Chemical differentiation of planets: a core issue
(Submitted on 14 Aug 2012)
Prevalent theories of the Solar System formation minimize the role of matter ionization and magnetic field in the Solar nebula. Here we propose that a magnetically driven chemical gradient at the scale of the Solar nebula predates radial chemical differentiation of each planet. We report an observed correlation between the first ionization potentials of the elements and their abundances on Earth surface relative to Sun, interpreted as a Boltzmann distribution depending on the distance from the Sun. This predictive model for distribution of the elements in the Solar System is successfully tested for relative abundance data from CI chondrites, Moon, Mars and Venus. Deviations from the proposed law for a given planet correspond to surface segregation of elements following periodic trends. Bulk Earth would have included up to 18%wt H, with definite consequences on theories about inner Earth composition. From this model, a new picture of the Solar System emerges.