<p>There are a couple of atmospheric phenomena that can create rings around the moon.</p>

<p>Corona are caused by water droplets diffracting the moon's light, they are fairly small, and close to the moon. They are coloured but not as brightly as a rainbow. Our eyes are also not so good at seeing colours in dim light.</p>

<p>The 22-degree halo is a larger ring, as big as two hands stretched out at arms length. Solar halos are clearly coloured, lunar halos are dimmer and I haven't seen lunar halos that are bright enough to appear coloured to me.</p>

<p>An eye condition, astagmatism, can also create rings, such as the "thin blue ring" (though I am not a doctor) You may be seeing a combination of all three at various times.</p>

CC BY-SA 4.0
2019-08-26T09:36:19.937Z
This is the answer in my opinion and plus 1. However a corona can be spectacular and not that small.  If one get to see a perfect corona, it is either wow or "scary" without previous knowledge. Tip: for capturing it with a smartphone put metering on full screen and use a sensitive setting. The moon will be a white fuzzy disk but one catch easily two orders of refraction (two inverted rainbow rings). Also add that C is due to diffraction while H are refractive phenomena.
Alchimista
CC BY-SA 4.0
2019-08-23T12:06:38.960Z
2019-08-23T12:06:38.960Z
James K
<p>I think you very nearly answered your own question. The rainbows are indeed due to light diffracting off high altitude ice crystals, but more in a kind of haze than in the form of clouds. I have seen something similar in Hereford UK, but only on very rare occasions. There must be something unusual about the climate where you live for you to see them so often. The other unusual thing is for you to see the colours so clearly. The human eye loses colour vision at night, though with a very bright full moon there is still a vestige of colour vision left. The fact that your concentric rings are off centre and slightly elliptical I put down to imperfect draughtsmanship rather than faulty vision.</p>

CC BY-SA 4.0
2019-08-23T06:31:12.270Z
2019-08-23T06:31:12.270Z
Michael Walsby
<p>Regularly, I see rainbows around the moon. Here is approximately what I see:</p>

<p><a href="https://i.sstatic.net/wTjLx.jpg" rel="noreferrer"><img src="https://i.sstatic.net/wTjLx.jpg" alt="enter image description here"></a></p>

<p>Right at the edge of the moon, I see a bright blue ring of light. Further out, I see an inner rainbow. This is not as bright as the ring, but is still clearly visible. Even further out, I see an outer rainbow that is very faint. </p>

<p>I see the blue ring during every full moon. I see the rainbows more frequently in late fall and winter than in spring or summer. But every year, I see these moon rainbows during a full moon.</p>

<p><strong>Since I see these moon rainbows more frequently in late fall and in winter, are these moon rainbows caused by moonlight reflecting off of ice crystals in cirrus clouds high up enough that I can't see the clouds? Also, why do I see a bright blue ring right at the edge of the moon during every full moon?</strong></p>

CC BY-SA 4.0
2019-08-23T04:34:07.150Z
Does it look like this? (Google Moon dog)  https://www.google.com/search?q=moon+dog&rlz=1C1OKWM_enUS860US860&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiZvNDclJjkAhXsYd8KHVOLAuUQ_AUIESgB&biw=1536&bih=754
userLTK
CC BY-SA 4.0
2019-08-23T04:36:53.150Z
No, I just see the rainbows around the moon. I don't see moon dogs with it.
Caters
CC BY-SA 4.0
2019-08-23T08:51:59.240Z
Do you wear thick eyeglasses?
Koray
CC BY-SA 4.0
2019-08-23T11:55:01.213Z
Does it look like https://apod.nasa.gov/apod/ap150615.html ?
samcarter_is_at_topanswers.xyz
CC BY-SA 4.0
2019-08-23T15:20:10.470Z
`+1` just fyi, questions like this (atmospheric effects in the sky) can also be asked in [Earth Science SE](https://earthscience.stackexchange.com/)
uhoh
CC BY-SA 4.0
2019-08-23T15:20:54.103Z
Yeah, it does kind of look like that. And no, I don't wear any kind of glasses at all. I'm just looking at the moon with the naked eye.
Caters
CC BY-SA 4.0
2019-08-24T17:34:24.417Z
Where do you live?   And can you get some decent photographs to back up your perceived colors?
Carl Witthoft
CC BY-SA 4.0
2019-08-24T17:48:46.570Z
I live in Columbus, Ohio. And, even during the time of year that I see the moon rainbows, I'm not sure that my phone camera will pick it up. I once tried to take a picture of a lunar eclipse, and the red of the moon did not get picked up at all, it just looked black as night. So no, I don't think I can get decent pictures of the moon rainbows. And I know for sure that I can't get the blue ring around the edge of the moon.
Caters
CC BY-SA 4.0
2019-08-26T09:39:51.437Z
Wikipedia has nice pages about moon corona, what you are asking about, and moon halos.
Alchimista
<the-moon><night-sky><visible-light>
Why do I see rainbows around the moon?
Caters
# Why do I see rainbows around the moon?

(Asked by: username_0 on 2019-08-23)

Regularly, I see rainbows around the moon. Here is approximately what I see:

[![enter image description here](https://i.sstatic.net/wTjLx.jpg)](https://i.sstatic.net/wTjLx.jpg)

Right at the edge of the moon, I see a bright blue ring of light. Further out, I see an inner rainbow. This is not as bright as the ring, but is still clearly visible. Even further out, I see an outer rainbow that is very faint.

I see the blue ring during every full moon. I see the rainbows more frequently in late fall and winter than in spring or summer. But every year, I see these moon rainbows during a full moon.

**Since I see these moon rainbows more frequently in late fall and in winter, are these moon rainbows caused by moonlight reflecting off of ice crystals in cirrus clouds high up enough that I can't see the clouds? Also, why do I see a bright blue ring right at the edge of the moon during every full moon?**

**Tags:** the-moon, night-sky, visible-light
> **Comments:**
> **username_1**: Does it look like this? (Google Moon dog)  https://www.google.com/search?q=moon+dog&rlz=1C1OKWM_enUS860US860&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiZvNDclJjkAhXsYd8KHVOLAuUQ_AUIESgB&biw=1536&bih=754  
> **username_0**: No, I just see the rainbows around the moon. I don't see moon dogs with it.  
> **username_2**: Do you wear thick eyeglasses?  
> **username_3**: Does it look like https://apod.nasa.gov/apod/ap150615.html ?  
> **username_4**: `+1` just fyi, questions like this (atmospheric effects in the sky) can also be asked in [Earth Science SE](https://earthscience.stackexchange.com/)  
> **username_0**: Yeah, it does kind of look like that. And no, I don't wear any kind of glasses at all. I'm just looking at the moon with the naked eye.  
> **username_5**: Where do you live?   And can you get some decent photographs to back up your perceived colors?  
> **username_0**: I live in Columbus, Ohio. And, even during the time of year that I see the moon rainbows, I'm not sure that my phone camera will pick it up. I once tried to take a picture of a lunar eclipse, and the red of the moon did not get picked up at all, it just looked black as night. So no, I don't think I can get decent pictures of the moon rainbows. And I know for sure that I can't get the blue ring around the edge of the moon.  
> **username_6**: Wikipedia has nice pages about moon corona, what you are asking about, and moon halos.  

---

## 2 answers

### Answer by username_7 on 2019-08-23. Score: 8

There are a couple of atmospheric phenomena that can create rings around the moon.

Corona are caused by water droplets diffracting the moon's light, they are fairly small, and close to the moon. They are coloured but not as brightly as a rainbow. Our eyes are also not so good at seeing colours in dim light.

The 22-degree halo is a larger ring, as big as two hands stretched out at arms length. Solar halos are clearly coloured, lunar halos are dimmer and I haven't seen lunar halos that are bright enough to appear coloured to me.

An eye condition, astagmatism, can also create rings, such as the "thin blue ring" (though I am not a doctor) You may be seeing a combination of all three at various times.

> **Comments:**
> **username_6**: This is the answer in my opinion and plus 1. However a corona can be spectacular and not that small.  If one get to see a perfect corona, it is either wow or "scary" without previous knowledge. Tip: for capturing it with a smartphone put metering on full screen and use a sensitive setting. The moon will be a white fuzzy disk but one catch easily two orders of refraction (two inverted rainbow rings). Also add that C is due to diffraction while H are refractive phenomena.  

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### Answer by username_8 on 2019-08-23. Score: 0

I think you very nearly answered your own question. The rainbows are indeed due to light diffracting off high altitude ice crystals, but more in a kind of haze than in the form of clouds. I have seen something similar in Hereford UK, but only on very rare occasions. There must be something unusual about the climate where you live for you to see them so often. The other unusual thing is for you to see the colours so clearly. The human eye loses colour vision at night, though with a very bright full moon there is still a vestige of colour vision left. The fact that your concentric rings are off centre and slightly elliptical I put down to imperfect draughtsmanship rather than faulty vision.


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