UFO camouflage the building of a cloud !! …Businessman Mr. TM was walking his dog, on Sunday 17-Nov-1975 ca.9:00am, along the eastern side of lake Nørre Sø in Viborg. He looked up and saw a strange object, shrouded in a white “cloud”. He estimated it to be 500-1000m away, silent. He took a photo with his 35mm camera, which he kept for taking photos of birds near the lake. The incident was investigated by Danish police officer K.K., who sent the negatives to the Central Bureau for Colour Photography, a branch of Police in Copenhagen. The object or phenomenon was estimated to be 20m or more in size. (note: this case is icluded in the declassified UFO files of the Danish Airforce, published in Jan-2009..     http://forsvaret.dk/FTK/omflyvev%C3%A5bnet/Flyvev%C3%A5bnets%20historie/Documents/UFO_materiale.pdf