"The aurora borealis of the Northern Hemisphere is often called the northern lights, and the aurora australis of the Southern Hemisphere is known as the southern lights.... Among the most magnificent of natural phenomena, auroral displays appear in shades of red, yellow, green, blue, and violet and are usually brightest in their most northern latitudes. The aurora is seen in a variety of forms, e.g., as patches of light, in the form of streamers, arcs, banks, rays, or resembling hanging draperies.... It is caused by high-speed electrons and protons from the sun, which are trapped in the Van Allen radiation belt high above the earth and then channeled toward the polar regions by the earth's magnetic field."
SOURCE: encyclopedia.com |
