Three-dimensional shape distribution of lunar regolith particles collected by the Apollo and Luna programs
نویسندگان
چکیده
Abstract The shapes of regolith particles on airless bodies, such as the Moon and asteroids, are important to understand their formation evolution surfaces. Limited studies have shown that three-dimensional (3D) lunar are, average, more equant (spherical) than those asteroid Itokawa or fragments by impact experiments. Therefore, required determine whether a feature is common. Accordingly, we performed X-ray microtomography imaging collected Apollo program NASA Luna Soviet Union obtain 3D shapes. ten samples (65 1108 particles/sample) examined had varieties sampling sites (maria highlands), reflecting difference in materials (basalts anorthosites, respectively, general), maturities, particle size ranges (< 74 450 µm), petrographic textures (monomineralic, polymineralic, agglutinate). shape distributions regarding three-axial length ratios ( L : I S , where I, longest, intermediate, shortest lengths, respectively) showed average were almost similar among samples, irrespective sites, [ / = 0.770(8), 0.758(10), 0.581(11) for whole samples]. from hypervelocity experiments which 2D silver ratio 0.707 0.500). These findings balance between fragmentation mechanical abrasion controls because motion Moon’s surface occur longer duration; however, this small primarily particles. We also found dependence particles, could be explained strength against abrasion. results obtained study will basic data compared with upcoming new results, Ryugu, possibly Bennu Martian moons. Graphical
منابع مشابه
The Lunar Regolith
Regolith is a terrestrial term, also used for the Moon. It has been defined as " a general term for the layer or mantle of fragmental and unconsolidated rock material, whether residual or transported and of highly varied character, that nearly everywhere forms the surface of the land and overlies or covers bedrock. It includes rock debris of all kinds, [including] volcanic ash. .. " (Bates and ...
متن کاملLunar rock-rain: Diverse silicate impact-vapor condensates in an Apollo-14 regolith breccia
Apollo 14 regolith breccia 14076, long known to be uniquely endowed with high-alumina, silica-poor (HASP) material of evaporation-residue origin, has been found to contain a diverse suite of complementary condensates, dubbed GASP (gas-associated spheroidal precipitates). GASP occurs in two forms: as glassy or extremely fine grained quenched-melt spheroids, mostly less than 5 lm across; and as q...
متن کاملLunar Ranging, Gravitomagnetism, and APOLLO
The technique of lunar laser ranging (LLR) has for many decades contributed to cutting-edge tests of the fundamental nature of gravity. These include the best tests to date of the strong equivalence principle, the time-rate-of-change of the gravitational constant, gravitomagnetism, the inverse square law, and preferred frame effects. The phenomenologies of each are briefly discussed, followed b...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Earth, Planets and Space
سال: 2022
ISSN: ['1880-5981', '1343-8832']
DOI: https://doi.org/10.1186/s40623-022-01737-9