Photo of the Week for January 6, 2017
Light pollution is the scourge of backyard stargazers. There’s almost nothing good about it, and a lot that’s bad. But sometimes, when conditions are right, ordinary street lights can create interesting and even beautiful effects. The light pillars shown in this photo are one example. Although these streaks of luminosity superficially resemble an auroral display, they’re very different. Pillars are caused by atmospheric ice crystal reflecting artificial light—the various tints arising from the different colour-temperatures of the illumination sources.
Thomas Jacquin captured this scene from Whitehorse, Yukon Territory, last November. He used a Canon EOS 7D DSLR camera fitted with a Tokina 11-16mm zoom lens set to 11mm and f/2.8 for this 10-second exposure at ISO 1000.