Editing Saturn (section)

== History of observation and exploration ==

The observation and exploration of Saturn can be divided into three phases: (1) pre-modern observations with the [[naked eye]], (2) telescopic observations from Earth beginning in the 17th century, and (3) visitation by [[space probe]]s, in orbit or on [[planetary flyby|flyby]]. In the 21st century, telescopic observations continue from Earth (including [[Geocentric orbit|Earth-orbiting]] [[space telescope|observatories]] like the [[Hubble Space Telescope]]) and, until [[Cassini retirement|its 2017 retirement]], from the ''[[Cassini–Huygens|Cassini]]'' orbiter around Saturn.

=== Pre-telescopic observation ===
{{See also|Saturn (mythology)|Planets in astrology#Saturn}}

Saturn has been known since prehistoric times,<ref name="NMM Saturn 2">{{cite web |title=Observing Saturn |url=http://www.nmm.ac.uk/server/show/conWebDoc.13852/viewPage/5 |publisher=[[National Maritime Museum]] |access-date=6 July 2007 |archive-url=https://web.archive.org/web/20070422014136/http://www.nmm.ac.uk/server/show/conWebDoc.13852/viewPage/5 <!--Added by H3llBot--> |archive-date=22 April 2007|date=20 August 2015 }}</ref> and in early recorded history it was a major character in various mythologies. [[Babylonian astronomy|Babylonian astronomers]] systematically observed and recorded the movements of Saturn.<ref name=ptrsl276_1257_43/> In ancient Greek, the planet was known as {{lang|grc|Φαίνων}} '''''[[Phaenon|Phainon]]''''',<ref>{{LSJ|*fai/nwn|Φαίνων|ref|mLSJ}}.</ref> and in Roman times it was known as the "star of [[Saturn (mythology)|Saturn]]" or the "star of the [[Sun]] (i.e. [[Helios]])".<ref>Cicero, ''De Natura Deorum''.</ref><ref>{{Cite journal |last1=Neuhäuser |first1=R |last2=Torres |first2=G |last3=Mugrauer |first3=M |last4=Neuhäuser |first4=D L |last5=Chapman |first5=J |last6=Luge |first6=D |last7=Cosci |first7=M |date=2022-10-11 |title=Colour evolution of Betelgeuse and Antares over two millennia, derived from historical records, as a new constraint on mass and age |url=https://academic.oup.com/mnras/article/516/1/693/6651563 |journal=Monthly Notices of the Royal Astronomical Society |volume=516 |issue=1 |pages=693–719 |doi=10.1093/mnras/stac1969 |doi-access=free |issn=0035-8711|arxiv=2207.04702 }}</ref> In [[Roman mythology|ancient Roman mythology]], the planet Phainon was sacred to this agricultural god, from which the planet takes its modern name.<ref name="Saturn in ancient mythologies" /> The Romans considered the god Saturnus the equivalent of the [[Greek mythology|Greek god]] [[Cronus]]; in modern [[Greek language|Greek]], the planet retains the name ''Cronus''—{{Langx|el|Κρόνος|label=none}}: ''Kronos''.<ref>{{cite web |url=http://www.greek-names.info/greek-names-of-the-planets/ |title=Greek Names of the Planets |access-date=14 July 2012 |quote=The Greek name of the planet Saturn is Kronos. The Titan Cronus was the father of [[Zeus]], while Saturn was the Roman God of agriculture. |date=25 April 2010 |archive-date=9 May 2010 |archive-url=https://web.archive.org/web/20100509164917/http://www.greek-names.info/greek-names-of-the-planets/ |url-status=live }} See also the [[:el:Κρόνος (πλανήτης)|Greek article about the planet]].</ref>

The Greek scientist [[Ptolemy]] based his calculations of Saturn's orbit on observations he made while it was in [[opposition (astronomy)|opposition]].<ref name=ps04_1893_862/> In [[Jyotisha|Hindu astrology]], there are nine astrological objects, known as [[Navagraha]]s. Saturn is known as "[[Shani]]" and judges everyone based on the good and bad deeds performed in life.<ref name="Saturn in ancient mythologies">{{cite web |title=Starry Night Times |url=http://www.starrynight.com/sntimes/2006/2006-01-full.html |access-date=5 July 2007 |date=2006 |publisher=Imaginova Corp. |archive-url=https://web.archive.org/web/20091001001723/http://starrynight.com/sntimes/2006/2006-01-full.html |archive-date=1 October 2009 |url-status=dead }}</ref><ref name=ps04_1893_862/> Ancient [[Chinese astrology|Chinese]] and Japanese culture designated the planet Saturn as the "earth star" ({{lang|zh|土星}}). This was based on [[Five elements (Chinese philosophy)|Five Elements]] which were traditionally used to classify natural elements.<ref>{{cite book |first=Jan Jakob Maria |last=De Groot |year=1912 |title=Religion in China: universism. a key to the study of Taoism and Confucianism |series=American lectures on the history of religions |volume=10 |page=300 |publisher=G. P. Putnam's Sons |url=https://books.google.com/books?id=ZAaP7dyjCrAC&pg=PA300 |access-date=8 January 2010 |archive-date=22 July 2011 |archive-url=https://web.archive.org/web/20110722005812/http://books.google.com/books?id=ZAaP7dyjCrAC&pg=PA300 |url-status=live }}</ref><ref>{{cite book |first=Thomas |last=Crump |year=1992 |title=The Japanese numbers game: the use and understanding of numbers in modern Japan |pages=39–40 |publisher=Routledge |isbn=978-0415056090}}</ref><ref>{{cite book |first=Homer Bezaleel |last=Hulbert |year=1909 |title=The passing of Korea |page=[https://archive.org/details/passingkorea01hulbgoog/page/n538 426] |publisher=Doubleday, Page & company |url=https://archive.org/details/passingkorea01hulbgoog |access-date=8 January 2010}}</ref>

In [[Hebrew language|Hebrew]], Saturn is called ''[[Shabtai|Shabbathai]]''.<ref>{{cite news |url=http://www.universetoday.com/45087/when-was-saturn-discovered/ |title=When Was Saturn Discovered? |work=Universe Today |last=Cessna |first=Abby |date=15 November 2009 |access-date=21 July 2011 |archive-url=https://web.archive.org/web/20120214113458/http://www.universetoday.com/45087/when-was-saturn-discovered/ |archive-date=14 February 2012 |url-status=live }}</ref> Its angel is [[Cassiel]]. Its intelligence or beneficial spirit is [[Agiel|'Agȋȇl]] ({{langx|he|אגיאל|ʿAgyal}}),<ref name="TheMagus" /> and its darker spirit ([[demon]]) is [[Zazel (spirit)|Zȃzȇl]] ({{langx|he|זאזל|Zazl}}).<ref name="TheMagus">{{cite web |title=The Magus, Book I: The Celestial Intelligencer: Chapter XXVIII |url=http://www.sacred-texts.com/grim/magus/ma150.htm |work=Sacred-Text.com |access-date=4 August 2018 |archive-date=19 June 2018 |archive-url=https://web.archive.org/web/20180619080731/http://www.sacred-texts.com/grim/magus/ma150.htm |url-status=live }}</ref><ref name="CrystalLinks">{{cite web |title=Saturn in Mythology |url=http://www.crystalinks.com/saturn.mythology.html |work=CrystalLinks.com |access-date=5 August 2018 |archive-date=8 July 2018 |archive-url=https://web.archive.org/web/20180708190230/http://crystalinks.com/saturn.mythology.html |url-status=live }}</ref><ref name="TC-20170308">{{cite web |last=Beyer |first=Catherine |title=Planetary Spirit Sigils – 01 Spirit of Saturn |url=https://www.thoughtco.com/planetary-spirit-sigils-4123081 |date=8 March 2017 |work=ThoughtCo.com |access-date=3 August 2018 |archive-date=4 August 2018 |archive-url=https://web.archive.org/web/20180804014119/https://www.thoughtco.com/planetary-spirit-sigils-4123081 |url-status=live }}</ref> Zazel has been described as a [[Angel|great angel]], invoked in [[Solomon#Angels and magic|Solomonic magic]], who is "effective in [[Evocation|love conjurations]]".<ref name="FE-2014">{{cite web |url=http://baby-names.familyeducation.com/name-meaning/zazel |title=Meaning and Origin of: Zazel |work=FamilyEducation.com |date=2014 |access-date=3 August 2018 |quote=Latin: Angel summoned for love invocations |archive-date=2 January 2015 |archive-url=https://web.archive.org/web/20150102063304/http://baby-names.familyeducation.com/name-meaning/zazel |url-status=live }}</ref><ref name="HP-1998">{{cite web |url=http://hafapea.com/angelpages/angels7.html |title=Angelic Beings |work=Hafapea.com |date=1998 |access-date=3 August 2018 |quote=a Solomonic angel of love rituals |archive-date=22 July 2018 |archive-url=https://web.archive.org/web/20180722154808/http://hafapea.com/angelpages/angels7.html |url-status=dead }}</ref> In [[Ottoman Turkish language|Ottoman Turkish]], [[Urdu]], and [[Malay language|Malay]], the name of Zazel is 'Zuhal', derived from the [[Arabic language]] ({{langx|ar|زحل|Zuhal}}).<ref name="CrystalLinks" />

=== Telescopic pre-spaceflight observations ===
[[File:Galileo.arp.300pix.jpg|thumb|180px|[[Galileo Galilei]] observed the rings of Saturn in 1610, but was unable to determine what they were.]]

[[File:Saturn Robert Hooke 1666.jpg|thumb|[[Robert Hooke]] noted the shadows ({{Var|a}} and {{Var|b}}) cast by both the globe and the rings on each other in this drawing of Saturn in 1666.|left]]

Saturn's rings require at least a 15-mm-diameter [[telescope]]<ref name=binoculars/> to resolve and thus were not known to exist until [[Christiaan Huygens]] saw them in 1655 and published his observations in 1659. [[Galileo]], with his primitive telescope in 1610,<ref name=chan2000/><ref name=cain2008_15390/> incorrectly thought of Saturn's appearing not quite round as two moons on Saturn's sides.<ref name=cain2008_15418/><ref name=cain2008_46237/> It was not until Huygens used greater telescopic magnification that this notion was refuted, and the rings were truly seen for the first time. Huygens also discovered Saturn's [[Titan (moon)|moon Titan]]; [[Giovanni Domenico Cassini]] later discovered four other moons: [[Iapetus (moon)|Iapetus]], [[Rhea (moon)|Rhea]], [[Tethys (moon)|Tethys]], and [[Dione (moon)|Dione]]. In 1675, Cassini discovered the gap now known as the [[Cassini Division]].<ref name=micek2007/>

No further discoveries of significance were made until 1789 when [[William Herschel]] discovered two further moons, [[Mimas (moon)|Mimas]] and [[Enceladus]]. The irregularly shaped satellite [[Hyperion (moon)|Hyperion]], which has a [[orbital resonance|resonance]] with Titan, was discovered in 1848 by a British team.<ref name=pa54_122/>

In 1899, [[William Henry Pickering]] discovered Phoebe, a highly [[irregular satellite]] that does not rotate synchronously with Saturn as the larger moons do.<ref name=pa54_122/> Phoebe was the first such satellite found and it took more than a year to orbit Saturn in a [[retrograde orbit]]. During the early 20th century, research on Titan led to the confirmation in 1944 that it had a thick atmosphere—a feature unique among the Solar System's moons.<ref name=apj100_378/>

=== Spaceflight missions ===
{{main|Exploration of Saturn}}

==== ''Pioneer 11'' flyby ====
[[File:P11saturnb.jpg|thumb|''Pioneer 11'' image of Saturn]]

''[[Pioneer 11]]'' made the first flyby of Saturn in September 1979, when it passed within {{Convert|20000|km|abbr=on}} of the planet's cloud tops. Images were taken of the planet and a few of its moons, although their resolution was too low to discern surface detail. The spacecraft also studied Saturn's rings, revealing the thin F-ring and the fact that dark gaps in the rings are bright when viewed at a high [[Phase angle (astronomy)|phase angle]] (towards the Sun), meaning that they contain fine light-scattering material. In addition, ''Pioneer 11'' measured the temperature of Titan.<ref>{{cite web |url=http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PN10&11.html |title=The Pioneer 10 & 11 Spacecraft |access-date=5 July 2007 |publisher=Mission Descriptions |archive-url=https://web.archive.org/web/20060130100401/http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PN10%2611.html |archive-date=30 January 2006 |url-status=dead }}</ref>

==== ''Voyager'' flybys ====
In November 1980, the ''[[Voyager 1]]'' probe visited the Saturn system. It sent back the first high-resolution images of the planet, its rings and satellites. Surface features of various moons were seen for the first time. ''Voyager 1'' performed a close flyby of Titan, increasing knowledge of the atmosphere of the moon. It proved that Titan's atmosphere is impenetrable at [[visible wavelength]]s; therefore no surface details were seen. The flyby changed the spacecraft's trajectory out of the plane of the Solar System.<ref name="Voyager">{{cite web |url=http://www.planetary.org/explore/topics/saturn/missions.html |title=Missions to Saturn |publisher=The Planetary Society |date=2007 |access-date=24 July 2007 |archive-url=https://web.archive.org/web/20110728044450/http://www.planetary.org/explore/topics/saturn/missions.html |archive-date=28 July 2011 |url-status=live }}</ref>

Almost a year later, in August 1981, ''[[Voyager 2]]'' continued the study of the Saturn system. More close-up images of Saturn's moons were acquired, as well as evidence of changes in the atmosphere and the rings. During the flyby, the probe's turnable camera platform stuck for a couple of days and some planned imaging was lost. Saturn's gravity was used to direct the spacecraft's trajectory towards Uranus.<ref name="Voyager" />

The probes discovered and confirmed several new satellites orbiting near or within the planet's rings, as well as the small [[Maxwell Gap]] (a gap within the [[Rings of Saturn#C Ring|C Ring]]) and [[Keeler gap]] (a 42&nbsp;km-wide gap in the [[A Ring]]).<ref>{{Cite book |last=Spence |first=Pam |url=https://books.google.com/books?id=DwR7JtuXnaQC |title=The Universe Revealed |date=1999 |publisher=Cambridge University Press |isbn=978-0-521-64239-2 |pages=64 |language=en}}</ref>

==== ''Cassini–Huygens'' spacecraft ====
{{main|Cassini–Huygens}}[[File:Enceladus geysers June 2009.jpg|thumb|At Enceladus's south pole geysers spray water from many locations along the [[Tiger stripes (Enceladus)|tiger stripes]].<ref name="NASA-20140728" />|left]]
The ''[[Cassini–Huygens]]'' [[space probe]] entered orbit around Saturn on 1 July 2004. In June 2004, it conducted a close flyby of [[Phoebe (moon)|Phoebe]], sending back high-resolution images and data. ''Cassini''{{'s}} flyby of Saturn's largest moon, Titan, captured radar images of large lakes and their coastlines with numerous islands and mountains. The orbiter completed two Titan flybys before releasing the [[Huygens (spacecraft)|''Huygens'' probe]] on 25 December 2004. ''Huygens'' descended onto the surface of Titan on 14 January 2005.<ref name="nature438_7069_758" />

Starting in early 2005, scientists used ''Cassini'' to track lightning on Saturn. The power of the lightning is approximately 1,000&nbsp;times that of lightning on Earth.<ref>{{cite web |url=http://www.sciencedaily.com/releases/2006/02/060215090726.htm |title=Astronomers Find Giant Lightning Storm At Saturn |date=2007 |access-date=27 July 2007 |publisher=ScienceDaily LLC |archive-url=https://web.archive.org/web/20110828092204/http://www.sciencedaily.com/releases/2006/02/060215090726.htm |archive-date=28 August 2011 |url-status=live }}</ref>

In 2006, NASA reported that ''Cassini'' had found evidence of liquid [[Reservoir|water reservoirs]] no more than tens of meters below the surface that erupt in [[geyser]]s on Saturn's moon [[Enceladus (moon)|Enceladus]]. These jets of icy particles are emitted into orbit around Saturn from vents in the moon's south polar region.<ref>{{cite web |last1=Pence |first1=Michael |url=http://www.nasa.gov/mission_pages/cassini/media/cassini-20060309.html |title=NASA's Cassini Discovers Potential Liquid Water on Enceladus |date=9 March 2006 |publisher=[[NASA Jet Propulsion Laboratory]] |access-date=3 June 2011 |archive-url=https://web.archive.org/web/20110811013419/http://www.nasa.gov/mission_pages/cassini/media/cassini-20060309.html |archive-date=11 August 2011 |url-status=live }}</ref> Over 100 geysers have been identified on Enceladus.<ref name="NASA-20140728">{{cite web |display-authors=1 |last1=Dyches |first1=Preston |last2=Brown |first2=Dwayne |last3=Mullins |first3=Steve |title=Cassini Spacecraft Reveals 101 Geysers and More on Icy Saturn Moon |url=http://www.jpl.nasa.gov/news/news.php?release=2014-246&2 |date=28 July 2014 |work=NASA |access-date=29 July 2014 |archive-date=14 July 2017 |archive-url=https://web.archive.org/web/20170714031155/https://www.jpl.nasa.gov/news/news.php?release=2014-246&2 |url-status=live }}</ref> In May 2011, NASA scientists reported that Enceladus "is emerging as the most habitable spot beyond Earth in the Solar System for life as we know it".<ref>{{cite journal |last1=Lovett |first1=Richard A. |title=Enceladus named sweetest spot for alien life |url=http://www.nature.com/news/2011/110531/full/news.2011.337.html |date=31 May 2011 |access-date=3 June 2011 |doi=10.1038/news.2011.337 |archive-url=https://web.archive.org/web/20110905061010/http://www.nature.com/news/2011/110531/full/news.2011.337.html |archive-date=5 September 2011 |url-status=live |journal=Nature |pages=news.2011.337 }}</ref><ref>{{cite web |last1=Kazan |first1=Casey |title=Saturn's Enceladus Moves to Top of "Most-Likely-to-Have-Life" List |url=http://www.dailygalaxy.com/my_weblog/2011/06/saturns-enceladus-moves-to-top-of-most-likely-to-have-life-list.html |date=2 June 2011 |publisher=The Daily Galaxy |access-date=3 June 2011 |archive-url=https://web.archive.org/web/20110806103640/http://www.dailygalaxy.com/my_weblog/2011/06/saturns-enceladus-moves-to-top-of-most-likely-to-have-life-list.html |archive-date=6 August 2011 |url-status=live }}</ref>[[File:Saturn eclipse.jpg|thumb|Saturn eclipses the Sun, as seen from ''[[Cassini–Huygens|Cassini]]''. The rings are visible, including the [[F Ring]].]]

''Cassini'' photographs have revealed a previously undiscovered planetary ring, outside the brighter main rings of Saturn and inside the G and E&nbsp;rings. The source of this ring is hypothesized to be the crashing of a meteoroid off [[Janus (moon)|Janus]] and [[Epimetheus (moon)|Epimetheus]].<ref>{{cite web |url=https://www.newscientist.com/article/dn10124-faint-new-ring-discovered-around-saturn/ |title=Faint new ring discovered around Saturn |access-date=8 July 2007 |date=20 September 2007 |last=Shiga |first=David |publisher=NewScientist.com |archive-url=https://web.archive.org/web/20080503212602/http://space.newscientist.com/channel/solar-system/cassini-huygens/dn10124-faint-new-ring-discovered-around-saturn.html |archive-date=3 May 2008 |url-status=live }}</ref> In July 2006, images were returned of hydrocarbon lakes near Titan's north pole, the presence of which were confirmed in January 2007. In March 2007, hydrocarbon seas were found near the North pole, the largest of which is almost the size of the [[Caspian Sea]].<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/6449081.stm |title=Probe reveals seas on Saturn moon |publisher=BBC |last=Rincon |first=Paul |access-date=26 September 2007 |date=14 March 2007 |archive-url=https://web.archive.org/web/20111111135219/http://news.bbc.co.uk/2/hi/science/nature/6449081.stm |archive-date=11 November 2011 |url-status=live }}</ref> In October 2006, the probe detected an {{Convert|8000|km|abbr=on}} diameter cyclone-like storm with an eyewall at Saturn's south pole.<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/6135450.stm |title=Huge 'hurricane' rages on Saturn |publisher=BBC |last=Rincon |first=Paul |access-date=12 July 2007 |date=10 November 2006 |archive-url=https://web.archive.org/web/20110902214204/http://news.bbc.co.uk/2/hi/science/nature/6135450.stm |archive-date=2 September 2011 |url-status=live }}</ref>

From 2004 to 2 November 2009, the probe discovered and confirmed eight new satellites.<ref>{{cite web |url=http://saturn.jpl.nasa.gov/mission/introduction/ |title=Mission overview – introduction |date=2010 |work=Cassini Solstice Mission |publisher=NASA / JPL |access-date=23 November 2010 |archive-url=https://web.archive.org/web/20110807005756/http://saturn.jpl.nasa.gov/mission/introduction/ |archive-date=7 August 2011 |url-status=dead }}</ref> In April 2013, ''Cassini'' sent back images of a hurricane at the planet's north pole 20 times larger than those found on Earth, with winds faster than {{convert|530|km/h|mph|abbr=on}}.<ref>{{cite news |url=http://www.3news.co.nz/Massive-storm-at-Saturns-north-pole/tabid/1160/articleID/296026/Default.aspx |work=3 News NZ |title=Massive storm at Saturn's north pole |date=30 April 2013 |access-date=30 April 2013 |archive-date=19 July 2014 |archive-url=https://web.archive.org/web/20140719200738/http://www.3news.co.nz/Massive-storm-at-Saturns-north-pole/tabid/1160/articleID/296026/Default.aspx |url-status=live }}</ref> On 15 September 2017, the ''Cassini–Huygens'' spacecraft performed the "Grand Finale" of its mission: a number of passes through gaps between Saturn and Saturn's inner rings.<ref name="NASA-20170915">{{cite news |last1=Brown |first1=Dwayne |last2=Cantillo |first2=Laurie |last3=Dyches |first3=Preston |title=NASA's Cassini Spacecraft Ends Its Historic Exploration of Saturn |url=https://www.jpl.nasa.gov/news/news.php?feature=6948 |date=15 September 2017 |work=NASA |access-date=15 September 2017 |archive-date=9 May 2019 |archive-url=https://web.archive.org/web/20190509044122/https://www.jpl.nasa.gov/news/news.php?feature=6948 |url-status=live }}</ref><ref name="NYT-20170914">{{cite news |last=Chang |first=Kenneth |title=Cassini Vanishes Into Saturn, Its Mission Celebrated and Mourned |url=https://www.nytimes.com/2017/09/14/science/cassini-grand-finale-saturn.html |date=14 September 2017 |work=[[The New York Times]] |access-date=15 September 2017 |archive-date=8 July 2018 |archive-url=https://web.archive.org/web/20180708162700/https://www.nytimes.com/2017/09/14/science/cassini-grand-finale-saturn.html |url-status=live }}</ref> The [[atmospheric entry]] of ''Cassini'' ended the mission.

==== Possible future missions ====
The continued exploration of Saturn is still considered to be a viable option for NASA as part of their ongoing [[New Frontiers program]] of missions. NASA previously requested for plans to be put forward for a mission to Saturn that included the [[Saturn Atmospheric Entry Probe]], and possible investigations into the habitability and possible discovery of life on Saturn's moons Titan and Enceladus by ''[[Dragonfly (Titan space probe)|Dragonfly]]''.<ref>{{cite news |url=http://spacenews.com/nasa-expands-frontiers-of-next-new-frontiers-competition/ |title=NASA Expands Frontiers of Next New Frontiers Competition |work=[[SpaceNews]] |first=Jeff |last=Foust |date=8 January 2016 |access-date=20 April 2017 |archive-date=18 August 2017 |archive-url=https://wayback.archive-it.org/all/20170818112258/http://spacenews.com/nasa-expands-frontiers-of-next-new-frontiers-competition/ |url-status=live }}</ref><ref>{{Cite web |author=Nola Taylor Redd |date=25 April 2017 |title='Dragonfly' Drone Could Explore Saturn Moon Titan |url=https://www.space.com/36598-dragonfly-quadcopter-saturn-moon-titan-explorer.html |access-date=13 June 2020 |website=Space.com |language=en |archive-date=30 June 2019 |archive-url=https://web.archive.org/web/20190630035114/https://www.space.com/36598-dragonfly-quadcopter-saturn-moon-titan-explorer.html|url-status=live}}</ref>