Noctilucent (Night Shining) Clouds over North Doncaster. They are typically observed during the summer months from latitudes between 50° and 70° north and south of the Equator. They only be seen during local summer months, when the Sun is below the observer's horizon, the clouds are at an altitude of around 50 miles, so are still in sunlight. They consist of ice crystals which reflect the Sunlight to the observer's location.
The focal length of the lens here is 35mm. the foreground consists of 5 images stacked for NR and then focus stacked which works I think here even though it is not perfect. It was still relatively dark, the sky is 13s and the foreground is 45s, @ f2.8 ISO 800.