article_snippet.sent: Scroll down for video .
article_snippet.sent: Another poster shows humans living on the surface of Mars in cities, which Frank says Frank thinks is ‘very possible’.
article_snippet.sent: Frank added: ‘I can see that happening in my lifetime.
article_snippet.sent: And I think it should.'
article_snippet.sent: If you would have told this to someone 100 years ago, you would have told this to someone 100 years ago would have thought you were out of your mind.