answer: #Person1# shares the news with #Person2# that Pluto was not a planet anymore. Then they start to talk about space and the cosmos and hope to live in an interplanetary society one day.
documents: #Person1#: Guess what! I know something you don't know! 
  #Person2#: What's that? 
  #Person1#: How many planets are there in the solar system? 
  #Person2#: That's easy. Everyone knows that there are nine. 
  #Person1#: Not anymore! Can you believe it? They've decided that Pluto is not a planet anymore! 
  #Person2#: Nice try. I wasn't born yesterday, you know. 
  #Person1#: I'm dead serious. They've decided that it's too small to be a planet, but actually they haven't yet agreed on how big something has to be in order to be a planet anymore. 
  #Person2#: That sounds crazy. But they can't just change their mind about things like that. 
  #Person1#: Yes, they can. If you remember correctly, people used to believe that the world was flat. 
  #Person2#: I suppose you're right. They also used to think that they were so important that the sun revolved around them, not the other way around. 
  #Person1#: We actually know relatively little about space and the cosmos. 
  #Person2#: Do you think that we'll one day be able to travel to another planet for a vacation? 
  #Person1#: I suppose we could actually live on a planet outside of the milky way. 
  #Person2#: Do you think we'll ever get to meet an alien from outer space? 
  #Person1#: I hope not. I think they would be a threat to those of us that lived on the Earth. 
  #Person2#: You're so old-fashioned. That's what people used to think about people from another country! 
  #Person1#: Point taken. Hopefully one day, we'll live in an interplanetary society.