It s well known that in 1888, Italian Giovanni Schiaparelli announced finding a network of narrow lines on Mars, which he described as "canali," which a lot of English speakers including American Astronomer Percival Lowell took to mean "canals" and assumed were created by intelligent beings. Others point out that the word can as well mean "channels," and even in English "canal" need not mean an artificially built thing.

But Schiaparelli lived until 1910 and there was a huge fuss about these canals and as far as I can find on line there is no record at all of any response by Schiaparelli.

Does anyone here know of a response by Schiaparelli? Did he ever clarify whether he thought these "canali" could have been created by intelligent beings?


I've found a place where he says that they did not need to be created by intelligent beings. That's something.

The source is Schiaparelli's book La Vita Sul Pianeta Marte (The Life on the Planet Mars), published in 1893.

Near the middle (in Part IV), he writes

Che del resto le linee dette _canali_siano veramente grandi solchi o depressioni delle superficie del pianeta destinate al passaggio di masse liquide, e costituiscano su di esso un vero sistema idrografico, è dimostrato dai fenomeni che in quelli si osservano durante lo struggersi delle nevi boreali. Già dicemmo che queste, nello sciogliersi appaiono circondate da una zona oscura, formante una specie di mare temporario. In tale epoca i canali delle regioni circostanti si fanno più neri e più larghi, ingrossando al punto da ridurre, in un certo momento, ad isole di poca estensione tutto le aree gialle comprese fra l'orlo della neve e il 60° parallelo nord. Tale stato di cose non cessa, se non quando le nevi, ridotte ormai al loro minimo di estensione, cessano di struggersi. Si attenuano allora le larghezze dei canali, scompare il mare temporario, e le aree gialle riprendono l'estensione primitiva. Le diverse fasi di questa grandiosa operazione si rinnovano ad ogni giro di stagioni ed i loro particolari si son potuti osservare con molta evidenza nelle opposizioni 1882, 1884, 1886, quando il pianeta presentava allo spettatore terrestre il suo polo boreale. L'interpretazione più naturale e più semplice è quella che abbiam riferito, di una grande inondazione prodotta dallo squagliarsi delle nevi; essa è interamente logica, e sostenuta da evidenti analogie con fenomeni terrestri. Concludiamo pertanto, che i canali son tali di fatto, e non solo di nome. La rete da essi formata probabilmente fu determinata in origine dallo stato geologico del pianeta, e si è venuta lentamente elaborando nel corso dei secoli. Non occorre suppor qui l'opera di esseri intelligenti; e malgrado l'apparenza quasi geometrica di tutto il loro sistema, per ora incliniamo a credere che essi siano prodotti dell'evoluzione del pianeta, appunto come sulla Terra il canale della Manica e quello di Mozambico.

I don't know Italian, but Google Translate seems to work reasonably well. It gives me (emphasis mine)

That the rest of the lines called "canali" [channels] are really great grooves or depressions of the surface of the planet destined to the passage of liquid masses, and constitute about it a real river system, is demonstrated by the phenomena which are observed during those pining snow borealis. We have said that these, in the melt appear surrounded by a dark area, forming a kind of temporary sea. At that time the channels of the surrounding regions are more blacks and wider, swelling to the point of reducing, at a certain moment, to the islands of little extension all the yellow areas ranging from the edge of the snow and the 60th parallel north. This situation does not cease, except when the snows, now reduced to their minimum extension, cease to droop. Then the widths of the channels are reduced, the temporary sea disappears, and yellow areas resume the primitive extension. The different phases of this great operation are renewed with every turn of the seasons and we were able to observe this phenomenon with much evidence during opposition in 1882, 1884, 1886, when the planet showed to the terrestrial viewer its north pole. The most natural and simplest interpretation is the one that we have reported, a great flood produced by melting snow; it is entirely logical, and supported by clear similarities with terrestrial phenomena. We conclude therefore, that the channels are such in fact, and not only in name. The network formed by them was probably determined in origin by the geological state of the planet, and it slowly developed over the centuries. There is no need to suppose here the work of intelligent beings; and despite the almost geometric appearance of the whole system, up to now we are inclined to believe that they are the product of the evolution of the planet, just as on Earth the English Channel and the Mozambique.

This appears to have been before Lowell got started, which means that Schaparelli saw this debate coming, and did his best to make it clear that he did not think that these features were created by intelligent beings.

  • $\begingroup$ Yes, this appeared well after Lowell was convinced the canali were intelligently built but before he had observations to report. He built Lowell Observatory in Flagstaff, Arizona, to observe Mars in the opposition of 1894 so as to prove the idea. He probably alluded to this publicly before his book Mars in 1895 but that book made his case very public. $\endgroup$ – Colin McLarty Feb 1 '15 at 1:43
  • $\begingroup$ @ColinMcLarty I haven't been able to find anything post-Lowell's-book. Do you want me to try to dig up something like that? $\endgroup$ – HDE 226868 Feb 1 '15 at 1:44
  • $\begingroup$ That would be great, but I think this is enough. Do you want to add this to the Wikipedia article en.wikipedia.org/wiki/Martian_canal#Controversy of should I? $\endgroup$ – Colin McLarty Feb 1 '15 at 1:47
  • $\begingroup$ @ColinMcLarty I actually don't edit Wikipedia, so you can, if you want. $\endgroup$ – HDE 226868 Feb 1 '15 at 1:48

Schiaparelli, unlike Lowell, was cautious not to declare that his canali were artificially made, but he was sympathetic to the possibility. In an article of 1893 he wrote "Their singular aspect, and their being drawn with absolute geometrical precision, as if they were the work of rule or compass, has led some to see in them the work of intelligent beings... I am very careful not to combat this supposition, which includes nothing impossible."

But Schiaparelli firmly believed that they were bodies of water despite some indications to the contrary. His preferred theory was that they were natural (and his preferred translation of "canali" into English probably would have been "channels"): "[W]e are inclined to believe them to be produced by an evolution of the planet, just as on the Earth we have the English Channel and the Channel of Mozambique." Accordingly, he named them after famous rivers: Gehon, Hiddekel, and Phison from Eden, Lethes and Nepenthes from Hades, and even some real ones, Ganges, Euphrates, and Nilus.

Schiaparelli was later similarly biased in favor of habitability of Mercury. But it is interesting that he was more cautious after originally observing the canali and the "seas" during the Mars opposition of 1877, and disclaimed that "these names may be regarded as a mere artifice... After all, we speak in a similar way of the seas of the Moon, knowing very well that they do not consist of liquid masses." Only after the subsequent opposition of 1879 when one of the bright areas darkened, which Schiaparelli interpreted as flooding, did he become convinced and wrote "It is [as] impossible to doubt their existence as that of the Rhine on the surface of the Earth." In 1888 Schiaparelli published the most detailed map of Mars to date, which included the canali, and remained in use until 1960-s.

However, Schiaparelli's late years were brutal to his signature discovery. In 1892 Pickering saw his "lakes" dissociate into clusters of dark dots, in 1903 experiments involving schoolboys demonstrated that the canali too could arise as an optical illusion, in 1907 Wallace pointed out that spectroscopic analysis detected no traces of water vapor in the Martian atmosphere, and finally in 1909 high quality photos taken at Pic du Midi observatory showed no channels. But by then the idea of Martians and their canali was already firmly entrenched in the popular culture.

P.S. Since it's HSM I'll point out off topic that Schiaparelli was also deeply interested in the history of ancient astronomy. In 1877 he published a reconstruction of the first geometric astronomical model of Eudoxian homocentric spheres based on very scant mentions in only two sources. It remains the consensus to this day.


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