I think aliens exist far away from us, and we won't have contact with any alien species in the forseeable future. Also, they're likely to be unlike anything we've ever experienced before. But yeah I'm not sure about the whole UFO thing, I think a better explanation for UFOs, if they do exist, is maybe future inhabitants of Earth (evolved on the planet from humans) with time-travel capabilities, going back for a history lesson and to experiment on their ancestors. I don't really belive it, but it would be pretty awesome if true. I also think the government made up the whole alien Area 51 thing to distract everyone from the real purpose of the base, to test out experimental military aircraft.