Users on social networks and experts referred, this Thursday, to the sighting from Cuba of a possible aurora borealis, as a remnant of an intense geomagnetic storm.
The aurora borealis is an atmospheric spectacle characterised by natural lights in the sky. Commonly observed colours include blue, red, yellow, green and orange. These brilliant ripples are most frequent in the regions near the poles.
The activity that generates the northern lights begins on the Sun. The star is made up of electrically charged particles. These are the ions, and those that flow continuously from the surface of the star give rise to the solar wind.
Faced with the approach of the solar wind, the Earth has its magnetic field, which prevents the star’s emanation from damaging the Earth’s atmosphere and thus making it impossible for any form of life to exist on the blue planet.
However, although most of the solar wind is blocked by the magnetosphere, some ions do get trapped in the ionosphere. This layer of the Earth’s atmosphere is centred around the geomagnetic poles, which mark the tilted axis of the Earth’s magnetic field.
Ions that have managed to be harboured in the ionosphere begin to collide with oxygen and nitrogen particles in the Earth’s atmosphere. When this happens, energy is released which, in turn, produces a bright halo around the poles. This is how the northern lights form.
(With information from social media and National Geographic)