Dictionary

Van Allen (belts)

Van Allen (belts)

They are two belts, formed by charged particles and interpolated in the Earth's magnetic field that surround our planet.

They were discovered in 1958 by the American physicist James van Allen, who was responsible for an experiment entrusted to the first American artificial satellite "Explorer 1".

With regard to the origin of the particles of van Allen belts, the flows of electrons and protons that reach us from the Sun in the form of solar wind must be sought. The particles are dragged in helical paths over the geomagnetic field lines by Lorentz force (force exerted by an electric field and a magnetic field on a moving electric charge). Since the magnetic field increases near the Earth's poles, the particles move from side to side on helical paths between the north and south poles of the Earth.

Belts are avoided by manned space missions, because their radiation can damage the human organism. This region extends from a few hundred kilometers on Earth to about 48,000 to 64,000 km. Most of the high energy protons (greater than 10 MeV) are in the inner belt at an altitude of 3,200 km; the electrons are more concentrated in an outer belt that extends to many radii of the Earth in space.


◄ PreviousNext ►
V-2Vanguard

ABCDEFGHIJKLMNOPQRSTU VWXYZ