Wismar, Germany,
June 22, 2010, 3:34:04 PM
This is a view from the mobile home parking  in Wismar on the Baltic coast of Germany, showing the sky  over the Aker Shipyard. With each and every  plane passing over the sky, the sky got more and more hazy, turning into a milky blue colour by the early evening. To me it appears as if the content of the  trails left by the planes is reacting with parts of the atmosphere , thereby expanding.  So, what the heck is the component in the exhaus from the engines, beyond  CO2 and water vapour? What is the difference between the normal trails which disappear and the ones on the above picture which simply grow , spread out and  remain up there?)