This is the back of one of the maps of Graves Park. The fibreglass backing has been eroded or damaged to reveal the filling of the board that the map is printed on. It looks rather like a view of the earth from space.
After 5 days of UK airspace being closed, some flights were allowed today, so long as they were above the ash cloud. The sky was completely cloudless, and I spotted the tiny vapour trails of a very high aircraft. The featureless sky and bright sunlight seem to have fooled the autofocus, and I couldn't see the LCD screen to frame the image, so appear to have missed the plane altogether! I quite like the way it looks like the BSOD (blue screen of death) that comes up when there is a serious system failure.