Making waves with the hot electrons within Earth`s radiation belts
(PHYSorg.com Physics)

Encircling the Earth, within its magnetosphere, are two concentric, doughnut-shaped radiation belts known as the Van Allen belts. The Van Allen belts swell and recede in response to incoming energy from the sun, sometimes billowing far enough to expose orbiting satellites and other spacecraft to damaging radiation that can disrupt electronic communications and navigation signals, as well as electric grids. These radiation belt electrons travel near the speed of light and emit and absorb waves that are used by scientists to understand space weather.