Changes

| color=Gray-brown

| color=Gray-brown

| albedo=0.43<ref name=ssdphys/>

| albedo=0.43<ref name=ssdphys/>

}}'''Ganymede''' ([[Greek]] ''Γανυμήδης'' or ''Ganumedes'') is the largest [[satellite]] of [[Jupiter]] and indeed the largest planetary satellite, by mass or radius, in the [[solar system]]. It is slightly larger than [[Mercury]] (though Mercury is twice as heavy) and is both larger and heavier than any of the [[dwarf planet]]s [[Eris]], [[Pluto]], and [[Ceres]]. Thus, if it orbited the [[Sun]] instead of Jupiter, it might be a true [[planet]]--if it "cleared its neighborhood" of all other objects, as all planets must do to be worthy of the name.

}}'''Ganymede''' ([[Greek]] ''Γανυμήδης'' or ''Ganumedes'') is the largest [[satellite]] of [[Jupiter]] and indeed the largest planetary satellite, by mass or radius, in the [[solar system]]. It is slightly larger than [[Mercury]] (though Mercury is twice as heavy) and is both larger and heavier than any of the [[dwarf planet]]s [[Eris]], [[Pluto]], and [[Ceres]]. Thus, if it orbited the [[Sun]] instead of Jupiter, it might be a true [[planet]]--if it "cleared its neighborhood" of all other objects, as all planets must do to be worthy of the name.

The model of Ganymede's interior has its basis in this most striking finding: Ganymede, unique among all planetary satellites, has its own magnetic field. This is most consistent with Ganymede having a metallic core, most likely of iron and iron sulfate.<ref name=Showman2>Showman, Adam P., and Malhotra, Renu. "[http://www.lpl.arizona.edu/~showman/publications/showman-malhotra-1999.pdf The Galilean Satellites]." ''Science'', 286: 77–84, 1999. Accessed February 18, 2008.</ref> Surrounding this core is a mantle of ice and silicates and an outer mantle of ice.

The model of Ganymede's interior has its basis in this most striking finding: Ganymede, unique among all planetary satellites, has its own magnetic field. This is most consistent with Ganymede having a metallic core, most likely of iron and iron sulfate.<ref name=Showman2>Showman, Adam P., and Malhotra, Renu. "[http://www.lpl.arizona.edu/~showman/publications/showman-malhotra-1999.pdf The Galilean Satellites]." ''Science'', 286: 77–84, 1999. Accessed February 18, 2008.</ref> Surrounding this core is a mantle of ice and silicates and an outer mantle of ice.

Ganymede appears to have a strong inductive magnetic moment. This implies a conductive liquid between the crust and the core, most likely a saltwater ocean about 146 km deep to the surface and extending to the outer mantle.<ref name=Kivelson>Kivelson, M. G.; Khurana, K. K.; Volwerk, M. "[http://www.igpp.ucla.edu/people/mkivelson/Publications/ICRUS1572507.pdf The Permanent and Inductive Magnetic Moments of Ganymede]." ''Icarus'', 157:507-522, 2002. Accessed February 18, 2008.</ref><ref name=jplocean>"[http://www.jpl.nasa.gov/releases/2000/aguganymederoundup.html Solar System's Largest Moon Likely Has a Hidden Ocean]." Press release 12/12/00 GW 00-XXX, [[JPL]], [[NASA]], December 12, 2000. Accessed February 18, 2008.</ref>

Ganymede appears to have a strong inductive magnetic moment. Its ''permanent'' equatorial magnetic flux density is 7.19 milligauss, stronger than that measured at any other moon. This is consistent with a magnetic dipole moment of 1.31 * 10²⁰ N-m/T. The magnetic dipole moment ''at creation'' was probably 3.49 * 10²² N-m/T, consistent with a decay time of about 1099 years and a half-life of 762 years.<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>

 

The above implies a conductive liquid between the crust and the core, most likely a saltwater ocean about 146 km deep to the surface and extending to the outer mantle.<ref name=Kivelson/><ref name=jplocean>"[http://www.jpl.nasa.gov/releases/2000/aguganymederoundup.html Solar System's Largest Moon Likely Has a Hidden Ocean]." Press release 12/12/00 GW 00-XXX, [[JPL]], [[NASA]], December 12, 2000. Accessed February 18, 2008.</ref>

In 1995, the [[Hubble Space Telescope]] team developed evidence for the manufacture of [[ozone]] on Ganymede.<ref name=HST>Villard, Ray, and Noll, Keith. "[http://www.solarviews.com/eng/ganypr.htm Hubble Finds Ozone on Jupiter's Moon Ganymede]." Press release STScI-PR95-36, October 10, 1995. Reproduced at ''Solarviews''. Accessed February 18, 1995.</ref> Speculation on the origin of this ozone has centered on radioactive particles trapped within Jupiter's own magnetic field in a Van Allen-type radiation belt that actually extends beyond Ganymede's orbit.

In 1995, the [[Hubble Space Telescope]] team developed evidence for the manufacture of [[ozone]] on Ganymede.<ref name=HST>Villard, Ray, and Noll, Keith. "[http://www.solarviews.com/eng/ganypr.htm Hubble Finds Ozone on Jupiter's Moon Ganymede]." Press release STScI-PR95-36, October 10, 1995. Reproduced at ''Solarviews''. Accessed February 18, 1995.</ref> Speculation on the origin of this ozone has centered on radioactive particles trapped within Jupiter's own magnetic field in a Van Allen-type radiation belt that actually extends beyond Ganymede's orbit.