For thousands of years Aurora has been one of the most conspicuous mysteries to be solved.
In ancient Romans, Aurora is known as the the goddess of the dawn.It is thought that aurora is
burning of volcanoes,an extensive prairie or a forest fire in the interior of the earth.
In North America it is called the dance of spirits.
Aurora is the natural colors lights which can be seen at poles. Mostly aurora occour at poles. In north pole it is called Aurora borailis and in south pole it is called aurora australis.
As you know that earth behaves like a magnet.There is a magnetic field around the earth. Earth magnetic activity is due to the molten iron present in the core of earth. Magnetic field of earth is extend from earth’s core to space.The field lines go into and out of the Earth . magnetic field of the earth prevents earth from solar radiations. These solar radiations are very harmful for life.
These solar radiations is of course also essential for life on earth. solar heating drives weather system and ocean currents and for photosynthesis. As the result of photosynthesis oxygen gas is released into the atmosphere. Oxygen and nitrogen are mainly present in the atmosphere as well as in ionosphere.the molecules of these gases are present in form of atoms because it absorbs high energy photons from the sun. .Ionization depends primarily on the Sun and its activity.The amount of ionization in the ionosphere varies greatly with the amount of radiation received from the Sun.
Aurora is caused by high energy particles from the solar wind which are trapped in earth’s magnetic field.As these particles enters in magnetic field they come down into the atmosphere near the north and south magnetic poles where magnetic lines disappear.
As these high energy particles stokes with oxygen and nitrogen molecules in ionosphere, this excited the molecules and they emit light when they when they come to their ground state.The emission of energy are of different color because of different gases.
Oxygen green or brownish red
Nitrogen blue or red
The extent of color shown also depend upon the amount of radiations absorb.