Named “Steve,” the swathes of purple light filling skies over Regina, Canada, spurred plenty of intrigue when discovered by citizen scientists.
The lights, the likes of which locals had never seen before, were understood by scientists to be a new aurora. Or so they thought.
Turns out “Steve,” which stands for Strong Thermal Emission Velocity Enhancement, is no aurora. It’s an entirely new celestial phenomenon, with a different atmospheric process to an aurora.
The conclusion was made by researchers from the University of Calgary in Canada, who authored a study which was published in Geophysical Research Letters.
“So right now, we know very little about it,” Bea Gallardo-Lacourt, a space physicist and the study’s lead author, said in a statement online.
“And that’s the cool thing, because this has been known by photographers for decades. But for the scientists, it’s completely unknown.”
Researchers refer to “Steve” as a “skyglow,” to make it distinct from an aurora. Auroras are produced when charged particles from the sun collide with the magnetic fields in Earth’s ionised upper atmosphere (the ionosphere), generating a stunning light display.
A NOAA satellite, POES-17, didn’t detect any charged particles raining down to Earth’s upper atmosphere when “Steve” took place, likely suggesting the “skyglow” could be a result of something else completely.
The next step for researchers is to see if streams of fast ions and hot electrons in the ionosphere are responsible for “Steve,” or if the light is produced in higher atmosphere.
So “Steve,” what the heck are you?