During the 1984 opposition, Italian astronomer Giovanni Schiaparelli used a telescope to help produce the first detailed map of Mars. What caught people's attention was that the maps had features he called "canali". These were later shown to be an optical illusion (not real). These "canali" were supposedly long straight lines on the surface of Mars to which he gave names of famous rivers on Earth. His term "canali" was popularly mistranslated in English as "canals", and thought to be made by intelligent beings.