Science Snapshots: Flipping Poles

Peckers, grab your rosaries and say your prayers! The sun's magnetic poles are due to flip, and it could happen this year!

NSF/AURA/NSO

I'm kidding, of course. Not about the flipping, but about the need to worry about it. This happens every 11 years, after all!

What even is a magnetic pole?

Gifer

A magnet is a material that produces a magnetic field. Super helpful, huh? A magnetic field is essentially an area that influences the motion of charged particles moving through it. You've probably run into magnets before. Maybe you stuck them on your fridge, or you're convinced the COVID vaccine lets you stick car keys to yourself. Magnets sticking is achieved due to the magnet producing a field that attracts the particles in the magnet to the particles in the refrigerator.

Magnetic fields look pretty cool. Here we see the structure of a magnetic field because of how it lines up pieces of metal that are aligned by the center magnet's field.

Wikipedia

If I went any further I'd start going into quantum mechanics, and no one wants to see that again.

One property of these magnets is that they have poles: a north pole and a south pole. It looks like this.

Wikipedia

And if we cut that bad boy in half, both pieces would have a north pole and a south pole. You've gotta have both! And we literally did name this after our own Earth's poles. Given totally free movement, the north pole of the magnet would rotate and point towards our north pole. Think compass.

If you want to collapse your brain further, read about magnetic fields and magnets here and here.

So...am I saying the sun is just a giant magnet?

Sort of? You won't be sticking the sun on your fridge any time soon, but it does have quite a beefy magnet field all its own. Plasma (a state of matter) moves around in the indescribably hot interior of a star and, due to being conductive of electricity, induces a magnetic field. Electricity moving through cords in your home does the same thing, just on a, you know, much smaller scale. And due to rotation (the sun rotates on its axis roughly every 24.5 Earth days), the field aligns such that magnetic poles form near the north and south poles of the star. One is a magnetic north and one is a magnetic south. You can see those lines on the illustration at the top of the page.

But they don't stay put! Every solar cycle, roughly 11 years, they flip flop with each other. This last happened in 2013 so we're due this year. The mechanism by which a star produces a magnetic field means it ends up being alternating current (AC, not DC!), so it does indeed alternate, or reverse direction of the poles. What's the result? Well, during the reversal phase, the magnetic field isn't quite as strong as normal, and sunspots are at their maximum. This results in more coronal mass ejections, or the sun vomiting particles and magnetic field towards us. They look pretty cool.

But they can really cause problems with our communications systems and satellites. So that's about that. It happens every 11 years give or take, we're used to it, your satellite radio might go down for a little bit or you might see a nice aurora. Hopefully nothing worse, although a very strong solar storm can cause major disruptions to our communication and power grid infrastructure, and can be dangerous to astronauts or those in high altitude like commercial jets over polar areas. That's a worse case scenario though, and one that space weather forecasters track and the people managing those assets prepare for.

Many of you are probably already thinking about how the Earth does the same thing as the sun and also has magnetic poles, hence the usability of a compass. The mechanism is only slightly different, in that the material moving around causing the magnetic field is the magma in our outer core, which is heated by our inner core. It's called Dynamo theory.

Our poles reverse too. But that only happens every several hundred thousand years. The last one was about 780,000 years ago. Our magnetic field is critical to protecting life on our planet, keeping dangerous radiation from space out there and away from us. While the magnetic field does weaken during a reversal, it doesn't disappear completely and nothing in the scientific record or models of magnetic fields suggests that we'd be facing a catastrophe when this inevitably does occur again. But your compass will be messed up.

Read more about a sun magnetic pole reversal here: https://nso.edu/blog/polar-magnetic-field-reversal/
Read more about an Earth magnetic pole reversal here: https://climate.nasa.gov/explore/ask-nasa-climate/3104/flip-flop-why-variations-in-earths-magnetic-field-arent-causing-todays-climate-change