Mars. Genre While the novel is an example of science fiction, it is most closely related to the planetary romance genre. The genre is similar to sword and sorcery, but includes scientific aspects. Planetary romances mostly take place on the surface of an alien world, frequently include sword fighting, monsters, supernatural elements such as telepathic abilities (as opposed to magic), and civilizations similar to Earth in pre-technological eras, particularly with the inclusion of kingdoms, empires or religious societies. Spacecraft may appear, but are not central to the story (something which makes these tales distinct from Space Opera, where spaceships are usually a key focus of the narrative). There were some Planetary Romances prior to the publication of the Barsoom novels, but A Princess of Mars and The Gods of Mars and other novels in the Barsoom series were the most influential on the numerous similar stories that were published subsequently. Setting Scientific basis Burroughs's vision of Mars was loosely inspired by astronomical speculation of the time, especially that of Percival Lowell, who saw the planet as a formerly Earthlike world now becoming less hospitable to life due to its advanced age, whose inhabitants had built canals to bring water from the polar caps to irrigate the remaining arable land. Lowell was influenced by Italian astronomer, Giovanni Virginio Schiaparelli, who in 1878, had observed features on Mars he called canali (Italian for "channels"). Mistranslation of this into English as "canals" fuelled belief the planet was inhabited. The theory of an inhabited planet with flowing water was disproved by data provided by Russian and American probes such as the two Viking missions which found a dead, frozen world where water does not exist in a fluid state. The Valley of Dor, with the ring of cliffs around it and Sea of Korus within it, is placed in a mile-deep crater at Mars' South Pole. However, Burroughs makes a mistake in that he has the sun rise in the east and set in the west as elsewhere in the planet, and the moons are visible from the Valley. In reality, at the South Pole, Mars' moons would not be seen, and the sun would not rise in the east and set in the west (all directions away from the Pole are "north" in any case), but instead ring the cliffs for half the Martian year, and leave the area shrouded in darkness for