The Adventures of Superman (radio) home planet of Krypton is located on the far side of the sun, as opposed to a distant star system as it is in most stories. During the journey to Earth, baby Kal-el grows into an adult and emerges fully grown from his ship after it lands on Earth. He is never adopted by the Kents but immediately begins his superhero career. This was eventually retconned in later episodes to match the narrative of the comic books. This serial introduced the fictional mineral kryptonite, the radiation from which can weaken and even (in some continuities) kill Superman. Aside from giving
Superman: Doomsday entirely. Aspects of these characters were combined to form the clone Superman (Superboy was a clone, the Eradicator killed criminals, and Cyborg Superman was a villain who pretended to be the real Superman). Also, while starting up the helicopter on the "Daily Planet" roof, Lois tells Jimmy that she was an "air force brat" (while in the comics her father, General Sam Lane, was in the army). Martha Kent is depicted as a widow in the film, whereas in the comics, Jonathan Kent is alive and would possibly play a key part in bringing Superman back from the afterlife. In