The northern lights are a unique part of nature, often seen as three green bands across the night sky, or the light comes as a dancing flickering curtain or rolling smoke. The northern lights are mainly luminous green, often with a hint of pink along the edge, and occassionally with a deep violet centre. The northern lights are caused by the collsion of electrically charged particles from the sun that enter the earth's atmosphere. These particles are then attracted to both the magnetic poles of the northern and southern hemispheres, in the north they are known as the "Aurora Borealis" and in the south they are called the "Aurora australis."
Late autumn and winter/early spring is when the lights are to be found at their most frequent. Between the autumn equinox and spring equinox (21st September - 21st March), it is usually dark between 6pm and 1am, allowing the maximum chance of seeing the lights. Weather is also a big factor in spotting the northern lights, September, October and November tend to be rain filled and snowless in the north. December onwards the weather dries out, with there being plenty of snow, and if you do visit in December or January, you can experience the polar nights with amazing atmospheric evenings and very short days. February and March the days start to become longer and more of the snow-clad landscapes can be seen during the daytime, with the evenings still offering maximum chances of seeing the northern lights.