Van Allen radiation belts

Van Allen radiation belts
Two doughnut-shaped zones of highly energetic charged particles (see electric charge) trapped at high altitudes in Earth's magnetic field.

Named for James A. Van Allen (b. 1914), who discovered them in 1958, they are most intense over the Equator and effectively absent above the poles. The two zones merge gradually, with the flux of charged particles showing two regions of maximum density. The inner one, mostly protons thought to be produced by primary cosmic rays striking the atmosphere, is centred about 3,700 mi (6,000 km) above Earth's surface. The outer region includes some helium ions from the solar wind and is centred about 12,500 mi (20,000 km) above Earth's surface. Intense solar activity (see solar cycle) causes disruptions of the belts, linked in turn with such phenomena as auroras and magnetic storms.

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Universalium. 2010.

Look at other dictionaries:

  • Van Allen radiation belts — Van Allen belts, Van Allen radiation belts /van alˈən (rā di āˈshən) belts/ plural noun Either of two rings of intense particle radiation surrounding the earth at a distance of above 1200 miles (1930km) from it ORIGIN: JA Van Allen (1914–2006),… …   Useful english dictionary

  • Van Allen Radiation Belts — two belts of charged particles in the Earth’s magnetic field discovered in 1958 by J A Van Allen, United States …   Eponyms, nicknames, and geographical games

  • Van Allen radiation belt — Van Allen radiation belts The Van Allen radiation belt is a torus of energetic charged particles (plasma) around Earth, which is held in place by Earth s magnetic field. It is believed that most of the particles that form the belts come from… …   Wikipedia

  • Van Allen beltsVan Allen radiation belts — Van Allen belts, Van Allen radiation belts /van alˈən (rā di āˈshən) belts/ plural noun Either of two rings of intense particle radiation surrounding the earth at a distance of above 1200 miles (1930km) from it ORIGIN: JA Van Allen (1914–2006),… …   Useful english dictionary

  • Van Allen radiation belt — ☆ Van Allen radiation belt [van al′ən ] n. 〚after James A. Van Allen (1914 ), U.S. physicist〛 1. a broad, doughnut shaped region surrounding the earth and composed of high energy electrons and protons trapped in the earth s magnetic field at… …   Universalium

  • Van Allen radiation belt — noun a) Either of two torus shaped areas of high energy charged particles which partly surround Earth, trapped by its magnetic field. The areas are characterised by intense radiation. When the belts overload , particles strike the upper… …   Wiktionary

  • Van-Allen-Gürtel — Van Allen Strahlungsgürtel Der Van Allen Strahlungsgürtel (benannt nach James van Allen) ist ein Ring (Torus) energiereicher geladener Teilchen, die durch das magnetische Feld der Erde eingefangen werden. Diese Teilchen stammen überwiegend vom… …   Deutsch Wikipedia

  • Van Allen belts — Van Allen belts, Van Allen radiation belts /van alˈən (rā di āˈshən) belts/ plural noun Either of two rings of intense particle radiation surrounding the earth at a distance of above 1200 miles (1930km) from it ORIGIN: JA Van Allen (1914–2006),… …   Useful english dictionary

  • radiation belts — see Van Allen (↑radiation) belts • • • Main Entry: ↑radiate …   Useful english dictionary

  • Van Allen, James A. — ▪ American physicist in full  James Alfred Van Allen  born Sept. 7, 1914, Mount Pleasant, Iowa, U.S. died Aug. 9, 2006, Iowa City, Iowa  American physicist, whose discovery of the Van Allen radiation belts (Van Allen radiation belt), two zones of …   Universalium

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