A century ago, most scientists thought Mars was devoid of animal life. Many thought it might contain plants, or at least primitive life such as lichens.

But in popular culture, Mars was abuzz with life. That was thanks to Percival Lowell. He saw “canals” crisscrossing the planet – structures built to save a dying civilization.

Lowell was born to a distinguished family in Boston. He worked in the family business, then traveled around Asia. But during that time he developed an interest in Mars. In the late 1800s, he built his own observatory to study Mars, in Flagstaff, Arizona.

During an especially close passage of Mars, in 1877, an Italian astronomer had described some lines he saw on the planet as “channels” – natural features. But Lowell thought of them as “canals” – created by living beings.

In Lowell’s reckoning, Mars was losing its atmosphere and getting colder. That turned it into a desert. Survivors built the canals to sustain their cities. Lowell’s books and lectures about Mars were popular, so the general public thought of Mars as inhabited.

But by 1924, it was clear to most scientists that Mars was too cold and dry to support much life. But one thought a civilization could still exist – perhaps supported by Lowell’s canals. So during another close passage of Mars, a century ago this week, he launched a project to listen for Martian radio broadcasts. More about that tomorrow.

Script by Damond Benningfield