8 Apr 2010

Aurora Borealis


Auroras, sometimes called the northern and southern (polar) lights or aurorae, are natural light displays in the sky, usually observed at night, particularly in the polar regions. They typically occur in the ionosphere. They are also referred to as polar auroras. In northern latitudes, the effect is known as the aurora borealis, named after the Roman Godness of dawn, Aurora, and the Greek name for north wind, Boreas, by Pierre Gassendi in 1621. The aurora borealis is also called the northern polar lights, as it is only visible in the sky from the Northern Hemisphere, with the chance of visibility increasing with proximity to the Northern Magnetic Pole. Auroras seen near the magnetic pole may be high overhead, but from further away, they illuminate the northern horizon as a greenish glow or sometimes a faint red, as if the sun were rising from an unusual direction.

1 comment:

ARO GERALDES said...

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Greetings from Argentina, Aro Geraldes
http://www.arogeraldes.com
I wait your visit and your messages