Big bang theory season 8 episode 17
Promotional picture from The Big Bang Theory season 8 episode 17 shows Sheldon and Amy smiling and holding handsCBS

The Big Bang Theory season 8 returns with a new episode tonight, 5 March, at 8pm on CBS Network.

Episode 17 is titled The Colonization Application, where Sheldon and Amy take their relationship to a new level by adopting a turtle together.

Click here to watch the episode via live stream online on CBS Go and click here to watch the episode online.

The official synopsis reads as follows:

Trouble arises when Amy learns Sheldon has applied for a one-way mission to colonize Mars. Also, a trip to the pet store ends in a fight for Sheldon and Amy, Leonard surprises Penny with a very "adult" purchase, and, Raj is caught snooping in Emily's apartment.

According to spoilers, Amy and Sheldon announce that they are taking their relationship to the next level by adopting a pet together. While at the pet store, Sheldon announces that he is applying to be one of the first colonists on Mars, and Amy is not happy.

But a new spoiler picture has emerged showing Amy and Sheldon hugging, from which we can guess that the genius figured a way to resolve their issues.

Sheldon and Amy
Sheldon and Amy hugging in The Big Bang Theory season 8 episode 17 promotional pictureCBS

According to a report in Tvline, Sheldon and Leonard will go on a short road trip to California.

"Extending its love affair with all things Stars and Warsy, the CBS smash will be sending Leonard and Sheldon on a road trip in early April to Marin, California, home of the sprawling and heavily fortified Skywalker Ranch," said the report.

Their goal is to pay its owner, George Lucas, a house call.

Executive producer Bill Prady tweeted a first look at their trip.

Watch all the promos here: