Space weather means you’re going to miss the concert tonight. Image: Wendy Marijnissen, via Nieuwsblad.be
‘As humanity is increasingly dependent on communication technologies and satellites circling the Earth, we have become more vulnerable to so-called space weather.’
Through a solar telescope, the Sun looks like a calm, yellow disk with some darker sunspots here and there. However, when you look at UV images of the Sun, you will be surprised by the intricate structures that decorate the solar disk and its edges. These are coronal loops resulting from the complex magnetic field of the Sun and its interaction with the surrounding hot matter . Do you remember the classic school experiment with a magnet and sawdust? That’s exactly what the Sun’s magnetic field does NOT look like. Unlike your school’s magnet, the Sun is made up of very hot gas. The Sun is so hot that some atoms fall apart and lose their electrons. This means our Sun is made out of a huge amount of charged, swarming particles. The Sun not only rotates on its axis, its matter constantly bubbles up to the surface. And this movement of charged particles induces an extremely complex magnetic field which, to make things even more unpredictable, is constantly changing. Do you remember the joy when the sawdust magically jumped into the loops around the magnet? In the case of the Sun, it is not metal sawdust that forms the coronal loops, but particles of hot material (up to a million degrees) that surround the Sun. These particles flow along magnetic field lines, creating these beautiful curves and loops.