When Ridley Scott gave movie fans 1979's Alien, he kickstarted the craze for extraterrestrials on the big screen. Indeed, the '80s marked the decade when we began seeing way more aliens in movies.

With a timeline as knotty as a Xenomorph's biomechanical skeleton, it's not the easiest thing in the world to work out how to watch the Alien movies in order. Alien: Earth's first season wrapped up ...