Why are there so many auroras these days?

Some people have spent a fortune traveling through the Nordic countries in search of Northern lights, to end up seeing them at the door of his home, much further south than expected. Skies over much of the world have turned green and red in recent days as auroras form in unconventional locations. The reason is clear: high solar activity. But what exactly does this mean?

We know that auroras They are very common near the poles.. In the north they are called Northern lightsand in the south they are called southern aurora. In these places they form almost every year, although there are peak times when they are much easier to see.

The fact is that these moments are sometimes so critical that you can see them in unconventional places. Countries like Spain and Mexico, where it is very unusual to see these phenomena, they enjoyed them all weekend long. We might even have another chance. Peaks in solar activity occur every 11 years approximately, but in this case it was especially intense. Let’s see what happened and why we were able to see the colored sky.

Solar cycles, spots and flares

The sun is a ball of hot, electrically charged gas that is in constant motion. This movement creates a magnetic field around the royal star, which is not fixed as its intensity varies throughout the planet. 11 year cycles.

At some points on the Sun, the magnetic field activity is so high that it prevents the internal heat of the star from transferring to its surface. This creates a kind of patches, much cooler, known as sunspots. They are given this name because if we look at the sun, we see them as dark areas. The more solar activity, the darker the spots appear.

The magnetic field lines around sunspots are very active to the point that they sometimes create small explosions, known as flares. When they are generated, large amounts of radiation and particles are ejected from the surface of the Sun from the corona surrounding our star. These flares, logically, occur at the peaks of the solar cycle. They are responsible for the formation of auroras, so the probability of seeing them is not always the same.

How are auroras formed?

Auroras form when these charged particles from solar flares collide with the gases that make up the Earth’s atmosphere. This effect leads to the fact that gas atoms they are worriedreleasing energy in the form of light, the color of which will depend on the gas in question and the altitude at which it is located.

Oxygen usually emits photons in the range of red and green, but there is a slight difference. The red photons take almost two minutes to be released. If during this time an excited atom collides with another, the process will stop and the photon will not come out. At higher levels of the atmosphere, there is less oxygen concentration, so it is more likely that photons will escape without collision. Something completely different happens with green photons, as they are released in less than a second. It doesn’t matter how many atoms are together, since light is emitted before they collide. For this reason, in the lowest layers of the atmosphere green color predominates, and at altitudes above 240 kilometers it mixes with red.

Sometimes we also see some blue and purpleresulting from the excitation of atoms nitrogenwhich are found in greater numbers in especially the lower layers.

Ultimately, aurora color This depends on the altitude at which they form. But there is one more question that we have not answered.

Why are they usually seen near the poles?

When charged particles from the Sun reach Earth, they collide with our magnetic field. It is more intense at the center and weaker at the poles, so the particles move north and south until they find a place where they can penetrate. This usually happens in polar regions.

On the other hand, when the Sun’s activity is very high, the density of charged particles is sufficient to pass through even denser regions of the magnetic field. That’s what’s been happening lately. This is why we see auroras in such unconventional places. As for its flowers, mostly reddishdue to the fact that they form in the highest layers of the atmosphere.

The least friendly face of the auroras

We have already seen that if auroras form far from the poles, this means that solar activity is very high. This can be dangerous because radiation and electrically charged particles They could interfere with our telecommunications infrastructure. Two solar cycles ago, in 2003, there were beautiful auroras, as well as several incidents such as power fluctuations in North America and power outages in Sweden. In addition, 12 electrical transformers were destroyed in South Africa.

In this case, although there were some fluctuations in the telecommunications sector, they are not as severe as then. On the other hand, the auroras are impressive. In Spain, for example, it is estimated that they have not been this visible since 1938, when the skies turned bright colors at the height of the civil war.

This is because activity occurs in the region of sunspots called AR3664, so active that they can be seen even with the naked eye from Earth. Of course, if you decide to look at them, be sure to use special glasses, like those used to view satellites. As for the auroras, you don’t need anything to enjoy them. We are used to the sky giving us unique views every night, but without a doubt, this time the panorama is special.