I was recently flying back from Palma de Mallorca Airport (PMI) to Birmingham Airport (BHX/EGBB) and I had the luxury of sitting at a window seat behind the wing. I think the plane was a Boeing 737-800 via Jet2.
Halfway though the flight I was looking out the window and noticed little specks on the outer window and was trying to work out if it was frozen water or frozen bacteria from the clouds?
Does anyone know what this is or how it forms? Does this happen to the pilot windows also?