Radiatsioonivöönditel

Radiatsioonivöönditel, also known as radiation belts or Van Allen belts, are regions of energetic charged particles held in place by the magnetic field of a planet. Earth has two main radiation belts, the inner and outer Van Allen belts. The inner belt, discovered in 1958, consists primarily of high-energy protons and electrons trapped by Earth's magnetic field. These particles originate from cosmic rays and solar energetic particle events. The outer belt, discovered shortly after, is larger and more dynamic, containing mainly electrons and some protons. Its shape and intensity vary significantly with solar activity.

The existence of these belts was predicted by Christoffel Hendrik van de Hulst in 1946 and confirmed by James Van Allen and his team using instruments on board the Explorer 1 satellite in 1958. The particles in the radiation belts are energized by processes within the Earth's magnetosphere, particularly during geomagnetic storms, which are caused by disturbances on the Sun. These storms can inject more energetic particles into the belts, increasing their intensity.

While these belts are crucial for understanding planetary magnetospheres and space weather, they pose a radiation hazard to satellites, spacecraft, and astronauts. Missions passing through the belts must often be shielded or have their sensitive electronics protected. Understanding and predicting the behavior of the Van Allen belts is essential for space exploration and the reliable operation of space-based technologies.