Why do you think we've never made contact with aliens? Considering the magnitude and size of the universe, I'd be shocked if humans were the only intelligent life forms around (and disappointed). Is it because no intelligent life form has the technology necessary to make contact with others? Have they died out? Are we the furthest along with our evolution? Have they spotted us and determined we're not worth contact? I fear that humans will go extinct before we ever have any of these answers.