The paper presents new radar maps of the south polar region of the Moon at 4.2 cm wavelength with an average spatial resolution of 90 m. The maps are based on radar images obtained in 2023 using the 64-m TNA-1500 antenna of the Bear Lakes Satellite Communications Center of the Special Design Bureau of the Moscow Power Engineering Institute and the 13.2-m RT-13 radio telescopes at the Svetloe and Zelenchukskaya observatories of the Institute of Applied Astronomy of the Russian Academy of Sciences. Radar images are formed in a specific coordinate system relating the Doppler frequency shift with the propagation time delay of the echo components, which makes it difficult to tie them to selenographic coordinates. In this paper, an original method for converting echo Doppler frequency and time delay to selenographic latitude and longitude is proposed, using bilinear interpolation by ephemeris nodal values, taking into account long integration times. The accuracy of the reference of the maps constructed in this way was assessed and compared with the LROC WAC global optical map of the Moon and mosaics of permanently shadowed regions from LROC NAC. It is shown that radar maps at 4.2 cm wavelength contain features of the lunar surface that are hidden in optical images and are located in the regolith at depths of up to 1 m or in permanently shadowed regions of the south polar region of the Moon. The maps of the lunar echoes specular and diffuse polarization components, as well as a map of the distribution of circular polarization ratios, are available on the Internet at http://luna.iaaras.ru/ and can be useful for studying the geological history of the Moon, searching for ice deposits, and selecting safe landing sites when planning future lunar missions.

Previous models of microbial survival on the moon do not directly consider the permanently shadowed regions (PSRs). These regions shield their interiors from many of the biocidal factors encountered in space flight, such as UV irradiation and high temperatures, and this shielding reduces the rate at which microbial spores become nonviable. We applied the Lunar Microbial Survival Model (LMS, Schuerger et al., 2019) to the environment found inside PSRs at two craters targeted for exploration by the Artemis missions, Shackleton and Faustini. The model produced rates of reduction of -0.0815 and -0.0683 logs per lunation, respectively, which implies that it would take 30.0 years for Shackleton and 30.8 years for Faustini to accumulate a single Sterility Assurance Level of -12 logs of reduction. The lunar PSRs are therefore one of the least biocidal environments in the solar system and would preserve viable terrestrial microbial contamination for decades.

Lunar regolith samples contain fragments of endogenic rocks and exogenous meteorites. We report the first discovery of a chondrule fragment preserved in Chang'e-5 (CE-5) regolith samples. Forsterite and enstatite phenocrysts have extremely high Mg# (> 99) and high Mn/Fe ratios in this chondrule fragment. Its glass mesostasis is heterogeneous and contains hydrogen and carbon, as indicated by Raman peaks. The mineral assemblage, chemical composition, and oxygen isotope anomaly of this fragment are similar to those of type-I chondrules from carbonaceous chondrites. This fragment and other chondritic relics with 3.4 Ga. This contrast suggests that there may have been a change of impactors to the Earth-Moon system during the Imbrian period. Furthermore, this CE-5 chondrule fragment is a direct record of volatile addition to the Moon's surface from meteorites during the Eratosthenian period.

The construction of a lunar base requires a huge amount of material, which cannot be entirely transported from Earth. Therefore, technologies are needed to build with locally available resources, such as the lunar regolith. One approach is to directly melt the lunar regolith on the surface and under the vacuum condition of the Moon, using laser radiation. In this article, a lunar regolith simulant is laser beam melted to two-dimensional singlelayer-structures using different ambient pressures from 0.05 mbar to 2000 mbar, laser process parameters from 60 W to 100 W laser power, and 1 mm s- 1 to 3 mm s- 1 feed rates. Additionally, the influence of the ambient gas was investigated using argon as an air alternative. The results show that the ambient pressure on the Moon is not negligible when studying the melting processes of lunar regolith on Earth. With decreasing ambient pressure, the appearance of the melted regolith simulant varies from a shiny to a matt surface. At the highest laser energy density, the thickness of a single-layer increases from 2.6 +/- 0.4 mm to 5.3 +/- 0.3 mm and the porosity of the melted regolith increases from 17.2 % to 52.2 % with decreasing ambient pressure. Additionally, mechanical properties are determined using 3-point bending tests. The maximum bending strength decreases by 60 % with the increased ambient pressure from 10 mbar to 2000 mbar. Consequently, the development of in-situ resource utilization technologies, which process the lunar regolith directly on the lunar surface, must consider the ambient pressure on the Moon. Otherwise, the processes will not work as expected from the experiments in Earth-based laboratories.

Permanently shadowed regions (PSRs) on the Moon are potential reservoirs for water ice, making them hot spots for future lunar exploration. The water ice in PSRs would cause distinctive changes in space weathering there, in particular reduction-oxidation processes that differ from those in illuminated regions. To determine the characteristics of products formed during space weathering in PSRs, the lunar meteorite NWA 10203 with artificially added water was irradiated with a nanosecond laser to simulate a micrometeorite bombardment of lunar soil containing water ice. The TEM results of the water-incorporated sample showed distinct amorphous rims that exhibited irregular thickness, poor stratification, the appearance of bubbles, and a reduced number of npFe0. Additionally, EELS analysis showed the presence of ferric iron at the rim of the nanophase metallic iron particles (npFe0) in the amorphous rim with the involvement of water. The results suggest that water ice is another possible factor contributing to oxidation during micrometeorite bombardment on the lunar surface. In addition, it offers a reference for a new space weathering model that incorporates water in PSRs, which could be widespread on asteroids with volatiles.

The photogeologic analysis of the ShadowCam images of the permanently shadowed floor and lower parts of inner slopes of the near-polar lunar crater Shoemaker confirmed the conclusion of Basilevsky and Li (2024)that the surface morphology of the Shoemaker floor is dominated by a population of small (D < 1 km) craters. Future studies hopefully will allow to describe the morphology and morphometry (especially d/D) of the decameter- scale craters seen in the ShadowCam images. The surface of the lower parts of inners slopes of crater Shoemaker, which are permanently shadowed, has the elephant hide texture, that is also typical for normally illuminated slopes. So, most issues of the surface morphology were found to be identical or very close to those in normally illuminated regions of the Moon. The new finding in permanently shadowed areas is the presence of lobate-rimmed craters, whose morphology is probably indicative of water ice in the target material.

Micro cold traps stand out as promising targets for future investigation missions to the lunar polar regions, due to their greater accessibility compared to macro cold traps. However, this advantage naturally comes at the cost of their size, which limits the amount of ice they can potentially harbor. Here, we investigate the permanently shadowed volume (PSV) of micro cold traps - an upper limit for their potential ice capacity. We find that, as expected, the PSV depth increases with latitude and surface roughness, but is on average much shallower (similar to similar to 0.5 . 5 - 1%) ) compared to the topographic baseline. By comparing the expected destruction and accumulation rates of ice to the potential maximum capacity of micro cold traps, we predict their infill as a function of lateral size, and the lifetime of the ice they harbor. Our results could be used by future investigation missions to the lunar polar regions to constrain the delivery rate and delivery mechanism of ice to the Moon.

A realistic model of physico-chemical processes during collisions between meteoroids and the Moon considering condensation of refractory elements in the form of minerals and variable adiabatic index during expansion of impact-produced clouds was developed. Quenched chemical composition of impact-produced cloud is estimated. In accordance with this model relative fraction of atoms delivered to the lunar exosphere by impacts of meteoroids is significantly higher than that previously estimated with usage of the model with constant adiabatic index and without considering condensation as a factor affecting on pressure in impact-produced clouds.

From the scientific perspective, Artemis lunar missions focus on the south circumpolar region (SCR) mainly to investigate the existence and abundance of volatiles and to explore and sample ancient lunar deposits. The volatile distribution is primarily related to the cold traps in permanently shadowed regions, while the availability of ancient material is due to the proximity to the early lunar -2300 km diameter South Pole-Aitken (SPA) impact basin. One of the critical factors for future missions will be determining the geological structure and provenance (sources) of material at each candidate landing site, which can be predicted utilizing three-dimensional stratigraphic reconstructions of geological map units and crater ejecta deposits. This type of reconstruction permits a better understanding of candidate material that can be collected and analyzed at each site, and a ranking of landing sites can be formulated on this basis. Here, we present reconstructed geological cross-sections at Artemis landing sites using our recent SCR geological map and numerical modelling of crater ejecta thicknesses and their sequence.

The study of volatiles and the search for water are the primary objectives of the Luna-27 mission, which is planned to land on the south pole of the Moon in 2028. Here we present the tunable Diode Laser Spectrometer (DLS-L) that will be onboard the lander. The DLS-L will perform isotopic analysis of volatiles that are pyrolytically evolved from regolith. This article dives into the design of the spectrometer and the characterisation of isotopic signature retrieval. We look forward to expanding our knowledge of Lunar geochemistry by measuring D/H, 18O/17O/16O, 13C/12C ratios in situ, which would be the one-of-a-kind direct study of the lunar soil isotopy without sample contamination.