And now an uglier, less twinkly side of the little stars. First up, aliens. Despite our endless fascination with them, Tim Ferris, author of Coming of Age in the Milky Way , will tell us how unlikely it is that we'll ever encounter life in the universe. There's just too much distance and time floating around out there. An idea which makes us suddenly scratch our heads and ask, what is space, anyways? We talk to physicist and mathematician Brian Greene , author of The Elegant Universe to try and sort it all out. And then, to really put things in perspective, we'll see how big space looks when compared to the tiny little spec that is you, or me, us humans. When Copernicus shifted the center of all creation from this planet to the sun, he set a chain of events in motion. Neil deGrasse Tyson tells us about the Copernican Principle, which says, if you think it's all about you then you are probably wrong.