I like the Terence McKenna approach. Psilocybin mushrooms spores can survive in outer space. They wafted about the space-ways and made their way to earth, in part to HIP us humans to "what is."
I grant you that Terence was a crackpot, but before you condemn him, try eating (at least) 5 dried grams of 'shrooms, then make up your mind...