A canal obsession

In the sky this week…

  • Jupiter rises about 7 p.m
  • Mars comes up around 2 a.m.
  • The Moon will be full on October 11 and reach Last Quarter on October 19.

Ken Tapping, October 12, 2011

“I still remember that vigil very distinctly: the black and silent observatory, the shadowed lantern throwing a feeble glow upon the floor in the corner, the steady ticking of the clockwork of the telescope, the little slit in the roof, an oblong profundity with the star dust streaked across it.”

The observatory was dark, other than the dim glow of scattered red lights. The telescope was a dark shape pointed upwards through the darkness of the dome to the slit in the roof. The sky looked grey against the dark, with stars and the sparkling trail of the Milky Way slanting across it.

Mosaic of the Valles Marineris hemisphere of Mars showing the entire Valles Marineris canyon system – over 3,000 kilometers long and up to 8 kilometers deep. Credit: NASA/NSSDC

Mosaic of the Valles Marineris hemisphere of Mars showing the entire Valles Marineris canyon system – over 3,000 kilometers long and up to 8 kilometers deep. Credit: NASA/NSSDC

The first paragraph is from H.G. Well's book “War of the Worlds” and describes the first observation of small flashes on Mars as the invaders started their journey to Earth. The second paragraph, not written by H.G. Wells, describes my recent visit to see an old telescope at an observatory at Flagstaff, Arizona. What do these things have in common?

The Phased-Array Demonstrator System (PHAD) installed on 10-m reflector antenna for testing

This image from NASA’s Mars Reconnaissance Orbiter shows gully channels in a crater in the southern highlands of Mars. The gullies emanating from the rocky cliffs near the crater’s rim (upper left) show meandering and braided patterns typical of water-carved channels. Credit: NASA/NSSDC.

In 1877, while observing Mars through his telescope, Giovanni Schiaparelli, an Italian astronomer, reported seeing streaks across the Martian surface, which resembled channels – possibly natural watercourses or canyons. Of course he used the Italian word canali. When these reports reached the English speaking world, the word was mistranslated to mean canals, which are a different sort of thing altogether. Channels can be natural; canals are works of advanced engineering. This idea fell on fertile ground because there were other things hinting at the presence of life.

First of all, Mars was more like our world than any of the other planets in the Solar System; it has an atmosphere, a desert surface and even polar icecaps. Another well-known occurrence was the “wave of darkening”. In the spring, the icecaps dwindled and a dark wave moved towards the equator. The suggested explanation was that meltwater from the poles stimulated the growth of vegetation. The idea of intelligent Martians building canals to better manage the limited water resources of their desert world was an easy idea to sell.

Percival Lowell was a successful businessman, but his real love was Mars. In 1894 he finally had enough funds to build himself an observatory. The site he chose was a hill above Flagstaff, Arizona. The observatory was dedicated to the study of Mars. He then worked hard for years, using every opportunity when the Earth and Mars passed close to each other to make even better maps of the canals, oases and junctions that could be sites of Martian cities. It is likely that the astronomer in “War of the Worlds” was modeled on Lowell.

Of course, those maps were the result of poor seeing and excellent imagination. Surprisingly, the idea of Martian life persisted into the early 1960’s, when a Mariner spacecraft passed close by and sent back pictures of mountains, craters and deserts. There were no canals, cities or Martians. One very real discovery made at Lowell’s observatory occurred in 1930, when Clyde Tombaugh discovered Pluto. However, whether Lowell was right or wrong, I got to look through his telescope!

Ken Tapping is an astronomer with the National Research Council's Dominion Radio Astrophysical Observatory, Penticton, BC, V2A 6J9.

Telephone: 250-497-2300
Fax: 250-497-2355
E-mail: ken.tapping@nrc-cnrc.gc.ca

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