Time evolution of grains in the protosolar nebula

The problem of the motion of grains in the protosolar nebula is discussed. Time scales of the vertical and radial displacement are computed. The structure of the dust disk that can be formed is discussed in the framework of different protosolar nebula models.The results obtained under the hypothesis of quiescience of the gas component are compared with those in presence of a fully developed turbulence.Paper presented at the European Workshop on Planetary Sciences, organised by the Laboratorio di Astrofisica Spaziale di Frascati, and held between April 23–27, 1979, at the Accademia Nazionale del Lincei in Rome, Italy.