Shadow on a wall of coastal fog (facing away from the Sun). Mavic 2 Pro.

[alpineph]

 

[Thomas B]

Cool capture of the rainbow refraction from a round object!

 

[GregE]

It's not from a round object ( other than the earth

All rainbows are circular- most we see the bottom half is blocked by the ground. While flying above mist, fog, clouds you see full rainbows like the picture 'down sun'.

 

[old man mavic]

no pot of gold at the end of that one then,then again it has no end

 

[bumper]

It's called a "glory" and is sometimes seen by glider pilots flying "mountain wave" if the sun is in the right position. In wave, the glider can fly up the windward face of standing lenticular clouds, often climbing at 2 to over 4 thousand feet per minute in perfectly smooth laminar flow.

 

[Cymruflyer]

A "glory" can actually be seen by any aircraft when the atmospherics are just right and the sun is just at the correct angle to the aircraft and the clouds. In fact not just aircraft but also mountain climbers can experience this phenomenon, and were the first ones to see this, long before an aircraft was invented.

It can be seen by the pilot at varying angles of the sun to the aircraft with clouds on the opposite side, but may be best when the shadow falls 10-20 degrees below the aircraft's level flight position. I have experienced it many times over the years when I have been up flying in my plane. And you don't have to be against a cloud, you can also sometimes see a similar thing around your aircraft shadow on the ground. It is a great thing to see though, from the seat of your aircraft and it is fun to fly right into your shadow when going into thin cloud, wispy cloud when the sun is right behind you, because as you get closer to that cloud/fog etc. your shadow get larger until you go into that cloud.