The northern and southern lights have dazzled sky watchers for millennia with their eerie, greenish glows. Now, a new purplish aurora is joining the show, stretching from east to west at lower latitudes. Discovered by citizen scientists, and substantiated by professional scientists using photographs and satellite data, the new type of aurora is similar to a previously measured—but never seen—atmospheric phenomenon. Its nickname: Steve. Citizen scientists first began posting about Steve on social media several years ago. Across New Zealand, Canada, the United States, and the United Kingdom, they reported an unusual sight in the night sky: a purplish line that arced across the heavens for about an hour at a time, visible at lower latitudes than classical aurorae, mostly in the spring and fall. (You can see video of the aurora above.) “It’s similar to a contrail but doesn’t disperse,” says Notanee Bourassa, an aurora photographer in Saskatchewan province in Canada. Traditional aurorae are often green, because oxygen atoms present in Earth’s atmosphere emit that color light when they’re bombarded by charged particles trapped in Earth’s magnetic field. They also appear as a diffuse glow—rather than a distinct line—on the northern or southern horizon. Without a scientific theory to explain the new sight, a group of citizen scientists led by aurora enthusiast Chris Ratzlaff of Canada’s Alberta province playfully dubbed it Steve, after a line in the 2006 children’s movie Over the Hedge. http://www.sciencemag.org/news/2018/03/there-s-new-aurora-subpolar-skies-its-name-steve
