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The objective of this study is to systematically examine the drilling efficiency and performance of various core drill bits in lunar rock formation using the discrete element method (DEM) and drilling experiments conducted in a lunar vacuum environment. This research aims to establish a scientific foundation for selecting core drill bits for lunar deep drilling operations. To achieve this, four distinct core drill bits were designed. Subsequently, a numerical model of lunar rock was constructed and the load characteristics and drilling efficiency of each bit during the drilling process were analyzed using DEM. Drilling and coring tests were then performed in both atmospheric and lunar vacuum environments, thereby validating the numerical simulation results and providing a comprehensive evaluation of the actual performance of the core drill bits. The study revealed that the carbide-tipped core drill bit with octagonal prisms design resulted in the core disking due to a significant rise in temperature, underscoring the critical importance of temperature control in maintaining core integrity. While the carbide-tipped core drill bit with cutting edges demonstrates exceptional drilling efficiency and coring quality, its inherent fragility and rapid wear of the cutting edges present considerable challenges for practical application. The diamond-impregnated core drill bit is unsuitable for drilling operations under lunar loads and power limitations due to its high weight-on-bit (WOB) requirements. In contrast, the PDC core drill bit exhibits excellent drilling stability, low rotary torque requirements, minimal temperature-rise effects, and significantly enhanced penetrating speed in the lunar vacuum environment, making it a recommended choice for lunar rock drilling. This study provides substantial theoretical and experimental support for the development of lunar drilling equipment and the formulation of effective drilling strategies. Highlights An improved HMB contact model was used in the numerical simulation calculations. Simulated lunar rock drilling tests were conducted in both atmospheric and vacuum environments, and a comparative analysis was performed with the numerical simulation results. Among the four self-designed drill bits, the PDC bit was identified as the most suitable for lunar rock drilling through comparative selection.

The lunar surface is ancient and well-preserved, recording Solar System history and planetary evolution processes. Ancient basin-scale impacts excavated lunar mantle rocks, which are still expected to be present on the surface. Sampling these rocks would provide insight into fundamental planetary processes, including differentiation and magmatic evolution. There is contention among lunar scientists as to what lithologies make up the upper lunar mantle, and where they may have been exposed on the surface. We review dynamical models of lunar differentiation in the context of recent experiments and spacecraft data, assessing candidate lithologies, their distribution, and implications for lunar evolution.

[...]Chang'e-6 autonomously deployed its drill and scoop to collect soil and regolith - the rocky material covering the Moon's surface. \"China is successfully carrying out complex operations on the lunar far side,\" says Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. Because the Moon is tidally locked to Earth, its far side never faces us - so it's a part of the Moon that few humans have seen.

Yutu-2 rover conducted an exciting expedition on the 41st lunar day to investigate a fin-shaped rock at Longji site (45.44°S, 177.56°E) by extending its locomotion margin on perilous peaks. The varied locomotion encountered, especially multi-form wheel slippage, during the journey to the target rock, established unique conditions for a fin-grained lunar regolith analysis regarding bearing, shear and lateral properties based on terramechanics. Here, we show a tri-aspect characterization of lunar regolith and infer the rock’s origin using a digital twin. We estimate internal friction angle within 21.5°−42.0° and associated cohesion of 520-3154 Pa in the Chang’E-4 operational site. These findings suggest shear characteristics similar to Apollo 12 mission samples but notably higher cohesion compared to regolith investigated on most nearside lunar missions. We estimate external friction angle in lateral properties to be within 8.3°−16.5°, which fills the gaps of the lateral property estimation of the lunar farside regolith and serves as a foundational parameter for subsequent engineering verifications. Our in-situ spectral investigations of the target rock unveil its composition of iron/magnesium-rich low-calcium pyroxene, linking it to the Zhinyu crater (45.34°S, 176.15°E) ejecta. Our results indicate that the combination of in-situ measurements with robotics technology in planetary exploration reveal the possibility of additional source regions contributing to the local materials at the Chang’E-4 site, implying a more complicated geological history in the vicinity. Digital twins can be used to support planetary operations and analysis. Here, the authors show tri-aspect characterization of lunar far side regolith and investigate the origin of a fin-shaped rock via digital twin of Yutu-2 rover.

The last giant impact on Earth is thought to have formed the Moon 1 . The timing of this event can be determined by dating the different rocks assumed to have crystallized from the lunar magma ocean (LMO). This has led to a wide range of estimates for the age of the Moon between 4.35 and 4.51 billion years ago (Ga), depending on whether ages for lunar whole-rock samples 2 , 3 – 4 or individual zircon grains 5 , 6 – 7 are used. Here we argue that the frequent occurrence of approximately 4.35-Ga ages among lunar rocks and a spike in zircon ages at about the same time 8 is indicative of a remelting event driven by the Moon’s orbital evolution rather than the original crystallization of the LMO. We show that during passage through the Laplace plane transition 9 , the Moon experienced sufficient tidal heating and melting to reset the formation ages of most lunar samples, while retaining an earlier frozen-in shape 10 and rare, earlier-formed zircons. This paradigm reconciles existing discrepancies in estimates for the crystallization time of the LMO, and permits formation of the Moon within a few tens of million years of Solar System formation, consistent with dynamical models of terrestrial planet formation 11 . Remelting of the Moon also explains the lower number of lunar impact basins than expected 12 , 13 , and allows metal from planetesimals accreted to the Moon after its formation to be removed to the lunar core, explaining the apparent deficit of such materials in the Moon compared with Earth 14 . Lunar rock and zircon ages were reset by a remelting event driven by the Moon’s orbital evolution, reconciling existing discrepancies in estimates for the formation time of the Moon and the crystallization time of its magma ocean.

The abundance of volatile elements and compounds, such as zinc, potassium, chlorine, and water, provide key evidence for how Earth and the Moon formed and evolved. Currently, evidence exists for a Moon depleted in volatile elements, as well as reservoirs within the Moon with volatile abundances like Earth’s depleted upper mantle. Volatile depletion is consistent with catastrophic formation, such as a giant impact, whereas a Moon with Earth-like volatile abundances suggests preservation of these volatiles, or addition through late accretion. We show, using the “Rusty Rock” impact melt breccia, 66095, that volatile enrichment on the lunar surface occurred through vapor condensation. Isotopically light Zn (δ66Zn = −13.7‰), heavy Cl (δ37Cl = +15‰), and high U/Pb supports the origin of condensates from a volatile-poor internal source formed during thermomagmatic evolution of the Moon, with long-term depletion in incompatible Cl and Pb, and lesser depletion of more-compatible Zn. Leaching experiments on mare basalt 14053 demonstrate that isotopically light Zn condensates also occur on some mare basalts after their crystallization, confirming a volatile-depleted lunar interior source with homogeneous δ66Zn ≈ +1.4‰. Our results show that much of the lunar interior must be significantly depleted in volatile elements and compounds and that volatile-rich rocks on the lunar surface formed through vapor condensation. Volatiles detected by remote sensing on the surface of the Moon likely have a partially condensate origin from its interior.

Rocks with P-bearing olivine were found in soil samples delivered by the “Luna-20” automated station. They are ascribed to the highland anorthosite–norite (more rarely, gabbro-norite)–troctolite rock series enriched in phosphorus and other incompatible elements, but are not related to typical KREEP rocks enriched in incompatible elements. Their source is presumably of hybrid origin and related to primary high- Mg suite (HMS) rocks. The occurrence of high- and low-Cr populations of P-bearing olivine in different structural rock types can be attributed to the annealing-related more rapid chromium diffusion (relative to that of phosphorus) in olivine from metamorphosed rocks. This assumption is supported by stoichiometric formula calculations of these olivines. An alternative explanation for these olivine populations is their derivation from at least two different sources. Disequilibrium crystallization of the P-bearing olivines, which is confirmed by an intricate phosphorus zoning, excludes the existence of P-rich melts, which is consistent with previous observations. At the same time, olivine fractionation can be responsible for the phosphorus content in lunar melts. The incorporation of phosphorus in olivine of the “Luna-20” anorthosite troctolites is presumably controlled by a coupled substitution mechanism of divalent cations and silicon for phosphorus and chromium in the tetrahedral and octahedral sites (Milman-Barris et al., 2008). Another possible mechanism is the substitution of divalent cations in octahedral sites by phosphorus and chromium, which provides the possible presence of P3+.

Extravehicular activities will play a crucial role in lunar exploration on upcoming Artemis missions and may involve astronauts operating a lunar terrain vehicle (LTV) in a standing posture. This study assessed kinematic response and injury risks using an active muscle human body model (HBM) restrained in an upright posture on the LTV by simulating dynamic acceleration pulses related to lunar surface irregularities. Linear accelerations and rotational displacements of 5 lunar obstacles (3 craters; 2 rocks) over 5 slope inclinations were applied across 25 simulations. All body injury metrics were below NASA’s injury tolerance limits, but compressive forces were highest in the lumbar (250–550N lumbar, tolerance: 5300N) and lower extremity (190–700N tibia, tolerance: 1350N) regions. There was a strong association between the magnitudes of body injury metrics and LTV resultant linear acceleration (ρ = 0.70–0.81). There was substantial upper body motion, with maximum forward excursion reaching 375 mm for the head and 260 mm for the chest. Our findings suggest driving a lunar rover in an upright posture for these scenarios is a low severity impact presenting low body injury risks. Injury metrics increased along the load path, from the lower body (highest metrics) to the upper body (lowest metrics). While upper body injury metrics were low, increased body motion could potentially pose a risk of injury from flail and occupant interaction with the surrounding vehicle, suit, and restraint hardware.

Lunar rock fragments, particularly those deemed pristine, have long been considered vital records of the Moon’s formation and magmatic evolution. These fragments were thought to have largely escaped the Moon’s intense impact history, offering a window into the early lunar crust. However, the concept of “pristine” is increasingly debated, as traditional criteria for identifying pristine samples—based on texture, mineral content, and siderophile element abundances—may overlook the extensive effects of impact reworking. In this study, we apply a novel high-resolution geochemical and experimental approach, linking zircon Al content to parent melt composition, to critically assess lunar samples. Our findings reveal that clast zircons, assumed to preserve magmatic history, and matrix zircons, considered the last igneous remnants in brecciated samples, are not in chemical equilibrium with their surrounding glass. This disequilibrium, coupled with heterogeneous zircon ages, provides compelling evidence for pervasive impact reworking, challenging the assumption that these samples represent primary igneous lithologies. These results underscore the need for a serious re-evaluation of lunar materials. New analytical tools, tailored to each critical lunar lithology, will be essential for this reassessment—such as the Al-in-zircon method employed here for zircon-bearing samples. This study challenges the long-standing assumption that some lunar samples are pristine, revealing pervasive impact modification. Using Al-in-zircon geochemistry, we demonstrate that key lunar rock fragments are not primary magmatic products, raising fundamental questions about the accuracy of lunar evolution models and the very records used to reconstruct the Moon’s history.

Numerous paleomagnetic studies attribute the magnetization preserved within Apollo samples to an ancient dynamo. However, other works propose that lunar rocks were instead magnetized by either transient impact‐related magnetic fields on the Moon or by the return spacecraft. To test whether lunar samples could have been magnetized during return to Earth, sample handling, or transport, we exposed lunar rocks to 5–10 mT fields for varying durations. We then determined how easily these magnetic overprints could be removed and how paleointensity estimates are affected by the overprints and their removal. We found that magnetic overprints were cleaned by alternating field (AF) demagnetization to ∼10–30 mT for nearly all samples and that acceptable paleointensities may be obtained from higher AF levels. Therefore, high coercivity (>30 mT) magnetizations observed within lunar rocks are generally not magnetic contamination and were initially acquired on the Moon. Plain Language Summary Scientists study magnetism preserved within rocks to understand the histories of magnetic fields on planets. However, exposure to strong magnetic fields such as those produced by spacecraft electronics or magnets can partially remagnetize rocks. Therefore, it is important to rule out magnetic contamination in samples prior to making inferences about the histories of natural magnetic fields generated by planets or by meteorite impacts. We conducted a series of experiments wherein we intentionally exposed various rocks from the Moon to strong magnetic fields to (a) see how easily magnetic contamination could be removed and (b) understand how the contamination and secondary effects related to its removal could skew our interpretation of ancient lunar magnetic field intensities. We found that, in nearly all cases, techniques commonly used by rock magnetism specialists were able to successfully remove magnetic contamination without sacrificing accuracy in determining the intensity of ancient lunar magnetic fields from magnetically uncontaminated portions of rocks. Therefore, we conclude that much of the magnetization observed in lunar rocks is natural in origin and was acquired on the Moon. Key Points Magnetic fields associated with spacecraft transit or certain laboratory procedures may impart lunar samples with magnetic overprints We find such magnetic contamination can be successfully cleaned from nearly all samples, enabling reliable paleointensity determinations The modern lunar paleointensity record reflects magnetization acquired on the Moon from ancient dynamo fields or impact‐related fields