Unfinished creative work planet Pluto, giving it the name "Pluto, The Renewer". When Holst had written the original piece Pluto had not been discovered, and this addition therefore updated the suite and completed the eight movements that represented the planets of the solar system (Earth was never included) some 80 years after it was originally performed. In August 2006 Pluto was officially demoted to a dwarf planet, meaning that Holst's original work now more accurately represents the solar system. Some extremely famous 20th century operas have been left incomplete at their composers' deaths. Giacomo Puccini left the finale of "Turandot" unfinished and the
Solar System icy objects. Astronomers sometimes informally divide this structure into separate regions. The inner Solar System includes the four terrestrial planets and the asteroid belt. The outer Solar System is beyond the asteroids, including the four giant planets. Since the discovery of the Kuiper belt, the outermost parts of the Solar System are considered a distinct region consisting of the objects beyond Neptune. Most of the planets in the Solar System have secondary systems of their own, being orbited by planetary objects called natural satellites, or moons (two of which, Titan and Ganymede, are larger than the planet Mercury), and, in