What Are Solar Flares? How Dangerous Are They?

(Last Updated On: March 31, 2021)

At some point you may have marveled at the raw power of the Sun. If you haven’t, maybe take a hot second to do that. The Sun’s about 92.879 million miles (about 149.5 km) from the Earth, yet it still is the primary driver for all energy on our planet. If the Sun turned off, we would all die. Very quickly. You’ve also maybe heard of solar flares, which you may have heard could definitely destroy civilization. If you haven’t, you might be skeptical that something like 93 million miles away could destroy the planet if it so much as blinked at us wrong. So what are solar flares, really? How dangerous could they be?

Special hint: very.

Further Reading: How Will the Sun Die?

Space Weather

You may think it a little weird that the big plasma ball in the sky that causes our weather has its own weather, but the Sun basically drives all the weather in the solar system. So it’s not that weird.

So what causes space weather? The answer is really complicated physics and electromagnetism. Just like the Earth, the Sun has its own magnetic field. Unlike the Earth, the Sun is super hot, so hot it’s just this kind of atomic soup of electrons and nuclei zipping around. The Sun’s magnetic field gives this electrically charged plasma movement, and the electrically charged particles generate the field. Bam. Electromagnetism.

This extends through all of the Solar System, making up this mild space wind we call solar wind. Except the Sun is really big, and there’s a lot of plasma and a lot of energy floating around. So things are bound to get chaotic. Which they do.

When ordered, the plasma spinning around the Sun at superspeed is chill, but every now and then it gets tangled up and bulges out of the sun, so to speak. Even though it’s spitting out 4.26 metric tonnes of stuff out of itself per second. The more kinked they get, the further away from the Sun these bulge out–like a bubble you keep inflating. Eventually, they get pushed too far out and the bubble “pops,” shooting a bunch of mass and energy out into the Solar System like the ultimate cosmic fart.

These make solar flares, which can make mild solar storms. Every now and then there’s a bigger fart, which can send billions of tons of plasma to us at 250 kilometers per second

Our Atmosphere

So how dangerous are these angry space farts? Most coronal mass ejections are pretty harmless to us. They can disrupt satellites and communication, but they won’t be messing with our health. The radiation is normally caught by our atmosphere, which is why we should take care of the ozone layer. Our magnetic field takes care of the plasma, redirecting it to the poles. 

By the way, that’s what generates the aurora.

Super Storms

Alright but harmless solar storms are boring. What about the dangerous stuff?

Yeah, the Sun’s got that. See, when coronal mass ejections hit the Earth, they push the magnetic field back behind the Earth. Kind of like when you pull an elastic band away from you. If the coronal mass ejection is large enough (these super storms occur roughly every century) or its own magnetic field lines up with the Earth’s just wrong, it pushes our magnetic field really far.

What happens when you pull an elastic band pretty far back? It snaps back. At you. Which is exactly what happens with our magnetic field, and all that energy coming straight back at us creates a more geomagnetic storm. 

Historically, severe geomagnetic storms haven’t been a problem for us beings made of meat. But also historically, we haven’t had a lot of technology and a reliance on electricity. Storms can not only knock out communications and satellites, but they can take down entire power grids. Think that’s far fetched? All of Quebec had its power grid taken out by a solar storm in 1989.

The Carrington Event

If you’re at all versed on this topic, you’ve heard of the Carrington Event. In 1859 a coronal mass ejection smacked us in the face and produced the largest geomagnetic storm on record. The aurora, normally reserved the poles, was observed all over the world–even closer to the equator. These weren’t just mild ones observed down south too, they were bright enough to simulate daytime. At night.

We were lucky in 1859, all we had was the telegram. Those did fail spectacularly though–globally. As in not only did they stop working, the machines just straight up broke. Replace it all.

If we were to be hit by something comparable to the Carrington Event today, it may cost over $2 trillion dollars (pushing $3 trillion) in damages (greater than Hurricane Katrina by a factor of 20). We’d be in a global blackout for potentially years. 

Why did scientists do all that math? Well it wasn’t for fun. It’s because we almost got smacked in the face by a solar storm as powerful as the Carrington Event in 2012. We missed it by 9 days. Yikes.

How likely is another super storm? About 12% in the next 10 years, so in the next 50 years it’s a coin toss as to whether or not we’ll have to deal with one again.

So are solar flares dangerous? If you don’t want a multi-year long power outage, yes. We’d argue that’s pretty dangerous when you think about how our society would basically collapse if nobody on Earth had electricity for an extended period of time.

But at least the atmosphere will probably protect your fleshy bits. 

Why not see if you know what elements the Sun is made of here?

About the Author:

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Kyler is a content writer at Sporcle living in Seattle, and is currently studying at the University of Washington School of Law. He's been writing for Sporcle since 2019; sometimes the blog is an excellent platform to answer random personal questions he has about the world. Most of his free time is spent drinking black coffee like water.