DSCN9398

DSCN9398

Observation - DSCN9398. Description: these oily looking patches appear on my pond from time to time but I have no idea where they are coming from other than the sky, is this possible as I do live under the flight path of Manchester airport?

these oily looking patches appear on my pond from time to time but I have no idea where they are coming from other than the sky, is this possible as I do live under the flight path of Manchester airport?