Why were northern lights seen over France and Switzerland on Saturday?

On Saturday evening, pink and violet skies surprised stargazers across western Europe. Sightings appeared over Marchésieux and Robertot in France, in Liège in neighbouring Belgium, and through gaps between clouds at Galmiz in Switzerland.

The display was linked to a geomagnetic storm after clouds of charged particles reached Earth. Analysts tracking the incoming solar wind reported that its speed stayed at over 800 kilometers per second.

Earth's magnetic field captured some particles, which excited atmospheric atoms and molecules to produce red, green, and violet light. Explaining the link between solar wind and colour, Meteo Schweiz noted: The more energetic the solar wind, the more colourful the polar light.