It starts quietly, then things swell. This is followed by a loud and impressive sound. Then crackling, loud tones, something that sounds like the squawk of a ship. You can unleash all kinds of wild fantasies on him, and listen for yourself:

But what are we really hearing? This requires a small astrophysics lesson, which Vincent Ike of Leiden University is happy to offer us.

Start by explaining the Earth’s magnetic field. In short: “The field protects us from the winds from the sun and from particles from the universe.”

Longer version: “All sorts of things are spinning in space. And that’s not nice for Earth when it’s falling. The magnetic field is a kind of shield that protects us. It’s created by currents in the Earth’s interior. Stars and other planets also have such a magnetic field.”

Then back to the part. It’s hard to pinpoint exactly where each sound comes from, but an astronomer can explain a few things.

waterfall

Icke likens the beginning to the sound of a waterfall. “It’s like standing at the bottom of it. Kind of roaring. That’s right,” he explains, “because the vibrations of the magnetic field are very low frequency, 50 to 60 vibrations per second. This creates low tones.”

According to the astronomy professor, most of the noise is caused by the sun’s winds blowing through the Earth’s magnetic field. “It’s fluttering, and you can hear it.”

“chiew, yay”

But if you pay close attention, you will hear another sound: “Tjiew, tjiew!” , Icke imitates. “Magnetic fields can be compared to tight wires or frayed strings. When something hits them, like a hot gas cloud emitting from the sun, the field begins to vibrate or oscillate. It happens so fast that you hear whistles. A kind of vibration bouncing back and forth between our poles.”

Now listen again, can you hear it?

The sound is obviously very interesting, but what is the use of this science? In fact, Ike says quite frankly, it’s not that much. It’s basically for us: the audience that can’t stop listening to these kinds of clips.

tax money

“The vast majority of science is done with taxpayer money. We are grateful for that, and this is our way of giving back. We hope people hear about this and can imagine how exciting our profession is.”

But this is not entirely meaningless. This part gives scientists a better idea of ​​the different parts that can be distinguished in the magnetic field, and what their origin is.

The European Space Agency launched special satellites in 2013 to conduct further research into the magnetic field. Because: every once in a while, and we’re talking about millennia, the Earth’s magnetic field temporarily disappears.

And suddenly, like this, the shield that protects our Earth from the “evil” of the universe has disappeared. “When that happens, you want to be prepared for it,” Ike says. “The more you know about the magnetic field, the better.”

It’s still exciting and a bit mysterious.