The English astronomer Richard A. Proctor was already a well-known populariser of science when he published Other Worlds Than Ours in 1870, joining a ferocious debate about the possibility of life on other planets in which Whewell (1853) and Brewster (1854) had also participated. Taking his cue from the seventeenth-century French astronomer Fontenelle’s classic book The Plurality of Worlds, Proctor discusses Victorian discoveries about the solar system and describes what was then known about each of the planets. He evaluates the habitability of Mars, Jupiter, Mercury, Venus and Saturn in the light of his belief in the possibility of extraterrestrial life. The text includes many illustrations of the planets, a spectacular map of Mars, and theoretical views of the Milky Way. Influenced by Darwin, Proctor had a teleological view of the universe and believed that eventually the cosmos would be filled with living things.