## 2 Moon Raw Material Surveying Strategy
### Water Ice Deposits
Areas on the Moon where various substances settle due to the low temperature are called cold traps. The temperature [38] in the permanently shaded regions (PSR) can drop even to \(-170\)\({}^{\circ}\)C. However, there are even colder places on the Moon [39] that are ultra-cold traps. These are [38] double-shaded areas where the temperature can drop even to \(-250\)\({}^{\circ}\)C. The ordinary permanently shaded regions (PSR) never reaches the light rays directly emitted by the Sun. However, heat rays emitted by sun-heated slopes or radiation reflected from these slopes may reach the area. A double-shaded area is one that does not even receive this secondary radiation, resulting in it being extremely cold and temperatures lower than in regular PSR areas. The importance of cold traps for the formation of some deposits on the Moon can be understood on the example of the mechanism for the formation of gold deposits proposed in [40]. There is no atmosphere or strong magnetic field on the Moon, which allows charged particles of the solar wind and cosmic rays to freely reach the lunar surface, which has its consequences. Charged particles falling on the lunar surface electrify the surface layer of the lunar soil. This means that particles of various minerals, if charged, can levitate in an electrostatic field. Particles [40] of gold can reach a dynamic equilibrium height of about 9 m in a few minutes. The levitating particles are carried away by particles of the solar wind, and their movement is influenced by the lines of the local residual magnetic field. The movement of charged particles is possible until they reach a non-electrified area, which occurs where sunlight does not reach, i.e., in shaded areas, which are therefore cool areas. The described mechanism affects not only the formation of gold deposits on the Moon, but also other minerals, as well as deposits of the so-called volatile substances that accumulate in colder regions. This is the reason why such places are called cold traps, and why looking for them is so important. Even in the case of helium-3 deposits, the described mechanism is important. Incident solar rays heating the regolith cause some of the helium contained in them to be released and carried away by particles of the solar wind, and then deposited in the areas of cold traps. A similar phenomenon also occurs for ilmenite, but to a lesser extent, because ilmenite binds helium more strongly. Therefore, higher concentrations of helium-3 should also be expected in shaded regions in cold traps. The ranking of cold traps in terms of the abundance of volatile substances can be found in the publication [41]. In turn, publication [42] presents the relationship between the crater depth and diameter ratio (d/D). The authors analyzed the d/D ratio for 753 craters ranging from 200 to 1000 miles in diameter and with an inclination of less than 25\({}^{\circ}\) located at the Moon's south pole and grouped the craters into two groups: craters containing perennially shadowed regions (PSR) and those without PSR. The d/D ratios of craters containing PSR compared to craters without PSR fall into two distinct groups, which means that these two groups may show some geomorphological differences. According to the authors, the difference in d/D ratios may be caused by the presence of a subsurface ice layer in the PSR. However, the influence of diffusive degradation of craters or various geological units cannot be rejected. Using this relatively simple method, it is possible to automatically pre-select craters containing PSR areas that are suspected of containing subsurface ice. When analyzing water ice deposits, the occurrence of the \"Moon gardening\" process should be taken into account [43]. This is a process in which the lunar surface material is mixed as a result of the bombardment of the moon by micrometeorites. As a result of these processes, water ice is mixed with regolith, or is located under a layer of regolith up to several meters high.