Terrestrial planet from the original solar nebula. The Solar System has four terrestrial planets: Mercury, Venus, Earth, and Mars. Only one terrestrial planet, Earth, is known to have an active hydrosphere. During the formation of the Solar System, there were probably many more terrestrial planetesimals, but most merged with or were ejected by the four terrestrial planets. Dwarf planets, such as Ceres, Pluto and Eris, and small Solar System bodies are similar to terrestrial planets in the fact that they do have a solid surface, but are, on average, composed of more icy materials (Ceres, Pluto and Eris have densities of 2.17,
Gustav Holst wrath. In 1912 Holst composed two psalm settings, in which he experimented with plainsong; the same year saw the enduringly popular "St Paul's Suite" (a "gay but retrogressive" piece according to Dickinson), and the failure of his large scale orchestral work "Phantastes". Holst conceived the idea of "The Planets" in 1913, partly as a result of his interest in astrology, and also from his determination, despite the failure of "Phantastes", to produce a large-scale orchestral work. The chosen format may have been influenced by Schoenberg's "Fünf Orchesterstücke", and shares something of the aesthetic, Matthews suggests, of Debussy's "Nocturnes" or "La