Jump to content
 







Main menu
   


Navigation  



Main page
Contents
Current events
Random article
About Wikipedia
Contact us
Donate
 




Contribute  



Help
Learn to edit
Community portal
Recent changes
Upload file
 








Search  

































Create account

Log in
 









Create account
 Log in
 




Pages for logged out editors learn more  



Contributions
Talk
 



















Contents

   



(Top)
 


1 Supposed "discoveries"  





2 Interpretation as engineering works  





3 Contemporary doubts and definitive debunk  





4 In popular culture  





5 See also  





6 References  





7 External links  














Martian canals







Català
Deutsch
Español
Français
Gaeilge

Հայերեն
Bahasa Indonesia
Italiano
Lëtzebuergesch
Lietuvių

Nederlands

Polski
Português
Română
Русский
Srpskohrvatski / српскохрватски
Suomi
Svenska

Українська
Tiếng Vit

 

Edit links
 









Article
Talk
 

















Read
Edit
View history
 








Tools
   


Actions  



Read
Edit
View history
 




General  



What links here
Related changes
Upload file
Special pages
Permanent link
Page information
Cite this page
Get shortened URL
Download QR code
Wikidata item
 




Print/export  



Download as PDF
Printable version
 




In other projects  



Wikimedia Commons
 
















Appearance
   

 






From Wikipedia, the free encyclopedia
 


A 1962 map of Mars published by the U.S. Aeronautical Chart and Information Center, showing canals snaking through the Martian landscape. At the time, the existence of the canals was still highly controversial as no close-up pictures of Mars had been taken (until Mariner 4's flyby in 1965).

During the late 19th and early 20th centuries, it was erroneously believed that there were "canals" on the planet Mars. These were a network of long straight lines in the equatorial regions from 60° north to 60° south latitude on Mars, observed by astronomers using early telescopes without photography.

They were first described by the Italian astronomer Giovanni Schiaparelli during the opposition of 1877, and attested to by later observers. Schiaparelli called these canali ("channels"), which was mis-translated into English as "canals". The Irish astronomer Charles E. Burton made some of the earliest drawings of straight-line features on Mars, although his drawings did not match Schiaparelli's.

Around the turn of the century there was even speculation that they were engineering works, irrigation canals constructed by a civilization of intelligent aliens indigenous to Mars. By the early 20th century, improved astronomical observations revealed the "canals" to be an optical illusion, and modern high-resolution mapping of the Martian surface by spacecraft shows no such features.

Supposed "discoveries"[edit]

1877 map of Mars by Giovanni Schiaparelli

The Italian word canale (plural canali) can mean "canal", "channel", "duct" or "gully".[1] The first person to use the word canale in connection with Mars was Angelo Secchi in 1858, although he did not see any straight lines and applied the term to large features—for example, he used the name "Canale Atlantico" for what later came to be called Syrtis Major Planum. The canals were named by Schiaparelli and others[who?] after both real and legendary rivers of various places on Earth, or the mythological underworld.

At this time in the late 19th century, astronomical observations were made without photography. Astronomers had to stare for hours through their telescopes, waiting for a moment of still air when the image was clear, and then draw a picture of what they had seen. Astronomers believed at the time that Mars had a relatively substantial atmosphere. They knew that the rotation period of Mars (the length of its day) was almost the same as Earth's, and they knew that Mars' axial tilt was also almost the same as Earth's, which meant it had seasons in the astronomical and meteorological sense. They could also see Mars' polar ice caps shrinking and growing with these changing seasons. The similarities with Earth led them to interpret darker albedo features (for instance Syrtis Major) on the lighter surface as oceans. By the late 1920s, however, it was known that Mars is very dry and has a very low atmospheric pressure.

This is a modern ground-based telescope picture of Mars which uses lucky imaging to achieve a near perfect theoretical resolution. However, due to astronomical seeing, it is extremely difficult to see finer details.

In 1889, American astronomer Charles A. Young reported that Schiaparelli's canal discovery of 1877 had been confirmed in 1881, though new canals had appeared where there had not been any before, prompting "very important and perplexing" questions as to their origin.[2]

During the favourable opposition of 1892, W. H. Pickering observed numerous small circular black spots occurring at every intersection or starting-point of the "canals". Many of these had been seen by Schiaparelli as larger dark patches, and were termed seasorlakes; but Pickering's observatory was at Arequipa, Peru, about 2400 meters above the sea, and with such atmospheric conditions as were, in his opinion, equal to a doubling of telescopic aperture. They were soon detected by other observers, especially by Lowell.[3]

During the oppositions of 1892 and 1894, seasonal color changes were reported. As the polar snows melted the adjacent seas appeared to overflow and spread out as far as the tropics, and were often seen to assume a distinctly green colour. At this time (1894) it began to be doubted whether there were any seas at all on Mars. Under the best conditions, these supposed 'seas' were seen to lose all trace of uniformity, their appearance being that of a mountainous country, broken by ridges, rifts, and canyons, seen from a great elevation. These doubts soon became certainties, and it is now universally agreed that Mars possesses no permanent bodies of surface water.

Interpretation as engineering works[edit]

Martian canals depicted by Percival Lowell

The hypothesis that there was life on Mars originated from seasonal changes observed in surface features, which began to be interpreted as due to seasonal growth of plants (in fact, Martian dust storms are responsible for some of this).

During the 1894 opposition, the idea that Schiaparelli's canali were really irrigation canals made by intelligent beings was first hinted at, and then adopted as the only intelligible explanation, by American astronomer Percival Lowell and a few others. The visible seasonal melting of Mars polar icecaps fueled speculation that an advanced alien race indigenous to Mars built canals to transport the water to drier equatorial regions. Newspaper and magazine articles about Martian canals and "Martians" captured the public imagination. Lowell published his views in three books: Mars (1895), Mars and Its Canals (1906), and Mars As the Abode of Life (1908). He remained a strong proponent for the rest of his life of the idea that the canals were built for irrigation by an intelligent civilization,[4] going much further than Schiaparelli, who for his part considered much of the detail on Lowell's drawings to be imaginary. Some observers drew maps in which dozens if not hundreds of canals were shown with an elaborate nomenclature for all of them. Some observers saw a phenomenon they called "gemination", or doubling – two parallel canals.[5]

Contemporary doubts and definitive debunk[edit]

Mars surface imaged by the Mariner 4 probe in 1965

Other observers disputed the notion of canals. The influential observer Eugène Antoniadi used the 83 cm (32.6 inch) aperture telescope at Meudon Observatory during the 1909 opposition of Mars and saw no canals, the outstanding photos of Mars taken at the new Baillaud dome at the Pic du Midi observatory also brought formal discredit to the Martian canals theory in 1909,[6] and the notion of canals began to fall out of favor. Around this time spectroscopic analysis also began to show that no water was present in the Martian atmosphere.[7] However, as of 1916 Waldemar Kaempffert (editor of Scientific American and later Popular Science Monthly) was still vigorously defending the Martian canals theory against skeptics.[8]

In 1907 the British naturalist Alfred Russel Wallace published the book Is Mars Habitable? that severely criticized Lowell's claims. Wallace's analysis showed that the surface of Mars was almost certainly much colder than Lowell had estimated, and that the atmospheric pressure was too low for liquid water to exist on the surface. He also pointed out that several recent efforts to find evidence of water vapor in the Martian atmosphere with spectroscopic analysis had failed. He concluded that complex life was impossible, let alone the planet-girding irrigation system claimed by Lowell.[9]

The existence of Martian canals was still controversial even at the dawn of the Space Race. In 1965, the Sourcebook on the space sciences said that "Although there is no unanimous opinion concerning the existence of the canals, most astronomers would probably agree that there are apparently linear (or approximately linear) markings, perhaps 40 to 160 kilometers (25 to 100 miles) or more across and of considerable length."[10] Later in the same year, the arrival of the United States' Mariner 4 spacecraft debunked for good the idea that Mars could be inhabited by higher forms of life, or that any canal features existed. It took pictures revealing impact craters and a generally barren Martian landscape, with a surface atmospheric pressure of 4.1 to 7.0 millibars (410 to 700 pascals), 0.4% to 0.7% of Earth atmospheric pressure, and daytime temperatures of −100 degrees Celsius were measured. No magnetic field,[11][12] nor radiation belts[13] were detected.

As early as 1903, Joseph Edward Evans and Edward Maunder conducted visual experiments using schoolboy volunteers that demonstrated how the canals could arise as an optical illusion.[14] This is because when a poor-quality telescope views many point-like features (e.g. sunspots or craters) they appear to join up to form lines.[7] Based on his own experiments, Lowell's assistant, A. E. Douglass, was led to explain the observations in essentially psychological terms.[15] In hindsight, William Kenneth Hartmann, a Mars imaging scientist from the 1960s to the 2000s, hypothesized that the "canals" were streaks of dust caused by wind on the leeward side of mountains and craters.[16]

In popular culture[edit]

Aclement twilight zone on a synchronously rotating Mercury, a swamp-and-jungle Venus, and a canal-infested Mars, while all classic science-fiction devices, are all, in fact, based upon earlier misapprehensions by planetary scientists.

— Carl Sagan, 1978[17]

Martian canals first appeared in fiction in the anonymously published 1883 novel Politics and Life in Mars.[18] Following the popularization of the idea that they were artificial constructs by Lowell's books, they appeared in numerous works of fiction until the Mariner 4 flyby conclusively demonstrated that they did not exist.[19][20][21]

See also[edit]

  • Face on Mars
  • History of Mars observation
  • Life on Mars
  • Lineae
  • Outflow channel
  • Solis Lacus
  • Valley networks (Mars)
  • Water on Mars
  • References[edit]

  • ^ Young, Charles A. (1889). A Textbook of General Astronomy. Boston, MA: Ginn and Co.
  • ^ Lane, K. Maria D. (2011). Geographies of Mars: Seeing and Knowing the Red Planet. University of Chicago Press, 2011. ISBN 978-0-226-47078-8. Retrieved 5 May 2024.
  • ^ Dunlap, David W. (October 1, 2015). "Life on Mars? You read it here first". The New York Times. Retrieved October 1, 2015.
  • ^ Martin, George R. R. (2012). "Introduction: Red Planet Blues". In Martin, George R. R.; Dozois, Gardner (eds.). Old Mars. Titan Books. ISBN 978-1-78329-949-2.
  • ^ Dollfus, A. (2010). "The first Pic du Midi photographs of Mars, 1909". Journal of the British Astronomical Association (abstract). 120: 240. Bibcode:2010JBAA..120..240D.
  • ^ a b Chambers, P. (1999). Life on Mars: The complete story. London, UK: Blandford. ISBN 0-7137-2747-0.
  • ^ Hickey, Walt (2017-03-21). "A mistranslated word led to some of the best fake news of the 20th century". FiveThirtyEight. Retrieved 2017-03-23.
  • ^ Wallace, Alfred (1907). Is Mars Habitable?. The Alfred Russel Wallace web page. Western Kentucky University. S730. Retrieved 2007-05-13.
  • ^ Glasstone, Samuel (1965). Sourcebook on the space sciences. Internet Archive. Princeton, N.J., D. Van Nostrand Co. p. 705.
  • ^ O'Gallagher, J.J.; Simpson, J.A. (1965-09-10). "Search for trapped electrons and a magnetic moment at Mars by Mariner IV". Science. New Series. 149 (3689): 1233–1239. Bibcode:1965Sci...149.1233O. doi:10.1126/science.149.3689.1233. PMID 17747452. S2CID 21249845.
  • ^ Smith, Edward J.; Davis, Leverett Jr.; Coleman, Paul J. Jr.; Jones, Douglas E. (1965-09-10). "Magnetic field measurements near Mars". Science. New Series. 149 (3689): 1241–1242. Bibcode:1965Sci...149.1241S. doi:10.1126/science.149.3689.1241. PMID 17747454. S2CID 43466009.
  • ^ van Allen, J.A.; Frank, L.A.; Krimigis, S.M.; Hills, H.K. (1965-09-10). "Absence of Martian radiation belts and implications thereof". Science. New Series. 149 (3689): 1228–1233. Bibcode:1965Sci...149.1228V. doi:10.1126/science.149.3689.1228. hdl:2060/19650024318. PMID 17747451. S2CID 29117648.
  • ^ Evans, J.E.; Maunder, E.W. (1903). "Experiments as to the actuality of the 'canals' observed on Mars". Monthly Notices of the Royal Astronomical Society (abstract). 63 (8): 488. Bibcode:1903MNRAS..63..488E. doi:10.1093/mnras/63.8.488.
  • ^ Sharps, Matthew J. (November–December 2019). "Part II: How to see things that aren't there". Skeptical Inquirer. Percival Lowell and the canals of Mars. Vol. 43, no. 6. Center for Inquiry. pp. 48–51. Archived from the original on 23 April 2020. Retrieved 23 April 2020.
  • ^ Robots on Mars search and catalog red planet (audio). National Public Radio.
  • ^ Sagan, Carl (1978-05-28). "Growing up with science fiction". The New York Times. p. SM7. ISSN 0362-4331. Retrieved 2018-12-12.
  • ^ Crossley, Robert (2011-01-03). "Mars and Utopia". Imagining Mars: A Literary History. Wesleyan University Press. pp. 90–91. ISBN 978-0-8195-7105-2.
  • ^ Killheffer, Robert K. J.; Stableford, Brian M.; Langford, David (2021). "Mars". In Clute, John; Langford, David; Sleight, Graham (eds.). The Encyclopedia of Science Fiction (4th ed.). Retrieved 2022-05-28.
  • ^ Stableford, Brian M. (2006). "Mars". Science Fact and Science Fiction: An Encyclopedia. Taylor & Francis. pp. 281–284. ISBN 978-0-415-97460-8.
  • ^ Westfahl, Gary (2020). "Lowell, Percival". In Clute, John; Langford, David; Sleight, Graham (eds.). The Encyclopedia of Science Fiction (4th ed.). Retrieved 2022-05-28.
  • External links[edit]

  • icon Stars
  • Spaceflight
  • Outer space
  • icon Science

  • Retrieved from "https://en.wikipedia.org/w/index.php?title=Martian_canals&oldid=1234831175"

    Categories: 
    Mars
    Obsolete scientific theories
    Canals
    Hidden categories: 
    Articles with short description
    Short description is different from Wikidata
    Articles needing additional references from September 2019
    All articles needing additional references
    Articles to be expanded from October 2020
    All articles to be expanded
    Articles using small message boxes
    All articles with specifically marked weasel-worded phrases
    Articles with specifically marked weasel-worded phrases from November 2022
    CS1 French-language sources (fr)
    Commons category link is on Wikidata
    CS1: long volume value
     



    This page was last edited on 16 July 2024, at 10:30 (UTC).

    Text is available under the Creative Commons Attribution-ShareAlike License 4.0; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.



    Privacy policy

    About Wikipedia

    Disclaimers

    Contact Wikipedia

    Code of Conduct

    Developers

    Statistics

    Cookie statement

    Mobile view



    Wikimedia Foundation
    Powered by MediaWiki