RINGS IN THE SKY WHAT COULD THEY BE ? ALIENS, UFO PORTALS, GOVERNMENT PROJECTS, OR JUST SMOKE

I've seen videos with black rings floating across the sky, some people think that they might be aliens, ufo portals, or even government projects but, none of that is the case, the solution to this mystery is simple, they are transformers blowing up, factory smoke stacks, and/or man made devices that make smoke rings