It’s hard to imagine both the horror and the science fiction cinematic landscape prior to Alien’s release. It’s one of those films that so profoundly readjusted audience expectations of the genres and the way a sci-fi future was depicted that there was no going back. It was even deemed by the Library of Congress to be “culturally, historically or aesthetically significant” and is preserved in the National Film Registry. Most sci-fi or horror movies owe something to Alien, whether its Event Horizon or the recent Underwater, all feature some element you can trace back to Ridley Scott’s masterpiece. There’s a lot of reasons why it had such an impact: the grungey ‘trucker’s-in-space’ aesthetic, the class critique embedded in the story, that eerie modernist score by Jerry Goldsmith, but it was the BBFC (of all things) who were perceptive enough to understand why it was so horrifying at the time of release, and why it still has lost none of its unsettling presence.
Back in 1979 the process of film certification was a little different. For instance, the BBFC was still the Board of Film Censorship back then (as opposed to ‘Classification’ now). Their job has always been to actively assess a film and then recommend an age limit but back then they had tighter controls and could order cuts depending on the certificate the filmmakers might want. Today their powers have lessened in a lot of ways but they still dictate an age range suitable for the film under consideration.
There’s an awful lot of politics involved in the certification process. I urge you to look up the wrangles studios had with the MPAA and BBFC over films like Temple of Doom, Batman Returns and Spider-Man, all of which led to the invention of new certifications. In the UK today the main cinema ratings are U, PG, 12, 15 and 18, but back in 1979 the certificates were U, A, AA and the notorious X. U meant Unrestricted (like ‘Universal’ today) meaning it was for everyone, A meant it was not intended for anyone under 14 years old but only restricted viewing for those below the age of five, AA meant strong adult content only for those over 14, and X was restricted to 18 and over. So it was similar to today’s ratings but not as clearly defined.