The idea of life on Mars appeared at the end of the 19th century after the Italian astronomer and director of the observatory in Milan, Giovanni Virginio Schiaparelli, discovered a network of fine lines,
which he called "canals," on the planet's surface. Also on the Martian surface, Schiaparelli observed
large dark areas, which he called "oceans." Dark areas of smaller size he named "lakes," and light yellow
areas he named "continents."
The discovery of Schiaparelli attracted the attention of many astronomers. Using powerful telescopes,
they managed to discover on the Martian surface many canals that always linked seas or lakes. In 1906,
assuming that the canals on Mars did exist, American astronomer Percival Lowell put forward a theory
that attempted to explain their origin. According to this theory, the canals were built by Martians to
transport water from polar to arid areas. Schiaparelli and Lowell observed that the Martian surface
changes with the seasons and suggested that this may be related to vegetation.