Over my long flying career, I have seen many so-called, "UFO's"… "Objects" I saw, that I thought might be "flying" and which I could not exactly "identify" what they were. (I.E. Mars on the horizon.)
Most were hilarious and would totally disappoint even the most rabid UFO fanatic. However….
As a commercial airline pilot in the early 1990's, past LAS on the descent to LAX, we switched frequencies to SOCAL approach control. We couldn't check in because of the unusual chatter. Apparently, something significant had happened, and had been reported by multiple aircraft. By the time we arrived on frequency, an ATC polling was ending as to who had seen what. Then approach polled each aircraft if they would file a report. It was: "Delta, no report." "Ah, Continental, negative." "Negative for Cactus", "no, we didn't really see anything," etc. (We felt cheated by being late.)
The following week, on the same trip, I saw the strangest thing I have ever seen, ever… physics be damned. I turned to my F/O and said, "Did you see that?" Unfortunately, he said "yes". Rather than report it – and have to go through the paperwork and incessant, "are you nuts" BS, we never said a thing.
And no, if you are not in an official capacity, will I tell to you, anymore today.