Magnetic Field, Planetary
The magnetic field of a planet or satellite can be measured by magnetometers onboard orbiting space craft or – more locally – onboard landers and rovers. The magnetic field at any given point has a strength and a direction and thus is a vector field. On a global scale and measured at some distance from the planet or satellite, planetary magnetic fields resemble dipole fields. On or close to the surface the field is typically of more complicated topology. Planetary magnetic fields are generated by a dynamo mechanism in the iron-rich liquid core shells of terrestrial planets and satellites, in metallic hydrogen shells in Jupiter and Saturn, and in ionic oceans in Uranus and Neptune. Magnetic fields may be also induced in electrically conducting oceans in icy moons such as the Jovian moon Europa. Local magnetic fields may be caused by remnantly magnetized rock.
Magnetic fields are – in general – detected by the force they exert on magnetic materials and electrical...
KeywordsCore Dipole field Dynamo Induced magnetic field Magnetometer Remnant magnetic field
References and Further Reading
- Baumjohann W, Nakamura R (2015) Magnetospheric contributions to the terrestrial magnetic field. In: Kono M, Schubert G (eds) Treatise on geophysics, 2nd ed, vol 5. Elsevier, Amsterdam, pp 79–90Google Scholar
- Connerney JEP (2015) Planetary magnetism. In: Spohn T, Schubert G (eds) Treatise on geophysics, 2nd ed, vol 10. Elsevier, Amsterdam, pp 195–237Google Scholar
- Johnson CL, Purucker ME, Korth H et al (2012) MESSENGER observations of Mercury’s magneitc field structure. J Geophys Res 117:E00L14Google Scholar
- Kono M, Schubert G (2007) Geomagnetism, treatise on geophysics, vol 5. Elsevier, Amsterdam, p 589Google Scholar
- Schubert G, Anderson JD, Spohn T, McKinnon WB (2004) Interior composition, structure, and dynamics of the Galilean satellites. In: Bagenal F, Dowling TE, McKinnon WB (eds) Jupiter. The planet, satellites, and magnetosphere. Cambridge University Press, Cambridge, pp 281–306Google Scholar
- Spohn T (2009) Magnetic fields. In: Trümper J (ed) Solar system, Landolt-Börnstein numerical data and functional relationships, vol VI/4B, New series. Springer, Berlin, pp 386–391Google Scholar