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The layers of the Earth, a differentiated planetary body. In planetary science, planetary differentiation is the process by which the chemical elements of a planetary body accumulate in different areas of that body, due to their physical or chemical behavior (e.g. density and chemical affinities).
This shift is the apex angle in an isosceles triangle, with 2 AU (the distance between the extreme positions of Earth's orbit around the Sun) making the base leg of the triangle and the distance to the star being the long equal-length legs (because of a very long distance from the Earth orbit to the observed star).
Jupiter has been estimated to shrink at a rate of approximately 1 mm/year by this process, [1] corresponding to an internal flux of 7.485 W/m 2. [ 2 ] The mechanism was originally proposed by Kelvin and Helmholtz in the late nineteenth century to explain the source of energy of the Sun .
Infographic showing the theorized origin of the chemical elements that make up the human body. Astrochemistry is the study of the abundance and reactions of molecules in the universe, and their interaction with radiation. [1] The discipline is an overlap of astronomy and chemistry.
The remaining 4.9% [11] comprises all ordinary matter observed as atoms, chemical elements, gas and plasma, the stuff of which visible planets, stars and galaxies are made. The great majority of ordinary matter in the universe is unseen, since visible stars and gas inside galaxies and clusters account for less than 10% of the ordinary matter ...
Practical Astronomy with your Calculator, Peter Duffett-Smith. Cambridge University Press; 3rd edition 1988. Advanced/graduate level: Numerical Methods in Astrophysics: An Introduction (Series in Astronomy and Astrophysics): Peter Bodenheimer, Gregory P. Laughlin, Michal Rozyczka, Harold. W Yorke. Taylor & Francis, 2006.
The need for a physical description was already inspired by the relative abundances of the chemical elements in the solar system. Those abundances, when plotted on a graph as a function of the atomic number of the element, have a jagged sawtooth shape that varies by factors of tens of millions (see history of nucleosynthesis theory ). [ 4 ]
A major source of differentiation is fractionation, an unequal distribution of elements and isotopes. This can be the result of chemical reactions, phase changes, kinetic effects, or radioactivity. [1]: 2–3 On the largest scale, planetary differentiation is a physical and chemical separation of a planet into chemically distinct regions. For ...