Giovanni Schiaparelli and the Martian Canals

Giovanni Virginio Schiaparelli (1835-1910)

On March 14, 1835, Italian astronomer and science historian Giovanni Schiaparelli was born. He is remembered best for his observations of planet Mars, where he discovered a dense network of linear structures on the surface of Mars which he called “canali” in Italian, meaning “channels” but the term was mistranslated into English as “canals” indicating that the observed structures should be of artificial origin.

“Mercury on its axis turns like the Moon:
One side has lasting day, the other night;
One side in everlasting fire doth swoon;
While th’other hides forever from the light.”
Giovanni Schiaparelli, (Originally in Latin; translated by Agnes Mary Clerke (1842–1907)) [7]

Early Years

Schiaparelli graduated in 1854 from the University of Turin in the engineering sciences of architecture and hydraulics. For some time he pursued private studies in astronomy, mathematics and languages. In 1856 he became a mathematics teacher at an elementary school in Turin. To become an astronomer, he studied from 1857 for two years at the Berlin Observatory under the then director Johann Franz Encke. Another year he worked at the Pulkovo Observatory under the direction of Wilhelm Struve. In 1860 Schiaparelli returned to Italy to take up a position as “secondo astronomo” at the Osservatorio Astronomico di Brera in Milan under Francesco Carlini.

Mars surface map of Giovanni Schiaparelli

The Planet Mars

Giovanni Schiaparelli devoted much of his time as a scientist to telescopic observations of planet Mars. In his initial observations, he named the “seas” and “continents” of Mars. These linear structures were close to the visibility limit of the then 30 to 50 cm telescopes and required special observation experience. During the planet’s Great Opposition of 1877, he observed a dense network of linear structures on the surface of Mars which he called “canali” in Italian, meaning “channels” but the term was mistranslated into English as “canals”. As we know, canals indicate artificial constructions, wherefore channels indicate natural configurations of the planetary surface. Only at the next Mars opposition in 1879 was her sighting confirmed by other astronomers.

“Rather than real channels of form to us more familiar, we must imagine soil depressions not very deep, extended in a straight direction for thousands of kilometers, over a width of 100, 200 kilometers or more. I have already pointed out once again that, lacking rain over Mars, these canals probably constitute the main mechanism with which water (and with it organic life) can spread on the dry surface of the planet “.
– Giovanni Schiaparelli, La vita sul planet Marte, extracted from booklet n° 11 – Year IV of the magazine Nature and Art, May 1895, Cap. I

The Martian Cannals

When the term was incorrectly translated, numerous research attempts were made about life on Mars as well as its conditions. The ‘canals’ became very popular and the result was a rise of hypotheses, and mad speculations on the possibilities of intelligent life on Mars. Theories about the ‘Martians’ established. The well known American astronomer Percival Lowell was known to be one of the greatest supporters of the canal-hypothesis.[4] He then spent a great time of his professional life attempting to find existing intelligent life on the planet. It was only in the 1910s after Lowell’s death that scientists officially rejected the artificial-canal-hypothesis.

The War of the Worlds

However, the science fiction culture did not let go off the mystical canal theory and the ‘possible’ life on Mars inspired numerous writers like H. G. Wells‘ The War of the Worlds.[5] Later, with notable thanks to the observations of the Italian astronomer Vincenzo Cerulli, scientists came to the conclusion that the famous channels were actually mere optical illusions (line amplification by correlated irritation of adjacent visual cells).  The last doubts were finally cleared in the 1960s, when Mariner 4 from the American Space Program photographed the surface with much higher resolution than Earth-based telescopes, confirming that there are no structures resembling “canals”. However, about half of the Martian channels mapped by Schiaparelli and other astronomers are likely to correspond to actual canyons, linear terrain shadows, valley systems or crater chains.

Later Life

Schiaparellis’ astronomical research also concerned Mercury, Venus, solar activity and the double stars. One crater each on the moon, Mercury and Mars was named after him. An observer of objects in the Solar System, Schiaparelli worked on binary stars, discovered the large main-belt asteroid 69 Hesperia on 29 April 1861, and demonstrated that the meteor showers were associated with comets. He proved, for example, that the orbit of the Leonid meteor shower coincided with that of the comet Tempel-Tuttle. These observations led the astronomer to formulate the hypothesis, subsequently proved to be correct, that the meteor showers could be the trails of comets.

Schiaparelli became a foreign member of the Royal Society on November 29, 1896. The famous fashion designer Elsa Schiaparelli was his niece. He died on July 4, 1910, in Milan, at age 75.

Andrew Coates, Looking for Life on Mars, [8]

References and Further Reading:

• [1] Schiaparelli, Giovanni Virginio (1835-1910) Biography
• [2] Schiaparelli and the “first Martians” at NASA
• [3] The “Canals” of Mars: How Giovanni Schiaparelli Saw Tharsis
• [4] Percival Lowell and the Search for Pluto, SciHi Blog
• [5] H. G. Wells and the Shape of Thing to Come, SciHi Blog
• [6] Giovanni Schiaparelli at Wikidata
• [7] Sky and Telescope, March 2011, p. 33
• [8] Andrew Coates, Looking for Life on Mars, Gresham College @ youtube
• [9] “Schiaparelli, Giovanni Virginio”. Lexico UK English Dictionary. Oxford University Press.
• [10] G. V. Schiaparelli, J. G. Galle, J. B. N. Hennessey J. Coles, J. E. Gore, The Observatory, Vol. 33, p. 311–318, August 1910
• [11] Works by or about Giovanni Schiaparelli at Internet Archive
• [12] Timeline of notable Italian Astronomers via DBpedia and Wikidata