Editing Callisto (moon) (section)

==Habitability==
It is speculated that there could be life in Callisto's subsurface ocean. Like [[Europa (moon)|Europa]] and [[Ganymede (moon)|Ganymede]], as well as [[Saturn]]'s [[Moons of Saturn|moons]] [[Enceladus]], [[Dione (moon)|Dione]] and [[Titan (moon)|Titan]] and [[Neptune]]'s moon [[Triton (moon)|Triton]],<ref name="Triton subsurface ocean">{{cite journal |last1=Nimmo |first1=Francis |title=Powering Triton's recent geological activity by obliquity tides: Implications for Pluto geology |journal=Icarus |date=15 January 2015 |volume=246 |pages=2–10 |doi=10.1016/j.icarus.2014.01.044 |bibcode=2015Icar..246....2N |s2cid=40342189 |url=https://escholarship.org/content/qt99s8t6zm/qt99s8t6zm.pdf?t=nnm476 |access-date=12 April 2020 |archive-date=27 July 2020 |archive-url=https://web.archive.org/web/20200727083959/https://escholarship.org/content/qt99s8t6zm/qt99s8t6zm.pdf?t=nnm476 |url-status=live }}</ref> a possible subsurface ocean might be composed of [[Saline water|salt water]].

It is possible that [[halophile]]s could thrive in the ocean.<ref name="NASA finds ocean">{{cite web | url=https://science.nasa.gov/science-news/science-at-nasa/1998/ast22oct98_2/ | title=Callisto makes a big splash | publisher=NASA | date=23 October 1998 | access-date=15 August 2015 | last=Phillips | first=Tony | archive-date=28 May 2019 | archive-url=https://web.archive.org/web/20190528024102/https://science.nasa.gov/science-news/science-at-nasa/1998/ast22oct98_2 | url-status=live }}</ref>
As with [[Europa (moon)|Europa]] and [[Ganymede (moon)|Ganymede]], the idea has been raised that [[Planetary habitability|habitable]] conditions and even [[extraterrestrial life|extraterrestrial microbial life]] may exist in the salty [[subsurface ocean|ocean]] under the Callistoan surface.<ref name=Lipps2004>{{cite journal|last1=Lipps |first1=Jere H. |last2=Delory, Gregory |last3=Pitman, Joe |editor3-first=Alexei Y |editor3-last=Rozanov |editor2-first=Gilbert V |editor2-last=Levin |editor1-first=Richard B |editor1-last=Hoover |title=Astrobiology of Jupiter's Icy Moons |journal=Proc. SPIE |year=2004 |volume=5555 |page=10 |doi=10.1117/12.560356 |url=http://learning.berkeley.edu/astrobiology/2004ppt/jupiter.pdf |series=Instruments, Methods, and Missions for Astrobiology VIII |display-authors=etal |url-status=dead |archive-url=https://web.archive.org/web/20080820014713/http://learning.berkeley.edu/astrobiology/2004ppt/jupiter.pdf |archive-date=20 August 2008|bibcode=2004SPIE.5555...78L |s2cid=140590649 }}</ref> However, the environmental conditions necessary for life appear to be less favorable on Callisto than on Europa. The principal reasons are the lack of contact with rocky material and the lower heat flux from the interior of Callisto.<ref name=Lipps2004/> Callisto's ocean is heated only by radioactive decay, while Europa's is also heated by tidal energy, as it is much closer to Jupiter.<ref name="NASA finds ocean"/> It is thought that of all of Jupiter's moons, Europa has the greatest chance of supporting [[microorganism|microbial life]].<ref name=Lipps2004/><ref name="François2005">{{cite journal|last=François|first=Raulin|s2cid=121543884|title=Exo-Astrobiological Aspects of Europa and Titan: from Observations to speculations|year=2005|volume=116|issue=1–2|pages=471–487|doi=10.1007/s11214-005-1967-x | journal = Space Science Reviews|bibcode = 2005SSRv..116..471R }}</ref>