Canals on Mars

How about those canals on Mars?

I was just wondering how widespread the belief in their existence was. A 2011 article by Richard Milner in Astrobiology Magazine gives some background.

About 120 years ago, however, at least one prominent astronomer was convinced that Mars not only supported life, but was home to an advanced civilization. Martians, the theory went, had built an extensive network of canals to draw water down from supposed icecaps at the Red Planet’s poles to irrigate a world that was drying out.

Imagine really believing there were “Martians” on another planet. It’s not a particularly outlandish belief given the available information…but it seems like quite a dramatic belief.

Martian canals as depicted by Percival Lowell.Martian canals as depicted by Percival Lowell.
Credit: Public domain

These immense illusory earthworks (Marsworks?) had been studied in detail by one of the greatest astronomers of the late nineteenth and early twentieth centuries, the wealthy and socially prominent Percival Lowell.

In his day, Lowell was far and away the most influential popularizer of planetary science in America. His widely read books included “Mars” (1895), “Mars and Its Canals” (1906), and “Mars As the Abode of Life” (1908).

Lowell was not the first to believe he saw vast canals on Mars. That distinction belongs to the Italian astronomer Giovanni Schiaparelli, who in 1877 reported the appearance of certain long, thin lines he called canali, meaning channels in Italian. But he stopped short of attributing them to the work of intelligent Martians.

Channels can just happen. Canals, not so much.

Lowell carried the matter much further. Captivated by these sketchily observed — and ultimately nonexistent — phenomena, Lowell spent many years attempting to elucidate and theorize about them. The lines, he thought, must “run for thousands of miles in an unswerving direction, as far relatively as from London to Bombay, and as far actually as from Boston to San Francisco.”

He thought the Red Planet must once have been covered by lush greenery, but was now desiccated; the “canals” were an admirable attempt by intelligent and cooperative beings to save their home planet. [5 Bold Claims of Alien Life]

The Canals of Mars became one of the most intense and wrongheaded obsessions in the history of science, capturing the popular imagination through dozens of newspaper and magazine articles, as well as such classic science fiction as “The Princess of Mars,” a pulp classic by Edgar Rice Burroughs…

With us it’s Roswell and alien abductions.



  1. Pierce R. Butler says

    I just did a search of the Project Gutenberg file of A Princess of Mars.

    The word “canal” shows up exactly three times, twice preceded by “so-called” and once as “… the famous Martian waterways, or canals, so-called by our earthly astronomers.” Apparently even ERB in his early days (APoM [1917] was his first published novel) recognized some problems with the idea.

  2. Blanche Quizno says

    Christian darling C. S. Lewis used the canals-on-Mars idea in his 1938 “Out of the Silent Planet.” I wanted to like it – I really did – but I found it tedious in the extreme and, some 100 or 150 pages in, I put it down, never to pick it back up again. This was before I realized what an apologist hack Lewis was.

  3. moarscienceplz says

    One of those British science series that PBS airs told of a prize that was offered by a rich lady about 100 years ago for definitive proof of extraterrestrial life, but life on Mars was specifically excluded from winning because she thought that it was just obvious already that Martians existed.

  4. Peter Nee says

    I wouldn’t lump Lowell in with the Roswell conspiracy crowd. He did see something, and so did some others, he just trusted his own eyes too much.

    Which is not to say he was unimpeachable. Spectroscopic study of Mars showed no water vapor in the atmosphere, and the best estimates at the time of the temperature on Mars were too cold for liquid water. So other scientific data was refuting Lowell’s most romantic interpretations of what he was seeing.

    These criticisms were published by Alfred Russel Wallace as early as 1903, and were presumably ignored by Lowell. The text of Wallace’s book is online:

  5. RJW says

    In the case of earlier generations, people thought that they were visited by in incubi or succubi rather than being kidnapped by aliens. Anyone who has experienced a ‘waking dream’ and the sense of a malevolent presence, will understand the source of the delusion.

    We’re probably alone in the galaxy, if not the entire universe….possibly.

  6. says

    RJW @ #5…

    We’re definitely alone in our galaxy (barring some comparatively simple lifeforms, like bacteria and such). We may be alone in our local galactic group, too.

    But the whole universe? I would argue based on the ever-increasing size of the universe and the amount of galaxy, stars, and planets likely in it, that us being alone in the universe is extremely improbable. I should stress here that in terms of communicating and interacting with these advanced alien lifeforms, the size of the universe makes that extremely unlikely, so we are “alone” in the sense that we’ve never been visited and that will likely remain true for the foreseeable future.

    But no… we’re not alone… just isolated by natural barriers (physics, the rate of the expansion of the universe, etc) that are probably impossible to break.

  7. RJW says

    @6 NateHevens,

    Yes, the vast size of the universe seems a plausible argument in favor of life existing somewhere. Some years ago, in a radio interview, the physicist Paul Davies, suggested that, until biologists can answer the question how life first appeared on earth (and what was the probability) that argument isn’t the definitive answer.

    “But no… we’re not alone… just isolated by natural barriers (physics, the rate of the expansion of the universe, etc) that are probably impossible to break.”

    So we will probably never know.

  8. lpetrich says

    The Planet Mars: A History of Observation and Discovery. Contents. University of Arizona Press. — a very nice history, especially of astronomers’ observations of Mars in the decades around the turn of the last century.

    The canals were a big controversy back then, with some astronomers claiming to be able to observe them, and some unable to do so. Like Edward Emerson Barnard:

    I have been watching and drawing the surface of Mars. It is wonderfully full of detail. There is certainly no question about there being mountains and large greatly elevated plateaus. To save my soul I can’t believe in the canals as Schiaparelli draws them. I see details where some of his canals are, but they are not straight lines at all. When best seen these details are very irregular and broken up—that is, some of the regions of his canals; I verily believe—for all the verifications—that the canals as depicted by Schiaparelli are a fallacy and that they will be so proved before many oppositions are past.

    Percival Lowell observed canals not only on Mars, but also on Venus and Mercury (!)

    The year that Lowell recovered the spoke system on Venus, thereby going against the grain of most observers of the planet before and since, Maunder and J. E. Evans made a significant contribution to the canal debate with their paper entitled “Experiments as to the Actuality of the `Canals’ of Mars.” The paper summarizes the results of an experiment in which boys at the Royal Greenwich Hospital school were asked to reproduce a disk on which no canals had been drawn but only “minute dot-like markings.” Maunder and Evans found that when the disk was viewed from a certain distance, the boys drew “canals.”

    But Percival Lowell continued to believe in his theories, stating shortly before his death in 1916 that

    Since the theory of intelligent life on the planet was first enunciated 21 years ago, every new fact discovered has been found to be accordant with it. Not a single thing has been detected which it does not explain. This is really a remarkable record for a theory. It has, of course, met the fate of any new idea, which has both the fortune and the misfortune to be ahead of the times and has risen above it. New facts have but buttressed the old, while every year adds to the number of those who have seen the evidence for themselves.

  9. lpetrich says

    After WWII, many astronomers went into astrophysics, leaving the Solar System behind, There was a lot to discover in the stars and galaxies, and the techniques that they developed enabled them to do so. But a few kept on observing Mars, and by the early 1960’s, some astronomers had discovered that Mars’s atmosphere was super thin, with a surface pressure at most 2.5% that of the Earth’s atmosphere. Carbon dioxide had a partial pressure about 0.42% the Earth’s atmosphere’s total pressure.

    But in 1965, Mariner 4 flew by Mars and revealed — craters! From its radio signals going through Mars’s atmosphere, it was evident that Mars has a pressure about 0.4% to 0.61% that of the Earth. Then Mariners 6 and 7 in 1969, with the same low atmospheric pressures and with more craters.

    In 1971, Mariner 9 arrived there, in the middle of one of Mars’s big dust storms. It saw four mysterious marks near Mars’s equator, marks that Carl Sagan was very interested in (“The Cosmic Connection”). His colleagues named them Carl’s Marks. But as the dust settled, it became evident what the marks were: the peaks of four huge shield volcanoes, volcanoes much like the ones of Hawaii but even bigger. Mariner 9 saw lots of other things, like the huge rift valley Valles Marineris and numerous dry riverbeds. Though Mariner 9 saw the larger albedo features, it did not see *any* of the traditional canals with one or two possible exceptions. Several other spacecraft have been sent to Mars since then, and they have also failed to see the traditional canals.

  10. Blondin says

    There is a short documentary called “Universe”, made by the Canadian Film Board in 1960, that is quite interesting for a number of reasons. At one point the narrator (Douglas Rain of HAL9000 fame) tells us that changes in the surface appearance of Mars are undoubtedly due to seasonal vegetation.

    You can watch it on Youtube or at the CFB website:

  11. freemage says

    When I was a kid in the 70s, Ray Bradbury’s Martian Chronicles gulled me into believing the canals were there. But hey, I was in single digits back then.

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