Travel Tips

Send Photo to a Friend

the Northern lights

The Northern Lights - what are they?

The Finnish name for the lights (revontulet) comes from an old Finnish legend whereby the tail of a fox running along snow- covered fells strikes the snow drifts, sending a trail of sparks into the sky. Revontulet literally means "foxfire".

The scientific studies of the Northern Lights have revealed that they are shining at a height of 100 km as a result of charged particles (electrons and protons) accelerating in the Earth's magnetic field and colliding with air molecules. These give up part of their surplus energy in the form of light. The phenomenon is rather similar to the formation of an image in a television tube, or to the emission of light by a halogen lamp. The usual greenish-yellow, and occasionally reddish, appearance of the aurora is produced by the oxygen in the atmosphere, whereas the blue and violet light is due to nitrogen. The particles causing the Northern Lights come ultimately from the sun, from which they are ejected out into space at speeds of up to 1000 km a second forming the so-called solar wind.

Send Photo to a Friend

The northern lights

Where and when are the Northern Lights most seen?

There are distinct seasonal variations in the appearance of the auroras. The highest incidence of the auroral phenomenon occurs in February-March and September-October, when 3/5ths of the year's total lights are seen. The lights are least common during the summer and around Christmas. The scarcity of the auroras in summer is, of course, partially due to the light summer nights.

Statistics reveal that most Northern Lights are observed in the Kilpisjärvi region, in Lapland. With a clear sky during the dark period of the year on average the auroras is seen there on three nights out of four.
In Finland's most southerly region, in the vicinity of Helsinki, it is statistically possible to observe the lights only on one night a month. On cloudy nights, of course, it is not possible to see them at all.