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: Doomed planet while Superman creates a new plan: use the Phantom Zone projector to seal both Earth and Brainiac's mothership in the Phantom Zone to give the heroes enough time to defeat Brainiac. Discovering the heroes' strategy, Brainiac destroys the Justice League satellite, disabling the Phantom Zone projector, and attempts to crash his mothership into the planet. Superman and Martian Manhunter push the mothership away from the planet, but Mongul and Non escape from the Phantom Zone and prepare to attack Earth. Although Mongul and Non have escaped from their Phantom Zone, Brainiac's invasion makes them quickly go back. Meanwhile, Superman