What a pleasant surprise to find this subject being debated seriously on Prpune.
I was riding the jump seat on a CO DC10-30 LAX-IAH back in the early '80s, and I listened in on a 2 hour conversation about UFOs between the three operating crew - two of whom were ex-military. Believe me, they weren't talking about mis-idents of Venus! Enough material for a book...
Think worm-holes......