Aurora Borealis (Northern Lights) by Sigurdur H Stefnisson

Auroras (Polar Lights; or aurorae, sing.: aurora) are natural different colored light displays, which are usually observed in the night sky, particularly in the polar zone. Some scientists therefore call them "polar auroras" (or "aurorae polaris"). In northern latitudes, it is known as the aurora borealis, named after the Roman goddess of the dawn, Aurora, and the Greek name for north wind, Boreas. It often appears as a greenish glow (or sometimes a faint red), as if the sun were rising from an unusual direction. The aurora borealis is also called the northern polar lights, as it is only visible in the North sky from the Northern Hemisphere. The aurora borealis most often occurs from September to October and from March to April.

Here are The Northern Lights photographed by Sigurdur H Stefnisson.
Sigurdur H Stefnisson has been involved in photography since the age of 7. He is highly regarded among professional photographers many of whom have used his services extensively.
"When the electrically charged particles contacts the outer layers of the atmosphere it causes them to glow. Different gases in the atmosphere cause different colors as can be observed from Earth in the many color variations of the auroras.
When solar activity is high the sun releases solar particles. These particles travel with solar winds towards the Earth and are drawn into the atmosphere by the earth's magnetic field.
The auroras have been a source for all kinds of ideas. Later, more realistically, people thought they were reflections of the Sun.
They can be seen in auroral belts that form 20-25 degrees around the geomagnetic poles, both the north and the south. The Northern Lights, also called Aurora Borealis (Southern lights or Aurora Australis in the southern hemisphere), are one of the most spectacular shows on this earth. Sometimes they cover almost all of the sky and seem to be dancing around with such grace and speed that one can only watch in awe."
These photographs are difficult to taken but Sigurdur H Stefnisson has mastered this techniques.

Source: iww.is