Thirty years ago, many researchers did not believe that the glow in the upper atmosphere existed. But in 1989, researchers at the University of Minnesota filmed the phenomenon.
A whole collection of atmospheric glow forms is now known: sprites, elves, giant jets, gnomes. These short-lived luminous phenomena appear above thunderclouds, rushing towards space, and not down to earth like ordinary lightning.
On August 14, 2017, amateur astronomer Thomas Ashcraft may have noticed a new kind of sprite. "I photographed a cluster of sprites above a thunderstorm in western Oklahoma as something curved flew up behind the main cluster." This strange shape is clearly visible in the frame cut from the video.
What it is? The experts don't have a definite answer.
Lightning researcher Oscar Van der Velde of the Technical University of Catalonia says it's a troll - a type of glow that sometimes appears under sprites, wriggling beneath the glowing clusters. “I've seen a lot of trolls,” says van der Velde, “But never so strange, wavy. This is truly an exceptional sight."
József Bohr from the Geodesic and Geophysical Research Institute in Hungary thinks it could be a kind of giant jet. Giant Jets are steroid-powered sprites, powerful and bright. “The working hypothesis is that the red sprites in the photo were the first to appear, creating a cloud of positive charge over the thundercloud. They were followed by a giant jet, also positively charged. He had to go around the cloud of positive charge on his way up."
Or it could have been something unprecedented. “Even after nearly 30 years of observing sprites, we're still finding something new,” says Walter Lyons, former president of the American Meteorological Society and longtime sprite observer. “I've seen thousands of sprites over the years, but only a few curved formations like this. Therefore, this is a rather rare phenomenon."
"I don't know what to call them," says Ashcraft, who regularly monitors the skies from his private observatory in New Mexico for strange phenomena. "But I'm going to look both ways for new phenomena."
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