There are people who are sure they have seen UFO's and are sure they come from distant planets and are crewed by extraterrestrials. Now this topic is fascinating, when I was in high school in a very small town with only one small store that sold magazines a group of us would wait patiently every second Wednesday for the magazines to arrive. You see, there was a Mexican magazine called Contactos Extraterrestres (Extraterrestrial Contacts) which had us hooked.
We knew about every sighting that had been made during those two weeks, we knew what some of these aliens looked like, we knew about their vehicles and how they were so fast they disappeared in seconds. I believed every single one of these accounts and was just aching to be able to have a sighting. It never happened, except a few times when I was drunk, but that was probably the alcohol working.
Later I became more sophisticated and bought better quality magazines with better pictures and even better stories. I still wished to see one of these things but it never happened. Many years later when my son was maybe ten or twelve years old, it turned out he had a knack for seeing UFO's, sometimes he would yell for me and at last I got a chance to see a few of them. I remember one that crossed the whole observable sky in seconds, and another one that was huge and was apparently carrying a smaller lighted object under it.
So I finally did see a UFO, more than one actually. The thing is, where they man made or actually of non human procedence? They could be either, but now that I am older I certainly go for the more conservative view, they were simply human made flying machines that for some reason flew over our city on those particular nights.
I am just thinking about this after all the noise made over the objects downed by the USA a few days back, probably they were just balloons sent by hobbyists. Do I believe in intelligent life forms on other planets? Why not? We developed here, I see no reason for intelligent life not to develop in some other places.