On dusty plasma processes in the physics of comets

Dusty plasma processes in the physics of comets are considered. The distribution functions of photoelectrons, the altitude dependences of the charges and sizes of dust particles, as well as electric fields are determined using a physicomathematical model for the self-consistent description of densities of photoelectrons and dust particles above the illuminated part of a comet nucleus. It has been shown that dusty plasma processes are significantly manifested when a comet is sufficiently far from the Sun. The dusty plasma near the comet nucleus with the parameters close to the parameters of the nucleus of Halley's comet at distances to the Sun no less than $\sim 2.5$–$3.5$ AU is formed due to the electrostatic interactions similar to the formation of dusty plasmas near other atmosphereless bodies (e.g., the Moon, satellites of Mars, and asteroids). The dynamics of dust particles at closer distances from the Sun is determined by the gas flow from the comet nucleus.