Formation and Change of Planetary Magnetic Field

Abstract

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.