By NBC News
Video of the sky lighting up over Russia's Sverdlovsk region last Friday calls to mind the enormous fireballs that fell over Chelyabinsk in early 2013 and Murmansk in April. But at least one expert seems sure that this particular phenomenon may not be celestial in origin. A meteor-watching blog quotes Marco Langbroek of the Dutch Meteor Society: "I doubt this one is a meteor." He points out that the onlookers already seemed to be aware of a red glow in the sky before the flare-up — and that when the light does appear, it's stationary. "To me, it looks like a fire or series of small explosions and subsequent large explosion or flash fire reflecting on a cloud deck," he concluded.
A local news site suggests there's an old chemical plant outside the nearby town of Rezh, the explosion of which would be consistent with this phenomenon, and one local on the forum of Astronomy.ru wrote there were also reports of the military setting off ammunition.
