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Van Allen radiation belts

(Encyclopedia)Van Allen radiation belts, belts of radiation outside the earth's atmosphere, extending from c.400 to c.40,000 mi (c.650–c.65,000 km) above the earth. The existence of two belts, sometimes considere...

Van Allen, James Alfred

(Encyclopedia)Van Allen, James Alfred, 1914–2006, American physicist and space scientist, Mt. Pleasant, Iowa. A graduate (Ph.D 1939) of and professor of physics (1951–85) at what is now the Univ. of Iowa, where...

magnetosphere

(Encyclopedia)magnetosphere: see Van Allen radiation belts.

radiation

(Encyclopedia)radiation rd´shn [key], term applied to the emission and transmission of energy through space or through a material medium and also to the radiated energy itself. In its widest sense the te...

Orbiting Solar Observatory

(Encyclopedia)Orbiting Solar Observatory (OSO), series of eight orbiting observatories (see observatory, orbiting) launched between 1962 and 1971 by the National Aeronautics and Space Administration (NASA) to study...

ionosphere

(Encyclopedia)ionosphere n´sfr [key], series of concentric ionized layers forming part of the upper atmosphere of the earth from around 30 to 50 mi (50 to 80 km) to 250 to 370 mi (400 to 600 km) where it m...

International Geophysical Year

(Encyclopedia)International Geophysical Year (IGY), 18-month period from July, 1957, through Dec., 1958, during a period of maximum sunspot activity, designated for cooperative study of the solar-terrestrial enviro...

radiation chemistry

(Encyclopedia)radiation chemistry: see radiochemistry.

radiation sickness

(Encyclopedia)radiation sickness, harmful effect produced on body tissues by exposure to radioactive substances. The biological action of radiation is not fully understood, but it is believed that a disturbance in ...

radiation weapon

(Encyclopedia)radiation weapon or radiological weapon, a bomb or warhead that uses conventional chemical explosives to disperse radioactive material, sometimes called a dirty bomb. Designed to produce radiation sic...