It shouldn’t be a surprise that as humans stretched into the great darkness of space, it also conjured fears of what would be out there. This naturally happened in the 1940s and ’50s as space exploration became a major topic of conversation, resulting in a rise of what could be deemed alien horror.
Notable authors that bridged the idea of aliens and horror are H.P. Lovecraft and Ray Bradbury. Some of the most influential early films include The Day the Early Stood Still (1951) and The Thing from Another World (1951). But of course there were many others, from Invasion of the Saucer-Men (1957) to Planet of the Vampires (1965)
By the 1970s and ’80s we had films like the Alien and Predator franchises giving new dimensions to alien horror.