You’ve probably heard of the Northern Lights (otherwise known as the aurora borealis), but now there is an entirely new kind of light show in the sky! This new type of aurora was recently first photographed by Canadian citizen scientists, and named “STEVE” which stands for “Strong Thermal Emission Velocity Enhancement.” I think I’ll stick with calling it STEVE.  Although STEVE seems to appear during the normal aurora borealis, it is usually a beautiful purple streak with hints of green. It also has a “picket fence” structure unlike the standard oval shape, and it appears closer to the equator. STEVE also only lasts 20 minutes to an hour, while the normal aurora lasts for multiple hours.  And researchers aren’t entirely sure what causes STEVE. Measurements collected by an orbiting satellite at the same time STEVE was observed from earth showed a strong correlation with the movement of ions in the upper atmosphere. But before now these ion particle flows were never known to emit visible light, which leaves scientists wondering what sort of chemical reaction is occurring in the atmosphere to cause this unusual effect. NASA and other groups are committed to continuing to study the phenomenon, but it is difficult to get satellite data and on-the-ground observation at the same time, so collecting data may be sporadic. Discoveries like STEVE show us how much more we still have to learn about our own planet and solar system, and leaves me in awe of these natural works of art.

Want to learn more? Visit https://www.nasa.gov/feature/goddard/2018/mystery-of-purple-lights-in-sky-solved-with-help-from-citizen-scientists

March 26, 2018