Published online by Cambridge University Press: 14 August 2015
It has become evident that comets and other small bodies are indications of eruptive evolution processes occurring in many of the planetary bodies of the solar system. The total number of near-parabolic comets moving in the solar system is 1011 to 1012, but as many as 10 to 15 percent of them are leaving the solar system with hyperbolic velocities. Taking into account also the number of short-period comets that degenerate into asteroids and meteor streams, we have estimated the total number of comets formed during the lifetime of the solar system as 1015 to 1016 (and total mass 1029 to 1031 g). The investigation of comets and other small bodies enables us to evaluate the scale of the processes of cosmic vulcanism and the tremendous internal energy of the planets, that energy being derived from the initial stellar nature of planetary material.