Our cover picture ...
... shows noctilucent clouds. Already in the evening twilight of 4 July 2021, brighter noctilucent clouds were beginning to appear. With increasing darkness, I could see them strikingly bright as a relatively limited field for more than an hour in the north western sky from the shore of the Schlänitzsee north west of Potsdam. The image was taken at 22:25 CET with a Canon EOS 6D II, lens Tamron 28 to 300 at f=28mm, f/d=6.3, 3.2s exposure, ISO 3200. The mirror smooth surface of the lake was a real invitation to take pictures. At the transition to the Earth’s shadow ("upper edge"), a reddish fringe can be seen, caused by the long light path through the atmosphere. Photo: Jürgen Rendtel