Early planetary processes

The processes which lead from a nebula of small particles to the evolved planets in our present solar system and the planets orbiting other stars are still not yet completely understood. Nowadays most of the traces are erased, and we have to rely on numerical simulation and laboratory experiments. Numerical simulations of processes in the early solar system are particularly challenging, because of the great variety of overlapping processes involved in the evolution of  planetary bodies. Fortunately, the terrestrial planets lets us collect data whose interpretation helps to construct an inner structure. With these models of the planetary interior, the early evolution can be constrained.