Selection of Lunar Rock Simulants Occurring on Earth for Rock Experiment Aiming at Lunar Development

In preparation for upcoming activities on the Moon, such as facility construction and resource development, which constitute the next step in the ongoing lunar exploration projects, we have compiled thoughts on the development of rock fracturing techniques on the Moon. This includes considerations for selecting lunar rock simulants, that is terrestrial rocks to simulate lunar rocks necessary for rock experiments aiming at these lunar developing activities. In detail, we have investigated the types of lunar rocks, and their textures and fundamental properties using the information of returned samples from the Moon, and then selected the suitable terrestrial rocks for lunar rock simulants. As the specific plans for lunar development progress, discussions of this nature become increasingly crucial in the technological discourse. Based on the current knowledge, the types of lunar rocks on the surface appear to be limited, with two types of rocks, namely anorthosite in the highlands and basalt in the mare, seeming adequately suitable for technological development. It is speculated that, for the time being, there may be no need to utilize other types of rocks. To simulate lunar anorthosite, it is estimated that terrestrial anorthosite formed at Precambrian 3.0-3.5 Ga is suitable, and also terrestrial gabbro or norite, with relatively high proportions of plagioclase, and diabase are useful. To simulate lunar basalt, it is estimated that terrestrial basalt and diabase are useful, by considering the relatively high concentration of pyroxene in lunar basalt. It is considered desirable to choose rocks that have undergone minimal alteration and contain as little hydrous and/or clay minerals as possible when selecting lunar rock simulants. Furthermore, chrematistics, including uniaxial compressive strength and tensile strength, of some terrestrial rocks of which types are candidates of lunar rock simulants are investigated. It is estimated that the failure strength of lunar rocks is widely ranged.