I have a hobby of looking through thousands of comic book covers for things that seem prophetic for the age we live in. Yes, I know it's a strange hobby, but what the heck?
The most recurring character in my studies is J'onn J'onzz, the Martian Manhunter. J'onn first showed up in the 50's, as a backup feature in Detective comics. A scientist had invented a powerful telescope that allowed him to view the surface of Mars. Somehow, the telescope transported J'onn J'onzz to Earth, and the scientist died of a heart attack. The story has now been retconned, the telescope peered through both time and space, to a time when there was life on Mars.
J'onn J'onzz was killed off in the Final Crisis event at DC comics last summer, although comic book death is never final. Don't rush out to buy Final Crisis, it's horrible.
In honor of J'onn J'onzz, here are some covers where he is portrayed.