STEVE

STEVE is an atmospheric optical phenomenon that appears as a ribbon of purple and green light in the night sky, distinct from the aurora though it often occurs alongside it. It was named in late 2016 by a group of aurora watchers in Alberta, Canada, who devised the backronym Strong Thermal Emission Velocity Enhancement for the name they had already been using informally. Data from the European Space Agency Swarm satellite mission showed that STEVE consists of a ribbon of hot plasma about twenty five kilometres wide at an altitude of around four hundred fifty kilometres, with a temperature of about three thousand degrees Celsius and a flow speed of about six kilometres per second. Although auroral photographers had been photographing the phenomenon for decades, it had not been investigated and described scientifically before that 2016 naming and the satellite study that followed. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/