Editing Jupiter (section)

=== Composition ===
The [[atmosphere of Jupiter]] is approximately 76% hydrogen and 24% helium by mass. By volume, the upper atmosphere is about 90% hydrogen and 10% helium, with the lower proportion owing to the individual helium atoms being more massive than the molecules of hydrogen formed in this part of the atmosphere.<ref>{{cite journal| title=NOTE: New Constraints on the Composition of Jupiter from Galileo Measurements and Interior Models | last1=Guillot | first1=Tristan | last2=Gautier | first2=Daniel | last3=Hubbard | first3=William B. |journal=Icarus | volume=130 | issue=2 | pages=534–539 | date=December 1997 | doi=10.1006/icar.1997.5812 | arxiv=astro-ph/9707210 | bibcode=1997Icar..130..534G
| s2cid=5466469 }}</ref> The atmosphere contains trace amounts of elemental [[carbon]], [[oxygen]], [[sulfur]], and [[neon]],<ref>{{cite book|title=Jupiter: The Planet, Satellites and Magnetosphere |editor-first=Fran |editor-last=Bagenal |editor-first2=Timothy E. |editor-last2=Dowling |editor-first3=William B. |editor-last3=McKinnon |publisher=Cambridge University Press |year=2006 |isbn=0521035457 |pages=59–75}}</ref> as well as [[ammonia]], [[water vapour]], [[phosphine]], [[hydrogen sulfide]], and [[hydrocarbons]] like [[methane]], [[ethane]] and [[benzene]].<ref>{{cite journal |journal=Icarus |volume=64 |issue=2 |pages=233–248 |year=1985 |title=Infrared Polar Brightening on Jupiter III. Spectrometry from the Voyager 1 IRIS Experiment |bibcode=1985Icar...64..233K | last1=Kim | first1=S. J. | last2=Caldwell | first2=J. | last3=Rivolo | first3=A. R. | last4=Wagner | first4=R. |doi=10.1016/0019-1035(85)90201-5}}</ref> Its outermost layer contains [[crystal]]s of frozen ammonia.<ref>{{cite journal|title=Zonal Features in the Behavior of Weak Molecular Absorption Bands on Jupiter|first1=V. D. |last1=Vdovichenko |first2=A. M. |last2=Karimov |first3=G. A. |last3=Kirienko |first4=P. G. |last4=Lysenko |first5=V. G. |last5=Tejfel’ |first6=V. A. |last6=Filippov |first7=G. A. |last7=Kharitonova |first8=A. P. |last8=Khozhenets |journal=Solar System Research |volume=55 |pages=35–46 |year=2021 |issue=1 |doi=10.1134/S003809462101010X |bibcode=2021SoSyR..55...35V |s2cid=255069821 }}</ref> The planet's interior is denser, with a composition of roughly 71% hydrogen, 24% helium, and 5% other elements by mass.<ref name="voyager">{{cite journal | last1=Gautier | first1=D. | last2=Conrath | first2=B. | last3=Flasar | first3=M. | last4=Hanel | first4=R. | last5=Kunde | first5=V. | last6=Chedin | first6=A. | last7=Scott | first7=N. |title=The helium abundance of Jupiter from Voyager |journal=Journal of Geophysical Research |volume=86 |issue=A10 |pages=8713–8720 |year=1981 |bibcode=1981JGR....86.8713G |doi=10.1029/JA086iA10p08713|hdl=2060/19810016480 |s2cid=122314894 |hdl-access=free }}</ref><ref name="cassini">{{cite journal | last1=Kunde | first1=V. G. | last2=Flasar | first2=F. M. | last3=Jennings | first3=D. E. | last4=Bézard | first4=B. | last5=Strobel | first5=D. F. | last6=Conrath | first6=B. J. | last7=Nixon | first7=C. A. | last8=Bjoraker | first8=G. L. | last9=Romani | first9=P. N. | last10=Achterberg | first10=R. K. | last11=Simon-Miller | first11=A. A. | last12=Irwin | first12=P. | last13=Brasunas | first13=J. C. | last14=Pearl | first14=J. C. | last15=Smith | first15=M. D. | last16=Orton | first16=G. S. | last17=Gierasch | first17=P. J. | last18=Spilker | first18=L. J. | last19=Carlson | first19=R. C. | last20=Mamoutkine | first20=A. A. | last21=Calcutt | first21=S. B. | last22=Read | first22=P. L. | last23=Taylor | first23=F. W. | last24=Fouchet | first24=T. | last25=Parrish | first25=P. | last26=Barucci | first26=A. | last27=Courtin | first27=R. | last28=Coustenis | first28=A. | last29=Gautier | first29=D. | last30=Lellouch | first30=E. | last31=Marten | first31=A. | last32=Prangé | first32=R. | last33=Biraud | first33=Y. | last34=Ferrari | first34=C. | last35=Owen | first35=T. C. | last36=Abbas | first36=M. M. | last37=Samuelson | first37=R. E. | last38=Raulin | first38=F. | last39=Ade | first39=P. | last40=Césarsky | first40=C. J. | last41=Grossman | first41=K. U. | last42=Coradini | first42=A. | display-authors=5 | title=Jupiter's Atmospheric Composition from the Cassini Thermal Infrared Spectroscopy Experiment | journal=Science | date=September 10, 2004 | volume=305 | issue=5690 | pages=1582–1586 | doi=10.1126/science.1100240 | pmid=15319491 | bibcode=2004Sci...305.1582K | s2cid=45296656 | doi-access=free }}</ref>

The atmospheric proportions of hydrogen and helium are close to the theoretical composition of the primordial [[solar nebula]].<ref>{{cite web|title=Solar Nebula Supermarket|date=December 2017 |publisher=nasa.gov|url=https://solarsystem.nasa.gov/genesismission/educate/scimodule/PlanetaryDiversity/plandiv_pdf/SupermarketST.pdf|access-date=July 10, 2023|archive-date=July 17, 2023|archive-url=https://web.archive.org/web/20230717222001/https://solarsystem.nasa.gov/genesismission/educate/scimodule/PlanetaryDiversity/plandiv_pdf/SupermarketST.pdf|url-status=live}}</ref> Neon in the upper atmosphere consists of 20 parts per million by mass, which is about a tenth as abundant as in the Sun.<ref>{{cite journal | last1=Niemann | first1=H. B. | last2=Atreya | first2=S. K. |  last3=Carignan | first3=G. R. | last4=Donahue | first4=T. M. | last5=Haberman | first5=J. A. | last6=Harpold | first6=D. N. | last7=Hartle | first7=R. E. | last8=Hunten | first8=D. M. | last9=Kasprzak | first9=W. T. | last10=Mahaffy | first10=P. R. | last11=Owen | first11=T. C. | last12=Spencer | first12=N. W. | last13=Way | first13=S. H. | display-authors=5 | title=The Galileo Probe Mass Spectrometer: Composition of Jupiter's Atmosphere | journal=Science | year=1996 | volume=272 | issue=5263 | pages=846–849 | bibcode=1996Sci...272..846N | doi=10.1126/science.272.5263.846 | pmid=8629016| s2cid=3242002 }}</ref> Jupiter's helium abundance is about 80% that of the Sun due to the [[Precipitation (meteorology)|precipitation]] of these elements as helium-rich droplets, a process that happens deep in the planet's interior.<ref name="galileo_ms">{{cite journal |first1=U. |last1=von Zahn |first2=D. M. |last2=Hunten |first3=G. |last3=Lehmacher |title=Helium in Jupiter's atmosphere: Results from the Galileo probe Helium Interferometer Experiment |journal=Journal of Geophysical Research |year=1998 |volume=103 |issue=E10 |pages=22815–22829 |doi=10.1029/98JE00695 |bibcode=1998JGR...10322815V |doi-access=free }}</ref><ref name="Juno">{{cite journal |title=Jupiter's Interior as Revealed by Juno |last=Stevenson |first=David J. |journal=Annual Review of Earth and Planetary Sciences |volume=48 |pages=465–489 |date=May 2020 |doi=10.1146/annurev-earth-081619-052855 |bibcode=2020AREPS..48..465S |s2cid=212832169 |doi-access=free }}</ref>

Based on [[spectroscopy]], [[Saturn]] is thought to be similar in composition to Jupiter, but the other giant planets [[Uranus]] and [[Neptune]] have relatively less hydrogen and helium and relatively more of the next [[Abundance of the chemical elements|most common elements]], including oxygen, carbon, nitrogen, and sulfur.<ref>{{cite web | last1=Ingersoll | first1=A. P. | last2=Hammel | first2=H. B. | last3=Spilker | first3=T. R. | last4=Young | first4=R. E. | date=June 1, 2005 | url=http://www.lpi.usra.edu/opag/outer_planets.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.lpi.usra.edu/opag/outer_planets.pdf |archive-date=October 9, 2022 |url-status=live | title=Outer Planets: The Ice Giants | publisher=Lunar & Planetary Institute | access-date=February 1, 2007 }}</ref> These planets are known as [[ice giants]] because during their formation, these elements are thought to have been incorporated into them as ice; however, they probably contain very little ice.<ref name=icegiantatmospheres>{{citation | url=https://www.lpi.usra.edu/decadal/opag/IceGiantAtmospheres_v7.pdf | last=Hofstadter | first=Mark | title=The Atmospheres of the Ice Giants, Uranus and Neptune | year=2011 | publisher=[[National Research Council (United States)|US National Research Council]] | access-date=January 18, 2015 | work=White Paper for the [[Planetary Science Decadal Survey]] | pages=1–2 | archive-date=July 17, 2023 | archive-url=https://web.archive.org/web/20230717232018/https://www.lpi.usra.edu/decadal/opag/IceGiantAtmospheres_v7.pdf | url-status=live }}</ref>