<p>Most probable you have been experiencing a weather phenomena: Ice crystals in the sky reflect or bend the light to form a <a href="https://en.m.wikipedia.org/wiki/22%C2%B0_halo" rel="nofollow noreferrer">halo</a>.</p>

<p>So, this depends on the temperatures and moisture content of the atmosphere and cannot be seen every day.</p>

CC BY-SA 3.0
2017-09-03T17:13:42.980Z
2017-09-03T17:13:42.980Z
Grimaldi
<p>One day when I was playing basketball I saw a circle around the bright Sun. It is a perfect circle with a radius of about 20-30 km. </p>

<p>Why does this circle of light form? I have seen the same also around the moon. But this does not happen every day. Why ?</p>

CC BY-SA 3.0
2017-09-03T17:01:59.420Z
Radius of 20 - 30 km? What do you base that on?
adrianmcmenamin
CC BY-SA 3.0
2017-09-04T09:06:00.980Z
I just imagine.
Mental Shakya
<light>
why there is a circle of light surrounding Sun and Moon?
Mental Shakya
# why there is a circle of light surrounding Sun and Moon?

(Asked by: username_0 on 2017-09-03)

One day when I was playing basketball I saw a circle around the bright Sun. It is a perfect circle with a radius of about 20-30 km.

Why does this circle of light form? I have seen the same also around the moon. But this does not happen every day. Why ?

**Tags:** light
> **Comments:**
> **username_1**: Radius of 20 - 30 km? What do you base that on?  
> **username_0**: I just imagine.  

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## 1 answers

### Answer by username_2 on 2017-09-03. Score: 2

Most probable you have been experiencing a weather phenomena: Ice crystals in the sky reflect or bend the light to form a [halo](https://en.m.wikipedia.org/wiki/22%C2%B0_halo).

So, this depends on the temperatures and moisture content of the atmosphere and cannot be seen every day.


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