The resulting clash of solar and terrestrial particles in Earth‘s atmosphere caused stunning auroras to seem at lower latitudes than usual and, in southern Canada, triggered a surprise cameo from the mysterious sky phenomenon referred to as STEVE.
Alan Dyer, an astronomy writer and photographer located in southern Alberta, Canada, caught the wispy ribbons of green and violet light on camera because they shot through the sky.
An excellent showing of @STEVEPhenomena yesterday evening, Aug 7-8, arcing over the sky, and showing his green fingers briefly for approximately 2 minutes. STEVE lasted about 40 minutes, appearing because the Kp5 aurora to the north subsided. This is 12: 30 am MDT from southern Alberta. @TweetAurora pic.twitter.com/EtKF6udfFkAugust 8, 2022
“STEVE lasted about 40 minutes, appearing because the aurora to the north subsided,” Dyer wrote on Twitter (opens in new tab) on Aug. 8. “STEVE was ‘discovered’ here so he likes appearing here a lot more than somewhere else!”
Related: Earliest documented aurora within ancient Chinese text (opens in new tab)
As Dyer noted, the strange sky glow called STEVE was initially described by citizen scientists and aurora hunters in northern Canada in 2017. STEVE is normally made up of a massive ribbon of purplish light, that may hang in the sky for one hour or more, along with a “picket fence” of green light that always disappears within minutes.
The glowing river of light may appear to be an aurora, but that it is a distinctive phenomenon that has been considered “completely unknown (opens in new tab)” to science upon its discovery. Today, scientists have a slightly better notion of what’s happening.
STEVE (short for “strong thermal velocity enhancement”) is really a long, thin type of hot gas that slices through the sky for a huge selection of miles. The heat inside STEVE can blaze at a lot more than 5,500 degrees Fahrenheit (3,000 degrees Celsius) and move roughly 500 times faster compared to the air on each side of it, satellite observations show.
Whereas the northern lights occur when charged solar particles bash into molecules in Earth’s upper atmosphere, STEVE appears lower in the sky, in an area called the subauroral zone. That likely means solar particles aren’t directly in charge of STEVE (opens in new tab), Live Science previously reported. However, STEVE more often than not appears during solar storms like Sunday’s, turning up following the northern lights have previously begun to fade.
One hypothesis (opens in new tab) shows that STEVE may be the result of an abrupt burst of thermal and kinetic energy in the subauroral zone, somehow set off by the clash of charged particles higher in the atmosphere during aurora-inducing solar storms. However, more research is required to uncover the real secrets of STEVE. For the time being, we are able to simply bask in its otherworldly glow and wave back at its twinkling green fingers.
Originally published on Live Science.
Brandon is a senior writer at Live Science since 2017, and was formerly an employee writer and editor at Reader’s Digest magazine. His writing has appeared in The Washington Post, CBS.com, the Richard Dawkins Foundation website along with other outlets. He holds a bachelor’s degree in creative writing from the University of Arizona, with minors in journalism and media arts. He enjoys writing most about space, geoscience and the mysteries of the universe.