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
Five-planet Nice model Five-planet Nice model The five-planet Nice model is a recent variation of the Nice model that begins with five giant planets, the current four plus an additional ice giant, in a chain of mean-motion resonances. After the resonance chain is broken, the five giant planets undergo a period of planetesimal-driven migration, followed by a gravitational instability similar to that in the original Nice model. During the instability the additional giant planet is scattered inward onto a Jupiter-crossing orbit and is ejected from the Solar System following an encounter with Jupiter. An early Solar System with five giant planets was proposed