(VIDEO) Noctilucent clouds are small ice crystals in the Earth"s upper-atmosphere. They are most often seen at times close to the summer solstice, when they appear against the backdrop of deep evening twilights.

This picture is taken in Draaby in Denmark during my summer holidays in 2009 and is one of thousands frames that are compiled to a time-lapse video. The video kan be seen on youtube.com here: NLC time lapse film. (Full HD 1080p)