The gun that Alex uses to shoot the alien and save J'onn was drawn by Chyler's 13 year old son, Noah, who drew it, showed his mum, Chyler, and said "I think Alex should have a gun like this." Chyler tried very hard to get that gun in an episode, and her line "have I mentioned how much I love my new gun?" was dedicated to her son.
The end credits featured a nod to the movie that came out before the airing of the episode, The Lego Batman Movie.
Armek appears in the first storyline of the JLA comic written by Grant Morrison
The movie that Kara is watching by herself at the end of the show is from Auntie Mame (1958)
The title of this episode "The Martian Chronicles" is also the title of a Ray Bradbury a collection of short stories published in 1950, and a TV miniseries (3 episodes) which first aired in 1980.