Recent nights have seen superb displays of noctilucent cloud (NLC) – blue-white cloud structures that form on the edge of space in the northern sky.These mysterious formations only occur at midsummer, and their cause is not fully understood. A particularly strong display was seen on 21 June, and was witnessed over much of Britain where skies were clear. Stuart Atkinson took some superb photographs, posted on his Facebook page, such as the one below.
The display was also very prominent from Watlington, Oxfordshire, though slightly hidden by meteorological clouds.
Members are urged to keep an eye on the northern horizon for the next few weeks. NLC appear when all traces of sunlight have stopped illuminating normal meteorological clouds, and may fade around midnight UT (1 am BST), only to reappear an hour or so later. They are characterised by a blue-white colour and often by ripples which are distinctively different from normal cirrus cloud. Time lapse video show them drifting and changing shape. Please send any sightings to the Aurora Section director, Sandra Brantingham (email@example.com)