It’s exciting and beautiful when the sun steals the show in the night sky. It’s also rare for the aurora borealis to be visible as far south as Wyoming, but the cowboy state has been treated to several of these unique events so far this year.
In the early morning hours. Tuesday, Wyomingites were treated to a spectacular showing of the aurora with its bright greens and streaks of purple. Thanks to a new cycle of solar energy, there have been several similar episodes like this in the last several months, a rare treat for a region so far south of the North Pole.
And those who missed it may get an encore early Wednesday morning, but probably not as intense as Tuesdays, the University of Alaska Geophysical Institute reports.
Marilyn Schmoker hasn’t missed any of the light shows this year. She has a special spot a few miles from her home in Newcastle where she goes in anticipation of a good showing of the aurora borealis.
Even by the high standards set by other sightings, this latest one was exceptional.
“There were two STEVES in it and a lot of streaking,” she told Cowboy State Daily.
STEVE stands for strong thermal emission velocity enhancement. It’s an atmospheric glow triggered by the interaction of solar plasma with Earth's atmosphere and magnetosphere. While related to the aurora borealis, STEVE is a much rarer sight.
The phenomenon contributed to the distinct streaks Schmoker captured in her photos, and she said she didn’t have to get up or stay late for this showing.
“I went out just after dark, and it was pretty much through by 10 p.m.(Monday),” she said. “Some of the other ones (this year), I was out around 11 p.m. to 1:30 a.m.”
Finicky But Fabulous
Cowboy State Daily meteorologist Don Day said an aurora borealis isn’t dependent on temperature or season. It’s the interaction between energy from the sun and the Earth’s atmosphere.
“When it ended up being in the path of a coronal mass ejection (CME), a solar flare directed toward Earth,” he said. “We ended up being in the path of one last night. You need a fairly strong one to get as far south as Wyoming, which last night’s was.”
The sun entered a new solar cycle recently, which has led to several episodes of the aurora in Wyoming this year. It’s lucky that there have been so many good showings, especially since there’s no reliable way to predict how good everything will look once it arrives, Day said.
“These things are really, really finicky,” he said. “A lot of times, they’ll be forecasted, and they’re a dud. Other times, they’re not very well forecasted, or you’ll get auroras that no one really expected. It’s not an exact science to nail these things down.”
The unpredictability of the aurora borealis in Wyoming makes it a must-see event. There may be little warning before the next one, and the conditions must be precise for a good showing. After all, each CME travels 93 million miles from the sun to Earth while both bodies move through space.
“Everything’s moving,” he said. “It’s not a straight line. You have to figure out all the physics to see if the solar flare action is going to hit the Earth at night when you can see it while the Earth is rotating around the sun. It’s very difficult to have everything lined up.”
Even Day agreed that the latest display was especially good.
Schmoker was delighted with the show, but each is different, she said.That keeps motivating her to step out with her camera whenever there’s word that the aurora borealis could be visible.
“They’re always different in the color and formation, so it’s fun to go out and see what it’s going to be,” she said.
One More Night?
The Sun’s latest CME is still in Earth’s vicinity. Day said there might be another chance to see the aurora borealis in Wyoming overnight Tuesday and early Wednesday. There could also be nothing to see and for a while longer.
“Tonight, there could be Aurora again,” he said Tuesday. “Or they may have peaked last night. And by tomorrow night, they’ll be done because the impact of the Sun will have worked its way through. It’s not an exact science.”