What are the Van Allen Belts?
The Van Allen belts, also referred to as the Van Allen radiation belts, are two large toruses of charged particles around the planet, held in place by the Earth’s magnetic field. The Van Allen belts exist because of “blind spots” in the Earth’s magnetic field caused by its compression and stretching from solar wind. The Earth’s magnetic field serves as a magnetic mirror, bouncing charged particles back and forth along force lines stretching between the North and South Magnetic Poles. The Van Allen belts are closely associated with the aurora borealis and the aurora australis, beautiful curtains of charged particles visible in locations on the Earth’s surface where the Van Allen belts intersect with the upper atmosphere. The Van Allen belts are also relevant to satellites and orbiting space stations, which have to avoid the belts due to the damage that their charged particles would cause. In the late 19th century and early 20th century, several scientists — Carl Størmer, Kristian Birke
Where are they located? What are they made of? – How do our magnetosphere and the Van Allen belts protect us? – What causes auroral displays? – What causes Earth’s magnetic field? – How are high and low ocean tides caused? – What are spring and neap tides? What phases of moon must be present for them? – What are the long-term tidal effects of the Moon on the Earth’s rotation? Chapter 8: the Moon and Mercury – Define “greatest elongation” – Does the Moon have a magnetic field? Does Mercury? Why or why not is there a magnetic field present? — How about atmosphere? — Particularly eccentric orbit? — What are the surface temperatures like? — What are the compositions? – What are lunar maria? – What are the lunar highlands like? – What is the range of size of lunar craters? – Are the maria older or younger than the highlands? How do you know? – Where are maria located on the Moon? Are they evenly distributed? – What is a synchronous orbit? – How is the rotation of Mercury most accura
J.M., Waltham A. These are two asymmetric belts of radiation outside the earth’s atmosphere. They are named for James Van Allen, the American astrophysicist who first predicted the belts and then was first to interpret the findings of the first US earth satellite, Explorer I, which confirmed their existence. The belts are composed of charged particles which circulate along the earth’s magnetic lines of force. These particles …
