1-152-580 - Ann Ronan Picture Library/Heritage-Images

Drawing of Mars showing 'canals' and dark areas, 1896. The American astronomer Percival Lowell (1855-1916) theorised that a Martian civilization, faced with climate change, had built the canals to transport water from the planet's ice caps to irrigate crops. In fact the canals did not exist; they are now thought to have been optical illusions possibly caused by dust storms. From Mars by Percival Lowell. (London, 1896).