Auroras are natural light displays in the sky, usually observed at night, particularly in the polar regions. In northern latitudes, the effect is known as the aurora borealis, named after the Roman goddess of dawn, Aurora, and the Greek name for north wind, Boreas by Pierre Gassendi in 1621. Sometimes called the northern and southern (polar) lights. It is most visible closer to the poles due to the longer periods of darkness and the magnetic field.

http://www.braindumps.com/C4060-156.htm
http://www.test-king.com/exams/117-201.htm
http://www.aamu.edu/
http://www.actualtests.com/exam-C4090-452.htm
http://www.certkiller.com/exam-ACMP_6-1.htm
https://www.apple.com/