Photo of the Week for July 15, 2016
There are several atmospheric phenomena in play in this photo by John Andersen. He set up his camera at Langdon, Alberta, during morning twilight on July 9, 2016, and captured this striking scene featuring noctilucent clouds and a band of green aurora. (Keen-eyed viewers will also note the great blue heron in the foreground.) Noctilucent clouds (also known as “night clouds”) are the highest clouds in Earth’s atmosphere, forming in the mesosphere at altitudes as great as 85 kilometres above our planet’s surface. They are usually observed in the summer months from latitudes greater than 50 degrees north, though displays can be seen occasionally from more southerly locations.
John used a Canon EOS 6D DSLR camera equipped with a 24-70mm zoom lens set to 70mm and f/2.8 for this 8-second exposure at ISO 1000.