In previous studies it was shown that the energy release during the decay of short-living radioactive elements in small bodies is sufficient for the temperature inside such a protoplanetary core to become larger than the melting temperature of iron. This ensures the realization of the process of differentiation of matter and the development of convection in the inner envelopes. At all stages of proto-Earth’s formation, convective heat and mass transfer is the most important factor in the dynamics of the planet. However, the release of heat due to friction in the viscous liquid of the outer regions of the core so far has not been taken into account at all or was taken into account only in the formed envelopes of a planet of constant radius. In this chapter, we present the results of a numerical simulation of the thermal evolution of a 3D spherical segment of a protoplanet of an increasing radius, taking into account the accidental falling of bodies and particles. An algorithm for the numerical solution of the problem is given, taking into account the dissipation of tidal energy in the Earth-Moon system at the stage of planetary accumulation.
Part of the book: Geophysics
The problem of the origin of the Moon is of fundamental importance to understanding the mechanism of the planetary solar system’s formation. It is important to know the mechanism of differentiation of substances in a growing planet. When planets are formed from a cold protoplanetary cloud, the matter of the inner regions of the Earth and the Moon remains at temperatures lower than the melting point of iron. The main volume of the matter of the protoplanet remains in its unmelted state, and its differentiation occurs in the formed planet. In this work, attention is paid to the most important internal sources of energy: the decay energy of short-lived isotopes, the dissipation of tidal friction energy, and thermal energy from accidental deposition of bodies and particles on a growing surface. Accounting for these sources provides a solution to the problem.
Part of the book: Lunar Science