Formation of cometary subnuclei

The combined effects of collisions between forming cometary nuclei and the heating and cooling of their interiors in the framework of the standard model of Solar System (SS) formation are discussed. At the stage preceding ejection of bodies to the periphery of the SS the interiors of the largest of them probably passed through differentiation. In the presence of a detectable 26Al abundance and amorphous ice heating up to the ice melting temperature and partial differentiation of interiors of the 10 km cometary nuclei are possible just to the end of the collision stage of evolution. Heating and differentiation of large (∼ 100 km) ice-dust planetesimals can occur even in Kuiper Belt and Oort cloud during the first 108 years after their formation. The method is presented for classification of dynamic states and evolution tracks on a basis of “relations of the order” made up from characteristic times of considered processes.