Originally Posted by Alistair
It is the shadow of the contrail?

https://www.atoptics.co.uk/atoptics/contr2.htm


Thanks Alistair, I'm assuming that the shadow was cast by the moon then, which must have been North of the trail?
The sun would have been ESE when I took the picture.

Gordon Duguid
2014 Duratec engine plus 4, Montreal blue.