<p>I observed a greenish blue patch in the red sky after sunset, and it stayed for not more than 5 minutes. It didn't curve or appear distorted; it was just like a carpet. Why is it so? Could it have been an aurora? </p>

<p>Thank you </p>

<p><strong>location:</strong> 9° N, 78° E; Temperature 35 deg C.</p>

<p><a href="https://i.sstatic.net/CXH6Z.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/CXH6Z.jpg" alt="enter image description here"></a></p>

CC BY-SA 3.0
2017-04-09T13:37:27.693Z
What was the shape, if any? Sunset sky can appear greenish for a short time due to refraction being stronger than usually.
Helen
CC BY-SA 3.0
2017-04-09T13:52:34.533Z
it was a definite rectangular patch between reddish sky. can such sort of refraction take place-just surrounding red and a definite green? could it be due to some odd atmospheric gas combo?
F.Fred
CC BY-SA 3.0
2017-04-09T13:57:20.920Z
What I had in mind appears around the sun's setting position. Interesting.
Helen
CC BY-SA 3.0
2017-04-09T15:09:49.760Z
Not aurora, not at 9 degrees north of the equator.
James K
CC BY-SA 3.0
2017-04-09T17:36:15.050Z
A cloud containing lots of water can look green against a red sky when backlit by the setting sun. http://optics.kulgun.net/Cloud-Colour/ This seems to fit with the general observation. If correct, this is a meteorological phenomenon
James K
CC BY-SA 3.0
2017-04-09T21:41:05.387Z
Perhaps it was your eye creating a green after-image of the red sunset. [See here](https://en.wikipedia.org/wiki/Afterimage) for an example.
TonyK
CC BY-SA 3.0
2017-04-10T05:59:53.983Z
Just curious, is that a view of the sky from above or below? Which way is north or south?
uhoh
<observational-astronomy><amateur-observing>
A greenish blue patch in the sky during sunset
F.Fred
# A greenish blue patch in the sky during sunset

(Asked by: username_0 on 2017-04-09)

I observed a greenish blue patch in the red sky after sunset, and it stayed for not more than 5 minutes. It didn't curve or appear distorted; it was just like a carpet. Why is it so? Could it have been an aurora?

Thank you

**location:** 9° N, 78° E; Temperature 35 deg C.

[![enter image description here](https://i.sstatic.net/CXH6Z.jpg)](https://i.sstatic.net/CXH6Z.jpg)

**Tags:** observational-astronomy, amateur-observing

> **Comments:**
> **username_1**: What was the shape, if any? Sunset sky can appear greenish for a short time due to refraction being stronger than usually.  
> **username_0**: it was a definite rectangular patch between reddish sky. can such sort of refraction take place-just surrounding red and a definite green? could it be due to some odd atmospheric gas combo?  
> **username_1**: What I had in mind appears around the sun's setting position. Interesting.  
> **username_2**: Not aurora, not at 9 degrees north of the equator.  
> **username_2**: A cloud containing lots of water can look green against a red sky when backlit by the setting sun. http://optics.kulgun.net/Cloud-Colour/ This seems to fit with the general observation. If correct, this is a meteorological phenomenon  
> **username_3**: Perhaps it was your eye creating a green after-image of the red sunset. [See here](https://en.wikipedia.org/wiki/Afterimage) for an example.  
> **username_4**: Just curious, is that a view of the sky from above or below? Which way is north or south?  

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## 0 answers

