Implications for the Earth of the early dynamical environment

The formation of the Earth, was mainly from sizeable bodies: perhaps moon sized. Models of interaction among small planetesimals which take into account only close encounters all lead to the formation of moon sized objects, thus leading to several 100 in the inner solar system. Longer term interactions, such as secular resonance sweepings, are needed to get these planetesimals together to form the observed terrestrial bodies. After the accumulation of the Earth, during which core formation certainly occurred, further impacts probably influenced the locations of rifting centers in the system of mantle convection and crustal differentiation. They may have affected craton stabilization by promoting lateral heterogeneity, but had little influence on the key problem of early recycling of sial.