Saturday, July 3, 2010
the BURNING SKY
One of the earth's most eerie natural displays is the pulsating bands of red, green and yellow light that appear in the skies of the polar regions. This are known as the AURORA BOREALIS (nothern lights) and the aurora australis (southern lights).
These atmospheric fireworks are set off when protons and free electrons released by the sun, and traveling at speeds of around 1,600km/s, collide with atoms or molecules in the earth's atmosphere at altitudes of 80-1,000km. The collisions cause the particles to light up. The aurora occur most frequently in two ring-shaped zones located 23 deg from the magnetic poles.
In these areas, particles approaching the earth are drawn to the poles by the earth's magnetic field.
Posted by switsmile at 2:34 PM