CENTIMETER TELESCOPE TO DRAW THE FIRST MAP OF MARS. HIS M...

22-centimeter telescope to draw the first map of Mars. His map depicted long lines that he called

canali, the Italian word for channels. But his term was mistakenly translated into English as canals.

Because channels are usually natural and canals are manmade, the mistake gave birth to imaginative

theories of life on Mars over the next 100 years.

The leading proponent of the view that the canals were built by intelligent beings was an American

astronomer, Percival Lowell. At the Lowell Observatory in the high altitude and clear air of Flagstaff,

Arizona, Lowell studied Mars extensively and made detailed drawings of its surface features. He

published books about his Mars studies, including Mars and Its Canals in 1906 and Mars As the Abode

of Life in 1908. Lowell proposed that the canals had been constructed by a long-extinct civilization as

an elaborate irrigation system. The canals conveyed water from the polar regions to the dry population

centers of the planet. Lowell’s ideas were embraced by popular culture. The British novelist H.G.

Wells wrote the most famous novel describing life on Mars,

War of the Worlds. He imagined that

Martians invaded Earth in order to flee the death of their own planet.

Bigger and better telescope lenses in the twentieth century failed to confirm that the features

Lowell observed really were canals. In fact, they ultimately were shown to be optical illusions.

Life on Mars was dealt a further blow beginning in 1965. The United States launched the Mariner

spacecrafts to fly close to the surface to take photographs and test the atmosphere. Those probes

showed that Mars has a thin atmosphere made mostly of carbon dioxide and that the polar ice caps are

frozen dioxide, not water. The photos revealed that Mars had no rivers, oceans, or any other visible

signs of life. Scientists concluded that Mars’ thin atmosphere and lack of a magnetic field made it

vulnerable to harmful cosmic radiation. Biological and soil experiments were conducted by the Viking

project in 1976. To the scientists’ surprise, the test showed that Mars’s surface has no organic matter at

all. Thus the present view is that Mars is a dead planet, though there may have been life early in its

history that later became extinct.

Beginning in 1996, the United States launched a highly successful series of landings on Mars.

While they have not found life, they have expanded our knowledge of Martian geology and chemistry.

A robotic exploration vehicle in 2001 sent back to Earth spectacular images of Mars’s terrain. Other

missions have detected hydrogen and methane. In 2004, Martian vehicles provided conclusive

evidence that water existed in the distant past. Additional American missions have been planned

through 2009. The European Space Agency wants to land humans on Mars by 2035. And in 2004, the

American president declared a national goal of sending astronauts to land on and explore Mars.