Editing Charon (moon) (section)

== Formation ==
Simulation work published in 2005 by [[Robin Canup]] suggested that Charon could have been formed by a collision around 4.5 [[1000000000 (number)|billion]] years ago, much like [[Earth]] and the [[Moon]]. In this model, a large [[Kuiper belt]] object struck Pluto at high velocity, destroying itself and blasting off much of Pluto's outer [[mantle (geology)|mantle]], and Charon coalesced from the debris.<ref>{{cite journal |title=A Giant Impact Origin of Pluto–Charon |last=Canup |first=Robin |author-link=Robin Canup |journal=Science |date=January 28, 2005 |url= http://www.sciencemag.org/cgi/content/full/307/5709/546|doi=10.1126/science.1106818 |bibcode=2005Sci...307..546C |pmid=15681378 |volume=307 |issue=5709 |pages=546–50|s2cid=19558835 }}</ref> However, such an impact should result in an icier Charon and rockier Pluto than scientists have found. It is now thought that Pluto and Charon might have been two bodies that collided before going into orbit around each other. The collision would have been violent enough to boil off volatile ices like [[methane]] ({{chem|C|H|4}}) but not violent enough to have destroyed either body. The very similar density of Pluto and Charon implies that the parent bodies were not fully differentiated when the impact occurred.<ref name="Stern_2015"/> The two bodies would have been stuck for a while, before separating from each other again, while remaining gravitationally bound. The internal heat in both bodies, created from both the collision and then the tidal friction as they separated, would have been sufficient to create Pluto's subsurface ocean without the need for radioactive elements.<ref>{{cite web|url=https://phys.org/news/2025-01-newly-capture-mechanism-formation-pluto.html|title=Newly discovered 'kiss and capture' mechanism explains the formation of Pluto and its largest moon|publisher=[[University of Arizona]]|date=January 6, 2025|access-date=February 10, 2025}}</ref>