They were first described by the Italian astronomer Giovanni Schiaparelli during the opposition of 1877, and attested to by later observers. Schiaparelli called these canali ("channels"), which was mis-translated into English as "canals". The Irish astronomer Charles E. Burton made some of the earliest drawings of straight-line features on Mars, although his drawings did not match Schiaparelli's.
Around the turn of the century there was even speculation that they were engineering works, irrigation canals constructed by a civilization of intelligent aliens indigenous to Mars. By the early 20th century, improved astronomical observations revealed the "canals" to be an optical illusion, and modern high-resolution mapping of the Martian surface by spacecraft shows no such features.
