Violent solar storm You could see auroras this weekend

Auroras could be visible over Switzerland this weekend. The sun is very active at the moment and is throwing large amounts of plasma into space.

Auroras could be visible over Switzerland on Saturday night and Sunday. This is because the sun is very active at the moment. It has just ejected large amounts of plasma into space twice.

Two coronal mass ejections, i.e. huge clouds of solar plasma, are currently on their way to Earth. "But we don't know whether it's a direct hit or a graze," explained Sami Solanki, Director at the Max Planck Institute for Solar System Research in Germany. One of the ejections is expected in the early hours of Saturday morning, the other on Saturday evening.

Geomagnetic stormAuroras could soon be shining over Switzerland again

When the coronal mass ejections reach the earth, they can generate geomagnetic storms. The US weather agency NOAA (National Oceanic and Atmospheric Administration) is expecting category G3 storms. The auroras visible in large parts of Switzerland in May were triggered by a category G5 storm, the highest category. Clouds could also block the view of the aurora borealis

Prediction difficult

Solanki explained that even with mass ejections that spread towards the earth, it is very difficult to predict in advance how strong they will be or how quickly they will spread. It is only possible to be more precise about half an hour before the plasma particles reach the earth, when satellites can measure them at a distance of around one million kilometers.

However, the European Space Agency Esa is currently working on a probe that will have a continuous view of the sun from a lateral observation position and will therefore be able to assess such solar activity earlier and better, thus enabling improved predictions.

SDA