And we’re back with another edition of In Search of Why 🤷♀️
Huge thanks to everyone who has subscribed so far! Yes, I do get an email every time someone subscribes/follows me, and no, I will not be turning those notifications off anytime soon. They are just too satisfying…
Welcome to In Search of Why 🤷♀️
My answers are your answers.
Even if you’re not someone who reads the news, I’m sure you heard about the solar storm that hit the world a while back. Probably because you’re social media blew up with photos like this:
And what are those bright colourful lights in the night sky? That’s what we can an ✨aurora✨
And yeah, this photo is one of mine. Sorry not sorry for the aurora spam 🤩
For any of you northern hemisphere dwellers, you weren’t the only ones getting dazed by the glowing colours. The Southern hemisphere also got lucky, with auroras visible across the entirety of New Zealand!
So, what even is an aurora?
Great question. Let’s get into it…
What is an aurora?
Auroras are naturally occurring light displays caused by an interaction between charged particles from the Sun and the Earth’s magnetosphere (sorry, too science-y. Don’t worry, I’ll explain!).
Auroras are typically only seen in regions close to the poles i.e. the Arctic and the Antarctic. So sorry to any of you equator-dwelling folk, you are likely out of luck. Auroras occurring in the Northern Hemisphere towards the Arctic are better known as the Northern Lights (or Aurora Borealis), while those in the Southern Hemisphere are equally cleverly named the Southern Lights (or Aurora Australis).
Photo by Lightscape on Unsplash
But where do auroras come from?
Short story:
Space
Long story:
The sun continuously emits charged particles as part of its everyday life, dreamily called “solar wind”. Sometimes it even releases large bursts at one time, termed coronal mass ejections ☄️
When solar wind reaches earth, they can clash with the magnetosphere. Which is basically the Earth’s magnetic field 🧲
Now when the magnetic fields carried by the coronal mass ejections align oppositely to Earth’s magnetic field, things get all messy and a large amount of energy can be released. This process is known as magnetic reconnection.
This magnetic reconnection causes the charged particles from the coronal mass ejections to be carried along the magnetic field lines towards the Earth’s magnetic poles 🧲
And where are the Earth’s magnetic poles? Yes, in the Arctic at the North pole and in the Antarctic at the South pole (well close enough anyway).
As the particles travel along these magnetic field lines they get closer and closer to the earth, entering our upper atmosphere and colliding with gas molecules, such as oxygen and nitrogen (which make up 99% of the earth’s atmosphere). And when these particles and gas molecules collide 💥, all that energy they’re carrying gets transferred over.
And finally, what goes up must come down. The now energy-filled molecules of oxygen and nitrogen can’t stay so excited forever, and so they release the excess energy. And they do so in the form of photons, also known as light. You get enough of these together, and bang you’ve got an aurora.
(Yes I do love a Schitt’s Creek meme)
And what about the different colours?
The variety of colours we see is due to the different types of gases involved, and the altitude (distance upwards from sea level) at which the 💥collisions💥 occur:
Oxygen at higher altitudes leads to red auroras
Oxygen at lower altitudes leads to green auroras
Nitrogen (at any height) leads to blue or purple-y/red auroras
And rainbow auroras like the photos above? Well that occurs when you get a combo of the lot.
Still confused?
Here’s a video that could help (also a shout out to the SciShow on YouTube who produce some amazing content if your curious about the world):
And what about solar storms? What are those?
Solar storms, like the one that hit the earth in May, are caused by the sun releasing lots of stuff all in one go.
And what is that “stuff”?
Great question. As mentioned above, sometimes the sun releases bursts of charged particles, better known as coronal mass ejections (CMEs) ☄️
Alongside CMEs, the sun can also release another fun energy-filled thing, intense bursts of radiation termed 💥solar flares💥.
This combination of CMEs and solar flares can result in huge amounts of electromagnetic activity, leading to insanely cool auroras appearing much further from the poles than typically seen. Such as across the entirety of New Zealand.
For context, they are usually only seen at the very bottom of the country. And yes, New Zealand is a much bigger country than you think, being about 1,600km long (or 1,000 miles).
While solar storms sound super cool, they do come with some unfortunate downsides. All that magnetic activity can interfere with the technological systems that we have come to depend on, such as GPS, power grids, and communication grids (and yes that can include your cellphone). There are also potential health risks from all the increased radiation, though this is largely only a concern for astronauts and high-altitude pilots flying in the polar regions.
(Another YouTube shout out - Dr Mike - pointing out all the medical inaccuracies of your favourite TV shows)
Should I be sad that I missed the great solar storm of May 2024?
If you were one of the unlucky ones who only heard about the solar storm after your social media was taken over by photos of the lights, I hope you aren’t too disappointed. To tell you the truth, while the photo above that my camera captured looks cool, that’s not really what it looked like for me 📷
Why? Great question.
Now, if you’ve been a subscriber of In Search of Why 🤷♀️ for a while, you might remember that I shared an article from an astrophotographer that answered this exact question. You can check it out here:
Photo by Thomas Tucker on Unsplash
And if linking off to another site is too difficult. It’s basically all down to the way our eyes work vs how a camera works. I’m sure it won’t surprise you that the two operate differently.
Anyway, that’s all for now.
Do you have any questions you want answered? Please let me know in the comments below!
Till next time…