Abstract
According to the theoretical and analytical studies on the formation of planetary system and the formation of meorites, there should be variations in the formation time of planetesimals, causing variations in the thermal evolution afterward.In this study, we carried out the numerical model on the thermal evolution of small planets with the size from a few km to a few hundred-km for various formation time.Our model contains effects of: (1) heating by short lived radio nuclides, (2) low thermal conductivity of porous media, (3) sintering induced by pressure and temperature, and (4) silicate-metal separation due to permeable flow of molten metal through silicate grains.Our numerical results show that there are obvious conditions to be satisfied to form a metallic core, which seems consistent with the formation condition of iron meteorites derived from the textural feature of iron meteorites.
