What causes the Northern Lights?

Summary

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Who Smarted? – What Causes the Northern Lights?

Podcast: Who Smarted?
Episode Date: December 29, 2025
Main Theme: Unraveling the science, mystery, and spectacle behind the Northern Lights.

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Episode Overview

This episode of Who Smarted? takes listeners on a whimsical and fact-filled journey to Tromsø, Norway, where the host and his local friend Bjorn explain the real science behind the astonishing Northern Lights (Aurora Borealis). The show delivers engaging storytelling, trivia questions for “smarty pants” listeners, and plenty of laughs while teaching about solar wind, Earth’s magnetosphere, and the conditions that create dazzling auroral displays.

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Key Discussion Points & Insights

1. Setting the Scene: Observing the Lights in Norway

• The host is in Tromsø with Bjorn, a local and self-proclaimed “northern lights expert.”
  • Quote [01:14]:
    Bjorn: “Oh, it just comes from being from the north of Norway. We get northern lights all the time.”

2. What Are the Northern Lights?

• Initial description: stunning, colorful, seemingly magical.
• Science vs. Magic:
  • Bjorn: “For starters, there's nothing magical about them, trusty. It's all science.” [02:45]

3. The Earth's Magnetosphere and Its Role

• Earth is surrounded by a magnetic field, the magnetosphere, originating from the core.
  • Bjorn explains the basics of magnetic fields and how they protect Earth from solar wind except at the poles. [03:37–04:44]
  • Quote [03:49]:
    Bjorn: “Earth has something called a magnetosphere. It’s basically the area surrounding the planet which is dominated by our magnetic field.”
• Northern lights occur primarily at the poles due to weaker magnetosphere shielding.

4. What Is Solar Wind?

• Solar wind: A stream of charged particles from the Sun, traveling about 1 million miles an hour.
  • Interactive Trivia [05:47]:
    • Host: “Smartypants, true or false. This solar wind, made up of charged particles from the sun, falls down to earth at about 1 million miles an hour. If you said true, you're right.”
• Interaction between solar wind and Earth's atmosphere (oxygen/nitrogen) creates the auroras.
  • Bjorn: “When the solar wind enters through those weak points in the atmosphere, it interacts with oxygen and nitrogen and boom, we get the northern lights.” [06:02]

5. Where and When Are the Northern Lights Visible?

• Places: Northern parts of Alaska, Canada, Greenland, Iceland, Scandinavia, and even upper Michigan and parts of Scotland.
• Time of Year: Mostly visible in the dark winter months, September to April, but technically occurring year-round.
  • Bjorn: “They're actually happening non stop 24/7 every single day of the year. ... But in order to see them, the conditions must be perfect.” [07:10–07:35]

6. What About the Southern Lights?

• Aurora Australis appears near the South Pole, in southern Australia, New Zealand, Argentina, Chile, and Antarctica.
  • Bjorn: “For some reason, the Southern lights aren't as famous as the northern lights. But they are exactly the same thing, just in a different location.” [08:12]

7. Why All the Different Colors?

• The color depends on the type of atmospheric gas and the altitude where the interaction occurs:
  • Oxygen (60–150 miles): Green
  • Oxygen (200+ miles): Red
  • Nitrogen (≤60 miles): Blue/Purple
  • Host recaps: “Blue and purple are the closest northern lights when reacting to nitrogen. Green lights mean close and reacting to oxygen, and red are the furthest away when reacting to oxygen.” [10:13–10:35]

8. The Fancy Names: Aurora Borealis and Aurora Australis

• Host quiz:
  “What do you think the Aurora Borealis means? ... It's actually B, northern dawn. The term was coined by the Italian astronomer Galileo Galilei.” [10:56–11:25]
• Aurora Australis = Southern dawn/lights

9. Auroras Further from the Poles: Extreme Solar Storms

• Rare solar storms can make auroras visible at unusual latitudes (e.g., London, Switzerland, Florida in May 2024).
  • Bjorn: “On rare occasions when solar storms are extra powerful, the lights can be seen further away. And that's exactly what happened in May of 2024.” [11:51–12:23]
• Scientists expect more chances in the near future.

10. Do Northern Lights Make Sounds?

• Sometimes, yes! Rarely, auroras generate a subtle sound in the right atmospheric conditions.
  • Bjorn: “After scientists studied the sounds in the north of Finland, they were able to prove they were indeed coming from the northern lights. ... But the sounds only occur if the static charge in the solar storm is especially powerful.” [13:27–14:05]
• Audio demonstration: a soft, eerie environmental sound.

11. Auroras on Other Planets

• Other planets have auroras too (if they have a magnetic field and atmosphere).
  • Bjorn: “Most of the other planets experience the northern lights as well. ... For the same reasons we do.” [14:51–14:56]
• Exception: Mercury, due to its closeness to the sun.
  • Host quiz: “Any guess which planet doesn't get any northern lights? ... If you said Mercury, you're right.” [15:22–15:34]

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Notable Quotes & Memorable Moments

• Host, jokingly exaggerating the magic of the lights:
  “Nope. I'm in the city of Tromso in the far north of Norway, and I'm looking at the northern lights… No, not jellybeans or Skittles or Christmas lights.” [00:51]
• Bjorn, dryly summing up the science:
  “No magic. Pure science. Solar wind is a stream of charged particles that rain down from the atmosphere of the sun.” [05:38]
• Host, marveling at planets’ auroras:
  “Those other planets may have northern and southern lights, but they don't have anyone to look at them. So there.” [15:08]

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Timestamps for Key Segments

| Timestamp | Segment Description | |-----------|------------------------------------------------------------| | 01:10 | Introduction to Bjorn, the local expert | | 02:45 | Science, not magic: Northern lights explained | | 03:37 | Role of Earth's magnetosphere | | 05:47 | “Solar wind” defined and explained | | 06:21 | Creating the auroras: Solar storms | | 07:10 | When and where to see northern lights | | 08:12 | The Southern Aurora explained | | 09:15 | Why the colors differ | | 10:56 | The meaning of Aurora Borealis | | 11:51 | Why auroras appear farther from the poles during storms | | 13:27 | Rare sounds of the northern lights | | 14:51 | Auroras on other planets | | 15:22 | Which planet can't have auroras? | | 16:05 | Close: “Maybe just a little bit magical.”/“Nope. Purely scientific.” |

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Episode Tone & Style

• Friendly, enthusiastic, pun-filled: The hosts banter, quiz the audience, and make science fun with light sarcasm and nods to “magic” and “folklore.”
• Interactive: Trivia questions encourage listeners to participate.
• Conversational and playful: The hosts use recurring jokes and playful challenges to keep kids engaged.

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Summary

Who Smarted? makes the science behind the Northern (and Southern) Lights exciting and accessible, covering Earth's magnetic field, solar wind, atmospheric chemistry, the colors’ origins, planet-level phenomena, and even the rare sounds auroras can produce. The episode also links learning to real-world events (solar storms of 2024) and gives listeners fun facts to spark curiosity, all wrapped in humor and interactive storytelling. This is a delightful and memorable introduction to one of nature's most magical-looking—yet thoroughly scientific—phenomena.

Transcript

[A]

Hello, dear listeners. I'm Snoop, a top notch dog detective from London, now stationed in the quaint town of Pflugerville to mentor Sniffy, a promising puppy recruit. Our mission is to keep Pflugerville crime free. And so far, Sniffy and I have a 100% success rate. Crime never sleeps. So Sniffy and I are always looking for new junior detectives. So come on, join us in solving mysteries and having a lot of fun by listening to Snoop and Sniffy on Spotify, Apple, or wherever you get your podcasts.

[B]

And now it's time for who's Smarted? Whoa. I see green ones and pink ones.

[C]

And I see some purple ones over here. Yeah.

[B]

Psst. Hey, smarty pants. Guess what I'm looking at. No, not jellybeans or Skittles or Christmas lights. Nope. I'm in the city of Tromso in the far north of Norway, and I'm looking at the northern lights with my friend Bjorn. Say hey, Bjorn.

[C]

Hey.

[B]

Bjorn is somewhat of a northern lights expert, you know.

[C]

Oh, it just comes from being from the north of Norway. We get northern lights all the time.

[B]

Don't downplay it, Bjorn. The sky here is nothing short of spectacular, breathtaking, dare I say, mind blowing. But what exactly causes the northern lights? And how come they only occur in certain parts of the world? And what's with all the different glowing colors?

[C]

Great questions. And just like pretty much every single Norwegian, I know exactly how to answer them. Come, let's climb this hill to get a better look and I'll tell you all about them.

[B]

Oh, you never said there'd be hills. Well, smarty pants, looks like it's time to climb. As we take another big whiff of science and history on who smarted.

[D]

Who'S smarted? Who's smart? Is it you? Is it me? Is it science or history? Listen up, everyone. We make smarting lots of fun, but who's smart and.

[B]

Made it? Okay, Bjorn, what exactly are the northern lights? I mean, other than a mystical, magical dance of color in the sky?

[C]

Well, for starters, there's nothing magical about them, trusty. It's all science.

[B]

Science? Are you saying these lights are blinding me with science?

[C]

I am. That's because the northern lights are merely a display of light caused by solar wind.

[B]

Oh, okay. Well, I guess that answers everything. Bye.

[C]

Goodbye.

[B]

I'm kidding, Bjorn. Sheesh, that hardly answers the question. For one thing, what do you mean by solar wind? You're gonna need to break this down for me and the smarty pants.

[C]

Okay, let's start at the Beginning in the core of the Earth.

[B]

The core of the Earth. What does the Earth's core have to do with the northern lights? Smarty pants, do you have any idea? Yeah, me neither.

[C]

You see, Trustee Earth has something called a magnetosphere. It's basically the area surrounding the planet which is dominated by our magnetic field. And that magnetic field comes from.

[B]

From what? Smarty pants, say it with me. The Earth's core.

[C]

Exactly. The core of the Earth is a very hot place that's under a lot of gravitational pressure. This creates magnetic fields which shoot out from the center of the Earth through the Earth's crust and up, up, up into the atmosphere.

[B]

Okay, okay, so to recap, we're surrounded by a magnetic field that shoots into, out from Earth's core. I'm with you so far.

[C]

Good. And that magnetosphere does a really good job of preventing that pesky solar wind I mentioned earlier from entering our atmosphere. Except. Except in the north and south poles where the magnetosphere is weaker.

[B]

Oh, I get it. So the solar wind breaks through the weak points of the magnetosphere and we get northern lights.

[C]

Pretty much. Which is also why it helps to be near the poles to see it.

[B]

Smarty pants. I'm going to name some places. Call out the ones where you think you could see the northern lights. Ready? Alaska, New York City, Northern Canada, Greenland, Iceland, Texas, Michigan. Yep, you can see the northern lights in the northern peninsula of Michigan, as well as parts of Europe like Switzerland, Austria, and even parts of Scotland. Okay, so we know why and where we see the northern lights, but I'm still unclear what solar wind is. Again, it sounds pretty magical.

[C]

No magic. Pure science. Solar wind is a stream of charged particles that rain down from the atmosphere of the sun.

[B]

Smartypants, true or false. This solar wind, made up of charged particles from the sun, falls down to earth at about 1 million miles an hour. If you said true, you're right. Wow, that's so fast.

[C]

Extremely. And when the solar wind enters through those weak points in the atmosphere, it interacts with oxygen and nitrogen and boom, we get the northern lights.

[B]

Amazing magnetic fields and million mile an hour particles and nitrogen and oxygen all mixing together. Sounds pretty exciting.

[C]

It is. That's why we call it a solar storm.

[B]

Oh, and the northern lights happen during the solar storm?

[C]

Yeah, yeah.

[B]

Yes. Say, how long does a display of northern lights last? Anyway, smarty pants, what do you think is the average northern lights display? A, about 30 seconds, B, one to two minutes. Or C, 15 to 30 minutes.

[C]

If you said 15 to 30 minutes. But that's just the average time. Sometimes they could go on for hours. Whoa.

[B]

Nice. My next question is when? When is the best time to see the northern lights? Smartypants, what do you think? Would you say the summer, the winter, the spring, or the fall?

[C]

The answer is the winter, but also a little in the fall and spring. Generally, September to April is best. That's when the sky is darkest and visibility is much better. But one of the coolest things about the northern lights that most people don't know is that they're actually happening non stop 247 every single day of the year.

[B]

Really?

[C]

Would Bjorn light you, trusty? No, Bjorn would not. Solar winds enter the magnetosphere constantly, which means the northern lights are always happening. But in order to see them, the conditions must be perfect. That means clear dark skies at night and no clouds. And even then, there's no guarantee.

[B]

Gotcha. Now, you did say the solar winds enter at both the north and south poles. If the lights we see in the north are called the northern lights, smartypants, what do you think the lights in the south are called? Why, of course, the Southern lights.

[C]

Exactly. For some reason, the Southern lights aren't as famous as the northern lights. But they are exactly the same thing, just in a different location.

[B]

Smarty pants. Some places you can see the southern lights include southern Australia, parts of New Zealand, the southern tip of Argentina and Chile, and of course, the frozen continent of Antarctica.

[C]

But again, if you want to see all the colors, it needs to be a dark, clear night with no clouds.

[B]

Oh, and speaking of those colors, is there a reason why the northern and southern lights are sometimes blue, sometimes pink, and sometimes green? Or a mix of each? What do you think, smarty pants? Is there a reason or is it just random?

[C]

The answer is there is a reason. The colors are created by photons, which are released when the particles from the solar wind interact with oxygen and nitrogen. And the colors we see in the sky are determined by how far away in the atmosphere that interaction takes place.

[B]

Oh, so you're saying northern lights that are further away appear a different color than northern lights that are closer up?

[C]

That's pretty much what I'm saying. But it's not just a matter of distance. It's also whether the charged particles are reacting with oxygen or with nitrogen. See, if the solar particles interact with oxygen molecules and it's between 60 to 150 miles or, or 96 to 241 kilometers from the Earth's surface, you'll get green. But if the interaction with oxygen occurs 200 miles or 321 kilometers above or further, you get red.

[B]

Oh, what about blue and purple?

[C]

You won't get blue or purple as a result of oxygen interaction, but if the particles interact with nitrogen and are 60 miles or 96 km or lower in the atmosphere, that will create blue. Blue and purple lights.

[B]

Whoa, that's a lot of info. And it'll all be on the test, smarty pants. Just kidding. No test, but all cool stuff to know. So to recap, blue and purple are the closest northern lights when reacting to nitrogen. Green lights mean close and reacting to oxygen, and red are the furthest away when reacting to oxygen. You got it.

[C]

Well done.

[B]

I think I can remember all that. Good.

[C]

But wait, there's more. Did you know that the northern lights have another fancier name? That's right. They are also commonly referred to as the Aurora Borealis, which is Latin.

[B]

Smarty pants. What do you think the Aurora Borealis means? Is it A, colored light, B, northern dawn, or C, painted sky? If you said A or C, those are good guesses, but it's actually B, northern dawn. The term was coined by the Italian astronomer Galileo Galilei and combines the word borealis, which means north or northern wind, with Aurora, the Roman goddess of dawn.

[C]

And of course, since the northern lights have a fate fancy name, so do the southern lights. Those are called Aurora Australis, where Australis means southern.

[B]

Nice. Say, Bjorn, I have another question. I recently read in the news that people were seeing the northern lights as far south as London and Switzerland and even Florida. So what's up with that? Is everything you taught us so far a lie?

[C]

No, no. Bjorn does not lie. Under normal circumstances, you really can only see them in places close to the north and south poles. But on rare occasions when solar storms are extra powerful, the lights can be seen further away. And that's exactly what happened in May of 2024. Due to big solar flares from the sun, the impact of the northern lights was bigger and they were visible much further south than usual.

[B]

That's crazy. Will it happen again?

[C]

Actually, yes. Scientists predict another big solar storm is just around the corner. Which means you may not have to come to Norway to catch a glimpse of the Aurora Borealis.

[B]

Great. As much as I love it here, this trip was not cheap. But it was worth it to see such a spectacle of lights. But guess what, smarty pants? Not only are the northern lights a feast for the eyes, I hear they might also provide music to my ears. Smartypants, is it true? Do the northern lights actually produce sound? Get ready to find out right after this quick break. And a word from our sponsors. Now back to who Smarted? You sure we need to climb a little higher?

[C]

Find out we can get a little bit closer to see and hear.

[B]

Okay, smarty pants. This is where I'm starting to think Bjorn is just messing with me. It's one thing for particles to react with the atmosphere and make cool colored lights, but how could it also make sounds?

[C]

I'm telling you Trusty, on rare occasions, the aurora Borealis makes sounds. Scientists used to think that the stories of the northern lights making sounds was just old Scandinavian folklore. But we showed them. After scientists studied the sounds in the north of Finland, they were able to prove they were indeed coming from the northern lights. But the sounds only occur if the static charge in the solar storm is especially powerful. And if there is a weather condition where the cold air is trapped under warm air.

[B]

So you're saying the chances of us hearing them tonight are highly unlikely. But since this is a podcast and we can do anything. What if we pretend it was one of those rare nights?

[C]

Well in that case, it would make sounds like this.

[B]

Whoa. That's totally spooky.

[C]

Nope. Sciencey.

[B]

Right? I gotta say, the northern lights are just about one of the coolest things I've ever seen on Earth, Smartypants. If you don't live somewhere you can see them, have an adult help you look them up online to see for sure.

[C]

But guess what? Did you know the northern lights don't just happen here on Earth?

[B]

What?

[C]

Most of the other planets experience the northern lights as well.

[B]

They do?

[C]

Yep. And for the same reasons we do. Charged particles from the sun interacting with those other planets magnetic fields. Guess we're not that special. Trusty, Speak for yourself.

[B]

Those other planets may have northern and southern lights, but they don't have anyone to look at them. So there.

[C]

Good point. However, there is one planet that does not experience the northern lights due to its proximity to the sun.

[B]

Smartypants. Any guess which planet doesn't get any northern lights? Is it A, Venus, B, Mars, or C Mercury? If you said Mercury, you're right.

[C]

Mercury is a bit too close to the sun to get the dazzling display of auroras.

[B]

Wow. I have learned so much about the northern and southern lights, Bjorn. Way more than I ever thought possible. Thank you.

[C]

You're very welcome, trusty narrator.

[B]

Now what do you say we sit back and take in the beauty of this one of a kind light display before they stop?

[C]

Great idea, Trosty.

[B]

They're just so breathtaking, Bjorn.

[C]

Uh huh.

[B]

And mind blowing.

[C]

Yeah.

[B]

And maybe just a little bit magical.

[C]

Nope. Purely scientific.

[B]

Oh, well, I tried a big shout out to Andrew in Damascus, Oregon, who wrote to say, I love who Smarted because it educates me, bruh. Well, Andrew, I am super happy to have you listening, laughing, and learning with us. Keep on smarting, bruh. This episode, the Northern Lights, was written by Phil Jarami and voiced by Taya Garland and Jerry Colbert. Technical direction and sound design by Josh Hahn. Our associate producer is Max Kamasky. The theme song is by Brian Suarez with lyrics written and performed by Adam Tex Davis. Who Smarted was created and produced by Adam Tex Davis and Jerry Colbert. This has been an Atomic Audio production.