(CBS) – Koothrappali is worried people won’t take him seriously in his own field after publishing a paper that suggests he may have discovered alien life on an all-new episode of The Big Bang Theory, tonight at 8:00 PM ET/PT, only on CBS. Also on tonight’s episode Penny encourages Leonard to stand up for himself when he strives to be the principal investigator on a plasma physics study.

There are only four episodes left until The Big Bang Theory finale on May 16th, catch up on episodes on demand with CBS All Access and be sure to tune in tonight at 8:00 PM ET/PT, only on CBS.