Free Extraterrestrial Civilizations by Isaac Asimov Page A

really was to see, or so it seemed; for later astronomers over the next 100 years saw generally what he had seen in the way of a pattern of light and dark areas.
    By that time, though, Maxwell and Boltzmann had come out with their kinetic theory of gases, and it didn’t seem that a body with the mass and gravitational field of Mars ought to have large, open bodies of water. Even at Mars’s low temperature, water vapor must have found it too easy to escape, if the atmosphere were thinner than Earth’s. The suspicion grew, therefore, that Mars must be water poor. It had its ice caps, to be sure, and it might have its marshy and boggy regions—but open seas and oceans seemed unlikely.
    What, then, were the dark areas?
    They might be areas of vegetation, growing in the boggy regions, while the light areas were sandy desert. It was interesting that when it was summer in a particular hemisphere, and the ice cap shrank as it presumably melted, the darkened areas became more extensive as though the melting ice irrigated the soil and allowed vegetation to spread.
    Many people began to take it for granted that Mars was the abode of life.
    In the course of his observations of Mars in 1877, moreover, Schiaparelli noticed there were rather thin dark lines present on Mars, each of which connected two larger dark areas. These had been noticed back in 1869 by another Italian astronomer, Pietro Angelo Secchi (1818–1878). Secchi had called them channels, a natural name for a long thin body of water connecting two larger bodies. Schiaparelli used the same term. Both Secchi and Schiaparelli naturally used the Italian word for channels, which is
canali
.
    Schiaparelli’s
canali
were longer and thinner than those Secchi had reported seeing, and they were more numerous. Schiaparelli saw about forty of them and included them on his map, giving them the names of rivers in ancient history and mythology.
    Schiaparelli’s map and his
canali
were greeted with great interest and enthusiasm. Nobody besides Schiaparelli had seen the
canali
in the course of the 1877 observations, but afterward astronomers started looking for them in particular and some reported seeing them.
    What’s more, the word
canali
was translated into the English word
canals
. That was important. A channel is any narrow waterway, and is usually a naturally formed body of water. A canal, however, is a narrow, artificial waterway constructed (on Earth) by human beings. As soon as Englishmen and Americans began calling the
canali
canals instead of channels, they began automatically to think of them as being artificial and therefore as having been built by intelligent beings.
    At once there came to be enormous new interest in Mars. It was the first time (so it seemed) that scientific evidence had been advanced that strongly favored the existence of extraterrestrial intelligence.
    The picture created was of a planet that was older than Earth and that was slowly losing its water because of the weakness of its gravitational field. The intelligent Martians, with a longer history than ours and with a more advanced technology, faced death by desiccation.
    Heroically, they strove to keep the planet alive. They built huge canals to transport needed water from the last planetary reservoir, the ice caps. It was a very dramatic picture of an ancient race of beings, perhaps a dying species, who refused to give up and who kept their world alive by resolution and hard work. For nearly a century, this view remained popular with many people, and even with a few astronomers.
    There were astronomers who added to Schiaparelli’s reports. The American astronomer William Henry Pickering (1858–1938) reported round dark spots where canals crossed, and these were called oases. Flammarion, who was a great believer in extraterrestrial life, as I said before, was particularly enthusiastic about the canals. In 1892, he published a large book called
The Planet Mars
, in which he argued infavor of a