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GREEN BELT, Md. — Not all science is performed by people in white lab coats under fluorescent lights in academic buildings. Sometimes, the course of the scientific record is changed forever during a casual conversation.
Such is the case with the sweeping purple and green lights that can hover above the horizon in the Northern Hemisphere. This phenomenon looks like the aurora borealis but is actually something completely different.
It’s called Steve.
The rare light spectacle has caused a sensation this year, as the sun enters its most active period, increasing the number of dazzling natural phenomena appearing in the night sky.
About eight years ago, when Elizabeth MacDonald, a space physicist at NASA’s Goddard Space Flight Center, was in Calgary, Canada, for a symposium, she had never seen this phenomenon in person before. It didn’t have a name yet.
In fact, few scientists who study the aurora and other night sky phenomena have witnessed STEVE, which appears closer to the equator than the aurora and is characterized by a pinkish-purple arc accompanied by green vertical stripes.
“At the time, we didn’t know exactly what it was,” MacDonald said of the phenomenon that appeared in the photos.
“I started spotting what we used to call the proton arc in 2015,” photographer Neil Zeller said. “It had been photographed in the past, but it had been misidentified, so when I attended that meeting in a Kilkenny pub… we started a bit of an argument about (whether) I had seen the proton arc.”
Eric Donovan, a professor at the University of Calgary who was at a bar with MacDonald that day, confirmed to Zeller that he had not seen the proton arc, which according to a paper Donovan later co-authored is “optically bright, broad, and diffuse,” while Steve is “optically bright and narrow.” And organized.”
“The upshot of that evening was that we don’t know what this is,” Zeller said. “But can we stop calling it a proton arc?”
Shortly after that bar meeting, another aurora chaser, Chris Ratzlaff, suggested a name for the mysterious lights on the group’s Facebook page.
Members of the group have been working to better understand the phenomenon, but “I suggest we call it Steve until then,” Ratzlaff wrote in a February 2016 Facebook post.
The name was borrowed from the 2006 DreamWorks animated film “Over the Hedge” in which a group of animals become frightened by a towering leafy shrub and decide to refer to him as Steve. “I’m less afraid of Steve,” the porcupine declared.
The name stuck. Even after this phenomenon can be better explained. Even after Steve’s explanations began to take shape in scientific papers.
Scientists later developed an abbreviation with the name: Strong Thermal Emission Velocity Enhancement.
What is steve?
STEVE is visually different from the aurora borealis, which are caused by electrically charged particles that glow when they interact with the atmosphere and appear as dancing bands of green, blue or red. But it appears at lower latitudes and appears as a streak of violet-colored light accompanied by distinct green bands, and is often referred to as a picket fence.
Steve can be frustratingly difficult to spot, as he appears alongside the aurora borealis with little regularity.
Photographer Donna Lash has seen and photographed Steve nearly two dozen times, a rare feat in the world of sky photography. She said she uses her family’s farm on a remote piece of land in southern Manitoba, where there is little light pollution.
Steve will always appear alongside the aurora, but not every aurora includes Steve, Lash and Zeller said.
Where and how to see Steve
MacDonald said Earth is entering a period of enhanced solar activity, or solar maximum, which occurs every 11 years or so.
During this time, viewers can expect more visible light displays in the sky, and perhaps the chance to view Steve at lower latitudes. She said light phenomena have been observed as far south as Wyoming and Utah.
Steve’s phenomenon is most likely to be captured during the spring and fall equinoxes, according to Zeller and Lash. This year’s autumn equinox occurred on September 23.
“I don’t think it’s Steve that occurs more during the equinox, but larger aurora storms are known to occur near the equinoxes,” MacDonald noted. Because STEVE tends to appear alongside the aurora borealis, this phenomenon is most likely to be observed in March or September.
Zeller and Lash said they usually saw Steve between the evening and midnight.
“It’s not an all-night thing,” Zeller said. “The longest I’ve ever seen Steve was an hour from start to finish.”
Zeller added that he waits until the auroral storm begins to fade before pointing his camera eastward — from his vantage point in Canada — or straight up, and then “you start seeing this purple river.”
This is Steve.