It could be visually equated with abstract drawings of familiar street layouts, rail networks, and irrigation systems, thus reinforcing the certainty of artificiality, intelligence, and civilization on the red planet.

It is therefore somewhat ironic to note that the Martian landscape inscribed in the map was quite different from that which astronomers reported seeing through their telescopes. Not a single astronomer ever actually saw or claimed to see an interlinked canal network while sitting at the telescope. Mars was notoriously difficult to see, even with a good telescope, and very few of the sketches that astronomers drew in their observation logbooks or sketchpads depicted more than a few Martian surface details at any given time. It was only through the process of gathering, compiling, and cartographically projecting dozens or even hundreds of sketches onto a comprehensive map that the canal network came into being. Lowell’s influential maps of the 1890s, for instance, were made by plotting the details from hundreds of his own and his colleagues’ sketches directly onto a wooden globe, which was then tilted to the proper angle and photographed before tracing the negative into a Mercator projection. [15] Thus, very simple sketches blossomed cartographically into complex and interlinked networks that had never been seen by any single individual or on any single night.