A aurora boreal Last night it dazzled its viewers from all over the country, who have shared images of the unusual phenomenon on social networks. This astronomical event is generally associated with the rarctic and subarctic egionsbut it has been observed by second time this year in Spain.
The northern lights are light shows generated by the interaction of the solar wind with the Earth’s magnetic field. Although it is very strange that they are visible in low latitudeson this occasion its presence has been documented in many areas of the territory, such as Catalonia, Castilla y León, Madrid, Andalusia and even the Canary Islands.
Image of the northern lights from the island of La Palma / EFE
The origin of the astronomical phenomenon
The Sun approaches peak activity of its solar cycle, which lasts about 11 years, called Solar Cycle 25. For this reason, a series of geomagnetic stormswhich generate the northern lights. The main cause of last night’s phenomenon was a coronal mass ejection: a massive explosion of charged particles that are ejected from the solar atmosphere and, upon reaching Earth, interact with the planet’s magnetic field.
Image of the northern lights captured from the island of Gran Canaria
The flare that the Sun has released on this occasion is one of the most powerful observed in recent months, as indicated by its type X1.8. Although it has not been the most intense recorded in this solar cycle, it has been enough to create the conditions that have allowed inhabitants of low latitudes to enjoy the astronomical spectacle. Usually, they occur at latitudes between 60º and 75º, but, on this occasion, it could be seen from latitudes lower than 36º.
Upon arrival in the thermosphere and exosphere, the upper layers of the atmosphere, electrons and protons from the solar wind collide with oxygen and nitrogen atoms. This causes the emission of photons, which are responsible for forming the characteristics light bands of the northern lights.
Light show in Spain
Since the early afternoon of October 10, the experts already predicted the arrival of an intense solar storm. The auroras began to be visible at sunset and, towards midnight, the skies of several Spanish regions were filled with green, pink and purple tones.
Image of the northern lights taken from the Castelltallat astronomical observatory, in Barcelona / Europa Press
The spectacle has been greater in the rural areas and in places away from light pollution. On social networks, users have shared images captured in places such as Segovia, Menorca, Madrid or Valencia. The photographs have received great attention due to the attractiveness of a natural event that rarely occurs this far south of Europe.
The tones seen in the images They show reddish auroras, with diffused light and weakeras Joan Anton Català, a scientific communicator specialized in astrophysics and astronomy, explained to RTVE.
Auroras throughout the northern hemisphere
Spain has not been the only territory in which the phenomenon has been observed. The northern lights have also been enjoyed in various points of Europe and North Americawhere they have been more intense and persistent due to the shorter distance of these regions from the Arctic, which is the place where auroras are usually concentrated.
Image of a northern lights seen from the Netherlands
In countries like Norway, Scotland and Canada, the auroras illuminate the skies more frequentlyalthough sightings have also been reported in areas of the United States.
The geomagnetic storm, according to the latest predictions from the National Office of Oceanic and Atmospheric Administration (NOAA), reaches a G4 category and has even reached G5, the highest levelcon a Kp index of up to 8 on a scale of 9. This magnitude is what favors your visibility much further south than usual. While this level of activity is fascinating, it also entails risks. Solar storms can disrupt satellite communication systems, interfere with GPS signals, and cause disruptions to power grids.
Image of a northern lights from northern Germany
When will they see each other again?
The reason behind the higher frequency of these phenomena is the increasing solar activitytypical of the peaks of the solar cycle. The Sun goes through a cycle of activity lasting between 10 and 12 years, during which sunspots, coronal mass ejections, and solar flares become more common. Now the Sun is in full active phasewhich means that these events could be repeated in the coming months, before the cycle reaches its maximum predicted for 2025. In this sense, Telmo Fernández, astrophysicist and director of the Madrid Planetarium, tells RTVE that the universe is unpredictable and it is difficult to anticipate a solar flare.
Image of the Northern Lights seen from Scotland
As the Sun moves toward the maximum of its cycle, astronomy buffs and photographers around the world eagerly await the possibility of see new auroras. The best places to observe this type of phenomenon are rural areas, national parks and areas far from large cities, where the darkness of the night allows the lights to be visible more clearly.
Image of the northern lights next to an art installation by Nikola Lenivets, in Russia
“The phenomenon has lasted many hours, in fact it has ended because it was daylight, it is not that the activity has ended,” Alex Roig, head of the Prades Observatory (Tarragona), explains to RTVE. The expert points out that the next night there could still be activity, although the trend is already decreasing.
