Meet ‘Steve’: Mysterious New Purple Night Lights Discovered by Aurora Chasers
No one knew what to call the mysterious strip of purple and green light that appeared in the sky. So, it was dubbed Steve.
According to a report from the European Space Agency (ESA), its citizen astronomers were the first one to get a glimpse of the strange ribbon of light. Now, the agency's magnetic field Swarm mission has also encountered Steve and is beginning to play their part in understanding this spectacular new-found feature of the northern lights.
"In 1997 we had just one all-sky imager in North America to observe the aurora borealis from the ground," University of Calgary professor Eric Donovan explained at a recent Swarm science meeting in Canada. "Back then we would be lucky if we got one photograph a night of the aurora taken from the ground that coincides with an observation from a satellite. Now, we have many more all-sky imagers and satellite missions like Swarm so we get more than 100 a night."
Social media and citizen astronomers also play a significant role in new discoveries, especially in a phenomenon as popular as the auroras.
Donovan met with several members of a Facebook group called the Alberta Aurora Chasers. From the group's collection of photographs, the professor spotted a bizarre purple streak of light. It was referred to as a "proton arc," but Donovan knew these arcs are invisible and the purple streak must be a different phenomenon.
It was named Steve instead.
Meanwhile, Donovan and other colleagues used data from the Swarm satellites to try and figure Steve out. They managed to match a ground sighting of the lights to a glimpse from one of the satellites.
"As the satellite flew straight though Steve, data from the electric field instrument showed very clear changes," Donovan revealed.
He explained that a temperature about 300 kilometers above the planet's surface increased by about 3,000 degrees Celsius. The data also spotted a 25-kilometer-wide strip of gas moving to the west at a speed of 6 kilometers per second as opposed to the 10 meters per second at either side of it.
It turned out Steve occurs frequently, but the scientific community is only starting to recognize it as a distinct atmospheric phenomenon. Donovan told Gizmodo that he and his colleague Bea Gallardo-Lacourt are working on explaining the conditions that Steve occurs in, which they're planning on publishing.