Editing Saturn (section)

==== Hexagonal cloud patterns ====
{{main|Saturn's hexagon}}
{{multiple image
| align             = right
| direction         = horizontal
| total_width       = 400
| image1            = Rotatingsaturnhexagon.gif
| image2            = Looking saturn in the eye.jpg
| image3            = |thumb
| caption3          = Hexagonal storm pattern around the north pole of Saturn
| footer            = Saturn's north and south pole in [[infrared]]
}}

{{Anchor|North pole hexagonal cloud pattern|South pole vortex}}A persisting [[hexagon]]al wave pattern around the north polar vortex in the atmosphere at about 78°N was first noted in the ''Voyager'' images.<ref>{{cite journal |bibcode=1988Icar...76..335G |doi=10.1016/0019-1035(88)90075-9 |title=A hexagonal feature around Saturn's North Pole |date=1988 |page=335 |author=Godfrey, D. A. |volume=76 |journal=Icarus |issue=2}}</ref><ref>{{cite journal |title=Ground-based observations of Saturn's north polar SPOT and hexagon |first4=P. |last4=Laques |first3=F. |last3=Colas |first2=J. |last2=Lecacheux |journal=Science |display-authors=1 |first1=A. |last1=Sanchez-Lavega |volume=260 |issue=5106 |date=1993 |pmid=17838249 |doi=10.1126/science.260.5106.329 |bibcode=1993Sci...260..329S |pages=329–32|s2cid=45574015 }}</ref><ref name="NYT-20140806">{{cite news |last=Overbye |first=Dennis |author-link=Dennis Overbye |title=Storm Chasing on Saturn |url=https://www.nytimes.com/2014/08/06/science/space/storm-chasing-on-saturn.html |date=6 August 2014 |work=[[New York Times]] |access-date=6 August 2014 |archive-date=12 July 2018 |archive-url=https://web.archive.org/web/20180712004804/https://www.nytimes.com/2014/08/06/science/space/storm-chasing-on-saturn.html |url-status=live }}</ref> The sides of the hexagon are each about {{Convert|14500|km|mi|-2|abbr=on}} long, which is longer than the diameter of the Earth.<ref name="Hexagon ref">{{cite news |url=https://www.nbcnews.com/id/wbna34352533 |title=New images show Saturn's weird hexagon cloud |publisher=NBC News |date=12 December 2009 |access-date=29 September 2011 |archive-date=21 October 2020 |archive-url=https://web.archive.org/web/20201021075355/http://www.nbcnews.com/id/34352533 |url-status=live }}</ref> The entire structure rotates with a period of {{RA|10|39|24}} (the same period as that of the planet's radio emissions) which is assumed to be equal to the period of rotation of Saturn's interior.<ref name=science247_4947_1206/> The hexagonal feature does not shift in longitude like the other clouds in the visible atmosphere.<ref name=pss57_14_1671/> The pattern's origin is a matter of much speculation. Most scientists think it is a [[standing wave]] pattern in the atmosphere. Polygonal shapes have been replicated in the laboratory through differential rotation of fluids.<ref>{{cite journal |doi=10.1038/news060515-17 |last1=Ball |first1=Philip |title=Geometric whirlpools revealed |journal=[[Nature (journal)|Nature]] |date=19 May 2006|s2cid=129016856 |doi-access=free }} Bizarre geometric shapes that appear at the center of swirling vortices in planetary atmospheres might be explained by a simple experiment with a bucket of water but correlating this to Saturn's pattern is by no means certain.</ref><ref name=labmodel>{{cite journal |doi=10.1016/j.icarus.2009.10.022 |display-authors=1 |last1=Aguiar |first1=Ana C. Barbosa |last2=Read |first2=Peter L. |last3=Wordsworth |first3=Robin D |title=A laboratory model of Saturn's North Polar Hexagon |volume=206 |issue=2 |date=April 2010 |pages=755–763 |last4=Salter |first4=Tara |last5=Hiro Yamazaki |first5=Y. |journal=Icarus |bibcode=2010Icar..206..755B}} Laboratory experiment of spinning disks in a liquid solution forms vortices around a stable hexagonal pattern similar to that of Saturn's.</ref>

[[Hubble Space Telescope|HST]] imaging of the south polar region indicates the presence of a [[jet stream]], but no strong polar vortex nor any hexagonal standing wave.<ref>{{Cite journal |display-authors=1 |author=Sánchez-Lavega, A. |author2=Pérez-Hoyos, S. |author3=French, R. G. |url=http://aas.org/archives/BAAS/v34n3/dps2002/10.htm |title=Hubble Space Telescope Observations of the Atmospheric Dynamics in Saturn's South Pole from 1997 to 2002 |journal=Bulletin of the American Astronomical Society |volume=34 |page=857 |access-date=6 July 2007 |date=8 October 2002 |bibcode=2002DPS....34.1307S |archive-date=30 June 2010 |archive-url=https://web.archive.org/web/20100630162647/http://aas.org/archives/BAAS/v34n3/dps2002/10.htm |url-status=live }}</ref> [[NASA]] reported in November 2006 that ''Cassini'' had observed a "[[hurricane]]-like" storm locked to the south pole that had a clearly defined [[eyewall]].<ref>{{cite web |url=http://photojournal.jpl.nasa.gov/catalog/PIA09187 |title=NASA catalog page for image PIA09187 |access-date=23 May 2007 |publisher=NASA Planetary Photojournal |archive-url=https://web.archive.org/web/20111109044235/http://photojournal.jpl.nasa.gov/catalog/PIA09187 |archive-date=9 November 2011 |url-status=live }}</ref><ref>{{cite news |url=http://news.bbc.co.uk/2/hi/6135450.stm?lsm |title=Huge 'hurricane' rages on Saturn |work=BBC News |date=10 November 2006 |access-date=29 September 2011 |archive-url=https://web.archive.org/web/20120803115422/http://news.bbc.co.uk/2/hi/6135450.stm?lsm |archive-date=3 August 2012 |url-status=live }}</ref> Eyewall clouds had not previously been seen on any planet other than Earth. For example, images from the ''[[Galileo (spacecraft)|Galileo]]'' spacecraft did not show an eyewall in the [[Great Red Spot]] of Jupiter.<ref>{{cite web |url=http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=703 |title=NASA Sees into the Eye of a Monster Storm on Saturn |publisher=NASA |date=9 November 2006 |access-date=20 November 2006 |archive-url=https://web.archive.org/web/20080507154317/http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=703 |archive-date=7 May 2008 |url-status=dead }}</ref>

The south pole storm may have been present for billions of years.<ref name="spole"/> This vortex is comparable to the size of Earth, and it has winds of 550&nbsp;km/h.<ref name="spole">{{Cite APOD | title=A Hurricane Over the South Pole of Saturn | date=13 November 2006 | access-date=1 May 2013}}</ref>