Italian astronomer whose first notable discovery was the asteroid Hesperia in 1861. He then went on to demonstrate that meteor swarms have orbits similar to certain comets and speculated that these swarms were probably the remains of spent comets. He also did some work on double stars and conducted extensive observations on Mercury, Venus, and Mars.
It was in 1877, while involved in this latter work at the Milan Observatory, when he was using only a 22.5- centimeter (9-inch) telescope, that he made the observation for which he is best known: He reported seeing groups of straight lines on Mars and called them canali, meaning “channels” to Schiaparelli. These observations were followed up using a more powerful telescope that had a 47-centimeter (18.5-inch) aperture. He then observed the channels begin to take on a more linear formation and also appear to alter from one day to the next, sometimes being single lines, sometimes two parallel lines separated by an estimated 80 kilometers (50 miles). This separation was called the gemination, meaning doubling. The word canali that Schiaparelli used to describe these formations was unfortunately translated into English in its first, more common meaning, as canals, rather than “channels,” thus giving the public and even some astronomers the idea that they were of human construction. There followed much speculation on the possibility of life on Mars.