Hello, I’m Zukky.
What I’m about to write is a true story. My mother raised me to believe that it’s okay to embellish a little if it makes a story more interesting, but I usually find that the real story is the most compelling.
So, I haven’t added much flair to this one… or maybe just a little.
The Red Aurora Flex (or “Mounting,” as we call it)
As soon as my supervising professor saw my face after I returned from Finland, he asked:
(Professor): “So, you saw the aurora, did you?”
(Me): “Yes, I did!”
Without skipping a beat, he immediately asked:
(Professor): “What color did you see?”
(Me): “Um… green, white, and maybe some purple?”
My professor immediately put on a triumphant look.
(Professor): “Hmph, you don’t get it. The red aurora is the best one!”
And just like that, I was instantly “flexed on” (or “mounted”) about the aurora the moment I returned home. I suppose that was his quirky way of welcoming me back. Gotta love the big personalities!
I Didn’t Know How Rare the Red Aurora Is
But, Professor.
The thing is, I don’t actually know if the red aurora is rare or not. So, your attempt to flex on me isn’t making me feel particularly bummed out right now.
If I actually said that out loud, I could easily picture him scoffing and ridiculing me.
“What’s wrong with you? You don’t even know that?”
Being told that would be far more humiliating than the initial flex, so I decided to look it up. More than anything, I felt obligated to look properly defeated for the professor who went to the trouble of flexing on me.
The Science: What Determines the Aurora’s Color?
First, how many colors of aurora are there, anyway?
According to Yosuke Kamide’s The Science of the Aurora, the primary colors are red, green, and blue. In addition to these, there are purple and pink. Colors can also mix to appear whitish, but these five are the basics.
Of all these, the red aurora is actually the most frequently occurring in the upper atmosphere.
The aurora is generated when plasma particles from the sun collide with Earth’s atmosphere, transferring energy. Red light is emitted by oxygen atoms at the highest altitudes (where the oxygen is thin) using the least amount of energy.
Because it occurs at altitudes of 150–200 km or higher (up to around 500 km), when the aurora is very active, the top of this red aurora is sometimes even visible from places like Japan.
I thought about all that I had learned and started to smirk, imagining my professor’s face.
Wait a minute… red auroras aren’t rare at all!
It seemed he had failed at his rare attempt to flex.
However, that’s when I discovered a twist.
The Catch: Why the Red Aurora is Hard to See with Your Eyes
A quick moment of reflection brought up a strange thought: if the red aurora isn’t rare, why had I, who lived in Oulu, near the edge of the Arctic Circle in Finland for a year, never seen a bright red one?
Almost all the auroras I saw were green.
W-why is that?
It turns out I needed to dig a little deeper.
Why is the red aurora rare?
I discovered three main reasons why the red aurora is rarely seen with the naked eye:
- The red aurora is dim and far away, so the light is attenuated before it reaches the ground.
- The wavelength of red light is harder for the human eye to perceive due to its mechanism.
- The human eye cannot accumulate light like a camera.
1. The Light is Weak and Distantい
First, the red aurora glows for a relatively long time. It doesn’t flash with a “BOOM!” of strong energy; it shines with a dim, sustained glow: “Piiiiiii-kaaaaaa…” The overall light is faint.
Furthermore, it shines at an altitude of 150–500 km. Considering the green aurora shines at 100–150 km, that’s quite distant. This is the first reason why the red aurora is difficult to see.
2. The Red Wavelength is Hard to See in the Dark
Here’s the more technical explanation.
The human eye senses light using two main types of cells: cone cells (for color vision in bright light) and rod cells (for perceiving brightness/darkness and shape in dim light).
Light has a wavelength, and broadly speaking, blue light is in the 430–490 nm range, green light is 490–550 nm, and red light is 620–780 nm.
The rod cells, which we rely on for vision in the dark, have a peak sensitivity at around 500 nm, which is in the blue-green light range. While the cone cells that sense red light can see into the red range, their peak sensitivity is at 560 nm, meaning the deep red wavelength is not where they are most sensitive.
Conclusion: In the dark, it’s easy for the human eye to see green light, but difficult to see red light.
This is the second reason why the red aurora is hard to see with the naked eye.
3. The Human Eye Can’t “Collect” Light
The third point explains why cameras can capture the red aurora. A camera can keep its shutter open for a long time to accumulate light. This allows it to capture colors that the human eye cannot pick up.
So, How Rare is the Red Aurora, Really?
While I don’t have precise data on its rarity, Alex from @aurorahunting (an aurora tour guide since 2012) posted on Instagram that he had only seen it about 10 times up until March 2023.
Red is the most rare colour of northern lights to see with naked eyes! You can capture it moderately often on camera, but seeing it in the sky is quite rare – I’ve only seen it around 10 times over the years. This March 2023, we were able to witness it 2 times! This is because we are at the start of the Solar Maximum – a few years with augment aurora activity!
This means the red aurora is so rare that a professional guide might only see it once a year, if that!
He also noted that in March 2023, he saw it twice in a single month. This is because we are currently entering the Solar Maximum (the peak of the solar activity cycle), making the aurora more intense. If you’re lucky, you might have a chance to see the red aurora now!
Conclusion: The Flex Was Justified!
Professor! I looked it up,
and I now know the red aurora is incredibly rare!
I totally understand why you said, “Hmph, you don’t get it. The red aurora is the best one!” Your flex was completely justified!
Wait, what? Now I suddenly feel the sting of being out-flexed! (૭ ᐕ)૭
Damn you, you boastful old man! (ᯅ̈ )/
Ugh! I swear, I’m going to see a red aurora someday! ᕕ( ᐛ )ᕗ
Now that you all know how rare the red aurora is, if someone ever tries to flex on you by mentioning they saw one, make sure you act properly jealous!
Try to overreact as much as possible, saying things like,
“Wait, you actually saw that? Really? The RED aurora!? The super-rare one!? With your naked eye!? That’s insane! Whoa!”
Alternatively, you could kneel on the floor in shock and bang the ground in utter defeat. That scores extra points.
See you next time!
Complete Aurora Borealis Guide
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