The aurora borealis from the Arctic migrated to the skies of Europe. In Portugal, the show of the "northern lights" was much more discreet and harder to see with the naked eye, but the moment was recorded on cameras like that of Miguel Marques, in Figueira da Foz.
The phenomenon was also recorded in the USA, not just in the state of Alaska, in the polar north, but much further south than usual. The colourful lights in the sky reached Texas and North Carolina.
According to Público, this expansion of the aurora borealis to low latitudes was triggered by a geomagnetic storm, resulting from the interaction between the solar wind and the Earth's magnetic field. It is the intensity of the solar particles that generates the colour bands in the skies in places not used to seeing them.
Ricardo Gafeira and Teresa Barata, specialists at the Institute of Astrophysics and Space Sciences, told Público: "Depending on the intensity of the geomagnetic storm, the auroras can extend to lower latitudes. Typically, when this happens, they tend to have a redder colour, as was seen in Ukraine, because we are observing higher layers of the atmosphere, where the composition is different, as opposed to the classic auroras of the polar circle."
Ricardo Gafeira considers this phenomenon "rare, but possible". The experts corroborated the authenticity of Miguel Marques' photograph due to the occurrence of "a strong geomagnetic storm" the night before. They emphasise that the lack of more sightings is natural because the photograph was taken under very particular conditions, related to the camera settings, direction and exposure time. Nevertheless, they make it clear that it is quite possible that it is indeed an aurora borealis.
It's not the first time an aurora borealis has been seen in Europe. In February this year, the "Northern Lights" also entered the UK sky, revealing the long reach of their impressive luminous trail. The aurora borealis is a phenomenon reserved for a few privileged places, but every now and then the fabulous "dance of lights" in the Earth's sky reveals itself beyond its territory.