The idea of life on other planets (or, in some cases, planetoids) is one that has been in the public consciousness since we knew other worlds existed. Perhaps you could say they even predate that, as myth-makers have always proposed fantastic creatures living in the remote areas of the world. It’s just that, once our own Earth had been largely explored and attention turned to outer space, the strange beings were essentially transported there. Most of the universe remains unexplored, so we don’t know yet whether alien life exists. Many people are certainly willing to accept accounts of such, however, even when they don’t make a whole lot of sense. Today, I came across something I’d meant to address before, a hoax created by the New York Sun in 1835. Editor Richard Adams Locke, through a combination of good storytelling and technical-sounding jargon, as well as dropping the name of real-life astronomer John Herschel, managed to convince people that life on the Moon had been discovered. The story was that Herschel invented a really powerful telescope that could see the Moon with incredible detail, and he came across first plants and then animals. These included small bison and one-horned goats, but perhaps the most interesting of all were the man-bats. These humanoids saw their parents gunned down in an alley behind a movie theater, and dedicated their lives and fortunes to fighting crime. Okay, maybe not, but they still captured the public imagination. What I’ve read suggests that the stories remained popular even after the hoax was revealed. As P.T. Barnum would later discover, many people WANT to be fooled, as long as the humbug is entertaining. Edgar Allan Poe was initially angry about the stories, not because he was fooled, but because he had been planning a story about life on the Moon. Eventually, however, he lightened up and recognized Locke’s writing skill.
While there was a certain amount of consideration of what conditions would be like on the Moon, for the most part these new life forms were created wholesale from the human imagination. This is generally the case with aliens, and it often seems to be the case that purported sightings of alien beings describe creatures that had appeared in science fiction. In live-action movies, the appearance of aliens was limited somewhat to what sort of costume could reasonably be created and worn, which is one reason a lot of the more popular aliens are humanoid in form. That said, it seems that people liked their aliens to be somewhat human anyway, since that presumably would make them more approachable. Speaking of which, while I haven’t seen the episode, I’ve heard that a Star Trek: The Next Generation episode credited the similarity of the main alien races to an older group of humanoids who influenced evolution so everyone would eventually look like them. Sounds like a long and complicated process, although it’s probably more likely that the writers just counted on people not understanding how evolution works.
When it comes to aliens, one trope that I’ve constantly seen mentioned is that of little green men from Mars. Why green? Well, if Wikipedia is to be believed, the term “green men” had existed in the vernacular for some time as a term to describe supernatural beings, so it’s not too surprising it came to be used for aliens. And Mars is the closest planet to us both in terms of distance and climate, so it makes sense as the origin for many early aliens in fiction and myth. Probably the most famous usage of green Martians was in Edgar Rice Burroughs’ science fiction novels, on which the recent movie John Carter was based, although his green men were giant instead of tiny.
I can’t help but suspect complementary colors also played a part, as green people on a red planet would likely be aesthetically pleasing.
Probably more popular than green men nowadays are the Greys, which are basically small humanoids with large heads, big eyes, and no ears or noses. Again, their exact origin is unknown, but Wikipedia proposes H.G. Wells and a Swedish writer named Gustav Sandgren as possible sources. Betty and Barney Hill, a couple who claimed to have seen aliens in 1961, described them as looking like our modern picture of the Greys. And for anyone whose mind works like mine, The Flintstones started in 1960, so the Rubbles couldn’t have been named after these alleged UFO viewers. On the other hand, the show’s alien character, the Great Gazoo, didn’t show up until 1965, the same year the Hills’ story started to spread in the newspapers. Of course, Gazoo was green.
The Greys are now commonly associated with the Roswell incident, and I can’t really say how that started. While the incident occurred in 1947, it wasn’t until 1978 that the idea of aliens landing there really caught on, and by then the Greys might have just been how people thought of aliens. It’s also thought that crash dummies from Roswell might have inspired some of the alien sightings.