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 vs. Muhammad Ali as the obvious choice. Intrigued, Rat'Lar decides that Superman and Ali should fight one another to see who really is Earth's champion. To make the fight fair, he decrees that the match should take place on his home planet, Bodace, which orbits a red star (which temporarily robs Superman of his powers). The winner would simply be the best boxer. The two would-be champions decide that Ali will train Superman in the finer points of boxing. They journey to Superman's Fortress of Solitude to have his powers temporarily deactivated, and to use a time warping device to extend Rat'Lar's 24-hour