It was the decade that gave the world the maverick New Hollywood drama, the Nixon-era paranoid thriller, the slasher flick, the all-star disaster movie, the gross-out comedy and the modern mega-blockbuster. But the Seventies were particularly kind to one specific cul-de-sac of cinema: the science fiction film, a subset category that was still buzzing from its late-Sixties head-trip phase courtesy of 2001: A Space Odyssey. As the Age of Aquarius slowly slid into the beginning of the nation’s Watergate-and-disco period, you could still find sci-fi movies that wanted to blow an audience’s possibly addled, probably enhanced mind. But by the end of the 1970s, it was possible to have checked out postapocalyptic action-adventures, future-shock case studies, technophobic nightmares, low-budget exploitation movies about what-if scenarios and big-budget space operas — all of which fell under the S.F. umbrella and helped turn the genre into a gamechanger. And the influences of this period are still showing up in theaters near you.

So, in honor of the 10-year-period that made science-fiction filmmaking what it is today, we are counting down the 50 best sci-fi movies of the 1970s. Some of them belong in the greatest-of-all-time canon; others, we will fully admit, are the cinematic equivalent of a ripe Camembert. But each of these helped the decade redefine where science fiction could go on the big screen, whether it was in a grungy grindhouse or a state-of-the-art multiplex. This is where the genre genuinely started to boldly go where it had never gone before.