When a mythical fox waved its tail…

Is it the wrath of the gods, what the ancient people thought caused the Northern Lights, also known as the “Lappish Lights” or the Aurora Borealis? Or is it a mythical fox waving it´s tail on the hard snow crust, what the ancient Finns believed caused the “Lappish Lights”? The Finnish word “revontulet” means namely the fox’s fires.

What are in fact those dancing lights called aurora borealis in the sky that can be seen in a clear night? Aurora is the name of Roman goddess of the dawn. She is the one who welcomes the sun. To put it simply aurora means a bearer of light. Boreas on the other hand comes from a Greek term that means the north wind. Therefore, we say aurora borealis, or northern lights, in the northern hemisphere.

However, auroras aren’t restricted only to the north. They appear around both magnetic poles. In the southern hemisphere auroras follow simultaneously and almost identically the changes of the auroras in the north. They are called aurora Australis, or southern lights, in the southern counterpart and can be seen, for instance, in New Zealand, Australia and Antarctica. 

Considered even in wider perspective, auroras aren’t characteristic only to the earth. Also, other planets like Jupiter, Saturn, Uranus, Neptune, Venus and Mars, are known to have auroras. Even extra-solar auroras have been discovered.

So auroral display is a huge phenomenon, and the research still continues.  As regards the basic origin of auroras scientists however tend to agree. Auroras occur because charged particles from the sun collide with gaseous molecules in the earth’s upper atmosphere. The solar wind blows electrons and neurons from the sun towards the earth’s magnetic field. Some of these particles enter the earth atmosphere because the magnetic field is weaker around the poles. These collisions result in the light display that we call auroras.

Auroras come in many colors and shapes. Rare ones are completely red auroras produced by oxygen molecules at high altitude. The most common are green ones that also oxygen produces but at lower altitude. Blue auroras, on the other hand, are produced by nitrogen at even lower altitudes. Auroras can occur from 80 km up to 640 km above the earth’s surface.

Auroral display is unpredictable. Sometimes auroras are still, sometimes they dance. The most distinctive auroras are probably rippling curtain-like auroras. They usually occur in east-west direction. At this point the legend and science meet. According to Samí people the northern lights rise in the east and go to the west.

According to the newest Finnish studies and if you are careful enough, you can also hear auroras talking. They make crackling like noise when they are not too far from the earth’s surface. “The sounds are loud, some of them even like a gun shot”, says professor emeritus Unto K. Laine from Aalto University. The Samí think, that people can hear them, however, they do not understand them. 

”Thus in the autumn we can see the most breathtaking aurora borealis. When there is no snow, during the night the ground is completely black and all the light there is comes from the sky. Then the contrast is as its peak and also the spectacle of aurora borealis looks much greater than in the winter when snow reflects all the light”, tells Jyrki Manninen, a  geophysicist based at the observatory of geophysics in Sodankylä.

Solar wind is a scientific explanation for rackling of light in the Lappish night sky. However we prefer the mystical one in Finnish Lapland, where they may be visible on clear nights up to 200 times a year.

Like the sun there is a cycle of 11 years in the activity of the” Lappish Lights”. The last peak was in winter 2013-2014. The next peak will be in winter 2024-2025.