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,
The Planets five then-known dwarf planets, Eris, Pluto, Haumea, Makemake, and Ceres. Unlike Matthews' composition, this work is not intended to be incorporated into a performance of Holst's suite. In 2006, the Berlin Philharmonic, with Sir Simon Rattle and EMI Classics, commissioned four composers (Kaija Saariaho, Matthias Pintscher, Mark-Anthony Turnage, and Brett Dean) and recorded an additional, four-movement suite based on asteroids in the Solar System. The four movements were: Holst adapted the melody of the central section of "Jupiter" in 1921 to fit the metre of a poem beginning "I Vow to Thee, My Country". As a hymn tune it has