The thing about sci-fi movies is that they tend to age rather quickly. What was great special effects a few years ago quickly loses its luster with the next round of CGI updates. And movies based on theoretical hard science is often disproven soon after the movie is made (if it was, in fact, correct at the time the movie was made).

So in order to endure for nearly 60 years, a sci-fi movie has to have something else: the core of an idea that grabs hold of your brain and won’t let go. Here are ten of those movies from the 50s that still have the power to blow your mind.

Invasion of the Body Snatchers

Invasion of the Body Snatchers goes at the bottom of this list because people are jaded to the basic premise and concept, even though most haven’t seen the original masterpiece (or even the equally-good 70s remake). But the way the movie explores the concept is chilling to this day.

At the early stages of the invasion, the people who come forward seem truly hysterical because they are gripped by a deep existential terror, even when their fears should be relieved. A woman’s terror at discovering the impostor actually has what she thought was an identifying scar sends shivers down the spine.

The Day the Earth Stood Still

Another movie that has been somewhat diminished by a lackluster sequel, The Day the Earth Stood Still captures Cold War paranoia perhaps better than any other film. People are so highly suspicious “John Carpenter,” a man who has so obviously come in peace. The images of people sitting around their television sets, ignorantly taking in limited diet of news that’s parceled out will make one grateful of the Internet, despite its faults and misinformation.

It might seem hard to believe that his overtly protective gesture would get Mr. Carpenter killed, but think what fear can make people do to innocents today.

The Crawling Eye

The Crawling Eye is a creature feature that packs a surprising wallop. Between the strange and brutal deaths on the mountain, the psychic tie-ins, and the overt threats to children who you aren’t sure are going to make it, this movie hits hard for its day.

It is lacking somewhat in social critique, but if you don’t find that the story really grips you as it has many viewers, you will still be amused by the effects, which range from compelling to hilarious, but are truly unique in all of sci-fi, and may just have inspired the beholder.

It Came from Outer Space

Speaking of monocular aliens, a much better production is this Ray-Bradbury-penned alien invasion flick. The movie does a great job of building some heady suspense with judicious use of “monstervision,” a creepy soundtrack, and a host of weird happenings. And the monsters, when we see them, are truly alien, and look as if they’re decades ahead of their time with the quality of effects.

For an early sci-fi movie, this one defies a lot of conventions and has a surprising turn at the end. Oh, and you’ll get to see stars from Gilligan’s Island and The Creature from the Black Lagoon, as well as another film on this list too!

The Monolith Monsters

The Monolith Monsters is a surprising sci-fi film whose “monsters” don’t meet most typical definitions of the term. Instead, they’re towering stone colossi that grow, tumble, and then grow up again from the broken pieces. (Sounds like a typical work week, right?)

What is mindblowing about this movie is the level of menace the film bestows on these stones. They are an implacable existential threat. The film also avoids the mistake so many modern movies do: it doesn’t outwear its welcome. It’s a taut film that will leave you thinking.

Them!

The precursor to wave upon wave of giant insect movies, this one deals with weighty ideas as big as its titular ants. And speaking of the ants, the practical effects hold up fairly well today. They don’t look “real,” but they do look substantial and the acting gives them the extra ingredient that puts you on the edge of your seat.

Not only is there the raw terror of facing off with these giant insects, but there’s also the existential dread that humanity’s position as lords of the earth is tenuous at best. It makes the case that ants will take over the world better than any movie, short of 1974’s Phase IV.

The Fly

This is one movie that hasn’t been hurt by its remake. David Cronenberg’s 1986 remake is not only such high quality, but so different, that the two can coexist as separate movies. What makes this movie mindblowing is not the horrific effects–again, quite good for their day–but the question of whether life would truly be worth living if an essential part of one’s nature where taken away, and the rest were slowly slipping.

Today, we might see this as an allegory of Alzheimer’s disease or other dementia, but the 1958 movie sees it as a vision of what will happen to humanity amidst the onrushing advance of science.

Forbidden Planet

No discussion of quality 50s sci-fi is complete without reference to Forbidden Planet. And with good reason. In addition to its outstanding effects and unique electronic tonalities, this movie is based on the premise of how terrible it would be if people unleashed their darkest selves, even for just a moment.

Think that’s not a mind-blowing idea? It’s enough to sustain The Purge movies and TV series. And to make the idea even harder to swallow, the movie shows that once we let that darker self out, we may not be able to put it back in. It shows that, in some ways, that darkest self is our truest self.

The Incredible Shrinking Man

The Incredible Shrinking Man sounds like your typical sci-fi schlockfest, along the lines of Attack of the 50-Foot Woman and The Amazing Colossal Man. But there’s a reason why giantism is so much more popular than shrinking: shrinking is so much harder to take.

Long before Downsizing, The Incredible Shrinking Man shows us the horror of humanity diminishing in stature before a world that is growing just too large for us to take in. Long before the Internet, the television brought this world into our homes, exposing us a terrifying world of commies and H-bombs, wars and revolutions that we just can’t do anything about. Our inevitable disappearance is a hard fact that we still face today in looking at our chaotic world.

When Worlds Collide

Imagine scientists saw the end of the world coming. But, fortunately, it was years off, reliably predicted with mathematical precision, and humanity could avoid it. It would be expensive, but we could survive. However, instead of believing the scientists, the world pounced on some minor, perceived inconsistencies in their data. It declared the entire catastrophe to be a work of fiction, manufactured by a conspiracy of scientists to raise their prestige.

Sound a bit too close for comfort? That’s the premise of When Worlds Collide, which also tracks the tense degradation of civilization as looming catastrophe becomes too obvious to ignore. This film stars Barbara Rush, who debuted in It Came from Outer Space and became beloved of generations as a soap star. It’s a short, taut gem of a movie that will pay back a hundredfold the 83 minutes you give it.