I hate how the term "UFO" has come to mean "aliens." If you break it down... Unidentified Flying Object... you can't identify it... and it's flying... it's a UFO. Doesn't mean aliens! The likelihood that 1) aliens would ever see our planet, 2) would be able to GET here... is soooooo insanely slim... But the probability that people see objects flying that are unidentified? Pretty high. I've seen a UFO... it was really bizarre, but then it turned out to be a bush plane flying at 1 in the morning. UFO: yes. Aliens? Nooope. (Chances are, life exists elsewhere. Chances are, however, that life from elsewhere has not encountered our planet yet.)