Meet Steve, a sky phenomenon coming into its own

One of the thrills of observing the northern lights in Minnesota is that you're never sure what the sky might produce. At any time, a faint green glow along the horizon might explode into a dazzle of multicolored arcs that fill the sky.

But if it doesn't, you might still get lucky — you might meet Steve.

I was fortunate enough to be introduced to Steve on a recent chilly evening while photographing the lights from a bridge near Stacy, Minn., a spot far enough north of the Twin Cities that light pollution won't obscure the aurora borealis.

I should be a little embarrassed that I didn't recognize Steve, given that he's become celebrity in the sky-watching world. I think I can be excused, however, because Steve's burst to prominence has been rapid. No one else knew who he was either until several months ago.

My experience making Steve's acquaintance was similar, I suspect, to others who have come to know him in recent months.

As I watched the end of the brief northern lights show that night in Stacy, a swath of bright vertical light appeared behind a line of trees near me, the radiance stretching high into the darkness from the ground.

I had no idea if this was part of the northern lights. It was to the west, not the north, and seemingly much closer than the aurora. But as I watched the column start twisting with green and purple light, I knew I had better get my camera out. Whatever this was, it was amazing.

It was well after midnight when the light finally faded and I headed home. In the morning, I sent photos of what I'd seen to some friends who know a lot more about this stuff than I do, hoping they'd have an explanation.

"Congratulations," one of them texted me back. "That's Steve."

Who? What?

Steve, I learned, is the name given to an atmospheric phenomenon that was identified only last spring — oddly enough, a development sparked not by astrophysicists or other scientists but by a Canadian Facebook group dedicated to aurora photography.

Members of the Alberta Aurora Chasers had been seeing something during their outings that looked different than normal northern lights. They were assuming it was a form of the aurora called a proton arc, but they asked Eric Donovan, a professor of physics and astronomy at University of Calgary, to look at their photos and give his opinion. Donovan told them that proton arcs can't be seen with the naked eye. What they were seeing had to be something else, he said.

Whatever it was, it had no name, so a member of the group decided to call it Steve. The reference is to a scene in the movie "Over the Hedge," in which the animated characters are fearful of a large hedge. They decide they'd be a lot less afraid of the greenery if it had a name. So, it becomes Steve.

Back in Canada, Donovan was able to match the group's sightings of Steve with data from satellites that record information about the earth's magnetic field. One satellite recorded obvious changes as it flew through an area where Steve had been observed by members of the Facebook group. Bingo. Steve, confirmed as a strip of ionized gas, was now officially a thing.

Steve has another name as well — a little more scientific — credited to Robert Lysak, a professor at the University of Minnesota's Institute for Astrophysics. He also is a good friend of Donovan's.

Last spring, Lysak was in the audience for one of Donovan's talks about Steve. As Donovan spoke, Lysak came up with a "bacronym," or invented acronym, for that strip of gas: Strong Thermal Emission Velocity Enhancement.

"He read it out during the question-and-answer period after the talk," Donovan told me in an e-mail. "And he received boisterous applause as a result. "

If Lysak is smart enough to come up with that, I figured he might be able to tell me how Steve could have, for so long, escaped the notice of aurora experts like him and Donovan.

"We've known there's this overall flow of plasma through the ionosphere that goes on all time, but gets stronger when there is a lot of solar activity," Lysak said. "The general idea that there could be a flow like this producing light is not too surprising in retrospect, but I'm not sure you could predict it and I don't think anybody did."

"It was one of those things that fell through the cracks and no one really noticed it before," he said. "If you weren't looking carefully or expecting it, you might just mistake it for another aurora."

Now that Steve is a big deal, however, I don't figure he'll be mistaken for just an aurora ever again. In fact, social media has become rife with Steve photos, including from other aurora chasers who saw him the same night I did. I just hope all the attention doesn't make him shy. I'd sure like to run into him again.

Jeff Moravec is a writer and photographer from Minneapolis. Reach him at jmoravec@mac.com.