Examine individual changes

'{{Short description|Persistent storm in Jupiter's atmosphere}} [[File:Jupiters iconic Great Red Spot.jpg|thumb|alt=Closer view of the Great Red Spot|''The Great Red Spot'' as seen by the [[Juno spacecraft]] via [[JunoCam]], in April 2018]] The '''Great Red Spot''' is a persistent [[high-pressure area|high-pressure region]] in the [[atmosphere of Jupiter]], producing an [[anticyclonic storm]] that is one of the largest in the [[Solar System]]. Located 22 [[degree (angle)|degree]]s south of [[Jupiter]]'s [[equator]], it produces wind-speeds up to 432&nbsp;km/h (268&nbsp;mph). Observations from 1665 to 1713 are believed to be of the same storm; if this is correct, it has existed for at least {{#expr: ({{CURRENTYEAR}} - 1665)}} years.<ref>*{{cite web |author=Staff |year=2007 |url=https://www.space.com/3134-jupiter-data-sheet.html |title=Jupiter Data Sheet – SPACE.com |publisher=Imaginova |access-date=2008-06-03}} *{{cite web |url=http://csep10.phys.utk.edu/astr161/lect/jupiter/redspot.html |archive-url=https://web.archive.org/web/20040610075946/http://csep10.phys.utk.edu/astr161/lect/jupiter/redspot.html |url-status=dead |archive-date=2004-06-10 |title=The Solar System - The Planet Jupiter – The Great Red Spot |publisher=Dept. Physics & Astronomy – University of Tennessee |access-date=2015-08-30}}</ref> It was next observed in September 1831, with 60 recorded observations between then and 1878, when continuous observations began.<ref name="Denning" /><ref>*{{cite news |last=Chang |first=Kenneth |title=The Great Red Spot Descends Deep Into Jupiter |url=https://www.nytimes.com/2017/12/13/science/jupiter-great-red-spot-juno.html |date=2017-12-13 |work=[[The New York Times]] |access-date=2017-12-15 }} *{{cite web |title=Great Red Spot |url=https://www.britannica.com/place/Great-Red-Spot |website=Encyclopædia Britannica |access-date=2018-12-04}}</ref> ==Observation history== [[Image:Great Red Spot From Voyager 1.jpg|thumb|right|240px|A wide view of Jupiter and the Great Red Spot as seen from ''Voyager 1'' in 1979. The white oval storm directly below the Great Red Spot has the approximate diameter of [[Earth]].]] [[Image:790106-0203 Voyager 58M to 31M reduced.gif|thumb|right|Time-lapse sequence from the approach of ''[[Voyager 1]]'' to Jupiter, showing the motion of atmospheric bands, and circulation of the Great Red Spot. ''NASA image''.]] * Great Red Pussy may have existed since before 1665, but it could also be the case that the present spot was first seen only in 1830, and well-studied only after a prominent apparition in 1879. The storm that was seen in the 17th century may have been different than the storm that exists today.<ref>{{cite web|url=https://www.nasa.gov/feature/goddard/jupiter-s-great-red-spot-a-swirling-mystery|author=Karl Hille|date=2015-08-04|title=Jupiter's Great Red Spot: A Swirling Mystery|publisher=NASA|access-date=2017-11-18}}</ref> A long gap separates its period of current study after 1830 from its 17th century discovery. Whether the original spot dissipated and reformed, whether it faded, or if the observational record was simply poor is unknown.<ref name="Beebe1" /> For example, the first sighting of the Great Red Spot is often credited to [[Robert Hooke]], who described a spot on the planet in May 1664. However, it is likely that Hooke's spot was not only in another belt altogether (the North Equatorial Belt, as opposed to the current Great Red Spot's location in the [[South Equatorial Belt]]), but also that it was the shadow of a transiting moon, most likely that of [[Callisto (moon)|Callisto]].<ref>{{Cite web|title=This Month in Physics History|url=http://www.aps.org/publications/apsnews/202005/history.cfm|access-date=2021-12-29|website=www.aps.org|language=en}}</ref> Far more convincing is [[Giovanni Cassini]]'s description of a "permanent spot" the following year.<ref>Rogers (1995), 6.</ref> With fluctuations in visibility, Cassini's spot was observed from 1665 to 1713, but the 118-year observational gap makes the identity of the two spots inconclusive. The older spot's shorter observational history and slower motion than the modern spot makes it difficult to conclude that they are the same.<ref>Rogers (1995), 188.</ref> A minor mystery concerns a Jovian spot depicted in a 1711 canvas by [[Donato Creti]], which is exhibited in the [[Vatican City|Vatican]].{{clarify|date=June 2021}}<ref>{{cite web |author=Staff |year=2003 |url=http://www.museivaticani.va/content/museivaticani/en/collezioni/musei/la-pinacoteca/sala-xv---secolo-xviii/donato-creti--osservazioni-astronomiche.html |title=Donato Creti, Astronomical observations |publisher=Vatican Museums |access-date=2019-12-16 |website=Musei Vaticani}}</ref><ref name="Hockey1">Hockey (1999), 40-1.</ref> Part of a series of panels in which different (magnified) heavenly bodies serve as backdrops for various [[Italy|Italian]] scenes, and all overseen by the astronomer [[Eustachio Manfredi]] for accuracy, Creti's painting is the first known to depict the Great Red Spot as red (albeit raised to the Jovian Northern hemisphere due to an optical inversion inherent to the era's telescopes). No Jovian feature was explicitly described in writing as red before the late 19th century.<ref name="Hockey1" /> The Great Red Spot has been observed since 5 September 1831. By 1879 over 60 observations were recorded.<ref name="Denning">{{cite journal |last1=Denning |first1=William Frederick |title=Early history of the great red spot on Jupiter |journal=Monthly Notices of the Royal Astronomical Society |date=June 1899 |volume=59 |issue=10 |page=574 |doi=10.1093/mnras/59.10.574 |publisher=Royal Astronomical Society |language=en |bibcode=1899MNRAS..59..574D|doi-access=free }}</ref> After it came into prominence in 1879, it has been under continuous observation. In the 21st century, the Great Red Spot was seen to be shrinking in size. At the start of 2004, it had approximately half the longitudinal extent it had had a century ago, when it reached a size of {{convert|40,000|km|mi|abbr=on}}, about three times the diameter of Earth. At the present rate of reduction, it would become circular by 2040. It is not known how long the spot will last, or whether the change is a result of normal fluctuations.<ref>{{cite journal |last=Beatty |first=J. Kelly |title=Jupiter's Shrinking Red Spot |journal=Sky and Telescope |year=2002 |volume=103 |issue=4 |pages=24 |bibcode=2002S&T...103d..24B |url=http://www.saburchill.com/HOS/astronomy/034.html |access-date=2007-06-21 }}</ref> In 2019, the Great Red Spot began "flaking" at its edge, with fragments of the storm breaking off and dissipating.<ref name="disintegrating">{{cite web|url=https://earthsky.org/space/is-jupiters-great-red-spot-disintegrating|title=Is Jupiter's Great Red Spot disintegrating?|author=Paul Scott Anderson|publisher=EarthSky|date=10 June 2019|access-date=2 July 2019}}</ref> The shrinking and "flaking" fueled concern from some astronomers that the Great Red Spot could dissipate within 20 years.{{citation needed|date=April 2021}} However, other astronomers believe that the apparent size of the Great Red Spot reflects its cloud coverage and not the size of the actual, underlying vortex, and they also believe that the flaking events can be explained by interactions with other cyclones or anticyclones, including incomplete absorptions of smaller systems; if this is the case, this would mean that the Great Red Spot is not in danger of dissipating.<ref name="may not">{{cite web|url=https://astronomy.com/news/2019/11/jupiters-great-red-spot-is-not-disappearing|title=Jupiter's Great Red Spot may not be disappearing|author=Philip Marcus|publisher=Astronomy|date=26 November 2019|access-date=25 December 2020}}</ref> A smaller spot, designated [[Oval BA]], formed in March 2000 from the merging of three white ovals,<ref>{{cite journal |last1=Sanchez-Lavega |first1=A. |display-authors=etal |title=The Merger of Two Giant Anticyclones in the Atmosphere of Jupiter |journal=[[Icarus (journal)|Icarus]] |date=February 2001 |volume=149 |issue=2 |pages=491–495 |bibcode=2001Icar..149..491S |doi=10.1006/icar.2000.6548}} </ref> has turned reddish in color. Astronomers have named it the ''Little Red Spot'' or ''Red, Jr.'' As of 5 June 2006, the Great Red Spot and Oval BA appeared to be approaching convergence.<ref>{{cite web |last=Phillips |first=Tony |url=https://science.nasa.gov/headlines/y2006/05jun_redperil.htm |title=Huge Storms Converge |publisher=Science@NASA |access-date=2007-01-08 |url-status=dead |archive-url=https://web.archive.org/web/20070202190145/https://science.nasa.gov/headlines/y2006/05jun_redperil.htm |archive-date=2007-02-02 }}</ref> The storms pass each other about every two years but the passings of 2002 and 2004 were of little significance. [[Amy Simon|Amy Simon-Miller]], of the [[Goddard Space Flight Center]], predicted the storms would have their closest passing on 4 July 2006. She worked with [[Imke de Pater]] and Phil Marcus of [[University of California, Berkeley|UC Berkeley]] and a team of professional astronomers since April 2006 to study the storms using the [[Hubble Space Telescope]]; on 20 July 2006, the two storms were photographed passing each other by the [[Gemini Observatory]] without converging.<ref>{{cite news |first=Peter |last=Michaud |title=Gemini Captures Close Encounter of Jupiter's Red Spots |publisher=Gemini Observatory |url=http://www.gemini.edu/index.php?option=content&task=view&id=196 |access-date=2007-06-15 }}</ref> In May 2008, a third storm turned red.<ref>{{cite magazine |first=David |last=Shiga |title=Third red spot erupts on Jupiter |magazine=New Scientist |url=https://www.newscientist.com/article/dn13963-third-red-spot-erupts-on-jupiter/ |access-date=2008-05-23}}</ref> The Great Red Spot should not be confused with the Great Dark Spot, a feature observed near the northern pole of Jupiter in 2000 with the ''[[Cassini–Huygens]]'' spacecraft.<ref>{{cite news |first=Tony |last=Phillips |title=The Great Dark Spot |publisher=Science at NASA |url=https://science.nasa.gov/headlines/y2003/12mar_darkspot.htm |access-date=2007-06-20 |url-status=dead |archive-url=https://web.archive.org/web/20070615100054/https://science.nasa.gov/headlines/y2003/12mar_darkspot.htm |archive-date=2007-06-15}}</ref> There is also a feature in the atmosphere of [[Neptune]] also called the [[Great Dark Spot]]. The latter feature was imaged by ''[[Voyager 2]]'' in 1989 and may have been an atmospheric hole rather than a storm. It was no longer present as of 1994, although a similar spot had appeared farther to the north. [[Image:Great red spot juno 20170712.jpg|thumb|right|200px|Closeup of the Great Red Spot taken from about {{convert|5000|mi|km|abbr=on|order=flip}} above it (July 11, 2017)]] ===Exploration=== On 25 February 1979,<ref>Smith ''et al'' (1979), 951-972.</ref> when the ''[[Voyager 1]]'' spacecraft was {{convert|9200000|km|mi|abbr=on}} from Jupiter, it transmitted the first detailed image of the Great Red Spot. Cloud details as small as {{convert|160|km|mi|abbr=on}} across were visible. The colorful, wavy cloud pattern seen to the left (west) of the Red Spot is a region of extraordinarily complex and variable wave motion. The [[Juno (spacecraft)|''Juno'' spacecraft]], which entered into a polar orbit around Jupiter in 2016, flew over the Great Red Spot upon its close approach to Jupiter on 11 July 2017, taking several images of the storm from a distance of about {{convert|5000|mi|km|abbr=on|order=flip}} above the surface.<ref name="junospots"/><ref>{{cite web|url=https://www.nytimes.com/2016/07/05/science/juno-enters-jupiters-orbit-capping-5-year-voyage.html|title=NASA's Juno Spacecraft Enters Into Orbit Around Jupiter|first=Kenneth|last=Chang|date=2016-07-05|website=[[The New York Times]]|access-date=2017-07-12}}</ref> Over the duration of the ''Juno'' mission, the spacecraft will continue to study the composition and evolution of Jupiter's atmosphere, especially its Great Red Spot.<ref name="junospots"/> ==Structure== [[Image:Jupiter-Earth-Spot comparison.jpg|thumb|right|250px|Approximate size comparison of Earth and the Great Red Spot.]] Jupiter's Great Red Spot rotates counterclockwise, with a period of about six Earth days<ref>Smith ''et al'' (1979), 954.</ref> or fourteen Jovian days. Measuring {{convert|16350|km|mi|abbr=on}} in width as of 3 April 2017, Jupiter's Great Red Spot is 1.3 times the diameter of Earth.<ref name="junospots">{{Cite news|url=http://www.nasa.gov/feature/jpl/nasa-s-juno-spacecraft-spots-jupiter-s-great-red-spot|title=NASA's Juno Spacecraft Spots Jupiter's Great Red Spot|last=Perez|first=Martin|date=2017-07-12|work=NASA|access-date=2017-07-16|language=en}}</ref> The cloud-tops of this storm are about {{convert|8|km|mi|abbr=on}} above the surrounding cloud-tops.<ref>{{cite book | title=Jupiter, the Giant of the Solar System | work=The Voyager Mission | page=5 | publisher=NASA | date=1979 | url=https://www.google.com/books/edition/The_Voyager_Mission/KuBYXLt4K9MC?hl=en&gbpv=1&pg=PA5 }}</ref> [[Infrared]] data have long indicated that the Great Red Spot is colder (and thus higher in altitude) than most of the other clouds on the planet.<ref>Rogers (1995), 191.</ref> The upper atmosphere above the storm, however, has substantially higher temperatures than the rest of the planet. Acoustic (sound) waves rising from the turbulence of the storm below have been proposed as an explanation for the heating of this region.<ref name="Heating of Jupiter's upper atmosphe">{{cite journal |last1=O’Donoghue |first1=J. |last2=Moore |first2=L. |last3=Stallard |first3=T. S. |last4=Melin |first4=H. |title=Heating of Jupiter's upper atmosphere above the Great Red Spot |journal=Nature |date=27 July 2016 |volume=536 |issue=7615 |pages=190–192 |doi=10.1038/nature18940|pmid=27462811 |bibcode=2016Natur.536..190O |hdl=2381/38554 |s2cid=4462322 |hdl-access=free }}</ref> Careful tracking of atmospheric features revealed the Great Red Spot's counter-clockwise circulation as far back as 1966, observations dramatically confirmed by the first time-lapse movies from the ''Voyager'' fly-bys.<ref>Rogers (1995), 194-6.</ref> The spot is confined by a modest eastward [[jet stream]] to its south and a very strong westward one to its north.<ref>Beebe (1997), 35.</ref> Though winds around the edge of the spot peak at about {{convert|432|km/h|mph|abbr=on}}, currents inside it seem stagnant, with little inflow or outflow.<ref>Rogers (1995), 195.</ref> The rotation period of the spot has decreased with time, perhaps as a direct result of its steady reduction in size.<ref>{{cite web |last=Rogers |first=John |url=http://www.britastro.org/jupiter/2006report09.htm |title=Interim reports on STB (Oval BA passing GRS), STropB, GRS (internal rotation measured), EZ(S. Eq. Disturbance; dramatic darkening; NEB interactions), & NNTB |publisher=British Astronomical Association |access-date=2007-06-15 }}</ref> The Great Red Spot's [[latitude]] has been stable for the duration of good observational records, typically varying by about a degree. Its [[longitude]], however, is subject to constant variation, including a 90-day longitudinal oscillation with an amplitude of ~1°.<ref>* {{cite journal|author1=Reese, Elmer J.|author2=Solberg, H. Gordon|year=1966|title=Recent measures of the latitude and longitude of Jupiter's red spot|journal=Icarus|volume=5|issue=1–6|pages=266–273|bibcode=1966Icar....5..266R|doi=10.1016/0019-1035(66)90036-4|hdl-access=free|hdl=2060/19650022425}}<!--|access-date=2007-06-20 --> * Rogers (1995), 192-3.</ref><ref>{{Cite journal |last=Trigo-Rodriguez |first=J.M |last2=Sánchez-Lavega |first2=A |last3=Gómez |first3=J.M |last4=Lecacheux |first4=J |last5=Colas |first5=F |last6=Miyazaki |first6=I |date=2000 |title=The 90-day oscillations of Jupiter’s Great Red Spot revisited |url=https://linkinghub.elsevier.com/retrieve/pii/S0032063300000027 |journal=Planetary and Space Science |language=en |volume=48 |issue=4 |pages=331–339 |doi=10.1016/S0032-0633(00)00002-7}}</ref> Because Jupiter does not rotate uniformly at all latitudes, astronomers have defined three different systems for defining the longitude. System II is used for latitudes of more than 10 degrees and was originally based on the average rotational period of the Great Red Spot of 9h&nbsp;55m&nbsp;42s.<ref> *{{cite journal |last=Stone |first=Peter H. |title=On Jupiter's Rate of Rotation |journal=Journal of the Atmospheric Sciences |year=1974 |volume=31 |issue=5 |pages=1471–1472 |url=http://ams.allenpress.com/archive/1520-0469/31/5/pdf/i1520-0469-31-5-1471.pdf |access-date=2007-06-20 |doi=10.1175/1520-0469(1974)031<1471:OJROR>2.0.CO;2 |bibcode=1974JAtS...31.1471S}} *Rogers (1995), 48, 193.</ref> Despite this, however, the spot has "lapped" the planet in System II at least 10 times since the early nineteenth century. Its drift rate has changed dramatically over the years and has been linked to the brightness of the [[South Equatorial Belt]] and the presence or absence of a South Tropical Disturbance.<ref>Rogers (1995), 193.</ref> === Internal Depth and Structure === Jupiter's Great Red Spot is an elliptical shaped anticyclone, occurring at 22 degrees below the equator, in Jupiter's southern hemisphere.<ref name=":2">{{Cite journal |last=Bjoraker |first=G. L. |last2=Wong |first2=M. H. |last3=Pater |first3=I. de |last4=Hewagama |first4=T. |last5=Ádámkovics |first5=M. |last6=Orton |first6=G. S. |date=2018-08-20 |title=The Gas Composition and Deep Cloud Structure of Jupiter's Great Red Spot |url=https://iopscience.iop.org/article/10.3847/1538-3881/aad186 |journal=The Astronomical Journal |volume=156 |issue=3 |pages=101 |doi=10.3847/1538-3881/aad186 |issn=1538-3881}}</ref> As the largest [[Anticyclone|anticyclonic]] storm (~16,000 Km) in our solar system, little is known about the internal depth and structure of Jupiter's Great Red Spot (GRS).<ref name=":0">{{Cite journal |last=Parisi |first=Marzia |last2=Kaspi |first2=Yohai |last3=Galanti |first3=Eli |last4=Durante |first4=Daniele |last5=Bolton |first5=Scott J. |last6=Levin |first6=Steven M. |last7=Buccino |first7=Dustin R. |last8=Fletcher |first8=Leigh N. |last9=Folkner |first9=William M. |last10=Guillot |first10=Tristan |last11=Helled |first11=Ravit |date=2021-11-19 |title=The depth of Jupiter’s Great Red Spot constrained by Juno gravity overflights |url=https://www.science.org/doi/10.1126/science.abf1396 |journal=Science |language=en |volume=374 |issue=6570 |pages=964–968 |doi=10.1126/science.abf1396 |issn=0036-8075}}</ref> Visible imaging and cloud-tracking from [[In situ|in-situ]] observation determined the velocity and vorticity of the GRS which is located in a thin anticyclonic ring at 70–85% of the radius and is located along Jupitar's fastest westward moving jet stream. <ref name=":1">{{Cite journal |last=Fletcher |first=Leigh N. |last2=Orton |first2=G. S. |last3=Mousis |first3=O. |last4=Yanamandra-Fisher |first4=P. |last5=Parrish |first5=P. D. |last6=Irwin |first6=P. G. J. |last7=Fisher |first7=B. M. |last8=Vanzi |first8=L. |last9=Fujiyoshi |first9=T. |last10=Fuse |first10=T. |last11=Simon-Miller |first11=A. A. |date=2010-07-01 |title=Thermal structure and composition of Jupiter’s Great Red Spot from high-resolution thermal imaging |url=https://www.sciencedirect.com/science/article/pii/S0019103510000084 |journal=Icarus |language=en |volume=208 |issue=1 |pages=306–328 |doi=10.1016/j.icarus.2010.01.005 |issn=0019-1035}}</ref> During NASA's, 2016 [[Juno (spacecraft)|Juno]] mission, gravity signature and thermal infrared<ref name=":1" /><ref name=":3">{{Cite journal |last=Choi |first=David S. |last2=Banfield |first2=Don |last3=Gierasch |first3=Peter |last4=Showman |first4=Adam P. |date=2007-05-01 |title=Velocity and vorticity measurements of Jupiter's Great Red Spot using automated cloud feature tracking |url=https://www.sciencedirect.com/science/article/pii/S0019103506004179 |journal=Icarus |language=en |volume=188 |issue=1 |pages=35–46 |doi=10.1016/j.icarus.2006.10.037 |issn=0019-1035}}</ref>data was obtained that offered insight into the structural dynamics and depth of the GRS.<ref name=":0" /><ref name=":1" /> During July of 2017, the Juno spacecraft conducted a second pass of the GRS to collect [[Microwave Radiometer (Juno)|Microwave Radiometer]] (MWR) scans of the GRS to determine how far the GRS extended toward the surface of the condensed H₂O layer.<ref name=":0" /> These MRW scans suggested that the GRS vertical depth extended to about ~240 Km below the cloud level, with an estimated drop in atmospheric pressure to 100-bar.<ref name=":0" /><ref name=":1" /> Two methods of analysis that constrain the data collected were the Mascon approach which found an depth of ~290 Km., and the Slepian approach showing wind extending to ~310 Km<ref name=":0" />. These methods, along with gravity signature MWR data suggest that the GRS zonal winds still increase at a rate of 50% the velocity of the viable cloud level, before the wind decay starts at lower levels, this rate of wind decay and Gravity data suggest the depth of the GRS is between 200 and 500 Km.<ref name=":0" /> [[Galileo (spacecraft)|Galileo]] and [[Cassini–Huygens|Cassini's]] thermal infrared imaging and [[spectroscopy]] were conducted of the GRS during 1995 - 2008, in order to find evidence of thermal inhomogeneities with in the internal structure vortex of the GRS. <ref name=":1" /> Previous thermal infrared temperature maps from the [[Voyager program|Voyager]], Galileo, and Cassini missions; suggested the GRS is a cold-core within a upwelling warmer annulus structure of an anticyclonic vortex, this data shows a gradient in the temperature of the GRS.<ref name=":2" /><ref name=":1" />To gain better understanding of Jupiter’s atmospheric temperature, aerosol particle opacity, and ammonia gas composition from thermal-IR imaging, a direct correlation of the visible-cloud layers reactions, thermal gradient and compositional mapping to observational data collected over decades.<ref name=":2" /><ref name=":1" /> During December 2000, high spatial resolution images from Galileo, of an atmospheric turbulent area to the northwest of the GSR, shows a thermal contrast between the warmest region of the anticyclone with regions to the east and west of the GRS.<ref name=":1" /><ref>{{Cite journal |last=Sánchez-Lavega |first=A. |last2=Hueso |first2=R. |last3=Eichstädt |first3=G. |last4=Orton |first4=G. |last5=Rogers |first5=J. |last6=Hansen |first6=C. J. |last7=Momary |first7=T. |last8=Tabataba-Vakili |first8=F. |last9=Bolton |first9=S. |date=2018-09-18 |title=The Rich Dynamics of Jupiter’s Great Red Spot from JunoCam: Juno Images |url=https://iopscience.iop.org/article/10.3847/1538-3881/aada81 |journal=The Astronomical Journal |volume=156 |issue=4 |pages=162 |doi=10.3847/1538-3881/aada81 |issn=1538-3881}}</ref> The vertical temperature of the structure of the GRS is constrained between the 100–600 mbar range, with the vertical temperature of the GSR core is approximately 400 mbar of pressure, being 1.0–1.5 K much warmer than regions of the GRS to the east–west, and 3.0–3.5 K warmer than regions to the north–south of the structures edge.<ref name=":1" /> This structure is consistent with the data collected by the VISIR (VLT Mid-Infrared Imager Spectrometer on the ESO Very Large Telescope) imaging obtain in 2006, this data revealed that the GSR was physically present in a wide range of altitudes that occur within the 80 - 600 mbar pressure of the atmosphere and confirmers the thermal infrared mapping result.<ref name=":1" /><ref name=":3" /><ref>{{Cite journal |last=Simon |first=Amy A. |last2=Tabataba-Vakili |first2=Fachreddin |last3=Cosentino |first3=Richard |last4=Beebe |first4=Reta F. |last5=Wong |first5=Michael H. |last6=Orton |first6=Glenn S. |date=2018-03-13 |title=Historical and Contemporary Trends in the Size, Drift, and Color of Jupiter's Great Red Spot |url=https://iopscience.iop.org/article/10.3847/1538-3881/aaae01 |journal=The Astronomical Journal |volume=155 |issue=4 |pages=151 |doi=10.3847/1538-3881/aaae01 |issn=1538-3881}}</ref>To develop a model of the internal structure of the GRS the Cassini mission Composite [[Infrared spectroscopy|Infrared Spectrometer]] (CIRS) and ground based spatial imaging mapped the composition of the [[Phosphine]] and [[ammonia]] aerosols (PH₃, NH₃ and [[Para-hydroxybenzoic acid|para-H₂]]) within the anticyclonic circulation of the GRS<ref name=":1" /><ref>{{Cite journal |last=Cho |first=James Y-K. |last2=de la Torre Juárez |first2=Manuel |last3=Ingersoll |first3=Andrew P. |last4=Dritschel |first4=David G. |date=2001-03-25 |title=A high-resolution, three-dimensional model of Jupiter's Great Red Spot |url=http://doi.wiley.com/10.1029/2000JE001287 |journal=Journal of Geophysical Research: Planets |language=en |volume=106 |issue=E3 |pages=5099–5105 |doi=10.1029/2000JE001287}}</ref>. The imaging that was collected form the CIRS and ground-based imaging trace the vertical motion in the Jovian atmosphere by PH₃ and NH₃ spectra.<ref name=":2" /><ref name=":1" /> The highest concentrations of PH₃ and NH₃ are found to the north of the GRS peripheral rotation and aided in determine the southward jet movement and shows data of an increase in altitude of the column of aerosols with ranging pressures of 200–500 mbar.<ref name=":1" /><ref>{{Cite journal |last=Morales-Juberías |first=Raúl |last2=Dowling |first2=Timothy E. |date=2013-07-01 |title=Jupiter’s Great Red Spot: Fine-scale matches of model vorticity patterns to prevailing cloud patterns |url=https://www.sciencedirect.com/science/article/pii/S0019103513001425 |journal=Icarus |language=en |volume=225 |issue=1 |pages=216–227 |doi=10.1016/j.icarus.2013.03.026 |issn=0019-1035}}</ref> However, the NH₃ composition data shows that there is a major depletion of NH₃ below the visible cloud layer at the southern peripheral ring of the GRS, this lower opacity is relative to a narrow band of atmospheric subsidence<ref name=":1" />. The low mid-IR aerosol opacity along with; the temperature gradients, the altitude difference, and the vertical movement of the zonal winds are involved with the development and sustainability of the vorticity.<ref name=":1" /> The stronger atmospheric [[subsidence]] and compositional asymmetries of the GRS suggest that the structure exhibits a degree of tilt form the northern edge to the southern edge of the structure.<ref name=":1" /><ref>{{Cite journal |last=Flasar |first=F. Michael |last2=Conrath |first2=Barney J. |last3=Pirraglia |first3=Joseph A. |last4=Clark |first4=Patrick C. |last5=French |first5=Richard G. |last6=Gierasch |first6=Peter J. |date=1981-09-30 |title=Thermal structure and dynamics of the Jovian atmosphere 1. The great red spot |url=http://doi.wiley.com/10.1029/JA086iA10p08759 |journal=Journal of Geophysical Research: Space Physics |language=en |volume=86 |issue=A10 |pages=8759–8767 |doi=10.1029/JA086iA10p08759}}</ref> The GSR depth and internal structure has been constant with changes over decades<ref name=":0" /> however there is still no logical reason why it is ~200 - 500 km in depth, but the jet streams that supply the force that powers the GRS vortex are well below the structure base.<ref name=":0" /><ref name=":1" /> ==Color and composition== [[File:Telescopes and Spacecraft Join Forces to Probe Deep into Jupiter's Atmosphere (49892941386).png|thumb|upright=1.2|Clockwise from top left: [[Hubble Space Telescope|Hubble]] image of [[visible spectrum]]; [[infrared]] from the [[Gemini Observatory]]; multiwavelength composite of Hubble and Gemini data showing visible light in blue and thermal infrared in red; [[ultraviolet]] image from Hubble; visible light detail]] It is not known what causes the Great Red Spot's reddish color. Hypotheses supported by laboratory experiments suppose that it may be caused by chemical products created from the solar ultraviolet irradiation of [[ammonium hydrosulfide]] and the organic compound [[acetylene]], which produces a reddish material—likely complex organic compounds called [[tholin]]s.<ref name="Hudson2018">{{cite journal |last1=Loeffer |first1=Mark J. |last2=Hudson |first2=Reggie L. |title=Coloring Jupiter's clouds: Radiolysis of ammonium hydrosulfide (NH4SH) |journal=Icarus |year=2018 |volume=302 |pages=418–425 |doi=10.1016/j.icarus.2017.10.041|bibcode=2018Icar..302..418L }}</ref> The high altitude of the compounds may also contribute to the coloring.<ref name="EarthSky">{{cite web|title=What makes Jupiter's Red Spot red?|date=2014-11-11|url=https://earthsky.org/space/what-makes-jupiters-red-spot-red|access-date=2019-03-13|publisher=[[EarthSky]]}}</ref> The Great Red Spot varies greatly in hue, from almost brick-red to pale salmon or even white. The spot occasionally disappears, becoming evident only through the Red Spot Hollow, which is its location in the [[South Equatorial Belt]] (SEB). Its visibility is apparently coupled to the SEB; when the belt is bright white, the spot tends to be dark, and when it is dark, the spot is usually light. These periods when the spot is dark or light occur at irregular intervals; from 1947 to 1997, the spot was darkest in the periods 1961–1966, 1968–1975, 1989–1990, and 1992–1993.<ref name="Beebe1">Beebe (1997), 38-41.</ref> <gallery widths="200px" heights="200px"> File:Jupiter’s Colourful Palette.tif|Jupiter's clouds taken on 27 June 2019 by Hubble's Wide Field Camera 3.<ref>{{cite web |title=Hubble Showcases New Portrait of Jupiter |url=https://www.spacetelescope.org/news/heic1914/ |website=www.spacetelescope.org |access-date=10 August 2019 |language=en}}</ref> File:PIA02863 - Jupiter surface motion animation.gif|Color animation of Jupiter's cloud motion and circulation of the Great Red Spot. </gallery> ==Mechanical dynamics== There is no definitive theory as to what causes the formation or color of the Great Red Spot. Laboratory studies are examining the effects that [[cosmic ray]]s or [[UV radiation|UV light]] from the Sun have on the chemical composition of the clouds of Jupiter. One question is whether the Sun's radiation reacts with [[ammonium hydrosulfide]] in the planet's outer atmosphere to create the deep red color.<ref>{{cite web|url=https://www.nasa.gov/feature/goddard/jupiter-s-great-red-spot-a-swirling-mystery|title=Jupiter's Great Red Spot: A Swirling Mystery|publisher=[[NASA]]|quote=[[Goddard Institute for Space Studies|Goddard]] scientists Mark Loeffler and Reggie Hudson have been performing laboratory studies to investigate whether cosmic rays, one type of radiation that strikes Jupiter’s clouds, can chemically alter ammonium hydrosulfide to produce new compounds that could explain the spot’s color. |date=August 4, 2015}}</ref> Research suggests that the storm produces extreme amounts of [[gravity wave]]s and [[acoustic wave]]s, owing to the turbulence of the storm. The acoustic waves travel vertically upwards to a height of {{cvt|800|km}} above the storm where they break in the upper atmosphere, converting wave energy into heat. This creates a region of upper atmosphere that is {{convert|1600|K}}—several hundred Kelvin warmer than the rest of the planet at this altitude.<ref name="Heating of Jupiter's upper atmosphe"/> The effect is described as being like "crashing [...] ocean waves on a beach".<ref>{{cite web |title=Jupiter's Great Red Spot Likely a Massive Heat Source |url=https://www.nasa.gov/feature/jupiter-s-great-red-spot-likely-a-massive-heat-source |website=NASA |date=27 July 2016 |publisher=NASA |access-date=23 December 2018}}</ref> The reason the storm has continued to exist for centuries is that there is no planetary surface (only a mantle of [[hydrogen]]) to provide friction; circulating gas eddies persist for a very long time in the atmosphere because there is nothing to oppose their angular momentum.<ref>{{cite web|url=http://www.astrophysicsspectator.com/topics/planets/JupiterGreatRedSpot.html|title=Jupiter's Atmosphere and Great Red Spot|publisher=www.astrophysicsspectator.com|date=November 24, 2004}}</ref> == Gallery == <gallery heights="200" mode="packed"> File:Winds in Jupiter’s Great Red Spot.jpg|Winds in Jupiter's Great Red Spot<ref>{{cite web|title=Hubble Shows Winds in Jupiter's Great Red Spot Are Speeding Up|url=https://esahubble.org/news/heic2110/|access-date=October 12, 2021}}</ref> </gallery> ==See also== {{portal|Solar System}} * [[Extraterrestrial vortex]] * [[Great White Spot]], a similar storm on [[Saturn]] * [[Hypercane]] * [[WISEP J190648.47+401106.8]] * The Great Prebiotic Spot, a concept in astrobiology, wherein the prebiotic processes leading to life occurred.<ref>{{cite journal |last1=von Hegner |first1=Ian |title=A limbus mundi elucidation of habitability: the Goldilocks Edge |journal=International Journal of Astrobiology |date=2020 |volume=19 |issue=pp. 320–329}}</ref> ==References== {{Reflist}} ==Further reading== *{{cite book |author=[Numerous authors] |editor1=Beatty, Kelly J. |editor2=Peterson, Carolyn Collins |editor3=Chaiki, Andrew |year=1999 |title=The New Solar System |edition=4th |publisher=Sky Publishing Corporation |location=Massachusetts |isbn=978-0933346864 }} *{{cite book |first=Reta |last=Beebe |year=1997 |title=Jupiter the Giant Planet |edition=2nd |publisher=Smithsonian Books |location=Washington |isbn=978-1560986850 }} *{{cite book |first=Thomas |last=Hockey |year=1999 |title=Galileo's Planet: Observing Jupiter Before Photography |publisher=IOP Publishing |location=Bristol, Philadelphia |isbn=978-0750304481 }} *{{cite book |first=Bertrand M. |last=Peek |author-link=Bertrand Meigh Peek |year=1981 |title=The Planet Jupiter: The Observer's Handbook |edition=Revised |publisher=Faber and Faber Limited |location=London |isbn=978-0571180264 |url-access=registration |url=https://archive.org/details/planetjupiter00peek }} *{{cite book |first=John H. |last=Rogers |year=1995 |title=The Giant Planet Jupiter |publisher=Cambridge University Press |location=Cambridge |isbn=978-0521410083 }} *{{cite journal |last=Smith |first=B. A. |display-authors=etal |year=1979 |title=The Jupiter system through the eyes of Voyager 1 |journal=Science |volume=204 |issue=4396|pages=951–957, 960–972 |bibcode=1979Sci...204..951S |doi=10.1126/science.204.4396.951 |pmid=17800430 |s2cid=33147728 }} ==External links== {{Commons category|Great Red Spot}} * {{cite news |first=Sarah |last=Yang |title=Researcher predicts global climate change on Jupiter as giant planet's spots disappear |publisher=UC Berkeley News |date=April 21, 2004 |url=http://www.berkeley.edu/news/media/releases/2004/04/21_jupiter.shtml |access-date=2007-06-14 }} * {{cite news |first=Tony |last=Phillips |title=Jupiter's New Red Spot |publisher=Science at NASA |date=March 3, 2006 |url=https://science.nasa.gov/headlines/y2006/02mar_redjr.htm |access-date=2007-06-14 |url-status=dead |archive-url=https://web.archive.org/web/20081019024917/https://science.nasa.gov/headlines/y2006/02mar_redjr.htm |archive-date=October 19, 2008 }} * {{cite news |first=Tony |last=Phillips |title=Huge Storms Converge |publisher=Science at NASA |date=June 5, 2006 |url=https://science.nasa.gov/headlines/y2006/05jun_redperil.htm?list56685 |access-date=2007-06-14 |archive-url=https://web.archive.org/web/20070505203040/http://science.nasa.gov/headlines/y2006/05jun_redperil.htm?list56685 |archive-date=May 5, 2007 |url-status=dead |df=mdy-all }} *{{cite journal |author1=Youssef, Ashraf |author2=Marcus, Philip S. |year=2003 |title=The dynamics of jovian white ovals from formation to merger |journal=Icarus |volume=162 |issue=1 |pages=74–93 |bibcode=2003Icar..162...74Y |doi=10.1016/S0019-1035(02)00060-X }} * {{cite web |last=Williams |first=Gareth P. |date=May 4, 2005 |url=http://www.gfdl.noaa.gov/~gw |title=NOAA Web Page |publisher=Geophysical Fluid Dynamics Laboratory |access-date=2007-07-21 }} * [https://www.flickr.com/photos/136797589@N04/35790218312/in/photostream/ Video based on Juno's Perijove 7 overflight] by Seán Doran (see [https://www.flickr.com/photos/136797589@N04/albums/72157684110532315 album] for more) {{Jupiter}} [[Category:Jupiter]] [[Category:Planetary spots]] [[Category:Anticyclones]] [[Category:Vortices]] [[Category:Storms]] [[Category:1830 in science]]'