Those among us who are fascinated by celestial phenomena will probably be familiar with the aurora borealis: the fantastic displays of light in the Earth’s sky, which are mostly seen in the northern regions — hence, their other name, the northern lights. They are wonders to behold, and recently, amateur scientists in Alberta, Canada have discovered a new kind of aurora borealis that they are calling “Steve.”
Coming as a combination of solar winds, magnetic fields and electrical currents, auroras have been studied for many years. But this new type of northern lights is a bit different than usual: according to The Atlantic, aurora “Steve” features narrow ribbons of purple and green, and can been seen running east-west at latitudes closer to the equator, and appears in areas twice as high in the sky compared to regular auroras. Watch this video of ‘Steve’ via Rory Aurorasaurus:
Previous to this, not much new has been discovered in the world of auroras for the last 20 years. This time, it was a group of aurora watchers in Canada that first identified and photographed Steve, before bringing it to the attention of scientists after a symposium in 2016. The findings about Steve (which apparently also stands for “Strong Thermal Emission Velocity Enhancement”) were published in Science Advances.
The Canadian aurora chasers initially misidentified Steve as a proton arc, but as it turns out, the collaboration between these aurora enthusiasts and professional scientists helped to flesh out what Steve might really be (via Wikipedia):
According to [University of Calgary aurora researcher] Eric Donovan’s analysis of satellite data from the European Space Agency (ESA)’s Swarm mission, Steve is caused by a 25 km wide ribbon of hot gases at an altitude of 450 km (280 miles), wih a 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.
As it now stands, it appears that Steve may be a “visual artifact” of “rivers” of electrically charged particles in the upper atmosphere, known as subauroral ion drifts, which scientists previously thought were invisible to the naked eye. There’s still some debate though as to whether Steve is a true aurora, or perhaps a form of airglow, which results from the upper atmosphere releasing a tiny amount of light as it is warmed by the sun and the Earth’s surface.
It’s a fascinating story of how even regular non-scientists can help advance our knowledge and appreciation of the natural world around us, and you can read the rest over at The Atlantic and Aurorasaurus.