I'm just trying a quick analysis of the image: 1) Rising sun appears in the left part of the photograph, so driving direction seems to be to the southeast while the cloud seems to have a west-east orientation. 2) Tube has a slightly different color than the rest of the clouds. This may have to do with the lighting situation.3) The cloud layer seems to be very thin. My guess is that a starting plane has caused some strange turbulences. E.g. the tube could have appeared along the plane's exhaust emissions working as condensation nuclei while the pilow could have been blown free by the wing's vortices. This is possible because of a) a
small airport nearby. There is a (north)west-(south)east runway so planes could start off in this direction.b) Oxford weather on 11 december 2007, as can be obtained from
here. Wind seems to blow in north-west direction, so probably the west-east-runway was used by planes.What I do not understand is how such a thin cloud layer could form, and why the tube being a kind of "condensation trail" is not longer than a few hundred meters.
