The aurora borealis is a phenomenon that almost everyone knows about, but few really know the exact reason why the sky is illuminated with these lights.

In fact, when we resort to searching on the internet, we can find an explanation that is too technical and complex, difficult to understand.

Why do the northern lights occur?

In order to understand the polar auroras we have to travel thousands of kilometers from our planet, in fact a few million kilometers, 150 to be exact, the responsible for which we can observe auroras on earth is the sun; a great mass of gas that is magnetized.

The result of this magnetization in the central star of the solar system originates a flow of particles towards the outside of its surface that is known as solar wind; when these particles are unstable, the arcs that are formed, are detached from the sun and travel towards the earth attracted by the magnetic poles of our planet, in the same way that happens when you approach an iron to a magnet.

Polar lights over dark trees

The particles travel through space at speeds of between 300 and 1000 kilometers per second; at that speed could travel the 9,077 km kilometers that separate the city of madrid from the city of mexico in less than 30 seconds.

Even so, these particles that detach from the sun and are attracted to the planet earth, take between 2 and 3 days to reach our planet, which makes it possible to foresee aurora borealis with some anticipation.

Finally they end up being captured by the magnetic field of the earth and are directed towards the North and South poles so that those particles that had been expelled from the sun can always penetrate through the poles, which will cause Aurora Borealis at the North Pole and Aurora Australis at the South Pole.

The particles coming from the sun don't emit by themselves the tones that we see in the auroras, therefore,

Why do we see different amazing colors in the auroras?

The reason is that the plasma particles that arrive highly charged with energy, react with the gases of the ionosphere and the atmosphere, causing this spectacular phenomenon.

The multicolored lights of the Aurora Borealis can reach an altitude of 80 km to 500 km above the earth's surface.  

Amazing light display from Mother Nature, very humbled and in awe to capture a multi-hued color Aurora at Tromso, Norway.

When the auroras are seen in the sky, the greenish tones are due to the reaction of the plasma particles coming from the sun with oxygen, whenever the reaction with oxygen occurs, the auroras are going to look green; at other times, there is a lot of plasma that penetrates lower in the atmosphere and reacts with nitrogen causing reddish colors.

Often, these nitrogen molecules are the ones responsible for the red or purple coloration of the lower edges of the Auroras, the curved outer parts of the Aurora's structures, shapes and colors, change very quickly and are always unpredictable, so an aurora can last from a few minutes to several hours but we did not always know everything we know now about the Northern Lights until the early 20th century.

Northern lights have clearly been observed for at least 4,000 years.

The first text describing an aurora borealis dates back to 2,600 BC and there are numerous mentions of them from the peoples of northern Europe to the Bible through Aristotle who spoke of bright clouds in the sky.

The Eskimo people who inhabit Greenland refer to these mysterious lights as "a path that leads to heavenly regions and through which pass the spirits of those who have died a violent death or those who have committed suicide.

A freezing cold night, but the sky just exploded for 2 minutes

The Eskimos believed that the aurora was a way for spirits to manifest themselves, but each of the peoples who inhabited the regions where these polar lights could be seen had their own legends about:

  • Souls
  • Animals
  • Dragons
  • Gods

In order to explain the reason for such celestial flashes today, we DO have the history, which shows us that these same flashes were the ones that produced such fascination to the inhabitants of those times, although we have a more scientific explanation about its origin, to observe a polar aurora, it is necessary to be located in a region of the earth at 70 degrees North or South which is where Auroras can normally be seen more easily.

The northern lights or auroras are better known than the southern auroras because in the southern regions where they occur, there is hardly any population and it is much more difficult to travel there, in the northern hemisphere instead, you can travel with some ease to regions such as:

  • Norway
  • Sweden
  • Finland
  • Island
  • Greenland
  • Canada
  • Russia
  • Alaska

One of the best times of the year to be able to see this phenomenon is during the winter since they can only be seen during the night and at this time of the year there are much less hours of sunlight in these regions.

Night Lights

One of the most important conditions to take into account in order not to miss a polar aurora is to make sure that the sky is clear since a cloudy sky won't let us enjoy at all the northern lights.