In 2015, a group of Northern Lights hobbyists discovered a different, purple, lightning bolt that crosses the skies from east to west when seen. Elizabeth MacDonald, a physicist at NASA’s Goddard Space Center, surprised all lovers of this phenomenon by declaring that it is a type of aurora borealis for which there were almost no bibliographic references in the scientific literature: STEVE.
STEVE is the acronym for Strong Thermal Emission Velocity Enhancement and is produced by a proton arc.
Science Advances magazine found that we are not looking at a common aurora borealis, as it is different in shape and colors. The northern lights usually appear in green, blue or reddish tones, but not purple, and their shape is usually oval, not like that of a lightning that curves, they explain from NASA. Sometimes, the northern lights (or subboreal) STEVE can present a small green region is one of its extremes.
20 years ago, when the northern lights began to be better observed and studied, it would not have been possible to obtain sharp images of the northern lights STEVE . Apparently, when it makes an appearance, it usually extends its visit between 20 minutes and an hour and appears in latitudes further south than expected (around Canada, for example). Although STEVE can also be seen in the typical boreal regions, which shows that there is a connection between both areas to be determined.
As with the other northern lights , STEVE is created as a result of the interaction of charged solar particles with the Earth’s magnetic field lines . But the discovery of this aurora borealis is proof that there are still unknown physical processes that can manifest themselves with the emission of light from the visible spectrum, for example purple.
And, as anecdotal data, after learning about the existence of STEVE and seeing that it was a very different aurora borealis, NASA asked for citizen collaboration to obtain as many images of the phenomenon as possible. The answer was immediate and STEVE is already part of the collection of images of the northern lights known as Aurorasaurus , created by NASA and the National Science Foundation.
STEVE is a phenomenon discovered almost by chance that raises new questions and can be of vital importance in the study of the interactions of the Earth’s magnetic fields with some cosmic particles.
