On the night of 1 to 2 September, the Northern Lights are visible

Between sunset on 1 September and sunrise on the 2nd, an aurora borealis may be visible, weather permitting of course.

Auroras are quite unpredictable in their manifestations, so they will certainly be seen in northern Europe, but it could be that the phenomenon will also descend towards northern and central Italy. The hours of the night between the 1st and 2nd are the best to look up at the sky in as dark a place as possible, as these phenomena, seen by the human eye, are very faint. However, together with the eclipses of the sun and moon, of which there will be one on 7 September, they are among the great spectacles of nature that are worth seeing at least once.

The genesis is always the same, a flare, a powerful jet of solar material, i.e. gas at very high temperature, up to tens of millions of kilometres long, breaks away from the sun. This time it happened to the sunspot AR4199 on 30 August, and spreads very energetic radiation at various frequencies and elementary particles into space. If they are directed towards our planet, when they arrive on Earth they are deflected, fortunately for us, by the Earth's magnetic field and what little they manage to enter, at the North or South Pole, excites molecules in the atmosphere which in turn release light radiation of various colours, depending on the chemical involved, from green to red.

We are warned by the Space Weather Prediction Center, SWPC, of NOAA, the American agency in charge of the oceans and atmosphere, and also by the legendary British Weather Centre now in Exeter, the one that made the forecasts for D-Day and the Normandy landings on 6 June 1944.

For lovers of acronyms, important in this case, it will be between G3, strong, and G4, severe, which in this case means problems for orbiting satellites. There were actually two solar flares, and if they overlap, the effect will be reinforced.