Percival Lowell drove his construction team hard. It was 1894, and up on a high plateau in the northern part of the Arizona Territory near Flagstaff, the wealthy Bostonian was racing to complete an observatory with a 24-inch telescope. He was anxious for the completion of the observatory because the large telescope would finally allow the surface features of Mars, which would be making its closest approach to Earth in 15 years, to be distinguished. It would only be a few months that Mars would be this accessible, looming large in the night sky. After a time that seemed like eternity, the building was finally complete. Lowell excitedly turned his telescope toward the red planet. He noted Mars' polar caps and the irregular complexion of the surface. But above all, his attention was captured by what appeared to be a set of linear markings, what he perceived as a hundred "canals" covering the planet.
Lowell was not the first person to see canals on Mars and he certainly was not the last. During the two previous close approaches of Mars, a couple of Italian astronomers also observed unique features on the surface. They made note of scraggly markings that they called "canali," or channels. When American journalists caught wind of the story, they mis-translated the word as "canals". Although similar to the true translation, the word canals carried with it the inference of intelligent engineering. Upon hearing about what the Italians had seen, Lowell wanted to look for similar features, only with a more powerful telescope. Lowell subsequently repeated the observations of the Italian astronomers and news of his discovery spread quickly. Even the sober Wall Street Journal picked up the Mars fever, writing in a year-end summary of major events that, "the most extraordinary event of the year is the proof afforded by astronomical observations that conscious, intelligent life exists on Mars."
Were Lowell's observations sufficient to serve as evidence of life on Mars? Lowell himself was thoroughly convinced. He reasoned that the linear features on Mars represented formations that could not possibly have occurred naturally. Lowell concluded that an intelligent civilization inhabited Mars. He proposed that, due to a lack of water on Mars, this civilization was struggling to stay alive. Therefore, Lowell said, the Martians had constructed water canals to transport water from the frozen polar caps to the arid lower latitudes. He admitted that his new telescope did not actually have the resolution to truly see the canals themselves. The dark lines that he saw were justified as strips of lush vegetation that were cultivated by water irrigation from the canals, thereby making the canals more visible from Earth.
Born in 1855 into an aristocratic Boston family, Percival Lowell made his money in trade. After graduating from Harvard, he traveled the world and became a scholar of Asian history and culture. But his true love was astronomy. Excited about the observations made with his new telescope, Lowell wrote a book entitled Mars in 1895. In this popular book Lowell strongly and persuasively presented his case for life on Mars. He wrote: "That beings constituted physically as we are would find Mars a most uncomfortable place is pretty certain. But there is nothing in the world or beyond it to prevent, so far as we know, a fish with gills, for example, from being a most superior person. A fish doubtless imagines life outside water to be impossible; and similarly to argue that life of an order as high as our own, or higher, is impossible because of less air to breathe is to argue, not as a philosopher but as a fish."
Despite the publicity and popularity of Lowell's observations, astronomers equal in respect to Lowell disagreed with his findings. During those times, astronomical photography was rudimentary and inefficient, so the only images of Mars were laboriously drawn by hand. There were a few professional astronomers that also claimed to see the canals, but there were many more that did not. It has been rumored that colleagues of Lowell challenged his hand-drawn maps of Mars. Fellow astronomers at the observatory drew lines on a ball the size of a basketball. They then placed a small telescope at a precise distance that would replicate the resolution achieved by the 24-inch telescope focused on the real planet Mars. Lowell's colleagues then challenged him to draw a map of the "canals" drawn on the ball. Upon comparison of the ball and the map, the astronomers found absolutely no correlation between the lines that Lowell drew and the lines that were drawn on the map. Had Lowell allowed his desire to see canals on Mars to influence his observations? This instance, coupled with astronomers' own observations, caused many to speak out against Lowell. For example, the director of Lick Observatory described Lowell's writings as "misleading and unfortunate half-truths." The head of the Mars observing section of the British Astronomical Society wrote: "Had it not been for the foreknowledge that the canals are there, I would have missed at least three-quarters of them."
The next close approach of Mars to Earth was in 1910. By this time astronomers had access to better methods for capturing images of planets and larger telescopes that yielded better resolution. Images of Mars now displayed the "canals" as highly irregular and disconnected surface features. Moreover, astronomers had made further observations that suggested Mars to be too dry to support large life forms. Instead of water, the polar caps are made of carbon dioxide, more commonly known as dry ice. Alfred Wallace, the co-creator of the theory of natural selection with Charles Darwin, wrote ardently: "Not only is Mars not inhabited by intelligent beings as Mr. Lowell postulates, it is absolutely uninhabitable." Lowell had fallen victim to the power of suggestion and the dangers of allowing subjectivity to influence his scientific conclusions.
Despite the new evidence to the contrary, public belief in canals and life in Mars did not subside. Images of Mars with intricate canal systems were depicted in school science textbooks well into the 1950s. Lowell's mistake about Mars started a century of speculation about life on Mars that is especially pervasive in popular culture. The first example of this was written within three years of Lowell's book. H.G. Wells published The War of the Worlds, a memorable and influential piece of science fiction. In this work, H.G. Wells described intelligent creatures living on Mars. The civilization on Mars realizes that the canals are not enough to sustain life on the dying planet. In desperation, the Martians seek a new source of water by invading Earth with superior military technology. The result is their sickness and demise due to common terrestrial microorganisms. Stemming from Lowell's observations over a century ago and sparked by The War of the Worlds, the numbers of books, movies, songs, and other media sources have been heavily influenced by human's curiosity about life in the universe.