NONGRAVITATIONAL FORCES AND METEOROID STREAMS

The action of the solar electromagnetic radiation on the moving interp lanetary dust particles in its more complete form than the special cas e known as the Poynting-Robertson effect is theoretically discussed in application to meteoroid stream of comet Encke. Normal and transversa l components of the perturbing nongravitational force are used due to the action of the solar electromagnetic radiation. It is shown that th e normal component of the force is negligible. However, transversal co mponent is very important: it can probably completely explain all the observed meteoroid streams situated along the orbit of comet Encke (an d, possibly, some asteroids) as the product of the comet Encke alone. Much shorter time is required for producing such a meteroid stream tha n is a general conception. If the idea about the significance of the t ransversal component of the nongravitational force (may be, not produc ed by electromagnetic radiation) is correct, it may have important con sequences for our understanding of ageing of comets, global evolution of the cometary (and, partially, asteroidal) system, and, of course, f or a long-term evolution of small interplanetary particles.