The Planets dedication notwithstanding, Imogen Holst "would have been both amused and dismayed by the venture." On 24 August 2006, the International Astronomical Union (IAU) defined what it means to be a "planet" within the Solar System. This definition excluded Pluto as a planet and added it as a member of the new category of "dwarf planets", along with Eris and Ceres. Following the IAU decision, Kenyon D. Wilson composed a trombone quintet piece titled "Songs of Distant Earth". The title comes from Arthur C. Clarke's novel of the same name. The composition contains five movements, each named after one of the
Emanuel Swedenborg well as spirits from planets beyond the solar system. From the 'encounters', he concluded that the planets of our solar system are inhabited and that such an enormous undertaking as the universe could not have been created for just one race on a planet or one 'Heaven' derived from its properties per planet. Many Heavenly societies were also needed to increase the perfection of the angelic Heavens and Heaven to fill in deficiencies and gaps in other societies. He argued: "What would this be to God, Who is infinite, and to whom a thousand or tens of thousands of planets,