A careful examination of collisional processes occurring on surfaces of Solar System objects requires data on the dynamic properties of porous geological materials. Shock waves traveling in sand with physical properties analogous to those of some types of Martian regolith are studied in a series of uniaxial plate impact experiments. The initial density of the samples and average grain size are 1.30 g cm−3 and 95 μm, respectively. The obtained Hugoniot of this simulant is in general agreement with those of previously studied sands. The effect of porosity and grain morphology on Hugoniots of these geological materials is also highlighted. A laser velocimetry technique is used to observe the structure of propagated waves. Wave fronts with rise times on the order of several hundred or tens of microseconds were recorded in the pressure range of 0.5 to 1.7 GPa. For the simulant, a value of 1.91 was found for an exponent in the relationship between rise time and pressure τ∼p−m. Additionally, exponents for different granular and silica-rich systems studied earlier were also provided. An analysis of wave thickness revealed that in the pressure range of 0.5–1.1 GPa, this parameter can be associated with the grain average size. At the highest pressure (1.7 GPa), the minimum particle size (∼20 μm) turned out to be a more suitable quantity to describe the shock wave structure.

The hazardous effect of lunar dust on hardware and humans is one of the most problematic factors in the planning of automated and human missions to the Moon. To reduce and possibly eliminate this impact, studies of lunar dust dynamics under laboratory conditions are being conducted. The most promising methods for determining the motion parameters of dust particles in such studies are optical methods based on digital image processing. The aim of this work is to develop algorithm for simulation stereo images of the trajectories of microparticles of simulated lunar soil observed under laboratory conditions. The results of the simulation for choosing optimal parameters of particle trajectory imaging are presented. They can be used in further studies to exclude the influence of these parameters on the results of larger scale simulation to estimate the optimal parameters of the optical measurement system.

A brief review of theoretical studies of circumlunar dusty plasma, the important factors in the formation of which are electrostatic processes and impacts of micrometeoroids on the lunar surface, is given. Observation data of dust particles in the vicinity of the Moon, obtained within the “Luna-25” mission, are described for the first time. It is shown that there is at least one reliable observation of a dust particle either of lunar origin or associated with the high-speed Perseid stream. The need to improve the Lunar Dust Monitor device on the “Luna-27” lander is discussed. The improvement is associated with the need to install a rod for placing electrostatic sensors at a sufficient distance from the device, which is desirable to reduce disturbances of the surrounding plasma and the near-surface electrostatic field because of the influence of the lander.

We review studies of physical processes associated with the impact of external factors in outer space flows of micrometeoroids and solar radiation on the lunar regolith. Under the influence of these factors, regolith microparticles can detach from the surface and levitate. Near-surface plasma and levitating dust particles form a plasma-dust exosphere of the Moon. Under anthropogenic effects on the lunar environment, charged levitating microparticles can have an extremely negative impact on the engineering systems of lunar landers and on the activity and health of astronauts on the Moon. Based on information gained by automated and manned lunar missions and in laboratory experiments, we discuss modern ideas about physical processes occurring near the Moon's surface. Unsolved problems associated with the plasma-dust exosphere of the Moon are considered, and the principal strategies for their solution are outlined.

Since the first automatic missions to the Moon, the activity of dust particles from atmosphereless bodies has been recorded. Since then, a lot of theoretical and experimental studies of this effect have been carried out, but at present there is no clear understanding of the influence of external actions on the dynamics of this phenomenon. This paper presents the results of experiments to determine the effect of hard UV radiation on the activity of dust particles, which makes a significant contribution to particle dynamics. The result of determining the conditions for particle removal from the surface is in accordance with theoretical calculations.

The process of gas ionization-recombination and dust particle charging under the effect of X-ray radiation in the conditions of space plasma has been investigated. Conditions have been found under which, as a result of radiation exposure, dust particles in a protoplanetary disk can acquire a positive charge even under low gas ionization.

To expand the possibilities of solving geophysical problems using fiber-optic distributed systems for recording acoustic waves, a comparison was made of the signals obtained by traditional hydrophones and a distributed fiber-optic system using a cable containing straight and helical fibers. The studies were carried out by the method of cross-well seismic survey. The possibility of separating direct and refracted head waves recorded by a distributed fiber-optic system and using them to obtain geological and geophysical information about the state of the massif is considered. It is shown that, when using a helically wound fiber, the first arrivals of a direct longitudinal wave can be traced to conduct cross-well seismic of the rock massif and evaluate the velocity distribution by the method of cross-well time-travel tomography on direct waves. For both straight and helical fibers, the stacking of the head waves makes it possible to obtain sufficiently clear arrivals of the head wave even in the dry part of the well and use it to determine the velocities of compressional waves of the near-borehole massif. The composition of the cross-well wave field depends on the radiation patterns of both the source and the receiver of acoustic waves. The use of multiple overlap systems makes it possible to vary the composition of the recorded wave field due to the mutual arrangement of the receiving and exciting lines depending on the tasks being solved.

Space dust and dusty (complex) plasma are one of the most common manifestations of matter in space. Non-atmospheric bodies of the Solar System, such as the Moon, asteroids, comets, some satellites of the planets, are directly affected by external factors of outer space—solar electromagnetic radiation, interplanetary plasma flows, cosmic rays, micrometeors. Under the influence of these factors, regolith is formed on the surface of bodies during geological epochs. Under the influence of impacts of high-speed micrometeors, dust particles of regolith scatter at different speeds. Most of them return to the surface, but some form dust clouds or lose their gravitational connection with the parent body. Under the action of solar radiation, the surface acquires an electric charge, and dust particles under certain conditions can break away from the regolith surface and levitate. Observational evidence of such dynamic phenomena has been recorded on the Moon and on some asteroids. The study of the physical processes responsible for the activation of dust particles and their dynamics is of great interest for fundamental science and practical purposes. The article discusses the main processes occurring under the influence of outer space factors on regolith, as a result of which dust particles move and a near-surface plasma-dust exosphere is formed. Unresolved issues are discussed. Methods and means of laboratory modeling in studying the activation and dynamics of dust particles are considered.

The article is a review of the state of research on physical processes occurring near the surface of airless bodies, in particular, the Moon, asteroids, comets, which lead to their erosion, that is, to the modification of superficial and sometimes even deeper layers. External influences on the bodies are considered—micrometeor streams, solar wind and geomagnetic tail plasma flows, solar electromagnetic radiation, and cosmic rays, which are the main causes of erosion. The main features of airless bodies belonging to different classes are given. The main physical mechanisms that can lead to the release and removal of dust particles from the surface of regolith are analyzed, in particular, the energy aspects of high-speed micrometeor impacts, electrostatic processes of particle release from the surface, and thermodynamic processes occurring in the near-surface layers of cometary nuclei. The conditions for the removal of dust particles from the surface of a rotating body and the conditions under which the body can collapse are considered. Depending on the characteristics of these bodies, the processes of erosion, as well as the causes of its occurrence, can vary significantly. The main unresolved problems associated with the processes of erosion of bodies, which require further research, are considered.

Among its principal purposes, the next ExoMars mission aims to the study of the martian climate and planetary boundary layer. The mission lander hosts the sensor MicroMED aimed to monitor the dust embedded into the atmosphere. This work presents the study of the MicroMED noise characteristics and the techniques adopted to filter the resulting false positive detections. In particular, it shows a simple algorithm able to optimize the instrument performances, when both an AC and DC signal interferences are involved.

The Dust Complex (DC) instrument was designed to be installed on the landing platform of the ExoMars project. The purpose of the experiment is to study the dynamics of dust particles in the near-surface atmosphere of Mars and to evaluate the main characteristics of the near-surface medium that determine their dynamics. The device makes it possible to register dust particles in the near-surface atmosphere of Mars, determine the main parameters and measure some characteristics of the plasma-dust medium related to the dynamics of dust particles near the Martian surface. The article provides a description of the device, its blocks and sensors, the main elements of the measurement program and characteristics of the measured parameters.

In 2022, our country will return to the Moon. This is a daunting task with many challenges and dangers. One of them, so far the least studied and most obscure, is the subject of this article, prepared using the materials of the report "Exploration of the Moon and Planets with the Help of Automatic Spacecraft: A Prelude to the Exploration of the Moon by Man" (it was heard at a scientific session of the General Meeting of RAS members on April 21, 2021). The surface of the Moon, like most atmosphereless bodies, is covered with a layer of dust: a fine fraction of regolith, crushed over hundreds of millions of years of being on the surface of the planet. Under the influence of external factors-both natural and anthropogenic-dust particles can rise from the surface, levitate under the influence of electrostatic forces, and settle on spacecraft. The experience of the six American Apollo manned missions showed that lunar dust microparticles affected the service systems of the lander, deposited on the astronauts' suits, got into the air recirculation systems of the sealed lander and, as a result, influenced the health of the astronauts. Considering the size of such particles, which can be tens or hundreds of nanometers, it has become clear that the toxicity of moondust is one of the most serious problems in the study of the Moon with human participation. This conclusion was made at the end of the Apollo program. The factor of lunar dust during manned missions to the Moon is discussed, and methods for solving this problem are outlined.

This study demonstrates the visualization and recovery of the 3D dynamic trajectories of charged microparticles in electric field conditions. The main aim of this work is to simulate plasma-dust processes above the surfaces of the Moon and other Solar system bodies without atmospheres. The experimental setup includes two parts: a vacuum chamber, in which microparticles imitate lunar dust dynamics under electrostatic field conditions, and a stereo camera system for image registration combined with laser and optics for illuminating the investigation volume. Image processing techniques for estimating the 3D particle trajectory were developed. Examples of processing results and their prospective application are discussed.

The program of scientific research of the Luna-25 lunar lander includes the experiment "Dust monitoring of the Moon" (in Russian, "Pylevoi monitoring Luny" (PmL)), which provides for the study of the dynamics of lunar microparticles and parameters of the near-surface dusty plasma. Using the PmL instrument, it is planned to record for a long time individual microparticles above the lunar surface, to measure and evaluate their physical characteristics (momentum, velocity, charge, mass, and concentration), as well as to monitor the dynamics of the parameters of the near-surface dusty plasma environment (density, temperature, and potential). The instrument has passed successfully the entire range of ground tests.

The dusty plasmas on the Moon are investigating through the direct detection of the dust particle fluxes on the lunar surface and through the measurements of the parameters of ambient plasma. The PmL instrument is the first device developed both to detect dust particles and to determine the characteristics of the plasma environment. The PmL instrument mounted on future Russian lunar missions Luna-25 and Luna-27 is described in the article. The suggested landing sites of the stations are situated nearby the Boguslavsky crater (nearby 70° south latitude of Moon). The values of the lunar surface potential, Debye length and electric field at a latitude of 70° were obtained in this paper. The distribution of the dust particles near the selected latitudes was also determined. A brief description of the methods for detecting the dusty plasma parameters near the lunar surface was suggested.

The future robotic and human lunar landing missions to the Moon has many factors which turn them into difficult technology and science tasks. One of these factors is the influence of the dust. Upper layers of the regolith are an insulator. The regolith exposed to permanent bombardment by micrometeorites and acquire a charge due to solar wind fluxes and solar UV radiation. These factors create a charge distribution on the surface of the Moon: positive on the illuminated side and negative on the night side. On the day side of the Moon near the surface layer exists possibility of formation an electric field. Charged dust particles of micron and submicron sizes can take off and levitate over the surface. The aim of the work is to get visualization of the dynamic of dust particles under a charged surface with simultaneously estimating its parameters as accurately as possible. The experimental setup based on vacuum chamber for physical modelling of dusty plasma levitation is described. For visualization of the dust particles trajectory a stereo system of two cameras with a laser as source of illumination is used. Image processing techniques for estimating the particle trajectory in three dimensional coordinates and examples of processing results are presented.

This paper presents first results of SPIS-DUST modelling of the interaction between the lunar plasma environment , regolith and a lander. The model takes into account the geometry of the Luna-Glob lander, the electric properties of materials used on the lander surface, as well as Luna-Glob landing place. Initial conditions were chosen based on the current theoretical models of formation of dusty plasma exosphere and levitating charged dust particles.