Mysterious aurora named ‘Steve’ stuns NASA and scientists across globe
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Mysterious aurora named ‘Steve’ stuns NASA and scientists across globe

Most of the time, people witness splendid auroras or the Northern lights in the night sky. They look very beautiful with a mixture of different colors like blue, green pink yellow etc. Recently, a group of citizen scientists got hold of a unique type of aurora that has surprised NASA. The citizen scientists have named the newfound aurora type as STEVE. STEVE stands for Strong Thermal Emission Velocity Enhancement and it is very different from the usual auroras. It appears as a distinct purple ribbon of light along with green “picket fence” accents.

According to NASA, the STEVE aurora is unique in appearance and also occurs at lower latitudes than most of the modern lights. STEVE is an atmospheric optical phenomenon which appears as a light ribbon in the sky, formally discovered in 2017 by aurora watchers from Alberta, Canada. According to Eric Donovan’s analysis of the Swarm satellite data, it was caused by a 25 km wide ribbon of hot gases at an altitude of 450 km (280 miles), temperature of 3000 °C and flowing at a speed of 6 km/s (compared to 10 m/s outside the ribbon). The phenomenon is not rare, but nobody had looked into it in detail prior to that.

NASA now wants that general public should help it give more details about the unusual phenomenon by photographing the unique aurora. The citizen scientists are the members of a Facebook group called Alberta Aurora Chasers, and they documented the aurora-like unique light show in the night skies over western Canada.

The scientists were able to study STEVE using the European Space Agency’s Swarm magnetic field mission. They found out that this unusual type of Aurora might be occurring due to a unique type of interaction known as “sub-auroral ion drift” (S.A.I.D.) occurring between the Earth’s magnetic field and the upper atmosphere containing the charged solar particles.

Informing about the new aurora watch, Elizabeth MacDonald, a space physicist at the NASA Goddard Space Flight Center in Greenbelt, Maryland said, “Dedicated aurora chasers, especially from Alberta, Canada, were out in the middle of the night, looking north and taking beautiful photos. Then farther south they happened to see a faint narrow purple arc as well.” About S.A.I.D, MacDonald informed that the phenomenon is not new and has been studied for past 40 years but there was no visual component related to it. It is for the first time that STEVE showed the visual features of S.A.I.D phenomenon.

“This is a light display that we can observe over thousands of kilometers from the ground,” said Liz MacDonald. “It corresponds to something happening way out in space. Gathering more data points on STEVE will help us understand more about its behavior and its influence on space weather.”

“So far, with STEVE we can’t find any evidence that there are electrons coming down,” said space physicist Eric Donovan from University of Calgary. “I think it’s probably not an aurora, certainly not a traditional aurora.”

Now, NASA wants to collect more information about STEVE. A citizen science project named Aurorasaurus, funded by NASA and the U.S. National Foundation, has urged skywatchers help to get more information about the appearance, lifecycle, and implications of STEVE.

Originally the aurora watchers, members of a Facebook group called Alberta Aurora Chasers, attributed the phenomenon to a proton aurora and erroneously called them “proton arcs”, but when physics professor Eric Donovan from the University of Calgary saw the pictures, he suspected that was not the case, because proton auroras are not visible. As he correlated the time and location of the phenomenon with European Space Agency (ESA)’s Swarm satellite data, and Song Despins photo (not seen here) including GPS coordinates, the phenomenon was very clearly distinguished. More details will be published by Donovan and his team later, including the suspected cause of the phenomenon.