Lonely Planet Writer

The mystery of Steve the purple celestial light has been solved by scientists

For the past three years, reports of a mysterious new light show in the night sky have been puzzling scientists. The phenomenon is a thin strip of purple light that looks almost like a picket fence and appears for between twenty minutes and an hour.

STEVE
STEVE (Strong Thermal Emission Velocity Enhancement) and the Milky Way at Childs Lake, Manitoba, Canada. Photo courtesy of Krista Trinder

Now, the mystery has been solved by a team of amateur astronomers working in collaboration with scientists at NASA’s Space Flight Center and the University of Calgary in Canada.

Between 2015 and 2016, around thirty reports of the mysterious lights were shared on online forums with a group of scientists working on what is called the Aurorasaurus project. The project tracks the Earth’s auroras through tweets along with online reports and photographs from stargazers around the world.

The purple light show was given the rather odd nickname of Steve. After the first reports, giant ground-based cameras called all-sky cameras and space satellites began to film it for closer study. The phenomenon is not a normal aurora, which are generally oval, last hours and flicker in shades of green, blue and red.

‘Steve’ on the other hand is purple with a distinctive structure that waves; it also appears to have a beginning and end unlike regular auroras. They are, however, all created in generally the same way with charged particles from the Sun interacting with the magnetic field lines of the Earth.

‘Steve’ travels along different magnetic field lines and is also visible at much lower latitudes than the Northern Lights, which is why there were quite a few sightings in southern Canada.

NASA Space scientist Liz McDonald said the Aurorasaurus team are still looking for sky gazers to send in their pictures and reports. “Gathering more data points on STEVE will help us understand more about its behaviour and its influence on space weather,” she said.

The purple light has also retained its nickname ‘STEVE’, although it has now been capitalised and given a rather more scientific slant … the Strong Thermal Emission Velocity Enhancement.

If you do happen to see it on your travels or in your area, you can submit your pictures to NASA or find out how to spot it.