Earth’s Magnetic Field( Van Allen Radiation Belts, 1958)

Eric AngatTeacher

Van Allen radiation belts are doughnut-shaped zones of highly energetic charged particles trapped at high altitudes in the magnetic field of Earth. The zones were named for James A. Van Allen, the American physicist who discovered them in 1958, using data transmitted by the U.S. Explorersatellite.

Nov. 26, 2014Share on facebookShare on twitterShare on google_plusone_shareShare on pinterest_shareMore Sharing ServicesNASA's Van Allen Probes Spot an Impenetrable Barrier in SpaceTwo donuts of seething radiation that surround Earth, called the Van Allen radiation belts, have been found to contain a nearly impenetrable barrier that prevents the fastest, most energetic electrons from reaching Earth.

This animated gif shows how particles move through Earth’s radiation belts, the large donuts around Earth. The sphere in the middle shows a cloud of colder material called the plasmasphere. New research shows that the plasmasphere helps keep fast electrons from the radiation belts away from Earth.Credits: NASA/Goddard/Scientific Visualization Studio

Van Allen radiation beltThe Van Allen radiation belts contained within Earth’s magnetosphere. Pressure from the solar wind is responsible for the asymmetrical shape of the magnetosphere and the belts.

the Earth's outer core is in a state of turbulent convection. This sets up a process that is a bit like a naturally occurring electrical generator, where the convective kinetic energy is converted to electrical and magnetic energy. Basically, the motion of the electrically conducting iron in the presence of the Earth's magnetic field induces electric currents. Those electric currents generate their own magnetic field, and as the result of this internal feedback, the process is self-sustaining so long as there is an energy source sufficient to maintain convection.

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