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 horrors". Nevertheless, the composer and critic Colin Matthews recognises even in these apprentice works an "instinctive orchestral flair". Of the few pieces from this period which demonstrate some originality, Matthews pinpoints the G minor String Trio of 1894 (unperformed until 1974) as the first underivative work produced by Holst. Matthews and Imogen Holst each highlight the "Elegy" movement in "The Cotswold Symphony" (1899–1900) as among the more accomplished of the apprentice works, and Imogen discerns glimpses of her father's real self in the 1899 "Suite de ballet" and the "Ave Maria" of 1900. She and Matthews have asserted that Holst