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
National Centre for Earth Observation National Centre for Earth Observation The National Centre for Earth Observation (NCEO) is part of the Natural Environment Research Council (NERC) and looks at improving knowledge of the earth by taking observations from space and aircraft, as well as observations from the ground to produce models which will help understand, respond and adapt to climate and environmental changes. The organisation was previously centred at the University of Reading, known nationally for its department of meteorology, which requires satellite observation of the Earth. The NCEO is now at the University of Leicester, known for its research into astronomy and its National