Still from video
The video, which studies the unusual phenomenon in slow motion and zoomed in segments, doesn't fit any of the usual categories for unidentified flying objects. But it's one of the coolest videos ever to hit the web.
In it, the camera is focused on a section of cloud over an unidentified locale. Suddenly, a giant smoke ring blows out the top, looking exactly as if it was blown by a cigar smoker. But it would have to be a smoker with a mouth 1000 feet wide.
Of course, only the YouTuber who posted this video is claiming this is some kind of UFO camouflage tactic. But, so far, even the channel comments are not coming up with a plausible explanation. Is it an eruption from a volcano? It seems too pristine a cloud to be a fiery volcanic belch.
So, what is it?
Here's the video:
It's not as slow mo as you might think; closer to real time actually. The smoke ring is only about 50 meters wide, and was caused by heavy artillery firing through a fog bank. The first part of the shot is edited out.