Martian canals
Encyclopedia
For a time in the late 19th and early 20th centuries, it was erroneously believed that there were canals on Mars. These were a network of long straight lines that appeared in drawings of the planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...

 Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

 in the equatorial regions from 60° N. to 60° S. Lat., first observed by the Italian astronomer Giovanni Schiaparelli
Giovanni Schiaparelli
Giovanni Virginio Schiaparelli was an Italian astronomer and science historian. He studied at the University of Turin and Berlin Observatory. In 1859-1860 he worked in Pulkovo Observatory and then worked for over forty years at Brera Observatory...

 during the opposition
Opposition (astronomy)
In positional astronomy, two celestial bodies are said to be in opposition when they are on opposite sides of the sky, viewed from a given place . In particular, two planets are in opposition to each other when their ecliptic longitudes differ by 180°.The astronomical symbol for opposition is ☍...

 of 1877, and confirmed by later observers. Schiaparelli called these canali, which was translated into English as "canals" (see below). The Irish astronomer Charles E. Burton
Charles E. Burton
Charles E. Burton was an Irish astronomer.For some time he worked as an assistant to Lord Rosse at Parsonstown, Ireland....

 made some of the earliest drawings of straight-line features on Mars, although his drawings did not match Schiaparelli's. By the early 20th century, improved astronomical observations had revealed the "canals" to be an optical illusion
Optical illusion
An optical illusion is characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a perception that does not tally with a physical measurement of the stimulus source...

, and modern high resolution mapping of the Martian surface by spacecraft shows no such features.

Controversy

Some people went so far as to propose the idea that the canals were irrigation canals built by a supposed intelligent civilization on Mars. Percival Lowell
Percival Lowell
Percival Lawrence Lowell was a businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars, founded the Lowell Observatory in Flagstaff, Arizona, and formed the beginning of the effort that led to the discovery of Pluto 14 years after his death...

 was a strong proponent of this view, pushing the idea 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.

Other observers disputed the notion of canals. The gifted observer E. E. Barnard did not see them. In 1903, Joseph Edward Evans and Edward Maunder
Edward Walter Maunder
Edward Walter Maunder was an English astronomer best remembered for his study of sunspots and the solar magnetic cycle that led to his identification of the period from 1645 to 1715 that is now known as the Maunder Minimum....

 conducted visual experiments using schoolboy volunteers that demonstrated how the canals could arise as an optical illusion
Optical illusion
An optical illusion is characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a perception that does not tally with a physical measurement of the stimulus source...

. 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. In 1907 the British naturalist Alfred Russel Wallace
Alfred Russel Wallace
Alfred Russel Wallace, OM, FRS was a British naturalist, explorer, geographer, anthropologist and biologist...

 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, that the atmospheric pressure was too low for liquid water to exist on the surface, and he 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. The influential observer Eugène Antoniadi used the 83-cm (32.6 inch) aperture telescope at Meudon Observatory at 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
Pic du Midi
Pic du Midi may refer to:*Pic du Midi de Bigorre - A mountain in the Frence Pyrenees famous for its astronomical observatory.*Pic du Midi d'Ossau - Another mountain in the Frence Pyrenees...

 observatory also brought formal discredit to the Martian Canals theory in 1909, 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.

The arrival of the United States' Mariner 4
Mariner 4
Mariner 4 was the fourth in a series of spacecraft, launched on November 28, 1964, intended for planetary exploration in a flyby mode and performed the first successful flyby of the planet Mars, returning the first pictures of the Martian surface...

 by NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 in 1965, which took pictures revealing impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

s and a generally barren landscape, was the final nail in the coffin of the idea that Mars could be inhabited by higher forms of life. A surface atmospheric pressure
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...

 of 4.1 to 7.0 millibars
Bar (unit)
The bar is a unit of pressure equal to 100 kilopascals, and roughly equal to the atmospheric pressure on Earth at sea level. Other units derived from the bar are the megabar , kilobar , decibar , centibar , and millibar...

 (410 to 700 pascals
Pascal (unit)
The pascal is the SI derived unit of pressure, internal pressure, stress, Young's modulus and tensile strength, named after the French mathematician, physicist, inventor, writer, and philosopher Blaise Pascal. It is a measure of force per unit area, defined as one newton per square metre...

) and daytime temperatures of −100 degrees Celsius
Celsius
Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...

 were estimated. No magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...

 or Martian radiation belts
Van Allen radiation belt
The Van Allen radiation belt is a torus of energetic charged particles around Earth, which is held in place by Earth's magnetic field. It is believed that most of the particles that form the belts come from solar wind, and other particles by cosmic rays. It is named after its discoverer, James...

 were detected.

William Kenneth Hartmann
William Kenneth Hartmann
William K. Hartmann is a noted planetary scientist, author, and writer. He was the first to convince the scientific mainstream that the Earth had once been hit by a planet sized body , creating both the moon and the Earth's 23° tilt....

, a Mars imaging scientist from the 1960s to the 2000s, explains the "canals" as streaks of dust caused by wind on the leeward side of mountains and craters.

History of canals

The Italian
Italian language
Italian is a Romance language spoken mainly in Europe: Italy, Switzerland, San Marino, Vatican City, by minorities in Malta, Monaco, Croatia, Slovenia, France, Libya, Eritrea, and Somalia, and by immigrant communities in the Americas and Australia...

 word canale (plural canali) can mean "canals" (including artificial canals or ducts) or "channels" or "gullies". The first person to use the word canale in connection with Mars was Angelo Secchi
Angelo Secchi
-External links:...

 in 1858, although he did not see any straight lines and applied the term to large features —for example, he used the name "Atlantic Canale" for what later came to be called Syrtis Major Planum.

It is often stated that Schiaparelli intended the meaning "channels" and that "canals" was a misunderstanding or mistranslation into English. Nevertheless, the English term "canals" was used from the very earliest accounts in English, and as far as is known, Schiaparelli made no effort to correct the supposed misunderstanding if he was aware of it. As the word "canal" can also mean "channel" or "watercourse" – not necessarily artificial – in English, the charge of "mistranslation" is unwarranted.

It is perhaps not so odd that the idea of Martian canals was so readily accepted by many. 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
Astronomical seeing
Astronomical seeing refers to the blurring and twinkling of astronomical objects such as stars caused by turbulent mixing in the Earth's atmosphere varying the optical refractive index...

 when the image was clear, and then draw a picture of what they had seen. They saw some lighter or darker albedo feature
Albedo feature
An albedo feature is a large area on the surface of a planet which shows a contrast in brightness or darkness with adjacent areas....

s (for instance Syrtis Major) and believed that they were seeing oceans and continents. They also believed that Mars had a relatively substantial atmosphere. They knew that the rotation period
Rotation period
The rotation period of an astronomical object is the time it takes to complete one revolution around its axis of rotation relative to the background stars...

 of Mars (the length of its day) was almost the same as Earth's, and they knew that Mars' axial tilt
Axial tilt
In astronomy, axial tilt is the angle between an object's rotational axis, and a line perpendicular to its orbital plane...

 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. It was only when they interpreted changes in surface features as being due to the seasonal growth of plants that life was hypothesized by them (in fact, Martian dust storm
Dust storm
A dust / sand storm is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Particles are transported by saltation and suspension, causing soil to move from one place and deposition...

s are responsible for some of this). By the late 1920s, however, it was known that Mars was very dry and had a very low atmospheric pressure.

In addition, the late 19th century was a time of great canal
Canal
Canals are man-made channels for water. There are two types of canal:#Waterways: navigable transportation canals used for carrying ships and boats shipping goods and conveying people, further subdivided into two kinds:...

 building on Earth. For instance, the Suez Canal
Suez Canal
The Suez Canal , also known by the nickname "The Highway to India", is an artificial sea-level waterway in Egypt, connecting the Mediterranean Sea and the Red Sea. Opened in November 1869 after 10 years of construction work, it allows water transportation between Europe and Asia without navigation...

 was completed in 1869, and the abortive French attempt to build the Panama Canal
Panama Canal
The Panama Canal is a ship canal in Panama that joins the Atlantic Ocean and the Pacific Ocean and is a key conduit for international maritime trade. Built from 1904 to 1914, the canal has seen annual traffic rise from about 1,000 ships early on to 14,702 vessels measuring a total of 309.6...

 began in 1880. It is perhaps natural that some thought similar projects were being undertaken on Mars. In 1889, astronomer Charles A. Young
Charles Augustus Young
Charles Augustus Young was an American astronomer.He graduated from Dartmouth and later became a professor there in 1865, remaining until 1877 when he went to Princeton....

 reported that Schiaparelli's canal discovery of 1877 had been confirmed in 1881, though new canals had appeared where there hadn't been any before, prompting "very important and perplexing" questions as to their origin.

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 seas or lakes; 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.

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. 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 Lowell and a few others. Newspaper and magazine articles about Martian canals captured the public imagination.

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.

Fiction

Although the concept of the canals had been available since Schiaparelli's 1877 description of them, early fictional descriptions of Mars omitted these features. They receive no mention, for instance, in H. G. Wells
H. G. Wells
Herbert George Wells was an English author, now best known for his work in the science fiction genre. He was also a prolific writer in many other genres, including contemporary novels, history, politics and social commentary, even writing text books and rules for war games...

' The War of the Worlds
The War of the Worlds
The War of the Worlds is an 1898 science fiction novel written by H. G. Wells.The War of the Worlds may also refer to:- Radio broadcasts :* The War of the Worlds , the 1938 radio broadcast by Orson Welles...

(1897), which describes a slowly drying Mars, covetous of Earth's resources, but one which still has dwindling oceans such as are depicted on Schiaparelli's maps. Later works of fiction, influenced by the works of Lowell, described an ever-more arid Mars, and the canals became a more prominent feature, though how they were explained varied widely from author to author.
  • Garrett P. Serviss
    Garrett P. Serviss
    Garrett Putnam Serviss was an astronomer, popularizer of astronomy, and early science fiction writer. Serviss was born in upstate New York, and majored in science at Cornell. He took a law degree at Columbia, but never worked as an attorney...

    ' Edison's Conquest of Mars
    Edison's Conquest of Mars
    Edison's Conquest of Mars, by Garrett P. Serviss, is one of the many science fiction novels published in the 19th century. Although science fiction was not at the time thought of as a distinct literary genre, it was a very popular literary form, with almost every fiction magazine regularly...

    (1898) repeatedly mentions Schiaparellian canals (which play a key part in the denouement of the story), but does not describe them in detail, apparently considering them simply irrigation canals comparable to those on Earth — ignoring the fact that, in that case, they could hardly be visible from Earth. Serviss' Mars also has lakes and oceans.
  • George Griffith
    George Griffith
    George Griffith , full name George Chetwyn Griffith-Jones, was a prolific British science fiction writer and noted explorer who wrote during the late Victorian and Edwardian age. Many of his visionary tales appeared in magazines such as Pearson's Magazine and Pearson's Weekly before being published...

    's A Honeymoon in Space (1900) describes the canals as the remnants of gulfs and straits "widened and deepened and lengthened by... Martian labour".
  • Edgar Rice Burroughs
    Edgar Rice Burroughs
    Edgar Rice Burroughs was an American author, best known for his creation of the jungle hero Tarzan and the heroic Mars adventurer John Carter, although he produced works in many genres.-Biography:...

    ' influential A Princess of Mars
    A Princess of Mars
    A Princess of Mars is a science fiction novel by Edgar Rice Burroughs, the first of his Barsoom series. It is also Burroughs' first novel, predating his famous Tarzan series. Full of swordplay and daring feats, the novel is considered a classic example of 20th century pulp fiction...

    (1912) describes an almost entirely desert Mars, with only one small body of liquid water on the surface (though swamps and forests appear in the sequels
    Barsoom
    Barsoom is a fictional representation of the planet Mars created by American pulp fiction author Edgar Rice Burroughs, who wrote close to 100 action adventure stories in various genres in the first half of the 20th century, and is now best known as the creator of the character Tarzan...

    ). The canals, or waterways as Burroughs calls them, are still irrigation works, but these are surrounded by wide cultivated tracts of farmland which make their visibility somewhat credible.
  • Alexander Bogdanov
    Alexander Bogdanov
    Alexander Aleksandrovich Bogdanov –7 April 1928, Moscow) was a Russian physician, philosopher, science fiction writer, and revolutionary of Belarusian ethnicity....

    's Engineer Menni (1913) details the social, scientific, and political history of the construction of the Martian canals and the socio-economic ramifications the construction had on Martian society.
  • Otis Adelbert Kline
    Otis Adelbert Kline
    Otis Adelbert Kline born in Chicago, Illinois, USA, was an adventure novelist and literary agent during the pulp era. Much of his work first appeared in the magazine Weird Tales. Kline was an amateur orientalist and a student of Arabic, like his friend and sometime collaborator, E...

    's Outlaws of Mars (1933) has multiple parallel canals, surrounded by walls and terraces, and describes the construction of the canals by Martian machines.
  • In C. S. Lewis
    C. S. Lewis
    Clive Staples Lewis , commonly referred to as C. S. Lewis and known to his friends and family as "Jack", was a novelist, academic, medievalist, literary critic, essayist, lay theologian and Christian apologist from Belfast, Ireland...

    ' Out of the Silent Planet
    Out of the Silent Planet
    Out of the Silent Planet is the first novel of a science fiction trilogy written by C. S. Lewis, sometimes referred to as the Space Trilogy, Ransom Trilogy or Cosmic Trilogy. The other volumes are Perelandra and That Hideous Strength, and a fragment of a sequel was published posthumously as The...

    (1938), the "canals" (handramit in Martian) are actually vast rifts in the surface of an almost airless, desert Mars, in which the only breathable atmosphere and water have collected where life is possible, with the rest of Mars being entirely dead.
  • In Robert A. Heinlein
    Robert A. Heinlein
    Robert Anson Heinlein was an American science fiction writer. Often called the "dean of science fiction writers", he was one of the most influential and controversial authors of the genre. He set a standard for science and engineering plausibility and helped to raise the genre's standards of...

    's Red Planet
    Red Planet
    Red Planet is a nickname for the planet Mars, due to its surface color. It may also refer to:* Red Planet by Robert A. Heinlein* Red Planet , an 1994 animated adaptation of the novel...

    (1949), colonists use the frozen canals for travel. Teenagers Jim Marlowe and Frank Sutton set out to skate the thousands of miles to their homes on the frozen Martian canals when escaping the Lowell Academy boarding school.
  • In Ray Bradbury
    Ray Bradbury
    Ray Douglas Bradbury is an American fantasy, horror, science fiction, and mystery writer. Best known for his dystopian novel Fahrenheit 451 and for the science fiction stories gathered together as The Martian Chronicles and The Illustrated Man , Bradbury is one of the most celebrated among 20th...

    's The Martian Chronicles
    The Martian Chronicles
    The Martian Chronicles is a 1950 science fiction short story collection by Ray Bradbury that chronicles the colonization of Mars by humans fleeing from a troubled and eventually atomically devastated Earth, and the conflict between aboriginal Martians and the new colonists...

    (1950), the canals are artificial waterways stretching between stone banks, filled with blue water, or sometimes poetically described as full of "green liquors" or "lavender wine". Bradbury revisited the martian canals in 1967 in his short story "The Lost City of Mars".
  • In the BBC
    BBC
    The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...

     radio production Journey into Space
    Journey Into Space
    Journey Into Space is a BBC Radio science fiction programme, written by BBC producer Charles Chilton. It was the last radio programme in the UK to attract a bigger evening audience than television...

    : The Red Planet
    (1954–1955), the canals are valleys filled with a plant life resembling giant rhubarb
    Rhubarb
    Rhubarb is a group of plants that belong to the genus Rheum in the family Polygonaceae. They are herbaceous perennial plants growing from short, thick rhizomes. They have large leaves that are somewhat triangular-shaped with long fleshy petioles...

    s.
  • In Robinson Crusoe on Mars
    Robinson Crusoe on Mars
    Robinson Crusoe on Mars is a 1964 Techniscope science fiction film retelling of the classic novel by Daniel Defoe. It was directed by Byron Haskin, produced by Aubrey Schenck and starred Paul Mantee, Victor Lundin and Adam West...

    (1964) Kit Draper and Friday flee from the enemy aliens through the underground canals on their way to the polar ice cap.
  • The Mars of the steampunk
    Steampunk
    Steampunk is a sub-genre of science fiction, fantasy, alternate history, and speculative fiction that came into prominence during the 1980s and early 1990s. Steampunk involves a setting where steam power is still widely used—usually Victorian era Britain or "Wild West"-era United...

     RPG
    Role-playing game
    A role-playing game is a game in which players assume the roles of characters in a fictional setting. Players take responsibility for acting out these roles within a narrative, either through literal acting, or through a process of structured decision-making or character development...

     Space: 1889
    Space: 1889
    Space: 1889 is a role-playing game of Victorian-era space-faring,created by Frank Chadwick and originally published by Game Designers' Workshop from 1988 to 1991 and later reprinted by Heliograph, Inc...

    (1988) is crisscrossed by artificial canals which support cities inhabited by the ancient civilization of the Canal Martians.
  • The 1991 computer game Ultima: Martian Dreams
    Martian Dreams
    Ultima: Worlds of Adventure 2: Martian Dreams is a computer RPG set in the Ultima series, published in 1991. It uses the same engine as Ultima VI, as did the first Worlds of Ultima game, The Savage Empire....

     features a plot based around Victorian expeditions to Mars. The Martian canals play a very prominent role as the main characters have to find a way to refill them using ice from the polar caps.

List of canals

The canals were named, by Schiaparelli and others, after real and legendary rivers of various places on Earth or the mythological underworld.

See also

  • Classical albedo features on Mars
    Classical albedo features on Mars
    The classical albedo features of Mars are the light and dark features that can be seen on the planet Mars through an Earth-based telescope. Before the age of space probes, several astronomers created maps of Mars on which they gave names to the features they could see. The most popular system of...

  • Face on Mars
  • History of Mars observation
    History of Mars observation
    The history of Mars observation dates back to the era of the ancient Egyptian astronomers. Detailed records regarding the position of the planet Mars were made by Babylonian astronomers who developed arithmetic techniques to predict the future position of the planet...

  • Life on Mars
    Life on Mars
    Scientists have long speculated about the possibility of life on Mars owing to the planet's proximity and similarity to Earth. Fictional Martians have been a recurring feature of popular entertainment of the 20th and 21st centuries, but it remains an open question whether life currently exists on...

  • Solis Lacus
    Solis Lacus
    Solis Lacus is a dark feature on Mars. It was once called "Oculus" and is still commonly called "The Eye of Mars" because with the surrounding light area called Thaumasia it resembles the pupil of one. Solis Lacus is known for the variability of its appearance, changing its size and shape when...

  • Linea
    Linea
    Linea is Latin for 'line'. In planetary geology it is used to refer to any long marking, dark or bright, on a planet or moon's surface. The planet Venus and Jupiter's moon Europa have numerous lineae; Saturn's moon Rhea has several.-See also:...

  • Outflow channel
  • Valley networks (Mars)
    Valley networks (Mars)
    Valley networks are branching networks of valleys on Mars that superficially resemble terrestrial river drainage basins. They are found mainly incised into the terrain of the martian southern highlands, and are typically - though not always - of Noachian age...


External links

  • http://www.theguardians.com/space/orbitalmech/gm_emoi1.htm
  • http://www.physics.purdue.edu/astr263l/SStour/mars.html
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK