The Earth's radiation belts are just one part of the system called the magnetosphere. The radiation belts of the Earth are made up of electrons, protons and heavier atomic ions. These particles get trapped in the magnetic field of the Earth. The radiation belts, like the plasmasphere, are toroidally shaped. There is an outer and an inner radiation belt.
The belts of trapped radiation near the Earth were discovered by James Van Allen in 1958. Therefore these belts are also known as Van Allen Belts.
It is really important that we have a good understanding of the radiation belts because the particles in these belts can be dangerous to humans, animals or even electronic equipment that flies in this area. "The particle population of the Earth's radiation belts makes it dangerous for humans without massive shielding to do more than quickly pass through them," reports Dr. James Van Allen.