answer: #Person1# and #Person2# are talking about UFOs. #Person2# believes there's life on other planets, and countries are working hard to find a planet that we can live on in the future.
documents: #Person1#: Do you believe in UFO's?
  #Person2#: Sure. A UFO is just a space vehicle from another planet. If you think about it, our space shuttles are UFOs.
  #Person1#: I've never thought about it like that before.
  #Person2#: I've seen photos of UFOs in America before, but they've all looked doctored up.
  #Person1#: Do you think that there's life on other planets?
  #Person2#: I think there must be.
  #Person1#: Why is that?
  #Person2#: I don't't think it would make sense if we were the only beings in this whole world. The world is just far too big for that.
  #Person1#: Do you think that there's intelligent life trying to contact us?
  #Person2#: No, but we're trying to contact them.
  #Person1#: I suppose you're right.
  #Person2#: I think that countries are working hard to find a planet that we can live on in the future so that when global warming destroys this planet, humankind will not become extinct.
  #Person1#: Do you really think that global warming Wil destroy Earth some day?
  #Person2#: There's a lot of evidence that suggest it will, but I don't think it's going to happen any time soon.