I was listening to an interview with Brian Michael Bendis and I got reminded that while superhero comics are usually delegated as power fantasy, there's a lot of science-fiction elements there too. Sure, it's not by any means hard science fiction, but there's lots of room for social science fiction (i.e. X-Men) and space opera among others.
Most of Marvel Comics's heroes easily have science-based origins. Spider-Man was bitten by a radioactive spider, the X-Men due to their mutant gene, Iron Man invented his armor, etc. Marvel honestly has few magic-based heroes (unless you count villains), although it does have a pantheon of deities (Greek and Norse). DC Comics, on the other hand, had many magic-based characters in its Golden Age but shifted to science-based ones during the Silver Age (i.e. Alan Scott Green Lantern vs Hal Jordan Green Lantern). Super-powered beings in the DC Universe usually fall under one of two categories: either you're an alien, or you have a latent metahuman gene (the equivalent of Marvel's mutant gene).