The lone curtain of purple and blue aurora appears briefly amid a broader band of green aurora over the sweeping Red Deer River and Badlands of southern Alberta. From Orkney Viewpoint looking north over the valley. The Bleriot Ferry crossing is in the distance at the lights. Cassiopeia is just above the purple curtain. The river reflects the aurora light. This is a stack of 84 x 15-second exposures for the ground to smooth noise, and one 15-second exposure for the sky, all with the 20mm Sigma lens at f/2.8 and Nikon D750 at ISO 3200. They were part of a 250-frame time-lapse.
An observer at the 2017 OzSky Star Party peers into the southern sky with the Milky Way galactic centre rising behind him and as a bright backdrop. At the Warrumbungles Motel site in Australia.
Observers at the 2017 OzSky Star Party in Australia check their charts for hunting down targets with one of the large Dobsonian telescopes at the Warrumbungles Motel site. The centre of the Galaxy rises behind them.