Editing Pluto (section)

=== Exploration ===
{{Main|Exploration of Pluto|New Horizons|}}
[[File:Barycentric view of Pluto and Charon 29 May-3 June by Ralph in near-true colours.gif|thumb|Pluto and Charon seen orbiting each other by ''New Horizons'']]

The ''New Horizons'' spacecraft, which [[planetary flyby|flew by]] Pluto in July 2015, is the first and so far only attempt to explore Pluto directly. Launched in 2006, it captured its first (distant) images of Pluto in late September 2006 during a test of the Long Range Reconnaissance Imager.<ref name="pluto.jhuapl First Pluto Sighting" /> The images, taken from a distance of approximately 4.2&nbsp;billion kilometers, confirmed the spacecraft's ability to track distant targets, critical for maneuvering toward Pluto and other Kuiper belt objects. In early 2007 the craft made use of a [[gravity assist]] from [[Jupiter]].

''New Horizons'' made its closest approach to Pluto on July 14, 2015, after a 3,462-day journey across the Solar System. Scientific observations of Pluto began five months before the closest approach and continued for at least a month after the encounter. Observations were conducted using a [[remote sensing]] package that included [[digital imaging|imaging]] instruments and a radio science investigation tool, as well as [[spectroscopic]] and other experiments. The scientific goals of ''New Horizons'' were to characterize the global geology and morphology of Pluto and its moon Charon, map their surface composition, and analyze Pluto's neutral atmosphere and its escape rate. On October 25, 2016, at 05:48 pm ET, the last bit of data (of a total of 50&nbsp;billion bits of data; or 6.25 gigabytes) was received from ''New Horizons'' from its close encounter with Pluto.<ref name="NYT-20161028">{{cite news |last=Chang |first=Kenneth |title=No More Data From Pluto |url=https://www.nytimes.com/2016/10/29/science/pluto-nasa-new-horizons.html |date=October 28, 2016 |work=[[New York Times]] |access-date=October 28, 2016 |archive-date=March 29, 2019 |archive-url=https://web.archive.org/web/20190329002642/https://www.nytimes.com/2016/10/29/science/pluto-nasa-new-horizons.html |url-status=live }}</ref><ref>{{cite web
 | url=http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20161027
 | title=Pluto Exploration Complete: New Horizons Returns Last Bits of 2015 Flyby Data to Earth
 | date=October 27, 2016
| publisher=Johns Hopkins Applied Research Laboratory
 | access-date=October 28, 2016
| archive-date=October 28, 2016
| archive-url=https://web.archive.org/web/20161028100437/http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20161027
 | url-status=live
 }}</ref><ref name="NASA-20150115(b)">{{cite web |last1=Brown |first1=Dwayne |last2=Buckley |first2=Michael |last3=Stothoff |first3=Maria |title=Release 15-011 – NASA's New Horizons Spacecraft Begins First Stages of Pluto Encounter |url=http://www.nasa.gov/press/2015/january/nasa-s-new-horizons-spacecraft-begins-first-stages-of-pluto-encounter |date=January 15, 2015 |work=NASA |access-date=January 15, 2015 |archive-date=April 7, 2020 |archive-url=https://web.archive.org/web/20200407083332/https://www.nasa.gov/press/2015/january/nasa-s-new-horizons-spacecraft-begins-first-stages-of-pluto-encounter |url-status=live }}</ref><ref>{{Cite web|url=http://pluto.jhuapl.edu/Mission/Spacecraft/Data-Collection.php|title=New Horizons|website=pluto.jhuapl.edu|access-date=May 15, 2016|archive-date=October 8, 2016|archive-url=https://web.archive.org/web/20161008104223/http://pluto.jhuapl.edu/Mission/Spacecraft/Data-Collection.php|url-status=live}}</ref>

Since the ''New Horizons'' flyby, scientists have advocated for an orbiter mission that would return to Pluto to fulfill new science objectives.<ref>{{Cite news|url=https://www.theverge.com/2017/4/26/15424770/nasa-spacecraft-new-horizons-flyby-pluto-moons-orbiter-mission|title=Why a group of scientists think we need another mission to Pluto|work=The Verge|access-date=July 14, 2018|archive-date=July 8, 2018|archive-url=https://web.archive.org/web/20180708104340/https://www.theverge.com/2017/4/26/15424770/nasa-spacecraft-new-horizons-flyby-pluto-moons-orbiter-mission|url-status=live}}</ref><ref>{{Cite web|url=https://www.technologyreview.com/2021/07/19/1029680/nasa-pluto-mission-persephone/|title=Why NASA should visit Pluto again|website=MIT Technology Review|access-date=January 18, 2022|archive-date=January 18, 2022|archive-url=https://web.archive.org/web/20220118115746/https://www.technologyreview.com/2021/07/19/1029680/nasa-pluto-mission-persephone/|url-status=live}}</ref><ref>{{Cite web|url = https://www.spaceflightinsider.com/missions/solar-system/videos-simulate-pluto-charon-flyby-follow-up-mission-proposed|title = New videos simulate Pluto and Charon flyby; return mission to Pluto proposed|date = August 2021|access-date = September 4, 2021|archive-date = September 4, 2021|archive-url = https://web.archive.org/web/20210904132010/https://www.spaceflightinsider.com/missions/solar-system/videos-simulate-pluto-charon-flyby-follow-up-mission-proposed/|url-status = dead}}</ref> They include mapping the surface at {{cvt|30|ft|m|sigfig=2|order=flip}} per pixel, observations of Pluto's smaller satellites, observations of how Pluto changes as it rotates on its axis, investigations of a possible subsurface ocean, and topographic mapping of Pluto's regions that are covered in long-term darkness due to its axial tilt. The last objective could be accomplished using laser pulses to generate a complete topographic map of Pluto. ''New Horizons'' principal investigator Alan Stern has advocated for a [[Cassini–Huygens|''Cassini'']]-style orbiter that would launch around 2030 (the 100th anniversary of Pluto's discovery) and use Charon's gravity to adjust its orbit as needed to fulfill science objectives after arriving at the Pluto system.<ref>{{Cite news|url=https://www.space.com/36697-pluto-orbiter-mission-after-new-horizons.html|title=Going Back to Pluto? Scientists to Push for Orbiter Mission|work=Space.com|access-date=July 14, 2018|archive-date=July 14, 2018|archive-url=https://web.archive.org/web/20180714110958/https://www.space.com/36697-pluto-orbiter-mission-after-new-horizons.html|url-status=live}}</ref> The orbiter could then use Charon's gravity to leave the Pluto system and study more KBOs after all Pluto science objectives are completed. A conceptual study funded by the NASA Innovative Advanced Concepts ([[NASA Institute for Advanced Concepts|NIAC]]) program describes a fusion-enabled Pluto orbiter and lander based on the [[Princeton field-reversed configuration experiment|Princeton field-reversed configuration reactor]].<ref>{{Cite news|url=https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_I_Phase_II/Fusion_Enabled_Pluto_Orbiter_and_Lander|title=Fusion-Enabled Pluto Orbiter and Lander|last=Hall|first=Loura|date=April 5, 2017|work=NASA|access-date=July 14, 2018|language=en|archive-date=April 21, 2017|archive-url=https://web.archive.org/web/20170421033505/https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_I_Phase_II/Fusion_Enabled_Pluto_Orbiter_and_Lander/|url-status=live}}</ref><ref name='PSS'>[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170003126.pdf Fusion-Enabled Pluto Orbiter and Lander – Phase I Final Report] {{Webarchive|url=https://web.archive.org/web/20190429071941/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170003126.pdf |date=April 29, 2019 }}. (PDF) Stephanie Thomas, Princeton Satellite Systems. 2017.</ref>

''New Horizons'' imaged all of Pluto's northern hemisphere, and the equatorial regions down to about 30° South. Higher southern latitudes have only been observed, at very low resolution, from Earth.<ref>{{cite web |access-date=August 19, 2021 |title=5 Amazing Things We've Learned a Year After Visiting Pluto |work=[[National Geographic]] |author=Nadia Drake |date=July 14, 2016 |url=https://www.nationalgeographic.com/science/article/pluto-planets-new-horizons-one-year-anniversary-nasa-space-science|archive-url=https://web.archive.org/web/20210307022014/https://www.nationalgeographic.com/science/article/pluto-planets-new-horizons-one-year-anniversary-nasa-space-science|url-status=dead|archive-date=March 7, 2021}}</ref> Images from the Hubble Space Telescope in 1996 cover 85% of Pluto and show large albedo features down to about 75° South.<ref>{{cite web |url=https://hubblesite.org/contents/news-releases/1996/news-1996-09.html |title=HUBBLE REVEALS SURFACE OF PLUTO FOR FIRST TIME |date=March 7, 1996 |work=HubbleSite.org |publisher=Space Telescope Science Institute |access-date=October 18, 2021 |archive-date=August 19, 2021 |archive-url=https://web.archive.org/web/20210819132618/https://hubblesite.org/contents/news-releases/1996/news-1996-09.html |url-status=live }}</ref><ref>{{cite web |url=https://hubblesite.org/contents/media/images/1996/09/401-Image.html?news=true |title=MAP OF PLUTO'S SURFACE |date=March 7, 1996 |work=HubbleSite.org |publisher=Space Telescope Science Institute |access-date=October 18, 2021 |archive-date=August 19, 2021 |archive-url=https://web.archive.org/web/20210819132616/https://hubblesite.org/contents/media/images/1996/09/401-Image.html?news=true |url-status=live }}</ref> This is enough to show the extent of the temperate-zone maculae. Later images had slightly better resolution, due to minor improvements in Hubble instrumentation.<ref name="theh_Seei">{{Cite news |title=Seeing Pluto like never before |author=A.S.Ganesh |work=The Hindu |date=March 7, 2021 |access-date=August 19, 2021 |url=https://www.thehindu.com/children/seeing-pluto-like-never-before/article33941881.ece |archive-date=August 19, 2021 |archive-url=https://web.archive.org/web/20210819132745/https://www.thehindu.com/children/seeing-pluto-like-never-before/article33941881.ece |url-status=live }}</ref> The equatorial region of the sub-Charon hemisphere of Pluto has only been imaged at low resolution, as ''New Horizons'' made its closest approach to the anti-Charon hemisphere.<ref>{{cite journal |last1=Rothery |first1=David A |date=October 2015 |title=Pluto and Charon from New Horizons |journal=Astronomy & Geophysics |volume=56 |issue=5 |pages=5.19–5.22 |doi=10.1093/astrogeo/atv168 |doi-access=free}}</ref>

Some albedo variations in the higher southern latitudes could be detected by ''New Horizons'' using [[planetshine|Charon-shine]] (light reflected off Charon). The south polar region seems to be darker than the north polar region, but there is a high-albedo region in the southern hemisphere that may be a regional nitrogen or methane ice deposit.<ref name="Charonshine">{{cite journal |last1=Lauer |first1=Todd R. |last2=Spencer |first2=John R. |first3=Tanguy |last3=Bertrand |first4=Ross A. |last4=Beyer |first5=Kirby D. |last5=Runyon |first6=Oliver L. |last6=White |first7=Leslie A. |last7=Young |first8=Kimberly |last8=Ennico |first9=William B. |last9=MacKinnon |first10=Jeffrey M. |last10=Moore |first11=Catherine B. |last11=Olkin |first12=S. Alan |last12=Stern |first13=Harold A. |last13=Weaver |date=October 20, 2021 |title=The Dark Side of Pluto |journal=The Planetary Science Journal |volume=2 |issue=214 |page=214 |doi=10.3847/PSJ/ac2743 |arxiv=2110.11976 |bibcode=2021PSJ.....2..214L |s2cid=239047659 |doi-access=free }}</ref>

[[File:MVIC sunset scan of Pluto.jpg|thumb|center|upright=2|Panoramic view of Pluto's icy mountains and flat ice plains, imaged by ''New Horizons'' 15 minutes after its closest approach to Pluto. Distinct haze layers in Pluto's atmosphere can be seen backlit by the Sun.]]