Map of Mars by Giovanni Schiaparelli.

For a time in the late 19th and early 20th centuries, it was believed that there were canals on Mars. These were a network of long straight lines that appeared in drawings of the planet Mars in the equatorial regions from 60° N. to 60° S. Lat., first observed by the Italian astronomer Giovanni Schiaparelli during the opposition of 1877, and confirmed by later observers. Schiaparelli called these canali, which was translated (perhaps mistranslated) 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. Image File history File links Karte_Mars_Schiaparelli_MKL1888. ... Image File history File links Karte_Mars_Schiaparelli_MKL1888. ... A planet is generally considered to be a relatively large mass of accreted matter in orbit around a star. ... Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ... Giovanni Virginio Schiaparelli (March 14, 1835 – July 4, 1910) was an Italian astronomer. ... Opposition is a term used in positional astronomy and astrology to indicate when one celestial body is on the opposite side of the sky when viewed from a particular place (usually the Earth). ... 1877 was a common year starting on Monday (see link for calendar). ... Charles E. Burton (1846 – June 9, 1882) was an Irish astronomer. ...

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 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. Percival observing Mars from the Lowell Observatory. ...

Other observers disputed the notion of canals as well. The gifted observer E. E. Barnard did not see them. In 1903, J. E. Evans and Edward Maunder conducted visual experiments using schoolboy volunteers that demonstrated how the canals could arise as an optical illusion. [1] The influential observer Eugène Antoniadi used the 83-cm telescope at Meudon Observatory at the 1909 opposition of Mars and saw no canals, and the notion of canals began to fall out of favor. Edward Emerson Barnard (December 16, 1857 – February 6, 1923) was an American astronomer. ... 1903 (MCMIII) was a common year starting on Thursday (see link for calendar). ... Edward Walter Maunder (April 12, 1851 – March 21, 1928) 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. ... An optical illusion is characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading [1]. Thus information gathered by the eye is processed by the brain to give, on the face of ir, a percept that does not tally with a physical measurement of... Eugène Michel Antoniadi (1870 – February 10, 1944) was a Greek astronomer, born in Asia Minor, who spent most of his life in France. ... The Paris Observatory (in French, Observatoire de Paris or Observatoire de Paris-Meudon) is the foremost astronomical observatory of France, and one of the largest astronomical centers in the world. ... 1909 (MCMIX) was a common year starting on Friday (see link for calendar). ... Opposition is a term used in positional astronomy and astrology. ...

The arrival of the space probe Mariner 4 in 1965, which took pictures revealing impact craters 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 space probe is an unmanned space mission in which a spacecraft leaves Earths orbit. ... The first close-up image ever taken of Mars, this photo shows an area about 330 km across by 1200 km from limb to bottom of frame. ... 1965 (MCMLXV) was a common year starting on Friday (the link is to a full 1965 calendar). ... Tycho crater on Earths moon. ...

History of canals

The Italian word canale (plural canali) can mean "canals" (including artificial canals or ducts) or "channels" or "gullies". [2] This ambiguity also exists in cognate words in other Romance languages such as French (canal), and also in German (Kanal). The Romance languages, also called Romanic languages, are a subfamily of the Italic languages, specifically the descendants of the Vulgar Latin dialects spoken by the common people evolving in different areas after the break-up of the Roman Empire. ...

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 "Atlantic Canale" for what later came to be called Syrtis Major. Pietro Angelo Secchi (1818–1878) was an Italian astronomer. ... 1858 (MDCCCLVIII) is a common year starting on Friday of the Gregorian calendar (or a common year starting on Sunday of the 12-day-slower Julian calendar). ... Syrtis Major is a dark spot (an albedo feature) located in the boundary between the northern lowlands and southern highlands of Mars. ...

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.

It is perhaps not so odd that the idea of Martian canals was so readily accepted by many. At the time, in the late 19th century, telescopic observers had difficulty distinguishing exactly what they were seeing when they looked at Mars (indeed, it was not until the era of space probes that a clear picture emerged). They saw some lighter or darker albedo features (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 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. 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 storms 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. Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... An albedo feature is a large area on the surface of a planet (or other solar system body) which shows a contrast in brightness or darkness (albedo) with adjacent areas. ... Syrtis Major is a dark spot (an albedo feature) located in the boundary between the northern lowlands and southern highlands of Mars. ... In astronomy, a rotation period is the time an astronomical object takes to complete one revolution around its rotation axis. ... Axial tilt is an astronomical term regarding the inclination angle of a planets rotational axis in relation to its orbital plane. ... This article or section needs to be wikified. ... It has been suggested that this article or section be merged with Social issues of the 1920s. ...

In addition, the late 19th century was a time of great canal building on Earth. For instance, the Suez Canal was completed in 1869, and the abortive French attempt to build the Panama Canal began in 1880. It is perhaps natural that some thought similar projects were being undertaken on Mars. The Canal du Midi in Toulouse, France. ... 1881 drawing of the Suez Canal. ... 1869 (MDCCCLXIX) is a common year starting on Friday (link will take you to calendar) of the Gregorian calendar or a common year starting on Sunday of the 12-day-slower Julian calendar. ... A canal tug, making its way down to the Caribbean end of the canal, waits to be joined by a ship in the uppermost chamber of the Gatun Locks. ... 1880 (MDCCCLXXX) was a leap year starting on Thursday (see link for calendar). ...

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. 1892 (MDCCCXCII) was a leap year starting on Friday (see link for calendar). ... William Henry Pickering (February 15, 1858 – January 17, 1938) was an American astronomer, brother of Edward Charles Pickering. ... For the cactus species formerly in genus Arequipa, see Oreocereus and Matucana. ...

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. This at once seized upon the public imagination and was spread by newspapers and magazines over the civilised world. 1892 (MDCCCXCII) was a leap year starting on Friday (see link for calendar). ... 1894 (MDCCCXCIV) was a common year starting on Monday (see link for calendar). ...

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 almost universally admitted that Mars possesses no permanent bodies of water.

Popular culture

The notion of a parched Martian civilization building gigantic irrigation canals perhaps inspired H. G. Wells to write The War of the Worlds in 1897, an account of an invasion by Martians coveting Earth's abundant water resources. Even after canals were largely discredited, Martian civilization remained a theme for science fiction such as the Barsoom of Edgar Rice Burroughs (see Mars in fiction). H. G. Wells Herbert George Wells (September 21, 1866 – August 13, 1946) was a British writer best known for his science fiction novels such as The War of the Worlds, The Invisible Man, The Island of Doctor Moreau and The Time Machine. ... A statue of a tripod inspired by the book, erected in Woking town centre. ... 1897 (MDCCCXCVII) was a common year starting on Friday (see link for calendar). ... Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... In 1911, Edgar Rice Burroughs, now best known as the creator of the character Tarzan, began his writing career with A Princess of Mars, a rousing tale of pulp adventure on the planet Barsoom or Mars. ... Edgar Rice Burroughs Edgar Rice Burroughs (September 1, 1875 – March 19, 1950) was an American author, best known for his creation of the jungle hero Tarzan, although he also produced works in many genres. ... Fictional representations of Mars have been popular for over a century. ...

List of canals

Main article: List of Martian canals

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

The classical albedo features of Mars are those light and dark features which can be seen on the planet Mars through an Earth-based telescope. ... Mars Orbital Cameras 2001 image of the face The Face on Mars is a large feature on the surface of the planet Mars located in the Cydonia region, thought by many to resemble a human face. ... Scientists have long speculated about the possibility of life on Mars due to that planets proximity and similarity to Earth. ...

References

• Wallace, A. R. (1907) Is Mars habitable? A critical examination of Professor Percival Lowell's book "Mars and its canals", with an alternative explanation, by Alfred Russel Wallace, F.R.S., etc. London, Macmillan and co.
• Evans, J. E. and Maunder, E. W. (1903) "Experiments as to the Actuality of the 'Canals' observed on Mars", MNRAS, 63 (1903) 488
• Antoniadi, E. M. (1910) "Sur la nature des »canaux« de Mars", AN 183 (1910) 221/222 (in French)

Alfred Russel Wallace for the Cornish painter see Alfred Wallis Alfred Russel Wallace, OM , FRS (January 8, 1823 – November 7, 1913) was a British naturalist, geographer, anthropologist and biologist. ... Edward Walter Maunder (April 12, 1851 – March 21, 1928) 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. ... Eugène Michel Antoniadi (1870 – February 10, 1944) was a Turkish-born Greek astronomer who spent most of his life in France. ...

External links

• http://www.theguardians.com/space/orbitalmech/gm_emoi1.htm
• http://www.physics.purdue.edu/astr263l/SStour/mars.html