Lowell's observations of Mars. Percival Lowell (1855-1916) was a US astronomer who was one of the proponents of the theory that the straight lines some observers saw on Mars were canals. This theory had been prompted by an 1890 paper by the Italian astronomer Giovanni Schiaparelli, when the Italian word 'canali' (channels) was mistranslated as canals. It is now thought that these straight lines were an optical illusion. Lowell published his views in three books: Mars (1895), Mars and Its Canals (1906), and Mars As the Abode of Life (1908). These books popularized the belief that these markings showed that Mars sustained intelligent life forms.