Canals on Mars
In 1877, Mars came to a perihelic opposition just 35 million miles from Earth. That year Asaph Hall, director of the U. S. Naval Observatory, turned that institution’s 26-inch refractor telescope toward the red planet in search of satellites. In August, he discovered two small moons orbiting Mars, which he named Phobos (fear) and Deimos (flight)—these were Mars’ attendants in Homers Iliad. Hall continued his observations for several months, using the data he acquired to make an estimate of the mass of Mars. His calculation of 0.1076 times that of Earth proved to be quite accurate (the current accepted value being 0.1074).[15]
While the discovery of two Martian moons was a significant astronomical finding, it was not the only important study of the planet that year. In Italy, the director of the Milan Observatory, Virginio Schiaparelli, spent the summer observing Mars with a fairly small, 8-inch telescope. During his study, he saw what he believed to be faint linear markings on the planet. His maps of the planet showed dark areas seemingly connected by a large system of long, straight lines. Schiaparelli called these lines canali, which in Italian means “channels” or “grooves.” However, another meaning of the word is “canal,” which seemed to indicate that intelligent beings may have constructed a water transport system on Mars. Schiaparelli himself tried to caution against jumping to this conclusion, but his observations fired the public’s imagination. As a result, French astronomer Camille Flammarion was justified in stating “[Schiaparelli’s] observations have made Mars the most interesting point for us in the entire heavens.”[16]
Nearly two decades later, an American named Percival Lowell began his famed observations of Mars. A Lowell biographer wrote that “of all the men through history who have posed questions and proposed answers about Mars, [he was] the most influential and by all odds the most controversial.”[17] An amateur astronomer with a gift for mathematics, Lowell plunged into the field aspiring to complete Schiaparelli’s earlier work. Using an inherited fortune, he constructed the Lowell Observatory (which had 18-inch and 12-inch telescopes) in the Arizona mountains near Flagstaff. During the summer and fall of 1894, Lowell studied Mars every night with unbounded enthusiasm. His maps of the planet displayed 184 canals, twice as many as Schiaparelli had portrayed. As a result of his observations, he announced to the world that there were indeed canals on Mars constructed by intelligent beings. In 1895, he published Mars, within which he vividly described his theories regarding the Martian canals and their builders.[18]
During the coming years, Lowell continued his observations of Mars. With each subsequent opposition, he became increasingly convinced that intelligent beings lived on Mars and had built the canals. Lowell also postulated that the shrinking of the white polar caps and the expansion of darker regions (which he believed to be vegetation) during the Martian summer indicated seasonal renewal. Despite his grand pronouncements, most astronomers were not convinced that his theories had any merit. Their criticism of Lowell was bolstered by the fact that many other astronomers, including Edward Barnard, had studied Mars with far more powerful telescopes and found no evidence of canals. Barnard wrote “I see details where some of his canals are but they are not straight lines at all.” It is now believed that Lowell’s canals were simply optical illusions produced because the human eye attempts to arrange scattered spots into aline. Despite the eventual erosion of his theories, however, there is little doubt that Lowell’s declarations about extraterrestrial Martian life led to greatly increased public interest in the red planet.[19]