Definitely an AI fake.

A complete Rainbow... photo was taken at around 30k ft above the Earth. On the ground, we usually only see the arc half of the circle.
Credit Photo: Lloyd J Ferraro
There seems to be doubt about the authenticity of the pic:
https://www.reddit.com/r/Damnthatsinteresting/comments/11c6yii/complete_rainbow_taken_from_30000_ft_in_altitude/

More details/photos: http://bit.ly/3SvxXbw

Complete Rainbow taken from 30,000 ft in altitude. Photo by pilot - Lloyd J Ferraro

Posted in r/Damnthatsinteresting by u/cenabollywood • 5,328 points and 106 comments

reddit
@Rojertb Pretty sure this is fake. Rainbows are always perfect (partial) circles, no matter how you look at them (you can’t look at them from the side). And they need the sun exactly behind them (maybe exactly in front for exotic variations). And the circle doesn’t continue in the bottom left after the cloud.
Tl;dr: probably AI gen, maybe old skool shopped.
@Rojertb Oh this version had suspicious Chinese(?) characters cropped off. Here’s a bigger version on Reddit:
https://www.reddit.com/r/Damnthatsinteresting/comments/11c6yii/complete_rainbow_taken_from_30000_ft_in_altitude/
Complete Rainbow taken from 30,000 ft in altitude. Photo by pilot - Lloyd J Ferraro

Posted in r/Damnthatsinteresting by u/cenabollywood • 5,328 points and 106 comments

reddit
@Wlm 'twould seem that your doubts are shared!