Archive of Astronomy Questions and Answers

What are the element abundances for the solar system, Earth and Moon?

                                             Crust
Element.............Sun.............Earth.............Moon
Hydrogen            27900           0.14              0.01
Helium               2700
Oxygen                 24.0         46.6              45.0
Carbon                 10.1
Nitrogen                3.1
Magnesium               1.1          2.1               5.0
Silicon                 1.0         27.7              21.0
Iron                    0.9          5.3               8.0
Sulpher                 0.515        0.05
Aluminum                0.085        8.1              13.0
Calcium                 0.061        3.6              10.0
Sodium                  0.057        2.8               5.0
Potassium               0.0038       2.6
Titanium                0.0024       0.4               5.0
Manganese               0.0096       0.1
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Note, the solar abundances is in terms of the number per billion atoms. The Earth and Moon values are in percent, but do not add up to 100 in each column because of variations within various rock types. These percentages are probobly good to 15 percent. ie the calcium abundance on the Moon varies from 8 to 12 percent between highland and mare regions. Titanium varies from 1 to 8 percent.