The ion-acoustic solitons are investigated in three-component plasmas, whose constituents are electrons, positrons, and singly charged ions. It is found that the presence of the positron component in such a multispecies plasma can result in reduction of the ion-acoustic soliton amplitudes.

Shock structures in plasmas containing variable-charge macro particles are shown to exist because of an effective dissipation associated with charging of the latter.

We investigate the possibility for dust ion-acoustic solitons to exist. Compressive solitonlike perturbations are damped and slowed down, mainly due to the plasma absorption and ion scattering on microparticles. The perturbations are shown to possess the main properties of solitons. There is a principal possibility to study experimentally the role of trapped electrons in the soliton formation.

The results on shock phenomena in dusty plasmas of the Solar System are reviewed. The problems of dust ion acoustic bow shock in interaction of the solar wind with dusty cometary coma and formation of transient atmospheres of atmosphereless cosmic bodies such as Moon, Mercury, asteroids and comets are considered. The latter assumes the evolution of meteoroid impact plumes and production of charged dust grains due to the condensation of both the plume substance and the vapor thrown from the crater and the surrounding regolith layer. Physical phenomena occurring during large meteoroid impacts can be modeled with the aid of active rocket experiments, which involve the release of some gaseous substance in near-Earth space. New vistas in investigation of shock processes in natural dusty plasmas are determined.

Shock waves with a linear front were experimentally studied in a monolayer hexagonal Yukawa lattice which was formed from charged monodisperse plastic microspheres and levitated in the sheath of a radio-frequency discharge. It was found that the shock can cause phase transitions from a crystalline to gaslike and liquidlike states. Melting occurred in two stages. First, the lattice was compressed in the direction of shock propagation and second, the particle velocities were randomized a few lattice lines downstream. The Mach number of the shock reached 2.7.

A theoretical model that provides a self-consistent description of the concentrations of photoelectrons and dust particles located over the illuminated part of the lunar surface is presented. The model takes account of the observation point location and the effects of production of photoelectrons at the surfaces of the Moon and dust particles, the dynamics of dust particles in the electric and gravitational fields, and the charging of dust particles through their interaction with the solar radiation photons, the solar wind electrons and ions, photoelectrons, etc. An expression that describes the distribution of photoelectrons over the illuminated part of the lunar surface is obtained. The size and elevation distributions of the charged dust particles located over the illuminated part of the lunar surface are calculated for different angles between the local normal and the direction to the Sun. It is shown that no substantial restrictions are imposed on the choice of the landing site for future lunar spacecraft missions aimed at studying the near-surface dust on the Moon.