The influence of the cometary particles dynamics on the activity of comets

The paper deals with the dynamics of particles which are on the surface of the cometary nucleus. The key point is to research the behavior of the particles as a result of local sublimation. Generally, we can describe three mechanisms related to the particles behavior. Relatively small particles (of the order of micrometers) are ejected into the atmosphere of the comet due to sublimation. Slightly larger particles (of the order of centimeters) can migrate across the comet’s surface towards the equator, while much larger rubbles of cometary matter remain at rest. The angular width of the particles is the main factor influencing the migration time towards the equator of the comet. The measure of angular width and particles’ migration time is its size and coefficient of friction. The numerical calculations presented in the paper refer to a hypothetical comet X/P and the comet 67P/Churyumov–Gerasimenko.