If this object is above the atmosphere, then it's immense, on an order of hundreds of miles across. Even if it's in the upper atmosphere, it's quite large. As to what it might be, your Out There editor won't even hazard a guess.
This is beautiful to watch, interesting colors that appear to flow and change, and it brings to mind a Stargate.
What puts me off, however, is a total lack of anything else showing up in the sky---no stars, no airplanes; nothing but this object, and no point of comparison.
The first thing I thought of, when seeing this clip, was the Aurora Borealis which, in reality, is circular shaped, plasma discharge that circles around the Northern (and Southern : Aurora Australis) hemisphere. Could this object be a form of plasma discharge caused by the activity of the Solar Wind only in a smaller scale? It does appear kind of ethereal as do the Northern and Southern Lights. Where in Russia was this seen? Was it anywhere near the Arctic circle? For detailed info about plasma discharges and electric/magnetic fields surrounding the Earth see : THUNDERBOLTS.COM/LINKS, THE ELECTRIC UNIVERSE, OR "Stars in an Electric Universe" DVD
Stars in an Electric Universe DVD by Wallace Thornhill(approx 69 minutes)
Wallace Thornhill’s outstanding lecture at the NPA 2011
Also, study the link on Plasma Physics at the same site.