In space no one can hear you scream. It’s an iconic tagline, and a perfect summary of what makes Alien so terrifying. The film takes the final frontier that is space, a place of inspiration, aspiration and wonder, and makes it a place of fear. Using cinematography and settings of both space and ship, the film plays with themes of isolation, claustrophobia, and agoraphobia. At the same time, the creature design and plot carry significant overtones of sexual assault. Together these are a truly horrifying experience. It taps into some of our most primal fears and lets them play out in a futuristic setting. It stands the test of time for exactly this reason, it spans human existence. The fears used were there when humans were painting in caves, and they’ll be there when we’re exploring the stars.