In the 1860s he discovered that there are similarities between the orbits of some meteor streams and the orbits of particular comets, showing in 1866, for example, that the Perseid meteor shower is associated with Comet Swift–Tuttle, and postulated that meteors are debris from comets. From 1877 he began a series of careful observations of Mars that resulted in a highly detailed map and a system of nomenclature for its albedo features. Much speculation and controversy followed his report of straight markings, the canali. This term, originally used by P. A. Secchi, means ‘channels’ but was translated into English as ‘canals’. Schiaparelli also prepared maps of Venus and Mercury, and studied the orbits of binary stars.