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Van Allen Belt
5 dictionary results for: Van Allen Belt
Dictionary.com Unabridged (v 1.1) - Cite This Source - Share This
Van Allen belt
–noun Physics.
| either of two regions of high-energy-charged particles surrounding the earth, the inner region centered at an altitude of 2000 mi. (3200 km) and the outer region at an altitude between 9000 and 12,000 mi. (14,500 and 19,000 km). |
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Dictionary.com Unabridged (v 1.1)
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
American Heritage Dictionary - Cite This Source - Share This
Van Al·len belt
 (vān āl'ən) Pronunciation Key
n. Either of two zones of high-intensity particulate radiation trapped in Earth's magnetic field and surrounding the planet, beginning at an altitude of about 800 kilometers (500 miles) and extending tens of thousands of kilometers into space. [After James Alfred Van Allen (1914-2006), American physicist.] |
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The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2006 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2006 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
WordNet - Cite This Source - Share This
| van allen belt | |
noun | |
| a belt of charged particles (resulting from cosmic rays) above the Earth trapped by the Earth's magnetic field |
WordNet® 3.0, © 2006 by Princeton University.
The American Heritage Science Dictionary - Cite This Source - Share This
Van Allen belt
(vān āl'ən) Pronunciation Key
(click for larger image in new window) Either of the two zones surrounding the Earth in which a thin distribution of atomic particles with very high energies are trapped by Earth's magnetic field. The inner belt lies between about 500 and 6,440 km (310 to 4,000 mi) above Earth's equator and consists mostly of a mix of protons and electrons. The upper belt lies between about 15,000 and 30,000 km (9,300 to 18,600 mi) and consists mostly of protons. Both belts are thickest at the equator and have irregular densities of particles. The outer radiation belt is much larger and the number of particles varies, increasing in the aftermath of solar flares. The polar auroras are caused when some of the charged particles from the outer Van Allen belt hit the upper atmosphere. The Van Allen belt is named after its discoverer, American astrophysicist James Van Allen (born 1914). |
The American Heritage® Science Dictionary
Copyright © 2002 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Copyright © 2002 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
American Heritage New Dictionary of Cultural Literacy, Third Edition - Cite This Source - Share This
Van Allen belt
[Chapter:] Earth Sciences
Van Allen belt
Either of two layers of electrically charged (see electrical charge) particles held in orbits above the atmosphere by the magnetic field of the Earth. The belt is named after its discoverer, the twentieth-century American physicist James Van Allen.
[Chapter:] Earth Sciences
The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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