Northern lights

Vol. 26, Issue 03, 06 October 2023

The aurora borealis, like natural fireworks in the sky, are an amazing sight. These magical light dances around the magnetic poles of nature leave everyone who sees them in complete admiration.

Colour dance

The main character of this light show is the green glow. This glow is caused by the collision of charged particles with atoms in the high layers of the atmosphere. As a result, the atoms begin to emit light. The green colour, characteristic of most auroras, is due to the interaction of these particles with oxygen. Red northern lights are also caused by oxygen atoms, but at altitudes between 150 and 500 km, where the temperature and density of the atmosphere create suitable conditions for atomic reactions that emit red photons. Blue colors are emitted by nitrogen. Due to the mixture of these radiations, a range of pink, purple and white lights is also possible.

Different forms of auroras can occur simultaneously, overlapping one another. Rays, ribbons, spots are not stationary at all: they move and at the same time the intensity of their glow changes over time. The speed of movement of rays and ribbons can reach tens of kilometers per second, and the shape of the observed aurora turns out to be unstable – it can completely change within an hour or even a few minutes.

Geographical diversity

Auroras are not limited to the polar regions alone. They can be observed in different parts of the world, including northern and southern latitudes. In the southern hemisphere, they are called “southern lights” or “aurora australis”. They create similar incredible pictures in the skies over Antarctica. The Northern Lights in Finland are best observed during the long winter nights, and in the period from February to March. It is best to observe the aurora in the northern regions of the country. The best place to observe the Northern Lights is the Kilpisjärvi region in Lapland. But you can also see them from anywhere in different cities, even in Helsinki.

Energy charge

Very often northern lights are accompanied by energetic events on the Sun, such as solar flares and solar winds. These phenomena direct the charged particles towards the Earth, where they enter the atmosphere and create this stunning light representation. You can also guess the solar activity. Its peak happens once every 11-12 years. At this time, the geography of the auroras is expanding, you can see them even in the center of Siberia and in the Trans-Urals. The last time the peak of activity was in 2013. There is a decline until 2024, so the brightness of the northern lights is lower now.

Watching the aurora borealis means meeting nature face to face. This is the moment when the earthly and cosmic merge in wonderful harmony. One has only to find a suitable place, prepare a warm drink and wait for heaven to open its gates.