Brass Knuckles]]" (a series of equatorial dark areas on the leading hemisphere).

Sputnik Planitia, the western lobe of the "Heart", is a 1,000&nbsp;km-wide basin of frozen nitrogen and carbon monoxide ices, divided into polygonal cells, which are interpreted as [[convection cell]]s that carry floating blocks of water ice crust and [[Sublimation (phase transition)|sublimation]] pits towards their margins;<ref name="lakdawalla-DPS-2016-10-26">{{cite web| url = http://www.planetary.org/blogs/emily-lakdawalla/2016/10251718-dpsepsc-new-horizons-pluto.html| title = DPS/EPSC update on New Horizons at the Pluto system and beyond| last = Lakdawalla| first = Emily| author-link = Emily Lakdawalla| date = October 26, 2016| publisher = [[The Planetary Society]]| access-date = October 26, 2016| archive-date = October 8, 2018| archive-url = https://web.archive.org/web/20181008021643/http://www.planetary.org/blogs/emily-lakdawalla/2016/10251718-dpsepsc-new-horizons-pluto.html| url-status = live}}</ref><ref name="McKinnon2016">{{cite journal|last1=McKinnon|first1=W. B.|last2=Nimmo|first2= F.|last3=Wong|first3= T.|last4= Schenk|first4=P. M.|last5=White|first5=O. L.|last6=Roberts|first6=J. H.|last7=Moore|first7=J. M.|last8=Spencer|first8=J. R.|last9=Howard|first9=A. D.|last10=Umurhan|first10=O. M.|last11= Stern|first11=S. A.|last12=Weaver|first12=H. A.|last13= Olkin|first13=C. B.|last14=Young|first14=L. A.|last15= Smith|first15=K. E.|last16=Beyer|first16= R.|last17= Buie|first17= M.|last18=Buratti|first18= B.|last19= Cheng|first19= A.|last20=Cruikshank|first20=D.|last21=Dalle Ore|first21= C.|last22= Gladstone|first22= R.|last23= Grundy|first23= W.|last24=Lauer|first24=T.|last25=Linscott|first25= I.|last26= Parker|first26= J.|last27=Porter|first27= S.|last28= Reitsema|first28= H.|last29=Reuter|first29= D.|last30= Robbins|first30= S.|last31= Showalter|first31= M.|last32= Singer|first32= K.|last33=Strobel|first33= D.|last34= Summers|first34= M.|last35= Tyler|first35= L.|last36= Banks|first36= M.|last37=Barnouin|first37= O.|last38= Bray|first38= V.|last39= Carcich|first39= B.|last40=Chaikin|first40= A.|last41= Chavez|first41=C.|last42= Conrad|first42= C.|last43= Hamilton|first43= D.|last44= Howett|first44= C.|last45=Hofgartner|first45= J.|last46= Kammer|first46= J.|last47= Lisse|first47= C.|last48= Marcotte|first48= A.|last49=Parker|first49= A.|last50= Retherford|first50= K.|last51=Saina|first51= M.|last52= Runyon|first52= K.|last53=Schindhelm|first53= E.|last54= Stansberry|first54= J.|last55= Steffl|first55= A.|last56= Stryk|first56=T.|last57=Throop|first57=H.|last58=Tsang|first58=C.|last59=Verbiscer|first59=A.|last60=Winters|first60=H.|last61=Zangari|first61=A.|display-authors=5|title=Convection in a volatile nitrogen-ice-rich layer drives Pluto's geological vigour|journal= Nature|volume=534|issue= 7605|date=June 1, 2016|pages= 82–85|doi= 10.1038/nature18289|pmid=27251279|bibcode = 2016Natur.534...82M |arxiv=1903.05571|s2cid=30903520}}</ref><ref name="Trowbridge2016">{{cite journal|last1=Trowbridge|first1=A. J.|last2= Melosh|first2=H. J.|last3= Steckloff|first3= J. K.|last4=Freed|first4=A. M.|title=Vigorous convection as the explanation for Pluto's polygonal terrain|journal= Nature|volume= 534|issue=7605|date= June 1, 2016|pages=79–81|doi=10.1038/nature18016|pmid=27251278|bibcode = 2016Natur.534...79T |s2cid=6743360 }}</ref> there are obvious signs of glacial flows both into and out of the basin.<ref name="Pluto updates">{{cite web| url = http://www.planetary.org/blogs/emily-lakdawalla/2015/12211538-pluto-updates-from-agu.html| title = Pluto updates from AGU and DPS: Pretty pictures from a confusing world| last = Lakdawalla| first = Emily| author-link = Emily Lakdawalla| date = December 21, 2015| publisher = [[The Planetary Society]]| access-date = January 24, 2016| archive-date = December 24, 2015| archive-url = https://web.archive.org/web/20151224193036/http://www.planetary.org/blogs/emily-lakdawalla/2015/12211538-pluto-updates-from-agu.html| url-status = live}}</ref><ref name="Umurhan2016-01-08">{{cite web
| url = https://blogs.nasa.gov/pluto/2016/01/08/probing-the-mysterious-glacial-flow-on-plutos-frozen-heart/
| title = Probing the Mysterious Glacial Flow on Pluto's Frozen 'Heart'
| last = Umurhan
| first = O.
| date = January 8, 2016
| website = blogs.nasa.gov
| publisher = NASA
| access-date = January 24, 2016
| archive-date = April 19, 2016
| archive-url = https://web.archive.org/web/20160419182828/https://blogs.nasa.gov/pluto/2016/01/08/probing-the-mysterious-glacial-flow-on-plutos-frozen-heart/
| url-status = live
}}</ref> It has no craters that were visible to ''New Horizons'', indicating that its surface is less than 10&nbsp;million years old.<ref name="Marchis2016">{{cite journal|last1=Marchis|first1=F.|last2=Trilling|first2=D. E.|title=The Surface Age of Sputnik Planum, Pluto, Must Be Less than 10 Million Years|journal=PLOS ONE|volume= 11|issue=1|date= January 20, 2016|pages= e0147386|doi= 10.1371/journal.pone.0147386|arxiv = 1601.02833 |bibcode = 2016PLoSO..1147386T|pmid=26790001|pmc=4720356|doi-access=free}}</ref> Latest studies have shown that the surface has an age of {{val|180000|-90000|+40000}} years.<ref name="LPSC2017Buhler">{{cite conference|last1=Buhler|first1=P. B.|last2=Ingersoll|first2=A. P.|url=https://www.hou.usra.edu/meetings/lpsc2017/pdf/1746.pdf|title=Sublimation pit distribution indicates convection cell surface velocity of ~10 centimeters per year in Sputnik Planitia, Pluto|book-title=48th Lunar and Planetary Science Conference|date=March 23, 2017|access-date=May 11, 2017|archive-date=August 13, 2017|archive-url=https://web.archive.org/web/20170813010426/https://www.hou.usra.edu/meetings/lpsc2017/pdf/1746.pdf|url-status=live}}</ref>
The New Horizons science team summarized initial findings as "Pluto displays a surprisingly wide variety of geological landforms, including those resulting from [[glaciological]] and surface–atmosphere interactions as well as impact, [[plate tectonics|tectonic]], possible [[cryovolcanic]], and [[mass wasting|mass-wasting]] processes."<ref name="Stern2015" />

In Western parts of Sputnik Planitia there are fields of [[transverse dunes]] formed by the winds blowing from the center of Sputnik Planitia in the direction of surrounding mountains. The dune wavelengths are in the range of 0.4–1&nbsp;km and likely consist of methane particles 200–300&nbsp;μm in size.<ref name="Brown2018">{{cite journal|doi=10.1126/science.aao2975|pmid=29853681|title=Dunes on Pluto|journal=Science|volume=360|issue=6392|pages=992–997|year=2018|last1=Telfer|first1=Matt W|last2=Parteli|first2=Eric J. R|last3=Radebaugh|first3=Jani|last4=Beyer|first4=Ross A|last5=Bertrand|first5=Tanguy|last6=Forget|first6=François|last7=Nimmo|first7=Francis|last8=Grundy|first8=Will M|last9=Moore|first9=Jeffrey M|last10=Stern|first10=S. Alan|last11=Spencer|first11=John|last12=Lauer|first12=Tod R|last13=Earle|first13=Alissa M|last14=Binzel|first14=Richard P|last15=Weaver|first15=Hal A|last16=Olkin|first16=Cathy B|last17=Young|first17=Leslie A|last18=Ennico|first18=Kimberly|last19=Runyon|first19=Kirby|bibcode=2018Sci...360..992T|s2cid=44159592|url=https://pearl.plymouth.ac.uk/bitstream/handle/10026.1/11613/UoP_Deposit_Agreement%20v1.1%2020160217.pdf?sequence=2&isAllowed=y|doi-access=free|access-date=April 12, 2020|archive-date=October 23, 2020|archive-url=https://web.archive.org/web/20201023114119/https://pearl.plymouth.ac.uk/bitstream/handle/10026.1/11613/UoP_Deposit_Agreement%20v1.1%2020160217.pdf?sequence=2&isAllowed=y|url-status=live}}</ref>

<gallery mode=packed heights=160>
File:Pluto-01 Stern 03 Pluto Color TXT.jpg|Multispectral Visual Imaging Camera image of Pluto in enhanced color to bring out differences in surface composition
File:Pluto_Charon_crater_map_Robbins_Dones_2023.jpg|Distribution of numerous impact craters and basins on both Pluto and Charon. The variation in density (with none found in [[Sputnik Planitia]]) indicates a long history of varying geological activity. Precisely for this reason, the confidence of numerous craters on Pluto remain uncertain.<ref name="Robbins2023"/> The lack of craters on the left and right of each map is due to low-resolution coverage of those anti-encounter regions.
File:Pluto's Sputnik Planum geologic map (cropped).jpg|Geologic map of Sputnik Planitia and surroundings ([[:File:Pluto's Sputnik Planum geologic map - context.jpg|context]]), with [[convection cell]] margins outlined in black
NH-Pluto-WaterIceDetected-BlueRegions-Released-20151008.jpg|Regions where water ice has been detected (blue regions)
</gallery>