Editing Europa (moon) (section)

==== Plumes ====
<!---[[File:Water vapour plumes on Jupiter's moon Europa (artist's impression).jpg|thumb|Water vapor plumes on Jupiter's moon Europa (artist's impression)<ref name="Plumes2013" />]] --->[[File:Photo composite of suspected water plumes on Europa.jpg|thumb|Photo composite of suspected water plumes on Europa<ref name="Plumes2013">{{cite web|title=Photo composite of suspected water plumes on Europa|url=https://www.spacetelescope.org/images/opo1633a/|website=www.spacetelescope.org|access-date=6 October 2016|archive-date=9 October 2016|archive-url=https://web.archive.org/web/20161009104726/https://www.spacetelescope.org/images/opo1633a/|url-status=live}}</ref>]]
The [[Hubble Space Telescope]] acquired an image of Europa in 2012 that was interpreted to be a plume of water vapour erupting from near its south pole.<ref>{{Cite web|url=https://www.spacetelescope.org/news/heic1322/|title=Hubble discovers water vapour venting from Jupiter's moon Europa|date=12 December 2013|website=www.spacetelescope.org|publisher=Hubble Space Telescope/European Space Agency|language=en|access-date=16 April 2019|archive-date=16 April 2019|archive-url=https://web.archive.org/web/20190416012613/https://www.spacetelescope.org/news/heic1322/|url-status=live}}</ref><ref name="Plumes2013"/> The image suggests the plume may be {{convert|200|km|mi|abbr=on}} high, or more than 20 times the height of Mt. Everest.,<ref name="NASA-20131212-EU" /><ref>{{cite news | first = Leigh | last = Fletcher | title = The Plumes of Europa | date = 12 December 2013 | url = http://www.planetary.org/blogs/guest-blogs/2013/1212-fletcher-the-plumes-of-europa.html | work = The Planetary Society | access-date = 17 December 2013 | archive-date = 15 December 2013 | archive-url = https://web.archive.org/web/20131215041956/http://www.planetary.org/blogs/guest-blogs/2013/1212-fletcher-the-plumes-of-europa.html | url-status = live }}</ref><ref>{{cite news | first = Charles Q. | last = Choi | title = Jupiter Moon Europa May Have Water Geysers Taller Than Everest | date = 12 December 2013 | url = http://www.space.com/23923-europa-water-geyers-taller-than-everest.html | work = Space.com | access-date = 17 December 2013 | archive-date = 15 December 2013 | archive-url = https://web.archive.org/web/20131215173940/http://www.space.com/23923-europa-water-geyers-taller-than-everest.html | url-status = live }}</ref> though recent observations and modeling suggest that typical Europan plumes may be much smaller.<ref>{{Cite journal|last1=Fagents|first1=Sarah A.|last2=Greeley|first2=Ronald|last3=Sullivan|first3=Robert J.|last4=Pappalardo|first4=Robert T.|last5=Prockter|first5=Louise M.|date=30 June 1999|title=Cryomagmatic Mechanisms for the Formation of Rhadamanthys Linea, Triple Band Margins, and Other Low-Albedo Features on Europa|url=https://www.sciencedirect.com/science/article/abs/pii/S0019103599962541|journal=Icarus|volume=144|issue=1 |pages=54–88|doi=10.1006/icar.1999.6254|access-date=16 June 2022|archive-date=16 June 2022|archive-url=https://web.archive.org/web/20220616235235/https://www.sciencedirect.com/science/article/abs/pii/S0019103599962541|url-status=live}}</ref><ref>{{Cite journal|last1=Quick|first1=Lynnae C.|author-link=Lynnae Quick|last2=Barnouin|first2=Olivier S.|last3=Prockter|first3=Louise|author-link3=Louise Prockter|last4=Patterson|first4=G. Wesley|date=15 September 2013|title=Constraints on the Detection of Cryovolcanic Plumes on Europa|url=https://www.sciencedirect.com/science/article/abs/pii/S0032063313001803|journal=Planetary and Space Science|volume=86|issue=1 |pages=1–9|doi=10.1006/icar.1999.6254|access-date=16 June 2022|archive-date=16 June 2022|archive-url=https://web.archive.org/web/20220616235322/https://www.sciencedirect.com/science/article/abs/pii/S0032063313001803|url-status=live}}</ref><ref>{{Cite journal|last1=Paganini|first1=L.|last2=Villanueva|first2=G.L.|last3=Mandell|first3=A.M.|last4=Hurford|first4=T.A.|last5=Retherford|first5=K.D.|last6=Mumma|first6=M.A.|title=CA measurement of water vapour amid a largely quiescent environment on Europa|date=18 November 2019|url=https://www.nature.com/articles/s41550-019-0933-6|journal=Nature Astronomy|volume=4|issue=3|pages=266–272|doi=10.1038/s41550-019-0933-6|s2cid=210278335|access-date=16 June 2022|archive-date=18 June 2022|archive-url=https://web.archive.org/web/20220618112026/https://www.nature.com/articles/s41550-019-0933-6|url-status=live}}</ref> It has been suggested that if plumes exist, they are episodic<ref>{{cite news |last=Dyches |first=Preston |url=http://www.nasa.gov/jpl/signs-of-europa-plumes-remain-elusive-in-search-of-cassini-data |title=Signs of Europa Plumes Remain Elusive in Search of Cassini Data |work=NASA |date=30 July 2015 |access-date=18 April 2016 |archive-date=16 April 2016 |archive-url=https://web.archive.org/web/20160416214519/http://www.nasa.gov/jpl/signs-of-europa-plumes-remain-elusive-in-search-of-cassini-data/ |url-status=live }}</ref> and likely to appear when Europa is at its farthest point from Jupiter, in agreement with [[tidal force]] modeling predictions.<ref name='Europa tidal forces 2013'>{{cite journal |last1=Roth |first1=L. |last2=Saur |first2=J. |last3=Retherford |first3=K. D. |last4=Strobel |first4=D. F. |last5=Feldman |first5=P. D. |last6=McGrath |first6=M. A. |last7=Nimmo |first7=F. |title=Transient Water Vapor at Europa's South Pole |journal=Science |date=12 December 2013 |volume=343 |issue=6167 |pages=171–174 |doi=10.1126/science.1247051 |pmid=24336567 |bibcode=2014Sci...343..171R |s2cid=27428538 }}</ref> Additional imaging evidence from the Hubble Space Telescope was presented in September 2016.<ref name="plumes 2016">{{cite news |last=Berger |first=Eric |url=https://arstechnica.com/science/2016/09/hubble-finds-additional-evidence-of-water-vapor-plumes-on-europa/ |title=Hubble finds additional evidence of water vapor plumes on Europa |work=NASA |publisher=ARS Technica |date=26 September 2016 |access-date=26 September 2016 |archive-date=26 September 2016 |archive-url=https://web.archive.org/web/20160926202346/http://arstechnica.com/science/2016/09/hubble-finds-additional-evidence-of-water-vapor-plumes-on-europa/ |url-status=live }}</ref><ref>{{cite news |last=Amos |first=Jonathan |url=https://www.bbc.com/news/science-environment-37473617 |title=Europa moon 'spewing water jets' |work=BBC News |date=26 September 2016 |access-date=26 September 2016 |archive-date=26 September 2016 |archive-url=https://web.archive.org/web/20160926204050/http://www.bbc.com/news/science-environment-37473617 |url-status=live }}</ref>

In May 2018, astronomers provided supporting evidence of water plume activity on Europa, based on an updated critical analysis of data obtained from the ''Galileo'' space probe, which orbited Jupiter between 1995 and 2003. ''Galileo'' flew by Europa in 1997 within {{convert|206|km|mi|abbr=on}} of the moon's surface and the researchers suggest it may have flown through a water plume.<ref name="NA-20180514">{{cite journal |last1=Jia |first1=Xianzhe |last2=Kivelson |first2=Margaret G. |last3=Khurana |first3=Krishan K. |last4=Kurth |first4=William S. |title=Evidence of a plume on Europa from Galileo magnetic and plasma wave signatures |date=14 May 2018 |journal=[[Nature Astronomy]] |volume=2 |issue=6 |pages=459–464 |doi=10.1038/s41550-018-0450-z |bibcode=2018NatAs...2..459J |s2cid=134370392 }}</ref><ref name="NASA-20180514">{{cite web |last1=McCartney |first1=Gretchen |last2=Brown |first2=Dwayne |last3=Wendel |first3=JoAnna |title=Old Data Reveal New Evidence of Europa Plumes |website=[[Jet Propulsion Laboratory]] |url=https://www.jpl.nasa.gov/news/news.php?feature=7122 |date=14 May 2018 |access-date=14 May 2018 |archive-date=17 June 2019 |archive-url=https://web.archive.org/web/20190617213109/https://www.jpl.nasa.gov/news/news.php?feature=7122 |url-status=live }}</ref><ref name="NYT-20180514">{{cite news |last=Chang |first=Kenneth |title=NASA Finds Signs of Plumes From Europa, Jupiter's Ocean Moon |url=https://www.nytimes.com/2018/05/14/science/europa-plumes-water.html |date=14 May 2018 |work=[[The New York Times]] |access-date=14 May 2018 |archive-date=14 May 2018 |archive-url=https://web.archive.org/web/20180514165834/https://www.nytimes.com/2018/05/14/science/europa-plumes-water.html |url-status=live }}</ref><ref name="SP-20180514">{{cite web |last=Wall |first=Mike |title=This May Be the Best Evidence Yet of a Water Plume on Jupiter's Moon Europa |url=https://www.space.com/40575-jupiter-moon-europa-plume-galileo-spacecraft.html |date=14 May 2018 |work=[[Space.com]] |access-date=14 May 2018 |archive-date=14 May 2018 |archive-url=https://web.archive.org/web/20180514183300/https://www.space.com/40575-jupiter-moon-europa-plume-galileo-spacecraft.html |url-status=live }}</ref> Such plume activity could help researchers in a [[Life|search for life]] from the subsurface Europan ocean without having to land on the moon.<ref name="NA-20180514"/>

The tidal forces are about 1,000 times stronger than the Moon's effect on [[Earth]]. The only other moon in the Solar System exhibiting water vapor plumes is [[Enceladus]].<ref name="NASA-20131212-EU" /> The estimated eruption rate at Europa is about 7000&nbsp;kg/s<ref name='Europa tidal forces 2013'/> compared to about 200&nbsp;kg/s for the plumes of Enceladus.<ref name="Hansen2006">{{Cite journal | last1 = Hansen | first1 = C. J. | last2 = Esposito | first2 = L. | last3 = Stewart | first3 = A. I. | last4 = Colwell | first4 = J. | last5 = Hendrix | first5 = A. | last6 = Pryor | first6 = W. | last7 = Shemansky | first7 = D. | last8 = West | first8 = R. | s2cid = 2954801 | doi = 10.1126/science.1121254 | title = Enceladus' Water Vapor Plume | journal = Science | volume = 311 | issue = 5766 | pages = 1422–1425 | date = 10 March 2006| pmid = 16527971|bibcode = 2006Sci...311.1422H }}</ref><ref name="Spencer2013">{{Cite journal | last1 = Spencer | first1 = J. R. | last2 = Nimmo | first2 = F. | s2cid = 140646028 | doi = 10.1146/annurev-earth-050212-124025 | title = Enceladus: An Active Ice World in the Saturn System | journal = [[Annual Review of Earth and Planetary Sciences]]| volume = 41 | page = 693 | date = May 2013| issue = 1 |bibcode = 2013AREPS..41..693S }}</ref> If confirmed, it would open the possibility of a flyby through the plume and obtain a sample to analyze ''in situ'' without having to use a lander and drill through kilometres of ice.<ref name="plumes 2016"/><ref>{{cite news |last=O'Neill |first=Ian |url=http://www.space.com/34151-nasa-activity-spied-on-europa-but-its-not-aliens.html |title=NASA: Activity Spied on Europa, But It's 'NOT Aliens' |work=Discovery News |publisher=Space |date=22 September 2016 |access-date=23 September 2016 |archive-date=23 September 2016 |archive-url=https://web.archive.org/web/20160923011825/http://www.space.com/34151-nasa-activity-spied-on-europa-but-its-not-aliens.html |url-status=live }}</ref><ref name="europa_plume_in_situ">{{cite journal |title=On the in-situ detectability of Europa's water vapour plumes from a flyby mission |author1=Huybrighs, Hans |author2=Futaana, Yoshifumi |author3=Barabash, Stas |author4=Wieser, Martin |author5=Wurz, Peter|author6=Krupp, Norbert|author7=Glassmeier, Karl-Heinz|author8=Vermeersen, Bert |journal=Icarus |date=June 2017 |volume=289 |pages=270–280 |doi=10.1016/j.icarus.2016.10.026|arxiv=1704.00912|bibcode=2017Icar..289..270H|s2cid=119470009 }}</ref>

In November 2020, a study was published in the peer-reviewed scientific journal ''[[Geophysical Research Letters]]'' suggesting that the plumes may originate from water within the crust of Europa as opposed to its subsurface ocean. The study's model, using images from the Galileo space probe, proposed that a combination of freezing and pressurization may result in at least some of the cryovolcanic activity. The pressure generated by migrating briny water pockets would thus, eventually, burst through the crust, thereby creating these plumes. The hypothesis that cryovolcanism on Europa could be triggered by freezing and pressurization of liquid pockets in the icy crust was first proposed by Sarah Fagents at the University of Hawai'i at Mānoa, who in 2003, was the first to model and publish work on this process.<ref>{{Cite journal|last1=Fagents|first1=Sarah A.|date=27 December 2003|title=Considerations for effusive cryovolcanism on Europa:The post-Galileo perspective|url=https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2003JE002128|journal=Icarus|language=en|volume=108|issue=E12|pages=5139|doi=10.1029/2003JE002128|bibcode=2003JGRE..108.5139F|access-date=16 June 2022|archive-date=16 June 2022|archive-url=https://web.archive.org/web/20220616235245/https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2003JE002128|url-status=live}}</ref> A press release from NASA's Jet Propulsion Laboratory referencing the November 2020 study suggested that plumes sourced from migrating liquid pockets could potentially be less hospitable to life. This is due to a lack of substantial energy for organisms to thrive off, unlike proposed hydrothermal vents on the subsurface ocean floor.<ref name="JPL20201113">{{cite web |last1=McCartney |first1=Gretchen |last2=Hautaluoma |first2=Grey |last3=Johnson |first3=Alana |last4=Tucker |first4=Danielle |title=Potential Plumes on Europa Could Come From Water in the Crust |website=[[Jet Propulsion Laboratory]] |url=https://www.jpl.nasa.gov/news/news.php?feature=7785 |date=13 November 2020 |access-date=13 November 2020 |archive-date=13 November 2020 |archive-url=https://web.archive.org/web/20201113191732/https://www.jpl.nasa.gov/news/news.php?feature=7785 |url-status=live }}</ref><ref name="GRL20201105">{{cite journal |last1=Steinbrügge |first1=G. |last2=Voigt |first2=J. R. C. |last3=Wolfenbarger |first3=N. S. |last4=Hamilton |first4=C. W. |last5=Soderlund |first5=K. M. |last6=Young D. |first6=D. A. |last7=Blankenship |first7=D. |last8=Vance D. |first8=S. D. |last9=Schroeder |first9=M. |title=Brine Migration and Impact-Induced Cryovolcanism on Europa |date=5 November 2020 |journal=[[Geophysical Research Letters]] |volume=47 |issue=21 |pages={e2020GL090797} |doi=10.1029/2020GL090797|bibcode=2020GeoRL..4790797S |s2cid=228890686 }}</ref>