Changes

|solarday=9.9259 h<ref name=nasa2/>

|solarday=9.9259 h<ref name=nasa2/>

|axialtilt=3.13°<ref name=nasa1/>

|axialtilt=3.13°<ref name=nasa1/>

|mass=1.8986 * 10²⁷ kg (317.705 * earth)<ref name=nasa1/>

|mass=1.8986 × 10²⁷ kg (317.705 × earth)<ref name=nasa1/>

|density=1,326 kg/m³<ref name=nasa1/>

|density=1,326 kg/m³<ref name=nasa1/>

|surfacegrav=22.88 m/s² (2.333 ''g'')<ref name=nasa1/>

|surfacegrav=22.88 m/s² (2.333 ''g'')<ref name=nasa1/>

|escapespeed=59.56 km/s<ref name=nasa1/>

|escapespeed=59.56 km/s<ref name=nasa1/>

|equatorradius =71,492 km<ref name=nasa1/>

|equatorradius =71,492 km<ref name=nasa1/>

|surfacearea=61,400,000,000 km² (120.375 * earth)<ref name=nasa1/>

|surfacearea=61,400,000,000 km² (120.375 × earth)<ref name=nasa1/>

|meantemp=152 K<ref name=nasa1/>

|meantemp=152 K<ref name=nasa1/>

|moons=66

|moons=66

|albedo=0.52<ref name=ssdphys>"[http://ssd.jpl.nasa.gov/?planet_phys_par Planet Physical Characteristics]." Solar System Dynamics, [[JPL]], [[NASA]]. Accessed March 3, 2008.</ref>

|albedo=0.52<ref name=ssdphys>"[http://ssd.jpl.nasa.gov/?planet_phys_par Planet Physical Characteristics]." Solar System Dynamics, [[JPL]], [[NASA]]. Accessed March 3, 2008.</ref>

|mfd=4.28 G <ref name=jupiterfact>"[http://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html Jupiter Fact Sheet]," [[National Aeronautics and Space Administration|NASA]], November 2, 2007. Accessed May 12, 2008.</ref>

|mfd=4.28 G <ref name=jupiterfact>"[http://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html Jupiter Fact Sheet]," [[National Aeronautics and Space Administration|NASA]], November 2, 2007. Accessed May 12, 2008.</ref>

|pmdm=1.55 * 10²⁷ N-m/T<ref name=Humphreys>Humphreys, D. R. "[http://www.creationresearch.org/crsq/articles/21/21_3/21_3.html The Creation of Planetary Magnetic Fields]." ''[[Creation Research Society Quarterly]]'' 21(3), December 1984. Accessed April 29, 2008.</ref>

|pmdm=1.55 × 10²⁷ N-m/T<ref name=Humphreys>Humphreys, D. R. "[http://www.creationresearch.org/crsq/articles/21/21_3/21_3.html The Creation of Planetary Magnetic Fields]." ''[[Creation Research Society Quarterly]]'' 21(3), December 1984. Accessed April 29, 2008.</ref>

|cmdm=1.79 * 10²⁷ N-m/T<ref name=Humphreys/>

|cmdm=1.79 × 10²⁷ N-m/T<ref name=Humphreys/>

|mdt=45,469 a<ref name=calc/>

|mdt=45,469 a<ref name=calc/>

|mhl=31,516 a<ref name=calc/>

|mhl=31,516 a<ref name=calc/>

== Rotational characteristics ==

== Rotational characteristics ==

Jupiter has a very short sidereal day of about 9.92 hours. However, its latitudinal cloud bands rotate at different speeds, and some of these appear to rotate retrograde. Astronomers once calculated the Jovian day from observations of the equatorial cloud band, but today they rely on the periodicity of Jupiter's magnetic field.<ref name=nasa3>Gierasch, Peter J., and Philip D. Nicholson. "Jupiter." World Book Online Reference Center. 2004. World Book, Inc. <http://www.worldbookonline.com/wb/Article?id=ar293080.> Hosted as "[http://www.nasa.gov/worldbook/jupiter_worldbook.html Entry for Jupiter]," World Book at NASA. Accessed March 3, 2008.</ref>

Jupiter has a very short sidereal day of about 9.92 hours. However, its latitudinal cloud bands rotate at different speeds, and some of these appear to rotate retrograde. Astronomers once calculated the Jovian day from observations of the equatorial cloud band, but today they rely on the periodicity of Jupiter's [[magnetic field]].<ref name=nasa3>Gierasch, Peter J., and Philip D. Nicholson. "Jupiter." World Book Online Reference Center. 2004. World Book, Inc. <http://www.worldbookonline.com/wb/Article?id=ar293080.> Hosted as "[http://www.nasa.gov/worldbook/jupiter_worldbook.html Entry for Jupiter]," World Book at NASA. Accessed March 3, 2008.</ref>

== Physical characteristics ==

== Physical characteristics ==

== Magnetosphere ==

== Magnetosphere ==

Jupiter has a magnetic field about 14 times as strong as that of Earth. Specifically, its [[magnetic dipole moment]] amounts to 1.55 * 10²⁷ N-m/T, higher than that of any object except the Sun. It is so high, in fact, that by [[Russell Humphreys]]' model for planetary magnetic fields, Jupiter's field must have formed with ''all'' of its mass aligned for the maximum cumulative magnetic dipole moment, instead of the usual 25%. By this assumption, the magnetic dipole moment of Jupiter at creation must have been 1.79 * 10²⁷ N-m/T. The half-life of this field is longer than 31,500 Julian years.

Jupiter has a [[magnetic field]] about 14 times as strong as that of Earth. Specifically, its [[magnetic dipole moment]] amounts to 1.55 × 10²⁷ N-m/T, higher than that of any object except the Sun. It is so high, in fact, that by [[Russell Humphreys]]' model for planetary magnetic fields, Jupiter's field must have formed with ''all'' of its mass aligned for the maximum cumulative magnetic dipole moment, instead of the usual 25%. By this assumption, the magnetic dipole moment of Jupiter at creation must have been 1.79 × 10²⁷ N-m/T. The half-life of this field is longer than 31,500 Julian years.

This field tends to shield Jupiter from the [[solar wind]]. However, the field has also trapped large numbers of radioactive particles in a [[Van Allen radiation belt|Van-Allen-like radiation belt]]<ref name=nasa3/> that actually encompasses the orbits of the seven innermost moons. The magnetic field extends beyond the far side of Jupiter for at least 700 million kilometers.<ref name=nasa3/>

This field tends to shield Jupiter from the [[solar wind]]. However, the field has also trapped large numbers of [[radioactivity|radioactive]] [[subatomic particle|particles]] in a [[Van Allen radiation belt|Van-Allen-like radiation belt]]<ref name=nasa3/> that actually encompasses the orbits of the seven innermost moons. The magnetic field extends beyond the far side of Jupiter for at least 700 million kilometers.<ref name=nasa3/>

The very strong magnetic field of Jupiter is extraordinary by any standard. The Humphreys model has passed two key tests of its predictive value, one at [[Uranus]] and the other at [[Neptune]].<ref name=Humphreys2>Humphreys, D. R. "[http://www.icr.org/index.php?module=articles&action=view&page=329 Beyond Neptune: Voyager II Supports Creation]." [[Institute for Creation Research]]. Accessed April 30, 2008</ref> That model normally assumes that God formed any given celestial body initially out of water, with its molecules partially aligned for maximum cumulative effect, and then transmuted the molecules after the magnetic field was established. For most celestial bodies thus far observed, an alignment fraction of 25% suffices to establish a magnetic dipole moment at creation. But Jupiter's magnetic dipole moment is far too high to have resulted from an initial alignment of 25%. An alignment of 100% seems to be required, the highest fraction allowable and the highest fraction of all celestial bodies observed to date. This implies that God made Jupiter to be a beacon in the night sky, in more ways than merely by making it large.

The very strong magnetic field of Jupiter is extraordinary by any standard. The Humphreys model has passed two key tests of its predictive value, one at [[Uranus]] and the other at [[Neptune]].<ref name=Humphreys2>Humphreys, D. R. "[http://www.icr.org/index.php?module=articles&action=view&page=329 Beyond Neptune: Voyager II Supports Creation]." [[Institute for Creation Research]]. Accessed April 30, 2008</ref> That model normally assumes that God formed any given celestial body initially out of water, with its molecules partially aligned for maximum cumulative effect, and then transmuted the molecules after the magnetic field was established. For most celestial bodies thus far observed, an alignment fraction of 25% suffices to establish a magnetic dipole moment at creation. But Jupiter's magnetic dipole moment is far too high to have resulted from an initial alignment of 25%. An alignment of 100% seems to be required, the highest fraction allowable and the highest fraction of all celestial bodies observed to date. This implies that God made Jupiter to be a beacon in the night sky, in more ways than merely by making it large.

Jupiter's orbit is inclined 1.305 degrees to the ecliptic, so Jupiter appears, in turn, in each constellation of the Zodiac. In fact, its 399-day synodic year places it in a different constellation of the Zodiac at the same point in each succeeding year. Pratt<ref name=Pratt>Pratt, John C. "[http://www.johnpratt.com/items/docs/lds/meridian/2005/zodiac.html The Constellations Tell of Christ]." ''Meridian'', June 15, 2005. Accessed May 12, 2008.</ref> shows that the members of the Zodiac, and a number of closely associated constellations, presage the life and ministry of [[Jesus Christ]]. If Jupiter is indeed a beacon, then it could not have been better placed.

Jupiter's orbit is inclined 1.305 degrees to the [[ecliptic]], so Jupiter appears, in turn, in each constellation of the Zodiac. In fact, its 399-day synodic year places it in a different constellation of the [[Zodiac]] at the same point in each succeeding year. Pratt<ref name=Pratt>Pratt, John C. "[http://www.johnpratt.com/items/docs/lds/meridian/2005/zodiac.html The Constellations Tell of Christ]." ''Meridian'', June 15, 2005. Accessed May 12, 2008.</ref> shows that the members of the Zodiac, and a number of closely associated constellations, presage the life and ministry of [[Jesus Christ]]. If Jupiter is indeed a beacon, then it could not have been better placed.

== Ring system ==

== Ring system ==

[[Galileo Galilei]] studied Jupiter extensively  and in the process discovered its four largest moons--[[Io]], [[Europa (moon)|Europa]], [[Ganymede]], and [[Callisto]], also known as the [[Galilean moons]]. Many other astronomers studied Jupiter from Earth-bound telescopes for hundreds of years. In the process they discovered twelve of Jupiter's moons and the Great Red Spot, but did not discover Jupiter's ring system.

[[Galileo Galilei]] studied Jupiter extensively  and in the process discovered its four largest moons--[[Io]], [[Europa (moon)|Europa]], [[Ganymede]], and [[Callisto]], also known as the [[Galilean moons]]. Many other astronomers studied Jupiter from Earth-bound telescopes for hundreds of years. In the process they discovered twelve of Jupiter's moons and the Great Red Spot, but did not discover Jupiter's ring system.

Seven spacecraft, all from the [[United States]], have visited Jupiter thus far. First to do so was [[Pioneer 10]] (December 3, 1973), which suffered tremendously from the radiation belt but still provided the evidence for Jupiter's [[magnetosphere]]. [[Pioneer 11]] was next (December, 1974) and took far better images of Jupiter and its Great Red Spot.

Eight spacecraft, all from the [[United States]], have visited Jupiter thus far. First to do so was [[Pioneer 10]] (December 3, 1973), which suffered tremendously from the radiation belt but still provided the evidence for Jupiter's [[magnetosphere]]. [[Pioneer 11]] was next (December, 1974) and took far better images of Jupiter and its Great Red Spot.

[[Voyager 1]] (March, 1979) and [[Voyager 2]] (July, 1979) gave the first comprehensive views of Jupiter and the Jovian system, including the discovery of its rings, the discovery of four moons inside [[Io]]'s orbit, and the first extensive studies of the Galilean moons.

[[Voyager 1]] (March, 1979) and [[Voyager 2]] (July, 1979) gave the first comprehensive views of Jupiter and the Jovian system, including the discovery of its rings, the discovery of four moons inside [[Io]]'s orbit, and the first extensive studies of the Galilean moons.

[[Galileo Project|Galileo]] reached Jupiter in 1995. It released a probe to dive into Jupiter's atmosphere; that probe transmitted for nearly an hour before the tremendous pressures crushed it. Galileo's orbiter remained in the system for nearly eight years, through two extensions of its mission, and conducted the most extensive surveys of the Galilean moons to day. Eventually, with the craft low on fuel, mission planners dived it into Jupiter to prevent its possibly crashing into [[Europa]], rupturing Europa's ice sheet, and contaminating the liquid ocean that astronomers now suspect lies a mere 10&nbsp;km deep to the ice and could yet harbor [[extraterrestrial life]].<ref name=nasa3/>

[[Galileo Project|Galileo]] reached Jupiter in 1995. It released a probe to dive into Jupiter's atmosphere; that probe transmitted for nearly an hour before the tremendous pressures crushed it. Galileo's orbiter remained in the system for nearly eight years, through two extensions of its mission, and conducted the most extensive surveys of the Galilean moons to day. Eventually, with the craft low on fuel, mission planners dived it into Jupiter to prevent its possibly crashing into [[Europa]], rupturing Europa's ice sheet, and contaminating the liquid ocean that astronomers now suspect lies a mere 10&nbsp;km deep to the ice and could yet harbor [[extraterrestrial life]].<ref name=nasa3/>

[[Cassini-Huygens Mission|Cassini]] flew by Jupiter briefly in 2000 on its way to [[Saturn]]. While in the Jovian system, it took the image shown at the top of this article.

[[Cassini-Huygens Mission|Cassini]] flew by Jupiter briefly in 2000 on its way to [[Saturn]]. While in the Jovian system, it took the image shown at the top of this article. Similarly the [[New Horizons mission]] included a Jupiter flyby in its journey to the [[Pluto]] system, passing Jupiter on February 28, 2007.<ref>[https://www.nasa.gov/mission_pages/newhorizons/news/nh_jupiter_oct09.html Pluto-Bound New Horizons Sees Changes in Jupiter System] from nasa.gov</ref>

The [[New Horizons mission]] will include a Jupiter flyby in its journey to the [[Pluto]] system.

The latest probe to visit Jupiter is [[NASA]]'s [[Juno (probe)|Juno mission]].<ref>[https://www.nasa.gov/mission_pages/juno/main/index.html Juno mission page]from nasa.gov</ref> It reached Jupiter in July 2016 and has returned highly detailed images of the planet. It aims to investigate Jupiter's magnetosphere further, as well as measuring its [[magnetic field|magnetic]] and [[gravitational]] fields to determine its internal structure.

== References==

==References==

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