Mmm, just seen a very strange thing. A Lufthansa 747, flying straight across the Sun, leaving a clear trail.
But, when it came back out of the glare, having passed the Sun, there was a 'dark trail', but emanating from the front
of the plane!
After a few moments, I realised that this was the shadow of the real trail on the haze below the plane, but it looked really weird for a few seconds...
By the time I could take this it had faded a lot and wasn't quite on line, but, initially, it looked like a fake image that I was looking at, in real life.