The Mysterious Purple Light

Citizen science is scientific research conducted, in whole or in part, by amateur scientists. One such citizen scientist is Notanee Bourassa. Since the last 30 years, he has observed and photographed auroras in the sky.

On the night of July 25, 2016, he took his two children also with him for showing them how auroras look. All of a sudden, a thin purple ribbon of light appeared and starting glowing. Bourassa quickly snapped the pictures. But his experience made him understand that this was’nt an aurora. It was something else. He shared the pictures that he took with online forums and with a team of scientists that run a project called Aurorasaurus.

The team started investigating about this mysterious light using all the evidences that they received from Bourassa and from other sources. They temporarily named this light as “Steve”. The team realised that Steve may help them to a great extent in understanding how Earth’s magnetic fields work. They found that Steve is not a usual aurora. It is different in shape and colour from the general aurora. The most unique feature about it is that it travels along different magnetic field lines than the aurora. Steve appeared at much lower latitudes meaning that charged particles that create Steve connect to magnetic field lines that are closer to Earth's equator. Also, it has been revealed that Steve comprises a fast moving stream of extremely hot particles called a sub auroral ion drift, or SAID.

The team inferred that knowing more about Steve is crucial because of its location in the sub auroral zone; Steve might be the only visual clue that exists to show a chemical or physical connection between the higher latitude auroral zone and lower latitude sub auroral zone. The scientists hope that together with the team of researchers, they will be able to soon unravel the mystery behind this. By then, this mysterious light shall be addressed with the same name, but now it will be STEVE, short for Strong Thermal Emission Velocity Enhancement.

By: Anuja Arora

Content: https://www.sciencedaily.com/releases/2018/03/180314144930.htm