Wells trained as a science teacher during the latter half of the 1880s. One of his teachers was T. H. Huxley, famous as a major advocate of Darwinism. He later taught science, and his first book was a biology textbook. He joined the scientific journal Nature as a reviewer in 1894. Much of his work is notable for making contemporary ideas of science and technology easily understandable to readers.
The scientific fascinations of the novel are established in the opening chapter where the narrator views Mars through a telescope, and Wells offers the image of the superior Martians having observed human affairs, as though watching tiny organisms through a microscope. Ironically it is microscopic Earth lifeforms that finally prove deadly to the Martian invasion force. In 1894 a French astronomer observed a 'strange light' on Mars, and published his findings in the scientific journal Nature on 2 August of that year. Wells used this observation to open the novel, imagining these lights to be the launching of the Martian cylinders towards Earth. American astronomer Percival Lowell published the book Mars in 1895 suggesting features of the planet’s surface observed through telescopes might be canals. He speculated that these might be irrigation channels constructed by a sentient life form to support existence on an arid, dying world, similar to that Wells suggests the Martians have left behind. The novel also presents ideas related to Charles Darwin's theory of natural selection, both in specific ideas discussed by the narrator, and themes explored by the story.
Wells also wrote an essay titled 'Intelligence on Mars', published in 1896 in the Saturday Review, which sets out many of the ideas for the Martians and their planet that are used almost unchanged in The War of the Worlds. In the essay he speculates about the nature of the Martian inhabitants and how their evolutionary progress might compare to humans. He also suggests that Mars, being an older world than the Earth, might have become frozen and desolate, conditions that might encourage the Martians to find another planet on which to settle.