1. "The Colonization Application"
Trouble arises when Amy learns Sheldon has applied for a one-way mission to colonize Mars and Leonard surprises Penny with a very "adult" purchase, on THE BIG BANG THEORY, Thursday, March 5 (8:00-8:31 PM, ET/PT), on the CBS Television Network. Pictured left to right: Johnny Galecki, Kaley Cuoco-Sweeting, Jim Parsons and Mayim Bialik Photo: Michael Yarish/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.