Supergirl goes to Mars in episode 3.03 trailer Following last night’s episode, The CW has released the first trailer for next week’s episode of Supergirl featuring the girl of steel and Martian Manhunter going to Mars! Check it out in the player below. Titled “Far From the Tree,” the new episode is set to air Monday, October 23 and is officially described as follows: “Eliza (guest star Helen Slater) throws Alex and Maggie (guest star Floriana Lima) a wedding shower, which causes Maggie to reach out to her estranged father (guest star Carlos Bernard).