Van Allen belts

Van Allen belts, 2 belts of high-energy charged particles, mainly protons and electrons, surrounding the earth, named for U.S. physicist James Van Allen, who discovered them in 1958. They extend from a few hundred to about 40,000 mi (65,000 km) above the earth's surface and radiate intensely enough that astronauts must be specially protected from them. The mechanisms for their existence are similar to those involved in the production of the aurora borealis.

See also: Radiation; Van Allen, James Alfred.