Starting from objective data and testimonies on the Tunguska event and introducing parameters calculated by modeling we selected a range of meaningful atmospheric trajectories for the Tunguska Cosmic Body (TCB). From these data we performed a comparative analysis by means of theoretical models and with the help of interplanetary (1 Mb) and atmospheric (304 kb) dynamics. The results obtained give 83% of the probability for a TCB coming from an asteroidal source, while only 17% correspond to a cometary source.