answer:For one, UFOs are unexplained phenomena and there is no conclusive evidence confirming or denying their existance. I say that overall, it is probably best to ignore the person when he tries to tell you about UFOs. If he badgers you, then tell him “Sorry, but I’m just not interested in UFOs,” and leave it at that. Since the person has a strong opinion for UFOs, trying to dissuade him from his beliefs would likely just spark an argument that nobody would win.