Van Allen Belts


The Earth is surrounded by giant donut-shaped fringes that are composed of a large number of magnetically charged particles that are trapped and are highly energetic . These radiation belts were discovered in 1958 by the United States’ first satellite, Explorer 1 . The discovery was led by James Van Allen at the University of Iowa , which is why the belts were named after him. The Van Allen belts are a group of particles charged with energythat are held in place by the Earth’s magnetic field . They can rise and fall in response to incoming energy from the sun, sometimes swelling enough to expose low-orbiting satellites to harmful radiation.


What are the Van Allen belts?

The Van Allen belts are two donut-shaped areas that surround the earth and are charged with energy , moving at a speed almost equal to the speed of light , these particles are mainly electrons and protons .

  • Discovery of the Van Allen belts
  • Source
  • Function of the Van Allen belts
  • Classification
  • Importance of the Van Allen belts

Discovery of the Van Allen belts

The Van Allen belts were discovered in 1958 by James Van Allen . The Van Allen experiment in Explorer 1 , was launched on January 31, 1958, and consisted of a simple cosmic ray experiment that consisted of a Geiger counter , which is a device that is responsible for detecting radiation and a recorder . The scientist had already been exploring the Earth’s upper atmosphere with balloons that could measure the levels of radiation in the atmosphere. Follow-up experiments on three other missions with Explorer 3, Explorer 4 and Pioneer 3, established that there were twodifferent types of belts of radiation that were circling the Earth. During the flight, radiation levels spiked and then suddenly dropped to zero and then again spiked again, and suddenly dropped to zero. What the team immediately noticed was that the regions showing zero were actually off scale . These regions of high radiation were mapped and are now known as Van Allen radiation belts.



At the beginning of the investigations on the Van Allen belts, it was thought that they had their origin in the radiation of the belts in space , but today it is known that their origin may be due to the lightning that occurs within the storms electrical events that occur within the earth’s atmosphere .

Function of the Van Allen belts

The data that have been collected to date by the probes have succeeded in showing that the radiation belts are responsible for protecting the Earth from particles of high energy that could damage, mainly the barrier for electrons ultrafast . They trap the charged particles that come from the sun and some that are produced from the interaction of the earth’s atmosphere with the sun’s radiation, so they act as barriers against radiation .


There is an internal belt that is classified as the most intense and extends from 1000 kilometers in height to 6000 kilometers above our planet. This inner belt is formed mainly by energetic protons from the decomposition of other neutrons as a product of collisions that occur between cosmic rays . The outer belt begins at approximately 15,000 kilometers high and manages to reach 25,000 kilometers. This outer belt is made up for the most part by compounds of electrons that come from storms ofsolar wind interacting with the earth’s magnetic field . Inside the external and internal belts we can find a hole which has been classified as a safe zone caused bylow frequency radio waves . These radio waves also have their origin, according to studies, in electrical storms . There is a third Van Allen belt known as the proton belt , which contains large amounts of energetic protons, which are thought to be the result of cosmic radiation from the solar wind.

Importance of the Van Allen belts

Although it may not seem like it at first glance, the importance of the Van Allen belts is very important and lies in the fact that without them the Earth would not have a magnetic field and we would be exposed to great radiation . This means that cosmic ray particles could freely collide with the Earth’s atmosphere , causing a higher background level of secondary neutrons to exist in the air, leading to higher doses of background radiation at the surface . Belts do not directly impact human life, but if they did not exist, it would imply that other effects that occur in space would affect life on earth.

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