Volume 8, Issue 3, September 2020, Page: 61-65
Formation and Change of Planetary Magnetic Field
Cuixiang Zhong, Department of Physics, Jiangxi Normal University, Nanchang, China
Received: Aug. 26, 2020;       Accepted: Sep. 14, 2020;       Published: Sep. 25, 2020
DOI: 10.11648/j.ajaa.20200803.13      View  58      Downloads  56
The influential theories about the origin of planetary magnetic field hold that the planetary magnetic field is produced by the flow of conductive fluid in the core. But these hypotheses have serious defects, unable to explain the inhomogeneity of the spatial distribution of planetary magnetic field and its changing characteristics with time. Thus, the author analyzed the formation and evolution of solar system planets as well as their internal structures and external environments, and has found the formation mechanism and change law of various planetary magnetic fields. The polar vortices at Earth’s North and South Poles can produce spiral currents, which then form a magnetic dipole at Earth’s North and South Poles respectively. Mercury is about 70% metal and 30% silicate, so it has been magnetized by the Sun's magnetic field. Venus’ rotation speed is too slow to form polar vortices needed to produce dipole magnetic field, and Venus is far away from the Sun, causing the solar magnetic field has little effect on the magnetization of Venus, so Venus’ magnetic field is extremely weak. During the first 500 million to1 billion years of Mars formation, polar vortices existed for a long time. The dipole magnetic field produced by the polar vortices has a long-term magnetization effect on the Mars' surface, therefore a magnetized crust on the surface of Mars has been formed. But with the heat inside the Mars accumulated to a certain extent, a large part of Mars Polar ice sheet melt into water. The melting of the Martian polar ice sheet greatly weakened the polar vortex and therefore the magnetic field. Especially, in the northern part of Mars, there are large-scale lava activities in the lowlands or volcanic areas, the ice sheet melted a lot there, therefore no polar vortex could be formed, causing the dipolar field disappeared. During Jupiter's rapid rotation, a series of strong polar vortices are produced at the poles of Jupiter. These vortices contain a series of strong spiral currents, which can form a series of strong dipole magnetic fields. The superposition of these dipole magnetic fields form the original magnetic field of Jupiter. But some of Jupiter's massive moons can induce some sub cyclones from the Jupiter's vortices, these sub cyclones form powerful cyclones by absorbing dense clouds and generate some new magnetic fields, which are superimposed on the original magnetic field to form more complex magnetic field of Jupiter.
Mercury, Venus, Earth, Mars, Jupiter, Planets, Magnetic Fields
To cite this article
Cuixiang Zhong, Formation and Change of Planetary Magnetic Field, American Journal of Astronomy and Astrophysics. Vol. 8, No. 3, 2020, pp. 61-65. doi: 10.11648/j.ajaa.20200803.13
Copyright © 2020 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Schubert G, Soderlund K M. Planetary magnetic fields: Observations and models [J]. Physics of the Earth & Planetary Interiors, 2011, 187 (3-4): 92-108.
Jones, Chris A. Planetary Magnetic Fields and Fluid Dynamos [J]. Annual Review of Fluid Mechanics, 2011, 43 (1): 583-614.
Cuixiang Zhong. Movement of Polar Vortices and its Close Relationship with Global Climate Change [J]. American Journal of Earth and Environmental Sciences, 2019-07-04.
Uno, H. (2009). New constraints on Mercury’s internal magnetic field (T). University of British Columbia. Retrieved from https://open.library.ubc.ca/collections/ubctheses/24/items/1.0053468.
GOLDSTEIN, M., NESS, N. & WASILEWSKI, P. Mercury's magnetic field. Nature 262, 741 (1976). https://doi.org/10.1038/262741a0.
Luhmann J G, Russell C T. Venus: Magnetic field and magnetosphere [M]. Springer Netherlands, 1997.
Nimmo F. Why does Venus lack a magnetic field? [J]. Geology, 2002, 30 (11): 987-990.
Russell C T, Luhmann J G, Spreiter J R, et al. The magnetic field of Mars - Implications from gas dynamic modeling [J]. Journal of Geophysical Research Space Physics, 1984, 89 (A5): 2997-3003.
Roberts, J. H. Lillis, R. J. Manga, M. Giant impacts on early Mars and the cessation of the Martian dynamo [J]. Journal of Geophysical Research Planets, 2009/04/23.
Zaghoo Mohamed, Collins G. W. Size and Strength of Self-excited Dynamos in Jupiter-like Extrasolar Planets [J]. The Astrophysical Journal, 862 (1), March 2018.
Yue-Kin Tsang; Chris A. Jones. Characterising Jupiter's dynamo radius using its magnetic energy spectrum [J]. Earth and Planetary Science Letters, 2020-01-15.
Jones Chris. Jupiter's magnetic field revealed by the Juno spacecraft [J]. Nature, 2018.
K. M. Moore, H. Cao, J. Bloxham, D. J. Stevenson, J. E. P. Connerney & S. J. Bolton. Time variation of Jupiter’s internal magnetic field consistent with zonal wind advection [J]. Nature Astronomy, vol. 3, pp. 730–735 (2019).
J. Wicht; T. Gastine; L. D. V. Duarte; W. Dietrich. Dynamo action of the zonal winds in Jupiter [J]. Astronomy & Astrophysics, 2019-09-19.
Christopher Crockett. Jupiter's magnetic field is surprisingly weird [J]. Science News, 2018-09-29.
Cuixiang Zhong. Formation and Change of Jupiter's Magnetic Field [J]. American Journal of Astronomy and Astrophsics. Vol. 8, No. 2, 2020, pp. 35-38. doi: 10.11648/j.ajaa.20200802.14.
Browse journals by subject