On October 3, 2024, the Sun emitted its largest X-ray flash in years. It was heading straight for the ground! © NASA / SDO
We have at least several episodes of northern lights at low latitudes, including two in the south of France and further down. And it’s not over yet. NASA Goddard (named after the aerospace pioneer) confirmed Thursday that the solar maximum has been reached as our star’s magnetic field reverses. The accompanying video is impressive as always:
Let’s try to see it more clearly.
One of the best indicators of the sun’s activity is its sunspots. These are areas where the magnetic field is very active. Their black color is only a contrasting effect due to the temperature difference between the photosphere, which is about 5500 °C, and space itself, 2000 °C less hot. The more spots there are, the closer they are to the equator and the closer the cycle is to its maximum.
Impressive Sunspot Group from October 3, 2024 © Spaceweather, NASA SDO
The number of minimum and maximum sunspots during a solar eclipse. © NASA/Goddard Space Flight Center
Here is a wonderful video of the appearance and evolution of a group of sunspots from three animations designed by Pascal Paquereau with a 254 mm telescope equipped with an Astrosolar solar filter* of density 3.8:
Sunspot group from 10/20/2024: We note that they are all near the equator, which is characteristic of the maximum cycle. © Space Weather, (NASA, SDO)
What is solar magnetic field reversal? Is it dangerous?
We are in the midst of a solar magnetic field reversal. © Wilcox Solar Observatory
The Sun is made of moving plasma. Plasma is an electrically charged material, not neutral like so-called “normal” matter. Thus, the rotation of our star creates a magnetic field through the dynamo effect on itself. The Sun makes one complete revolution in about 25 days, which doesn’t seem like much compared to Earth, but it is 109 times larger with a diameter of about 1,390,000 km, or a rotation speed of about 7,190 km/h. Not so lazy dude!
So the magnetic field produced is very complex, here is a diagram:
Image taken from CEA video on the solar magnetic field. © CEA
Rest assured to the most concerned: the solar magnetic poles are always reversed and there is no real danger to us. You’ll just have to take advantage of the aurora borealis caused by solar flares that still occur pretty much every year. Of course, if you have a network of satellites, there are risks when our star emits a large X-ray flash, as it did about twenty days ago.
CMe, or Coronal Mass Injection. © US National Oceanic and Atmospheric Administration
A solar flare. © NASA Sun and Space (GIF created at Ezgif.com)
If you want to be informed in real time about your chances of seeing and photographing the spectacular Northern Lights on October 10, we recommend you follow some X-(Twitter) accounts, including NotreEspace ( Author these lines) or Astropier.
And as we never tire of it, here are some photos of the last northern lights from the famous episode of October 10, 2024, taken in France:
© Sylvain Gairaud & Brice Haziza
Show EXIF.
This argument is unfortunately disconnected from any objective scientific reality, especially since solar cycles are decadal (11-year cycles) while temperature increases have continued since the industrial age.
