Aurora borealis
Aurora borealis
Near the Earth's poles a magnificent spectacle of shimmering colored light can sometimes be seen --- the aurora. The aurora is called the aurora borealis (Northern lights) and the aurora austrails (Southern lights); it can appear as bright as a full moon. The aurora usually appears near the Earth's poles, and more northerly (or southerly) your latitude, the more impressive the displays you will see. The lights vary in color from whitish-green to deep red and take on shapes such as streamers, arcs, curtains, and shells. But we still don't know what causes them. Lets find out.
Aurorae are produced when charged particles from the sun enter the Earth's atmosphere. This stream of particles, a form of plasma, is carried away from the sun by the solar wind. As the plasma approaches Earth, it is trapped for a time in the outermost parts of the Earth's magnetic field, an...
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