Photo of the Week for July 12, 2019
There are many lights at night—some familiar, some not. In this photo we can readily identify the brilliant beacon that is the planet Jupiter and, of course, the bright span of Milky Way flowing northward from Sagittarius into Aquila. But what are those subtle green bands stretching across the frame? They’re an atmospheric phenomenon known as airglow, or nightglow. The green tint comes from energy released by oxygen molecules—the same element that produces green auroras. However, despite their superficial similarities, nightglow and the aurora arise from distinctly different processes.
David Moug captured the scene on May 28, 2019, from a site near Richer, Manitoba. He used a Canon EOS 6D DSLR camera and 24mm f/2.8 lens (working at f/3.0) for this 104-second, tracked exposure at ISO 2000.