Abundance of the chemical elements in the Sun and outer planets is similar to that in the universe. Due to solar heating, the elements of Earth and the inner rocky planets of the Solar System have undergone an additional depletion of volatile hydrogen, helium, neon, nitrogen, and carbon (which volatilizes as methane). The crust, mantle, and core of the Earth show evidence of chemical segregation plus some sequestration by density. Lighter silicates of aluminum are found in the crust, with more magnesium silicate in the mantle, while metallic iron and nickel compose the core. The abundance of elements in specialized environments, such as atmospheres, or
Return to the Centre of the Earth Return to the Centre of the Earth Return to the Centre of the Earth is a studio album by the English keyboardist Rick Wakeman, released on 15 March 1999 on EMI Classics. The album is a sequel to his 1974 concept album "Journey to the Centre of the Earth", itself based on the same-titled science fiction novel by Jules Verne. Wakeman wrote a new story of three unnamed travellers who attempt to follow the original journey two hundred years later, including the music which features guest performances from Ozzy Osbourne, Bonnie Tyler, Tony Mitchell, Trevor Rabin, Justin Hayward, and Katrina