Northern lights in sight? A group of gigantic sunspots faces Earth

A group of sunspots spanning a distance greater than 30 times Earth’s diameter has been slowly rotating toward us since around December 1. It has been many years since such a strongly magnetized region was seen, especially facing the Earth.

This group is so massive that it would be visible to the naked eye, but should we? NO ! The Sun is much too bright for our retina; you must therefore protect yourself, for example with special glasses for eclipses — especially not ordinary sunglasses. Suitable equipment generally blocks around 99.999% of the star’s brightness.

It’s quite surprising, but sunspots aren’t really black. These are areas of intense magnetic activity, crossed by field lines on both sides, which are in reality less hot than the surrounding photosphere. The solar photosphere, what we see, is 5500°C, while the sunspots are 2500°C cooler. By contrast, we see black, but if we isolated a sunspot, it should instead appear red.

On either side of this “cold” matter are polarized regions, made of “plus” and “minus”, the filaments connecting a “plus” to a “minus”. And sometimes such energy swells these filaments so much that they twist and break. By giving way, they then release the plasma trapped in the magnetic cage and we obtain a solar flare, also called CMe (for Coronal Mass ejection).

This group of spots recalls the Carrington event of 1859

Richard Carrington is known for having given his name to the largest geomagnetic storm experienced on Earth since humanity had electrical installations. In 1859, it was said that the telegraph poles crackled and caught fire in the streets, and that the Northern Lights were seen as far away as Cuba, although little known for being located near the poles.

Is there a risk of destruction for our electromagnetic installations? Yes in principle, but in reality, the current group of spots is less compact than that of 1859. The intensity of the X-ray flash and possible eruptions should be more contained.

Northern lights expected?

Episodes of aurora borealis follow solar eruptions. It will therefore be necessary for it to occur during the few days when these spots face the Earth, which is indeed the case currently. Then, the magnetic field must have the desired south orientation (index BZ). We will not fail to keep you informed of this eventuality.

Want to save even more? Discover our promo codes selected for you.