Aurora Borealis in La Palma: an unusual spectacle
Aurora boreal La Palma. Ana García, La Palma stars

Aurora Borealis in La Palma, an amazing phenomenon

In the early morning of May 10, a wonderful spectacle of aurora borealis could be seen from some points of northern Europe, the Iberian Peninsula and, surprisingly, also from the Canary Islands. This spectacle has left us impressive images of a night sky with a reddish and magenta glow.

Aurora boreal La Palma. Ana García, La Palma stars
Aurora boreal La Palma. Ana García, La Palma stars

Aurora boreal La Palma. Ana García, La Palma stars
Aurora boreal La Palma. Ana García, La Palma stars

What are the Aurora Borealis?

Definition and origin

The northern lights are a natural phenomenon that we can enjoy as the benign part of solar storms. They occur when colossal explosions take place in the active regions of the Sun, releasing a tremendous amount of energy, equivalent to millions of atomic bombs detonated at the same time. This magnetic energy accumulates and is released in areas of the Sun that can be 10 to 20 times the size of the Earth.

Formation and process

When these explosions occur in the solar magnetic field, a large amount of energy is released, resulting in a coronal mass ejection (CME). This is the ejection of a huge amount of plasma and charged particles that propagate through the interplanetary medium. If our planet is in the path of this eruption, a portion of these particles may impact with us. The interaction between the cloud of charged particles and the magnetosphere surrounding the Earth produces the aurora borealis.

Aurora Borealis on La Palma: Why now?

Unusual solar activity

These days, the Sun has been unusually active, and we have begun to notice it here on Earth since last Friday, May 10, with the arrival of solar flares originating, above all, in an active region known as AR 3664. This is a very large and complex group of sunspots in which the magnetic field is very twisted, producing tensions that culminate in very violent explosions.

Impact on the Earth

These explosions expel solar material, called solar plasma, at high speed, at thousands of kilometers per second. The current relative location between our planet and this active region of the Sun means that we are within its range of influence, which has allowed us to observe aurora borealis from points as unusual as the Canary Islands.

Colors of the auroras

Auroras Boreales en La Palma. Fuente: Toño González de Cielos La Palma.
Auroras Boreales en La Palma. Fuente: Toño González de Cielos La Palma.

Interaction with the atmosphere

The colors of the auroras are produced by the interaction between solar particles and the atoms present in our atmosphere. For example, if the solar particles interact with nitrogen atoms, which are the most abundant in our atmosphere, the energy is emitted in reddish color. If the interaction is with oxygen atoms, the energy is emitted in green color. In cases of very energetic events, such as the recent one, the particles interact with oxygen and the energy is transmitted in red.

Consequences and frequency of auroras

Potential risks

This situation has no serious consequences for humans, although it could pose a problem for electric or telecommunication companies.

Frequency of the phenomena

An activity as intense as that of these days has not been recorded for almost 20 years. Let us remember that the Sun is approaching the maximum of its activity cycle, which has a duration of 11 years. It is expected to reach its maximum next year, and then gradually decline. The activity observed now is to be expected for this phase of the cycle, although the situation experienced these days is relatively infrequent.

Prediction and preparation

Part of the most negative consequences of these solar storms, when they occur with extraordinarily high intensity, is something that, by probability, will occur at some point. Therefore, we must be prepared, especially by improving our predictive capabilities.

For more information about the northern lights in La Palma and other astronomical phenomena, you can take one of our astronomical tours.