Been there, done that meself ..
Nice image all the same ....
although personally I'd reduce the brightness a bit to show more detail.
Your lower white edge is possibly a processing artefact from sharpening and or contrast enhancement.
Your interference .... ain't seen anything like that before. Can you give us some more technical details ? Camera, frame count, processing software. Is it visible in single frames in just the one capture ?.
Almost like dew or something on the camera window\sensor but then I'd expect it to be visble elswhere in other captures for the mosaic
It may be a mosaic processing issue.
Fun eh ?