Bizarre Natural Phenomena Vol. 47 - Rainbows In The Night (Moonbows)
Spring is taking a break in Greece as rainy weather is what we had yesterday and what comes usually after the rain? A rainbow!
Image source: commons.wikimedia.org - Creator: Arne-kaiser - License: CC BY-SA 4.0
Now, if you look closer, you'll see something that doesn't match.
Wait, wait! Are there stars in the sky?
Oh yeah! And this, my friends, is not a rainbow but a moonbow (or a lunar rainbow if you prefer)!
A moonbow? But it looks like a rainbow, are you sure?
Of course I am. Well, technically it is a rainbow, only it is caused by the moon. First, let's see how a rainbow is formed and then we'll explain the differences.
A rainbow is a meteorological phenomenon, an optical illusion from the combination of dispersion, refraction and reflection of light. In order to see it you need:
- Water in the air: we need water droplets in the air, from rain or mist, at a direction opposite the sun, that's the reason you can see it to the west in the morning time and to the east in the evening.
- The sun at the right place: to see a rainbow the sun must be low in the sky. You will spot it if you look at an angle of about 40° from the ground.
How is it done?
![](https://steemitimages.com/640x0/https://upload.wikimedia.org/wikipedia/commons/thumb/7/70/Rainbow1.svg/572px-Rainbow1.svg.png)
Each water droplet acts like a single prism, when they all combine the final result is a colorful circular band across the sky (with a pot of gold on its end and a leprechaun guarding it). Sunlight enters the suspending water droplets, the rays are refracted (bended due to the change in the medium), internally reflected (bounce back) on the walls of the droplet and then refracted again as they exit the water medium and return to the air; but the incoming ray won't be the same coming out, as some of it will be reflected once more at the time of the second refraction and will exit the droplet from the opposite side or keep reflectng inside the droplet. The double refraction can occur in various angles, with the red light frequencies refracted at about 42° and therefore visible at the top of the arc; whereas the blue light is refracted at 40° and is visible at the inner part of it, but the whole visible light (ROYGBIV) spectrum is refracted in every single droplet.
I got it, now how can you do that with moonlight?
This is really rare and difficult to happen, but not impossible. For a moon bow the same requirements must be met:
- water droplets in the air,
- bright moonlight (full moon or near-full-moon phases) opposite the droplets,
- the moon must be low in the sky (not higher than 42° from the ground), and
- there must be darkness, as light might hide it.
Note that, a moonbow's colors are not as bright as a rainbow's. This means it might look white to your eyes, but you can "trick" them using long exposure photography to capture the variety of colors in it.
I really, really want to see it! How can I find one?
Although moonbows are a rarity, there are certain places where you actually have higher chances of witnessing one. That is near waterfalls that create mist layers of splashing water droplets. They are called spray moonbows for this reason. Places like Waimea (Hawaii), Cumberland Falls State Resort Park (Kentucky), Yosemite National Park (California), Plitvice Lakes (Croatia) and Victoria Falls between Zambia and Zimbabwe (Africa) are ideal if you want to experience this miracle first hand.
If you want to, you can always have a look at this gallery from nightskyhunter.com.
Did you know?
![](https://steemitimages.com/640x0/https://upload.wikimedia.org/wikipedia/commons/thumb/3/38/Circular_rainbow.jpg/337px-Circular_rainbow.jpg)
Rainbows do not have a specific location, they are not stationary and they are certainly not tangible. Two different people will see two different rainbows depending on their place and angle of viewing relatively to the light source. Pretty cool, huh? There are as many rainbows in the sky as the possible viewing angles but we can only see one every time!
We can see rainbows as colorful arcs in the sky, but they are actually full circles. On the ground we miss the lower half of the circle because there are no water droplets for the light to refract, disperse and reflect through. But if you can make it higher, on a tall building or, even better, a plane, you might get lucky to view the whole of it!
(You miss so much when your feet stay pinned on the ground, flying changes so much of your perspective... in many ways)
References
wikipedia.org_1
wikipedia.org_2
discoverykids.com
physicsclassroom.com
wonderopolis.org
timeanddate.com
Thank you so much for your time!
Until my next post,
Steem on and keep smiling, people!
Very accurate & enthusiastic presentation of phyical-every-day facts that everybody should be aware of! - Great job my dear! :)
Light phenomena are truly brilliant. I was really impressed the first time I saw a rainbow that was very defined in the sense the spectrum of light was mirrored through the rainbow. You could see the normal rainbow seperated almost by a grey band and then another rainbow but with the colour arrangement mirrored. It was very cool!
I wasn't aware of "moonbows", now that would be a sight to see. Now that I know, when conditions are right I will try to see one. I think it will be difficult though. Thank you @ruth-girl for bringing it to our attention.
Hello there! That sight you just described sounds beautiful. The weirdest rainbow I have ever seen is a double one, about a year ago.
Thank you for reading that @physics.bemjamin! :)
@ruth-girl, that was the term I was looking for, a "double rainbow", there is the almost an eiry grey boundary between the two right? and then the red's of each rainbow are next to each other but separated by the grey band. That's what I remember seeing anyway haha. It looked very different to usual ones.
I love Physics for these type of things. The number of incredible phenomena in nature is beyond, I'll tel you something cool to check out if you fancy it. There is something called triboluminescence, a phenomena associated with the high stress in crystal structures, I wrote an article about it before, if you have time check it out, you may find it interesting.
https://steemit.com/steemstem/@physics.benjamin/x-rays-with-selotape-x-ray-your-finger-triboluminescence
Take care and have a nice day malaka :) (sorry only Greek word i remember from my crazy mates from Athens)
It didn't look exactly like that, I'll have to check on my photos to see if I remember well :P
Yeah, triboluminescence, I 've written about it in a past post only I can't remember now. I'll have a read of yours in a while.
And you just called me an asshole LOL!!!
Lol... hahahaha!
well who could have guessed. of all words in the greek dictionary. ;D
Well written. i had it in mind to research on this topic someday. your work seems to make it a lot easier to understand.
Truth is, i haven't really seen the moonbow before. Maybe someday.
I couldn't help laughing when I read it too!
Cool topic, isn't it? There were so much to write about, but I didn't want to make it too long. Thanks for reading @pangoli! And let's hope we'll see a moonbow sometime...
Oh we sure will. For one, i've had my eyes on Greece for... errr... well, since @trumpman told me about it.
Moonbows, the moon's rainbow!
Kinda wondering why it wasnt termed 'sunbow' instead of rainbow. wait, don't tell me there actually is ''sunbow' :O
Nooooo, is that what it literally means. I'm sorry, now I am embarrassed haha. If anyone's the arse hole here its me, haha. Sono un buco del culo (Italian).
It's a cool effect right, triboluminescence? I tried it by hitting my quartz crystals together, only to break my favourite piece, I was quite upset and just stood there for 1 minute contemplating my stupid mistake.
Looking forward to your next article anyway, keep up the good work :)
I couldn't help laughing when I read it too!
Cool topic, isn't it? There were so much to write about, but I didn't want to make it too long. Thanks for reading @pangoli! And let's hope we'll see a moonbow sometime...
I know but know thinking back to it, i should have known that Yanis and Nikos were telling me silly things to say. I blame them haha.
Yeah maybe @pangoli we will see one one day, for now we are just average rainbow observers. We'll do it bro!
Lol... Someone got pranked! hahahaha!
I do that to my friends a lot ;P
Hehe! No worries, I took no offence. :D
I know, I know, it's really cool. And I remember @erh.germany had suggested covering another similar topic, fire through friction. Maybe I should some time soon. I'm sorry about your quartz :(
I know, I was being silly. That's a good topic to write about actually, remember to warn people about carpet burns, i hated those as a child, burning my knees sliding around.
And thanks, I like my crystals a lot, the planet is filled with quartz but there's one quartz that belonged to Benjamin, now I have to find some more, or maybe it will find me......
Ooh tell me about those burns, last summer I got some in a water slides park :P
No worries, you will find another piece to cover the loss. I'm sure :)
I did a post on the rainbow waaaayy back, and i explained why the colours are inverted. wanna see it? i could go pull it right out. hehehe :D I love the blockchain!
Oooh yes please! :D
https://steemit.com/steemstem/@pangoli/the-rainbow-the-perfect-wonder-of-light-water-and-tons-of-physics
There you go. this one was done when i was just starting to contribute to the steemstem community. Have a great day dear, Ruth.
Thank you! I'm reading it tonight!! ;)
Hey there! I'm just getting in touch to let you know I gave you a shoutout on my most recent post. I have an ongoing series as well called, Oddball Geological Features. As I mentioned in my post, I promoted your blog (this article in particular) as a sign of good faith I'm not copying you. I gave you a follow and an upvote. Love your blog. :)
Oh! Thank you!! I'll jump to it in a while ;)
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Awarded 4 out of 6 owls:
The citation and sources owl was not awarded since it requires in text citations. The originality owl was not awarded since it is only considered when the science behind results/observations are discussed (in a original way). This post focusses on the results/observations itself.
Learn more about the owls over here
Thank you for those cute nocturnal creatures!!
I'm just curious about the citations, there are references at the end of the post, do you mean I should put numbered indicators in my text and number the sources as well?
Yup. I should have been a bit more clearer.
The most scientific way to cite is when you mention a fact to directly give the citation. In that way your work can be easily checked. If you put it at the end then it is not clear where I need to look to verify a specific fact :)
I see, I just don't like the way it looks with the citations in the middle of the text, but your point is absolutely right! :)
I agree this is not very pretty [1]. But science is not always beautiful :)
Love rainbows 💗!!!
When I was a child my mother tells me, I was chasing them trying to catch them lol!!!
But I had never heard of Moonbows, beautiful post @ruth-girl!!!!
Oooh! That's super-cute! ^_^
Children's minds are so innocent!
TBH I had never heard about them until yesterday :P
Thank you for reading @alinak15! :)
Wow, it's really amazing, I did not know all that. I still learned a lot of interesting things tonight, thank you very much @ruth-girl ^^
Thank you once again for being here @marie2018!
I would love to see a moonbow someday.
Never knew they exist till now, thanks for sharing. 😊
Thanks for reading!
poli wraio!!! ki emena mou aresei to ouranio tokso!! panta to xazeyw!!!! :)
Ευχαριστώ, Νίκο! :)
Wow, I've never seen a moonbow. What magic!
Me neither. I wish I get to see one some day!
A rainbow that pierces the eternal night. I have I heard those words from my granpa describing "a rainbow at night". Wouldn't it still be called a rainbow, not a "moonbow"? because we don't call normal rainbows, "sunbows".
Lovely words yiur grandpa's!
Actually they are still rainbows, but they call them moonbows just to distinguish them from the ones we see in daytime.
He used to tell me that all rainbows have double rainbows. And triples for that matter. It's just whether or not you can detect them with your eye. Most of the time they are simply too dim to be visible. Which I found was true once I grown up.
Your grandpa must have taught you so much, he sounds like a great man.