The particles of the broken solar envelope may have been accelerated by more than one brief explosion. As nuclear reactions ignited the solar interior, explosions could recur periodically /14/, filling the space around the Sun with meteoritic dust. The initial explosion of the envelope of a celestial body may also occur under conditions when the energy of the nuclear reactions is insufficient to heat up the entire original star. In such a case, the creation of the meteoritic dust is not always accompanied by an ignition of the source (by the formation of a luminous star). Consequently, the swarms of meteoritic dust out of which larger celestial bodies will subsequently be formed may accompany cold, dark stars as well as ordinary stars. It is possible, too, that types of explosions of celestial bodies may take place in nature which result in the formation of dust swarms that do not have monolithic central parts. Then, just as in the case of partial explosions of celestial bodies, the meteoritic dust may either be collected again into a single body, or may form several indepen dent bodies, or it may supplement the masses of other celestial bodies and change their angular momenta.
Asymmetrical explosions on planets may, without leading to destruction of the planet, displace the planetary center of mass, as a result of which external-force moments will be produced. As time goes by, the celestial body works toward a reduction of the external-force moment and toward a stable situation. The reduction of the external-force moment must take place mainly via a redistribution of the mass of the body. For example, such a redistribution was effected on the Earth by means of the previously mentioned continental drift, and it is revealed, in particular, during studies of the paleomagnetism of the Earth /6/. Displacements of individual regions or continents continue as long as the shifting forces are available, that is, as long as the external-force moment of the body is not completely compensated. The nature of the tangential forces
necessary to produce the tremendous thrusts and overthrusts taking place at various depths in the Earth's crust is explained convincingly and comparatively simply by the above scheme. These external-force moments, which modify the spatial orientations of the rotation axes of celestial bodies (in particular, the Earth) and which cause mass displace ments, change the orientation of the Earth's surface relative to the Sun accordingly. Thus, there are particular zones in which the geological conditions are right for the formation of certain rocks and minerals / 13/ .
Following the above general scheme, we may remark that the formation of central bodies (the Sun) and peripheral bodies (the planets) simultaneous ly (Fesenkov) during a single condensation of an interstellar cloud (V.A.Krat) represents a definite phase in the evolution of a solar system. This evolutionary phase, which corresponds to the time interval between the accumulation of the cold cloud into a large body and the beginning of mass and momentum transfer from it, is a phase during which attractive forces compete with repulsive forces.
One of the reasons for writing this article was to illustrate the nature of the forces responsible for variations in the geological situation during different epochs. If the article proves to be of some use to the Earth sciences, then our studies of these forces have not been in vain.
If the described scheme can be extended to serve as an approximate description of the origin and development of other stellar-planetary systems, then we may conclude that the number of planets in the universe on which conditions are favorable (according to Oparin /8/) for organic life must be very large, and apparently is commensurable with the number of stars in the sky.
The author expresses his sincere thanks to N. I. Taranov and to K. M. Sadilenko for their discussions of the article, their valuable comments, and their advice.