CBS has released the first trailer for The Big Bang Theory, returning on its new night Thursday, September 27 at 8 PM ET with the Season 6 Premiere. Big changes are afoot for this nerdy band of scientists, with Sheldon (Jim Parsons) facing the possibility of losing Amy Farrah Fowler (Mayim Bialik), and Howard (Simon Helberg) venturing into outer space... although he still can't escape the piercing voice of his mother. Take a look at all the latest footage from this anticipated new Season.