by Katelynn Fleming
You may be familiar with the aurora borealis, the mesmerizing northern lights, named after the Roman goddess of the dawn, Aurora, and the Greek god of the north wind, Boreas. However, you probably have not heard of a more recently discovered northern light with a much more modern name: Steve.
Steve is an atypical northern light in that it occurs south of the normal boundaries of the aurora borealis. It was discovered and documented by amateur sky-watchers, and its story gained popularity through the Alberta Aurora Chasers Facebook group. Some of the group’s members attended a lecture by NASA aurora borealis expert Dr. Elizabeth MacDonald, and afterward showed their photographs to her and Dr. Eric Donovan, a physics and astronomy professor at the University of Calgary.
According to Science Advances magazine, the northern lights are generated by interactions between the Earth’s magnetic field and the solar wind, a stream of charged particles that the sun emits into the solar system. The charged particles flowing into the magnetic field cause a current of ionized atmospheric gas particles, which then release radiation in the form of visible light that seems to wave through the night sky near the northern and southern poles.
Steve travels through the upper atmosphere at approximately four miles per second and reaches temperatures around 10,080 degrees fahrenheit, which is comparable to the Earth’s core. It is about 16 miles wide, runs the breadth of Canada from East to West and can last in the sky for anywhere from 20 minutes to an hour at a time. Steve normally appears as a light, near-white streak in the sky, but long exposures and increased color saturation have allowed for pictures that capture the majestic purples and greens of Steve in all its glory.
Donovan and MacDonald realized that Steve did not fit into any of the previously known types of aurora borealis, so they collected data from the European Space Agency’s satellite network, Swarm. They were able to track Steve in July 2015 using Swarm’s magnetosphere monitoring system and found that Steve is similar to a sub-auroral ion drift. Although they had narrowed down the type of aurora, and thus could rename the phenomenon, it seemed that “Steve” had really caught on. So as not to lose the appeal, they used a “backronym” or a retroactive acronym, and renamed him “Strong Thermal Emission Velocity Enhancement,” which luckily, can still be shortened to Steve.
Although Steve is now better understood, we still have a long way to go to understand why it happens where it does. Last week, NASA launched an initiative called Aurorasaurus to gather civilian observations of Steve. The global network of observers is made possible by recent advances in technology which have led to publicly available cameras with near-scientific grade resolutions.
Steve, discovered by amateurs and advanced with their observations, is just one more example of how technology is helping make science accessible to everyone. Kayla Rockhill (‘21) remarks, “Steve inspires amateur astronomers because it shows that we, too, can make fascinating discoveries.”