INTERPLANETARY DUST PARTICLES AND SOLAR-RADIATION

The problem of the action of the solar radiation on the motion of inte rplanetary dust particle is discussed. Differences between the action of electromagnetic solar radiation and that of the solar wind are expl ained not only from the point of view of the physical nature of these phenomena but also from the point of view of dust particle's orbital e volution. As for the electromagnetic solar radiation, general equation of motion for the particle is written and the most important conseque nces are. (i) the process of inspiralling toward the Sun is not the on ly possible motion - even spiralling from the Sun is also possible, an d, (ii) the orbital plane of the particle (its inclination) may change in time. As for the solar wind, the effect corresponding to the fact that solar wind particles spread out from the Sun in nonradial directi on causes that the process of inspiralling toward the Sun is in more t han 50% less effective than for radial spread out; in the region of th e asteroid belt (long period orbits) the process of inspiralling is ch anged into off spiralling. Also shift in the perihelion of dust partic le's orbit exists.