Be sure to watch The Big Bang Theory Season 8 Episode 17 online right here via TV Fanatic to find out what happens when Amy finds out that Sheldon has applied for a one-way mission to live in a colony on Mars. Her reaction isn't a good one, but how will this affect their relationship? The couple also has a major announcement. What could that announcement be? Watch The Big Bang Theory online here to see for yourself!

Meanwhile, Leonard has a special surprise gift for Penny that he was embarrassed to give her. What is it? The gift reveals some important things about their relationship, but you'll have to watch online to find out why.

And Raj finds himself in trouble with his girlfriend when she leaves him alone in her apartment. He'll need Howard's help to get him through this one.

As always, there are plenty of hilarious moments that you won't want to miss Sheldon, Leonard, Howard, Raj, Penny, Amy, and Bernadette. So, what are you waiting for? Watch The Big Bang Theory Season 8 Episode 17 online right here via TV Fanatic to join in on all of the fun!