The episode is not only named for a 1953 episode of the TV show Adventures of Superman (1952), starring George Reeves, but is also named after a Superman Comic Book story also titled, "Panic In The Sky," where Brainiac is the main villain. This is intended as a nod to the viewers that the real villain behind the 8-episode "Cadmus" storyline, is not Lex Luthor, or the Government, but is actually Brainiac. (As indicated by Dwayne McDuffie, producer of Justice League Unlimited).
Flash's comment that the Batmobile lost a wheel, and the Joker got away is part of a song sung by the Joker in Batman the Animated Series.
Luthor's white button-down shirt and gray pants possibly reflect his early comics attire.
Included as a "Bruce Timm's Top Picks" bonus cartoon on the bluray release of Superman/Batman: Public Enemies (2009).
There is a brief scene where Supergirl picks up an unconscious Atom, still in a shrunken down state. In the 'Arrowverse' (an interconnected universe of live-action TV shows, also based on DC characters), The Atom/Ray Palmer is played by Brandon Routh, primarily in Arrow and DC's Legends of Tomorrow. Routh has previously played Supergirl's cousin, Superman, in the live-action movie Superman Returns (2006).