View source for Jupiter mass

{{Short description|Unit of mass equal to the total mass of the planet Jupiter}}
{{Infobox unit
| name         = Jupiter mass
| image        = Masses of gas giants.svg
| caption      = Relative masses of the giant planets of the [[outer Solar System]]
| standard     = [[Astronomical system of units]]
| quantity     = [[mass]]
| symbol       = {{Jupiter mass}}
| symbol2      = {{Jupiter mass|Jup=y}} or {{Jupiter mass|greek=yes}}
| units1       = [[SI base unit]]
| inunits1     = {{val|1.89813|0.00019|e=27|ul=kg}}<ref name="JPL Planets">{{cite web|title=Planets and Pluto: Physical Characteristics|url=https://ssd.jpl.nasa.gov/?planet_phys_par|website=ssd.jpl.nasa.gov|publisher=Jet Propulsion Labritory|access-date=31 October 2017}}</ref>
| units2       = [[United States customary units|U.S. customary]]
| inunits2     = ≈{{thinsp}}{{val|4.1847|e=27}} [[Pound (mass)|pounds]]
}}

The '''Jupiter mass''', also called '''Jovian mass''', is the [[units of mass|unit of mass]] equal to the total mass of the planet [[Jupiter]]. This value may refer to the mass of the [[planet]] alone, or the mass of the entire Jovian system to include the [[moons of Jupiter]]. Jupiter is by far the most [[giant planet|massive planet]] in the [[Solar System]]. It is approximately 2.5 times as massive as all of the other planets in the Solar System combined.<ref name="Universe Today">{{cite web |last=Coffey |first=Jerry |title=Mass of Jupiter |url=https://www.universetoday.com/15141/mass-of-jupiter/ |publisher=[[Universe Today]] |date=18 June 2008 |access-date=2017-10-31}}</ref>

Jupiter mass is a common unit of [[mass]] in [[astronomy]] that is used to indicate the masses of other similarly-sized objects, including the [[outer planet]]s, [[extrasolar planet]]s, and [[brown dwarf]]s, as this unit provides a convenient scale for comparison.

==Current best estimates==
The current best known value for the mass of Jupiter can be expressed as {{val|1898130|u=[[Orders of magnitude (mass)|yottagrams]]}}:<ref name="JPL Planets"/>

<math display="block">M_\mathrm{J}=(1.89813 \pm 0.00019)\times10^{27} \text{ kg},</math>

which is about {{frac|1000}} as massive as the Sun (is about {{solar mass|0.1%}}):<ref name="CBE">{{cite web|title=Numerical Standards for Fundamental Astronomy|url=http://maia.usno.navy.mil/NSFA/NSFA_cbe.html#MSMJ2009|website=maia.usno.navy.mil|publisher=IAU Working Group|access-date=31 October 2017|archive-url=https://web.archive.org/web/20160826200953/http://maia.usno.navy.mil/NSFA/NSFA_cbe.html#MSMJ2009|archive-date=26 August 2016|url-status=dead}}</ref>

<math display="block">M_\mathrm{J}=\frac{1}{1047.348644 \pm 0.000017} M_{\odot} \approx (9.547919 \pm 0.000002) \times10^{-4} M_{\odot}.</math>

Jupiter is 318 times as massive as Earth:

<math display="block">M_\mathrm{J} = 3.1782838 \times 10^2 M_\oplus. </math>

==Context and implications==
Jupiter's mass is 2.5 times that of all the other planets in the Solar System combined—this is so massive that its [[barycenter]] with the [[Sun]] lies beyond the [[Photosphere|Sun's surface]] at 1.068&nbsp;[[solar radius|solar radii]] from the Sun's center.<ref>{{cite book |last1=MacDougal |first1=Douglas W. |title=Newton's Gravity |url=https://archive.org/details/newtonsgravityin00macd |url-access=limited |date=November 6, 2012 |publisher=Springer New York |isbn=9781461454434 |pages=[https://archive.org/details/newtonsgravityin00macd/page/n208 193]–211 |language=en |chapter=A Binary System Close to Home: How the Moon and Earth Orbit Each Other |quote=the barycenter is 743,000 km from the center of the sun. The Sun's radius is 696,000 km, so it is 47,000 km above the surface.|doi=10.1007/978-1-4614-5444-1_10 |series=Undergraduate Lecture Notes in Physics }}</ref>

Because the mass of Jupiter is so large compared to the other objects in the [[Solar System]], the effects of its gravity must be included when calculating satellite trajectories and the precise orbits of other bodies in the Solar System, including the [[Moon]] and even Pluto.

Theoretical models indicate that if Jupiter had much more mass than it does at present, its atmosphere would collapse, and the planet would shrink.<ref name=Seager2007>{{cite journal
 |last=Seager |first=S.
 |author2=Kuchner, M.
 |author3=Hier-Majumder, C. A.
 |author4=Militzer, B.
 |title=Mass-Radius Relationships for Solid Exoplanets
 |journal=The Astrophysical Journal
 |volume=669 |issue=2 |pages=1279–1297 |date=2007
 |doi=10.1086/521346
 |arxiv=0707.2895 |bibcode=2007ApJ...669.1279S|s2cid=8369390
 }}</ref> For small changes in mass, the [[radius]] would not change appreciably, but above about {{earth mass|link=yes|500}} (1.6 Jupiter masses)<ref name=Seager2007/> the interior would become so much more compressed under the increased pressure that its volume would ''decrease'' despite the increasing amount of matter. As a result, Jupiter is thought to have about as large a diameter as a planet of its composition and evolutionary history can achieve.<ref name=HTUW>{{cite AV media | title=How the Universe Works 3
 | volume=Jupiter: Destroyer or Savior? | date=2014 | publisher=[[Discovery Channel]]}}</ref> The process of further shrinkage with increasing mass would continue until appreciable [[stellar ignition]] was achieved, as in high-mass [[brown dwarf]]s having around 50 Jupiter masses.<ref name="tristan286">{{cite journal
 |last=Guillot |first=Tristan
 |title=Interiors of Giant Planets Inside and Outside the Solar System
 |journal=Science
 |date=1999 |volume=286 |issue=5437 |pages=72–77 |doi=10.1126/science.286.5437.72 |pmid=10506563 |bibcode=1999Sci...286...72G}}</ref> Jupiter would need to be about 80 times as massive to [[hydrogen fusion|fuse hydrogen]] and become a [[star]].<ref>{{cite journal
 |author=Burrows, Adam |author2=Hubbard, William B. |author3=Saumon, D. |author4=Lunine, Jonathan I.
 |title=An expanded set of brown dwarf and very low mass star models
 |journal=Astrophysical Journal
 |date=1993 |volume=406 |issue=1 |pages=158–71 |bibcode=1993ApJ...406..158B |doi=10.1086/172427 |doi-access=free }}</ref>

== Gravitational constant==
The mass of Jupiter is derived from the measured value called the [[standard gravitational parameter|Jovian mass parameter]], which is denoted with ''GM''<sub>J</sub>. The mass of Jupiter is calculated by dividing ''GM''<sub>J</sub> by the constant ''[[gravitational constant|G]]''. For celestial bodies such as Jupiter, Earth and the Sun, the value of the ''GM'' product is known to many [[order of magnitude|orders of magnitude]] more precisely than either factor independently. The limited precision available for ''G'' limits the uncertainty of the derived mass. For this reason, astronomers often prefer to refer to the gravitational parameter, rather than the explicit mass. The ''GM'' products are used when computing the ratio of Jupiter mass relative to other objects.

In 2015, the [[International Astronomical Union]] defined the ''nominal Jovian mass parameter'' to remain constant regardless of subsequent improvements in measurement precision of {{Jupiter mass}}. This constant is defined as exactly

<math display="block">(\mathcal{GM})^\mathrm N_\mathrm J = 1.266\,8653 \times 10^{17} \text{ m}^3/\text{s}^2 </math>

If the explicit mass of Jupiter is needed in SI units, it can be calculated by dividing ''GM'' by ''G'', where ''G'' is the [[gravitational constant]].<ref name = "IAU XXIX">{{cite arXiv |eprint=1510.07674|last1=Mamajek|first1=E. E.|title=IAU 2015 Resolution B3 on Recommended Nominal Conversion Constants for Selected Solar and Planetary Properties| last2=Prsa|first2=A.|last3=Torres|first3=G.|last4=Harmanec|first4=P.|last5=Asplund|first5=M.|last6=Bennett|first6=P. D| last7= Capitaine|first7=N|last8=Christensen-Dalsgaard|first8=J|last9=Depagne|first9=E|last10=Folkner|first10=W. M.|last11=Haberreiter|first11=M.|last12=Hekker|first12=S.|last13=Hilton|first13=J. L.|last14=Kostov|first14=V|last15=Kurtz|first15=D. W|last16=Laskar|first16=J|last17=Mason|first17=B. D|last18=Milone|first18=E. F.|last19=Montgomery|first19=M. M.|last20=Richards|first20=M. T.|last21=Schou|first21=J|last22=Stewart|first22=S. G.|class=astro-ph.SR|year=2015|display-authors= 3}}</ref>

==Mass composition==
The majority of Jupiter's mass is hydrogen and helium. These two elements make up more than 87% of the total mass of Jupiter.<ref name = "Jupiters Interior">{{cite web|last1=Guillot|first1=Tristan|last2=Stevenson|first2=David J.|last3=Hubbard|first3=William B.|last4=Saumon|first4=Didier|title=The Interior of Jupiter| url=https://authors.library.caltech.edu/39188/1/Stevenson_2004p35.pdf|access-date=31 October 2017}}</ref> The total mass of heavy elements other than hydrogen and helium in the planet is between 11 and {{earth mass|45}}.<ref>{{cite journal|last1=Guillot|first1=Tristan|last2=Gautier|first2=Daniel|last3=Hubbard|first3=William B.|title=New Constraints on the Composition of Jupiter from Galileo Measurements and Interior Models|journal=Icarus|date=December 1997|volume=130|issue=2|pages=534–539|doi=10.1006/icar.1997.5812|arxiv=astro-ph/9707210|bibcode=1997Icar..130..534G|s2cid=5466469 }}</ref> The bulk of the hydrogen on Jupiter is solid hydrogen.<ref>{{cite journal|last1=Öpik|first1=E. J.|title=Jupiter: Chemical composition, structure, and origin of a giant planet|journal=Icarus|date=January 1962|volume=1|issue=1–6|pages=200–257|doi=10.1016/0019-1035(62)90022-2|bibcode=1962Icar....1..200O}}</ref> Evidence suggests that Jupiter contains a central dense core. If so, the mass of the core is predicted to be no larger than about {{earth mass|12}}. The exact mass of the core is uncertain due to the relatively poor knowledge of the behavior of solid hydrogen at very high pressures.<ref name = "Jupiters Interior"/>

==Relative mass==
{| class="wikitable sortable"
|+ Masses of noteworthy [[astronomical object]]s relative to the mass of Jupiter
|-
! Object
! {{Jupiter mass}} / ''M''<sub>object</sub>
! ''M''<sub>object</sub> / {{Jupiter mass}}
! class="unsortable"|Ref.
|-
| [[Sun]]
| {{val|9.547919|(15)|e=-4}}
| {{val|1047.348644|(17)|}}
| align="center" | <ref name="CBE"/>
|-
|[[Earth]]
| {{val|317.82838}}
| {{val|0.0031463520}}
| align="center" | <ref name="fact sheet">{{Cite web|title = Planetary Fact Sheet – Ratio to Earth|url = http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_ratio.html|website = nssdc.gsfc.nasa.gov|access-date = 2016-02-12}}</ref>
|-
| [[Jupiter]]
| '''{{val|1}}'''
| '''{{val|1}}'''
| by definition
|-
| [[Saturn]]
| {{val|3.3397683}}
| {{val|0.29942197}}
| align="center" | {{refn|name="sig fig"|group=note|Some of the values in this table are nominal values, derived from ''Numerical Standards for Fundamental Astronomy''<ref name="CBE"/> and rounded using appropriate attention to [[significant figures]], as recommended by the IAU Resolution B3.<ref name = "IAU XXIX" />}} 
|-
| [[Uranus]]
| {{val|21.867552}}
| {{val|0.045729856}}
| align="center" | {{refn|name="sig fig"|group=note}}
|-
| [[Neptune]]
| {{val|18.53467}}
| {{val|0.05395295}}
| align="center" | {{refn|name="sig fig"|group=note}}
|-
|[[GJ 229B|Gliese 229B]]
| 
| {{val|21|–|52.4}}
| align="center" | <ref name="apjss71">{{cite journal
  |author1=White, Stephen M. |author2=Jackson, Peter D. |author3=Kundu, Mukul R. | title=A VLA survey of nearby flare stars
  | journal=Astrophysical Journal Supplement Series
  | volume=71 |date=December 1989
  | pages=895–904 | doi=10.1086/191401 | bibcode=1989ApJS...71..895W}}</ref>
|-
| [[51 Pegasi b]]
|
| {{val|0.472|0.039}}
| align="center" |<ref>{{Cite journal|arxiv=1504.05962|last1=Martins|first1=J. H. C.|title=Evidence for a spectroscopic direct detection of reflected light from 51 Peg b|journal=Astronomy & Astrophysics|volume=576|issue=2015|pages=A134|last2=Santos|first2=N. C.|last3=Figueira|first3=P.|last4=Faria|first4=J. P.|last5=Montalto|first5=M.|last6=Boisse|first6=I|last7=Ehrenreich|first7=D.|last8=Lovis|first8=C|last9=Mayor|first9=M|last10=Melo|first10=C|last11=Pepe|first11=F.|last12=Sousa|first12=S. G.|last13=Udry|first13=S|last14=Cunha|first14=D.|display-authors=3|year=2015|doi=10.1051/0004-6361/201425298|bibcode=2015A&A...576A.134M|s2cid=119224213 }}</ref>
|}

==See also==
* [[Jupiter radius]]
* [[Hot Jupiter]]
* [[Orders of magnitude (mass)]]
* [[Planetary mass]]
* [[Solar mass]]

==Notes==
{{reflist|group=note}}

==References==
{{reflist}}

{{Jupiter}}

[[Category:Units of mass]]
[[Category:Planetary science]]
[[Category:Units of measurement in astronomy]]