For the past few days, one celestial phenomenon has been a darling of social media, partly because of its beauty, partly because of its unusual name. Whereas most atmospheric optical phenomena are given serious, regal-sounding titles like Rayleigh scattering, crepuscular ray, or lunar corona, this one has a humbler moniker. It’s Steve.
Steve looks like a neon purplish or green strip across the night sky, and he’s visible in Canada, though it’s not a streak of the aurora borealis. When Steve appears, he’s moving from east to West, from Ontario to Alaska, at about 4 miles per second, appearing static from the ground.
Scientists now know that the arc-shaped ribbon is actually an extremely hot (up to 10,000 degrees F), 16-mile thick river of ionized gas, about 200 miles above the earth’s surface, but much about Steve is still mysterious.
The Alberta Aurora Chasers, a group of photographers who trade tips and images of the famed northern lights, had been capturing images of the gorgeous arc for years. According to the New York Times, the group initially thought the sightings of what would become Steve, which is whitish to the naked eye, might be condensation trails from planes. After manipulating the settings on their cameras, however, they realized that the streaks were self-illuminated and multihued.
Last year, they met up with some astronomy professors at the University of Calgary at a bar and shared their photos, to find out what caused the mysterious stroke of light. No one had an certain answer, but Eric Donovan, a professor of physics and astronomy, took an interest in the question. He turned to the European Space Agency and their Swarm satellites to begin collecting data. It’s an ongoing project.
In the meantime, the arc needed to be called something. Chris Ratzlaff, who runs the Alberta Aurora Chasers’ Facebook page, chose “Steve,” a name pulled from a 2006 children’s movie, Over the Hedge, in which a gang of animals give the random name to an unknown, slightly frightening being they can’t see.
At a talk last month in Banff, Alberta, Donovan told the audience that he still occasionally turns to Ratzlaff’s team of citizen scientists for input as he investigates Steve. (NASA has also asked the Chasers for assistance.) So when one of his colleagues saw something unusual recently, Donovan explained, “I did something right then and there that I never thought I’d do as part of my professional work.” He logged onto Facebook and typed in: “Did anyone see Steve last night?”