DragonSerpent

The lights originate from our sun. During large explosions and flares, huge quantities of solar particles are thrown out of the sun and into deep space. These plasma clouds travel through space with speeds varying from 300 to 1000 kilometers per second.
But even with such speeds (over a million kilometer per hour), it takes these plasma clouds two to three days to reach our planet. When they are closing in on Earth, they are captured by Earth's magnetic field (the magnetosphere) and guided towards Earth's two magnetic poles; the geomagnetic south pole and the geomagnetic north pole.
On their way down towards the geomagnetic poles, the solar particles are stopped by Earth's atmosphere, which acts as an effective shield against these deadly particles.
When the solar particles are stopped by the atmosphere, they collide with the atmospheric gases present, and the collision energy between the solar particle and the gas molecule is emitted as a photon - a light particle. And when many of these collisions creates an aurora - lights that may seem to move across the sky.

The auroral zones represent the places on earth where auroras occur most often and with greatest intensity.
The momentary, instantenous distribution of the auroras as a function of both latitude and local time were mapped by ground, rocket and satellite measurements in the 1960s. The best overview was obtained by satellite photos of the earth. Then it was discovered that the auroras display a continous oval zone around the magnetic pole in both hemispheres. Thus the auroral ovals are the regions on earth where the auroras are seen most often and with the greatest intensity.
The auroral oval can be regarded as fixed in space with reference to the sun. As the earth revolves underneath, the daily variations in the aurora's position occur. In the Scandinavian sector you find that Andøya Rocket Range is located under the

oval at night, while the oval lies across Svalbard during daytime. Halfway between northern Norway and Svalbard, northern lights can be observed in zenith both morning (around 0600) and evening (around 1800).
Modern studies have clearly shown that the shapes and locations of the ovals vary greatly with solar activity. With increasing activity on the sun, the oval widens and spreads, mainly towards the equator.

The sun radiates all visible colours, which is why sunlight appears white. The auroral spectrum, on the other hand, is not continous, but is composed of a series of spectral lines and bands in the visible, the ultraviolet and the infrared ranges.
The main point in the auroral theory is that electrically charged particles excite the atmospheric gases, that is, the electrons begin to circle the nucleus in a different orbit because of an excess of energy. The excited particle is unstable and will give up its excess energy by emitting light. This is what is called aurora.
~ Fingerprint of the atmosphere ~
The atmosphere consists mainly of nitrogen and oxygen, which when ignited, emit characteristic colours. The spectrum of colours emitted by various atoms is shown below.
A particular gas emits photons of a fixed wavelength. By measuring the wavelength one can identify the different gases in the upper atmosphere. It can therefore be concluded that the colour composition of the aurora is the atmosphere's fingerprint.
~ Altitude affects auroral colour ~
The strong, green light originates at altitudes of 120 to 180 kilometres. Red northern lights occur at even higher altitudes, while blue and violet occur mostly below 120 kilometres. When the sun is "stormy", red colour occur at altitudes between 90 to 100 kilometres. Entirely red northern lights are sometimes seen, particularly at lower latitudes, and are often mistaken for a fire on the horizon.

Auroral Mythology

Since people in olden times did not understand what northern lights were, they often created mythology and superstition to explain the dancing spirits or fighting hordes in the sky. Auroras were commonly associated with dancing in Norway; inhabitants believed that northern lights were old maids, dancing and waving.

Vikings
During the Viking period, northern lights were referred to as reflections from dead maidens. The well-known Scottish expression for auroras is "merry dancers".
Among the Eskimos in Greenland and northern Canada, the aurora was the realm of the dead, and when the lights changed rapidly, it meant that dead friends were trying to contact their living relatives.

Native Americans
Many native Americans believed that they could conjure up ghosts and spirits by whistling to the lights. It was a common belief that the northern lights were the reflections in the sky of huge fires in the distant north, or that the mighty God himself lighted up the dark and cold parts of the world.

Danish
One romantic conception found in Danish folklore is that these lights were due to a throng of swans flying so far to the north that they were caught in the ice. Each time they flapped their wings, they created reflections which created the northern lights.

A Vengeful Force
In ancient times, most people were afraid of the lights. Children would be brought inside when the mystifying flames of auroras spread across the heavens, for the lights could descend and cut their heads off. Thus, in many places northern lights were a threat to people's lives and health.
In many areas in the Nordic countries it was widely believed that the northern lights were a vengeful force which killed those who mocked it.
The mythological role of the aurora was important in religion. Many believed it was a message from the creator. Flaming auroras reminded people that their creator still cared for them. An old tale from the Nordic countries said that, "God is angry when the aurora flames".
It was a common interpretation during medival times that northern lights were an omen of war, or disasters or plagues. It was concluded that many serious disasters were caused by the aurora.

Piczo