What Causes The Northern Lights?

There are many misconceptions about what causes the Aurora Borealis when it really requires solar winds, magnetic fields and excited atmospheric gases.

The Northern Lights are beautiful and odd and have understandably inspired many myths. The Vikings thought they were a bridge between our world and Asgard where Thor and the other gods live. In another Norse myth, they are the light reflected of the armor of the Valkyries. And people in Finland thought it was the archangel Michael (John Travolta) battling Beelzebub (the devil).

Wrong. Wrong. Wrong. All wrong.

It was the famous early astronomer and recanter of science, Galileo Galilei, who gave the Northern lights the name Aurora Borealis, which means “dawn of the North” in Latin. But it wasn’t until Norwegian scientist Christian Birkeland figured it out in 1896 that the true origin of the auroras was understood.

In the center of the Earth, the molten iron core generates magnetic fields that extend through the crust and into space around the planet, creating what’s called Earth’s magnetosphere. It’s a pretty great thing that Earth has it, because the magnetosphere protects us from all manner of charged particles spit out from the Sun.

The Sun is so hot that it produces plasma (a fourth state of matter) where positively charged atoms (ions) and negatively charge electrons flow freely around one another. These highly charged particles have enough energy to escape the Sun’s gravity and fly out into space, barreling toward Earth at 1 million miles per hour like a shotgun blast of solar hate. This is called solar wind.

When they encounter our magnetosphere, most of these ions and electrons bounce harmlessly off and Earth is saved. But some of these particles make it through the magnetosphere where it’s weakest (at the north and south poles), and when they do the light show begins.

The electrons that make it into our atmosphere interact with some of the elements there, particularly oxygen and nitrogen. The electrons transfer energy to them, exciting them in the process. To calm down, the excited atoms must release some energy, which they do as tiny packets of light called photons -- beautiful, beautiful photons.

Depending on where in the atmosphere the electrons interact with these other atoms, different colors are produced. Oxygen emits a yellow-green color up to about 150 miles in the atmosphere. After that, it turns red. Nitrogen emits a nice blue color about 60 miles up. And don’t forget these colors can blend, which can create glowing pinks, purples and whites. It’s like Miami Beach up there.

This interplay is most vibrant during solar storms, which depend somewhat on the Sun’s solar cycle. And, although these lights can be produced at all hours, they aren’t visible during the day, since the sunlight outshines them.

SOURCES:

[mariannmartinussen]

i live in northern norway, so yes i've seen it many times. it's one of the most beautiful things i know

[OpticHectz]

I saw the lights last year just outside of Reykjavik, Iceland. It was very unlikely that we would see them as it was very cloudy and we waited for hours in the freezing cold with little to no activity, when all of a sudden, everyone behind us began screaming and we looked up into the sky as colours of green and yellow danced beautifully. Definitely the most amazing thing I’ve ever witnessed and would recommend it to anyone. It is a must see, no words can describe the beauty.

[TrevorHanson]

Always like to know the answers to these kinds of questions in case my kids ask me someday.

[ximecreature]

You guys are awesome. I find it heartwarming that some people just spend their time learning stuff to people for free. Education and general knowledge is what prevent masses to be used and influenced.
Keep it on, guys, I dream of the same world as you are.

[NEHAPEELU]

0:31

My teacher when I submit my Homework

[jennyp]

So breathtakingly awe-inspiring I think I'll burst into tears when I actually see it in person. Perfect reminder of a reality we have no concept, let alone control of, that somehow always defends our continued existence, no matter how terrible human civilization has been, we are reminded of the love and beauty out there that's so much bigger than us!

[pzsflynn]

I've been listening to your podcast for a while now and for some reason never knew you had a Youtube channel. I just randomly stumbled across this video and when I heard Josh's voice, I shed a tear, a single intellectual tear.

[irmaadams]

This is the first time I've understood how the northern lights work. Good at explaining. Thanks.

[chloetry]

I flew over Norway some years ago and saw a beautiful green and blue light show. It was one of the best moments of my life.

[gusbakeru]

A... Aurora Borealis! At this time of year? At this time of day? In this part of the country? Localized entirely within your kitchen?

[TimWrightDJ]

I wonder how many Brits, or even fellow Europeans, will be watching and commenting on this after tonight. We've just witnessed a once-in-a-lifetime opportunity to see them from all over the country.

[baheer]

Thank you so much for all the information that really helped me out. I was watching other videos on this topic but none quite matched your level of explaining it and helping me understand it. I have watched the video a couple time and each time I understood the concept better. Thank you.

[krabbypatty]

2014: just regular comments

2018: steamed hams related comments

[Rodpile]

Aurora Borealis is caused by purchasing fast food and disguising it as your own cooking.

[ichiyatheman]

Yes I have. I’ve recently moved up to Fairbanks Alaska and you can see them late at night if you’re lucky. They are absolutely breathtaking when seen in person.

[daniellehughes]

I live in Northern Canada and see them a lot, they will never get old to me 💜

[ModernZyzz]

Thank you so much for making this video! I wanna be an astronomer when I grow up and I'm just really curious cause this stuff is actually so exciting and interesting. So thank you for making this video and helping me understand it better :)

[fanni]

I went Iceland a couple months ago, we had a huge solar storm, so i saw it on land and also from our plane. It was magical to be almost next to it :)

[Togynar]

Just saw northern lights for the first time yesterday. As I'm in central Europe, they were quite dim, however when I took my phone out and took a photo with a long exposure, much more rays, colors and overall light popped up in the photo. And I got a little confused - how did the camera managed to capture more colors? I get why it's brighter with longer exposure, but why there were more colors is something I really don't understand.

[holographictacosalad]

What if you were to purchase fast food and disguise it as your own cooking? Would that be delightfully devilish?