At the beginning of this year, the scientists found themselves puzzled by a mysterious aurora dubbed as Steve (Strong Thermal Emission Velocity Enhancement), which presented some unique features in comparison to the common auroras. But a new study conducted by the researchers from the Universtiy of Calgary, also involved in the research carried out earlier this year, found that the mysterious Steve is not an aurora.
Commonly, auroras occur when particles hit the magnetic field of the Earth charging the atmospheric molecules and atoms which radiate light. At its turn, Steve phenomenon, although it’s similar in appearance to auroras, is not an aurora, the new study concludes.
“The aurora you see in the sky, at least from our data, is moving at a certain speed, and then you have [Steve] moving crazy fast at lower latitudes, passing from east to west, super narrow, almost like a comet,” explained Bea Gallardo-Lacourt from the University of Calgary and the study’s leading author.
According to Eric Donovan, a professor of physics and astronomy at the University of Calgary, he knew since the beginning that Steve is not an aurora. However, he said the scientists are still struggling to find out what Steve is.
Steve is not an aurora – Then what is it?
“With Steve what’s happening is we can’t find evidence of that particle precipitation, so it seems like the energy that’s causing the light is coming from somewhere else,” added Eric Donovan.
The mysterious phenomenon known as Steve is under scientists’ focus for a long time, but it became thoroughly researched only in 2016. Since then, many researchers came up with different theories, but none proved correct.
However, the new study carried out by the Universtiy of Calgary analyzed Steve using the All-Sky Imagers, the so-called Canadian sky cameras, and the National Oceanic and Atmospheric Administration’s Polar-orbiting Environmental Satellites’ particle detectors. They revealed that Steve is not forming in the same way as regular auroras do.
Thus, according to the scientists, the mysterious aurora known as Steve is not an aurora, but it might be a new and yet unknown phenomenon in the ionosphere, its glow being given by a different mechanism than auroras.