The Blue Hour

Silver birches in the fresh snow near Ballater, against a turquoise sky and an almost full moon.

Tonight I learned that twilight, when this picture was taken, is often known as the "blue hour" and is when the sun has set, but light scattering in the upper the atmosphere illuminates the lower atmosphere often creating a fantastic light quality. It precedes dusk (and night!) and they are collectively called gloaming. So there you have it.