A video of the Prez boarding Air Force One is, pardon the phrase, blowing up on the Internet and it's exposed a bizarre UFO situation.

Watch and try to explain what the hell is flying on top of Trump's head. There's always been a buzz about combovers in the front of his 'do -- but this video, shot earlier this month, proves there's more action 'round back.

Trump has long insisted he does NOT wear a wig, or any hairpiece, but the stiff breeze seemed to temporarily remove ALL the hair from the back of his head.