20 Mind-Blowing Facts You Didn't Know About Superman

17. ...And It Took Years For It To Make It Into Them

It wasn't until six years after that radio show that Kryptonite found its way into the comics, and it's remained a constant threat to Superman ever since. However, the substance's early origins can actually be traced back to 1940 in a script which predates The Meteor From Krypton. Jerry Siegel penned a story which featured the Man of Steel coming across the mysterious K-Metal from his homeworld. This had the ability to rob Superman of his powers, and the only way he could save Lois Lane was by revealing his identity to her. The publisher's wouldn't allow that, and it took nine years for it to be reintroduced.