The Northern Lights; the stunning beams of light that dance across the arctic winter skies. There’s been many nights we have stood in awe, freezing, but still not able take our eyes from the sky, ignoring the wish to be snug under our blankets in bed, maybe even with a warm cup of chocolate. Ever wondered what these magical lights actually are? And do the Northern Lights mean more than just pretty lights that reduce the dull of the long, dark winter nights?
Lets first get into what the Northern Lights are. The short (and very complicated) answer:
The Northern lights, or Aurora Borealis, are the results of electrically charged particles that are sent from the sun as a result of solar winds that interact with oxygen and nitrogen in the atmosphere, creating (mostly) green and pink light.
Maybe not. So let’s delve deeper into the mysteries of this winter light show.
Let’s start with the electrically charged particles. You may have heard that it takes just a few days for solar winds, or in this case tiny electrically charged particles, to get from the sun to earth. Well sort of. It takes that amount of time for it to get from the sun’s surface to earth. The story began long before that. Up to a million years before that in fact.
The super massive nuclear fusion reactor that we happen to call our Sun condensed a few basic elements a million years ago. Managed to smash them together and in the process created a vast amount of by product, mainly energy and fast moving particles.
These by-products were really excited about their new existence and wanted to share it with the universe. Only problem was that it was at the center of an incredibly dense star. So just like being late for work and trying to get your train in a crowded station the particle started pushing its way out banging into everything it could at lightning speed. Eventually it makes its way to the surface….then with the solar winds and interaction with the suns magnetic field it gets pushed away from the surface, and a few days later it gets to us.
So next time someone tells you it takes only a few days to get to us you can say, “well a million years and a few days actually.”
Then there is our atmosphere. Interesting fact about our atmosphere. If you squeezed all the particles together to the density of concrete it would be 15ft thick all around the world. It’s our forcefield. Our shield from everything the sun and solar system throws at us. Without it life would not exist. The magnetosphere is our protective coating around the atmosphere and focuses on redirecting and absorbing a lot of the cosmic radiation that at worst would kill us, and at best only interfere with our satellites.
So when a particularly strong solar flare or solar wind hits us it could potentially be quite damaging. Luckily the majority of these particles are redirected back out into space and around us. The small remainder that enters our atmosphere create what we call the Northern Lights.
The northern lights occur around the poles of the earth (yes, North and South Pole) because the magnetosphere is less strong around those areas and absorbs more of the cosmic radiation. They say that on any given night the northern lights will be practically the same as the southern lights in terms of strength, though don’t quote me on that one as I can’t say I’ve experienced it on both sides.
Finally the colours are produced because the electrically charged particles (or by-product) react with mainly oxygen and nitrogen in the atmosphere. Though there are reportedly many different colours, the majority of light shows are green or pink. The green light is from the reaction with oxygen and nitrogen. The pink is from the reaction with oxygen much higher up in the atmosphere, and is a lot less common.
So next time you are lucky enough to see the Northern Lights try to think about how this glimmer of light is a stark reminder that our little planet is always being bombarded and affected by everything in space. And thanks to our amazing atmosphere we are always protected.
Now that you know all about this wonder of nature, I bet you want to to know how you can see them. You can read all about that here, or have a look at this tour, which has a chance to see them in winter.
Hi I’m Ryan Connolly, I’ve guided in multiple countries and spent the last three years travelling across the globe. I have spent the past 2 years studying everything related to glaciers, climate change, and Iceland in my spare time.