The inhabited-Mars hypothesis probably would have survived the cartography-to-photography transition if the photographs had shown more detail on the Martian surface. The problem for Lowell and his advocates was that the photographs did not reveal anything like a complex geometric network in their representations of Mars. After 1909, then, observers were not expected to compare their observations to a spiderweb-like map but to a mottled photograph. When the French-British astronomer Eugene Antoniadi observed Mars in 1909 at Meudon Observatory outside Paris with one of the world’s biggest telescopes, he credibly reported an absence of canals for the first time since Schiaparelli’s confirmation. [17] Claiming instead to see an intricate mess of detail that was almost impossible to sketch or represent accurately, Antoniadi submitted a map-like rendering that looked very similar to the latest photographs [fig.7].
If Antoniadi had submitted a map like this in 1903, he would not have trumped Lowell, because the visual authority of Lowell’s maps was still dominant. After those maps had been weakened, however, the detailed artistic representation available through sketching became legitimate once again. Confirmed by photography, Antoniadi’s sketches were thus very powerful in changing astronomers’ and general audiences’ opinions about the geometric or «artificial» appearance of the red planet’s surface.
Conclusions
With Antoniadi’s observations, an era of excitement and speculation over Martian inhabitants began to close. Popular belief in the canals actually persisted over several decades, with astronomy textbooks reproducing canal-maps well into the 1950s and science fiction novels and movies addressing the theme of intelligent Martians even into the present. But the active scientific debates over cartography and Martian surface geography changed considerably after Antoniadi’s 1909 map was produced. The speculation about Martian irrigation practices, the debates over Martian social organization, and the discussions about Martian global environmental control faded into the background of scientific and popular attention. The geographical themes, methods and theories that had seemed so critical for a general understanding of Mars lost their importance as the quintessential and iconic geographic format – the map – ceased to be relevant as a form of representing observational Mars data.
In this episode, we can therefore see the powerful visual and scientific role of the cartographic icon. Maps and map-images turned discussions about Mars to geographical themes, allowed data accuracy to be perceived as a visually obvious element, and became powerful indicators of Martian civilization.
