Editing Dry ice (section)

==Extraterrestrial occurrence==
Following the Mars flyby of the [[Mariner 4]] spacecraft in 1966, scientists concluded that [[Martian polar ice caps|Mars' polar caps]] consist entirely of dry ice.<ref name="NGMars">{{Cite book|title = Mars Poles Covered by Water Ice, Research Shows|publisher = [[National Geographic Society|National Geographic]]|date = 13 February 2003|access-date = 2009-07-26|url = http://news.nationalgeographic.com/news/2003/02/0213_030213_marspoles.html|archive-date = 2009-07-01|archive-url = https://web.archive.org/web/20090701045810/http://news.nationalgeographic.com/news/2003/02/0213_030213_marspoles.html|url-status = dead}}</ref> However, findings made in 2003 by researchers at the [[California Institute of Technology]] have shown that Mars' polar caps are almost completely made of water ice, and that dry ice only forms a thin surface layer that thickens and thins seasonally.<ref name="NGMars"/><ref name="ScienceJournal">{{Cite journal|journal=[[Science (journal)|Science]]|date=2003-02-14|volume=299|issue=5609|doi=10.1126/science.1080148|title=A Sublimation Model for Martian South Polar Ice Features|last1=Byrne|first1=S.|pages=1051–1053|pmid=12586939|last2=Ingersoll|first2=AP|s2cid=7819614|bibcode = 2003Sci...299.1051B}}</ref> A phenomenon named dry ice storms was proposed to occur over the polar regions of Mars. They are comparable to Earth's thunderstorms, with crystalline CO<sub>2</sub> taking the place of water in the clouds.<ref name="NGMars2">{{Cite book|title = Dry Ice Storms May Pelt Martian Poles, Experts Say|publisher = [[National Geographic Society|National Geographic]]|date = 19 December 2005|access-date = 2009-07-26|url = http://news.nationalgeographic.com/news/2005/12/1219_051219_mars_ice.html|archive-date = 2010-09-04|archive-url = https://web.archive.org/web/20100904165650/http://news.nationalgeographic.com/news/2005/12/1219_051219_mars_ice.html|url-status = dead}}</ref> Dry ice is also proposed as a mechanism for the [[geysers on Mars]].<ref name=LPS2006>{{Cite web| title=Lunar and Planetary Science XXXVII (2006) – Observation of the Martian Cryptic Region from Mars Orbiter Camera| editor1-first=J. J. |editor1-last=Jian| editor2-first=W. H. |editor2-last=Ip| date=2006| url=http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1313.pdf| access-date=4 September 2009| archive-date=4 August 2020| archive-url=https://web.archive.org/web/20200804004623/https://www.lpi.usra.edu/meetings/lpsc2006/pdf/1313.pdf| url-status=live}}</ref>

In 2012, the [[European Space Agency]]'s [[Venus Express]] probe detected a cold layer in the atmosphere of [[Venus]] where temperatures are close to the triple point of carbon dioxide and it is possible that flakes of dry ice precipitate.<ref>[http://www.esa.int/Our_Activities/Space_Science/Venus_Express/A_curious_cold_layer_in_the_atmosphere_of_Venus "A curious cold layer in the atmosphere of Venus"]. {{Webarchive|url=https://web.archive.org/web/20151223190434/http://www.esa.int/Our_Activities/Space_Science/Venus_Express/A_curious_cold_layer_in_the_atmosphere_of_Venus |date=2015-12-23 }}. European Space Agency (1 October 2012).</ref>

Observations from the [[Uranus]] flyby by ''[[Voyager 2]]'' indicates that dry ice is present on the surface of its large moons [[Ariel (moon)|Ariel]],<ref name="Grundy Young et al. 2006">{{cite journal| doi = 10.1016/j.icarus.2006.04.016| last1 = Grundy| first1 = W. M.| last2 = Young| first2 = L. A.| last3 = Spencer| first3 = J. R.| last4 = Johnson| first4 = R. E.| last5 = Young| first5 = E. F.| last6 = Buie| first6 = M. W.| date=October 2006 | title = Distributions of H<sub>2</sub>O and CO<sub>2</sub> ices on Ariel, Umbriel, Titania, and Oberon from IRTF/SpeX observations| journal = Icarus| volume = 184| issue = 2| pages = 543–555| arxiv = 0704.1525| bibcode = 2006Icar..184..543G| s2cid = 12105236| ref = {{sfnRef|Grundy Young et al.|2006}}}}</ref> [[Umbriel]]<ref name="Grundy Young et al. 2006" /> and [[Titania (moon)|Titania]].<ref name="Grundy Young et al. 2006" /> Scientists speculate that the magnetic field of Uranus contributes to the generation of CO<sub>2</sub> ice on the surfaces of its moons.<ref name="CartwrightEmery2015">{{cite journal |last1=Cartwright |first1=R. J. |last2=Emery |first2=J. P. |last3=Rivkin |first3=A. S. |last4=Trilling |first4=D. E. |last5=Pinilla-Alonso|first5=N.|title=Distribution of {{CO2}} ice on the large moons of Uranus and evidence for compositional stratification of their near-surfaces |journal=Icarus |volume=257 |year=2015 |pages=428–456 |issn=0019-1035 |doi=10.1016/j.icarus.2015.05.020 |arxiv=1506.04673|bibcode=2015Icar..257..428C|s2cid=117850580}}</ref> ''Voyager 2'' observations of Neptune's moon [[Triton (moon)|Triton]] suggested the presence of dry ice on the surface, though followup observations indicate that the carbon ices on the surface are carbon monoxide but that the moon's crust is composed of a significant quantity of dry ice.<ref name="Lellouchde Bergh2010">{{cite journal|last1=Lellouch|first1=E.|last2=de Bergh |first2=C. |last3=Sicardy |first3=B. |last4=Ferron |first4=S. |last5=Käufl|first5=H.-U.|title=Detection of CO in Triton's atmosphere and the nature of surface-atmosphere interactions|journal=Astronomy and Astrophysics|volume=512|year=2010|pages=L8|issn=0004-6361|doi=10.1051/0004-6361/201014339 |arxiv=1003.2866 |bibcode=2010A&A...512L...8L |s2cid=58889896}}</ref>