|Posted by Rohan Baidya on April 7, 2009 at 11:19 AM|
A general notion :
Auroras are the vividly colored curtain of light seen at the polar skies.
Named after the "Roman Godess of Dawn" - "Aurora"
North Pole, they're named: "Aurora Borealis" ("Boreas" - Greek name for North Wind)
South Pole, they're named: "Aurora Australis" ("Australis" - Latin name for "South")
How are they formed?
Time of their display is specified with accord to the geomagnetic storms because, when and only there is a burst of solar flare on the sun's surface or CME (Coronal Mass Ejection), the solar charged particles are produced which are blown away by the solar wind.
On way, they then deflect against the earth's magnetosphere and carried to the magnetic poles, where they collide with the atoms of the gases present in the earth's atmosphere.
While the collision course, Alfven wave is relevant in the context, which is then called the theory of Aurora's formation. The molecules of the gases get electrically excited and the electrons take quantum leap - i. e. a mechanism in which electron's kinetic energy is converted into visible light.
Nitrogen emit "Blue" while Oxygen emit "Green" and some other including, Hydrogen and Helium emit "Pink". Mostly while returning from state of excitation, generally, "Red" is emitted too.