For instance, in John Carter of Mars, Boroughs writes about the "great white ape," something that most writers never would have thought about in an alien culture. UFO researchers have found many ape-like faces on Mars. I understand this is speculation, but the evidence is there to back up my claim. Just look at the ape faces in the photos above.
Also on Earth there is only one intelligent species...humans and their faces have very little deviation among them, but on Mars, there are dozens of species that we have identified carved in stone...just like the novel John Carter of Mars. There are many competing species in the novel, each believing itself superior to the others, going to war with one another, destroying Mars in the process.
The novel also takes place on a barren dry planet surface with almost no vegetation or water...how did boroughs know what the surface of Mars was like in 1917? Was he an alien himself or was someone close to him an alien that inspired him to write this story? For a writer to speculate about future technology is easy, but for a writer to speculate about intelligent species on other worlds...that a different ballgame altogether. Boroughs hit the nail on the head with his predictions, but how did he know? How many other facts in his novel about Mars is in John Carter of Mars? Only the future will tell. SCW