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While the surface missions to the Moon of the 1970s achieved a great deal, scientifically much was also left unresolved. The recent plethora of lunar missions (flown or proposed) reflects a resurgence in interest in the Moon, not ...
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While the surface missions to the Moon of the 1970s achieved a great deal, scientifically much was also left unresolved. The recent plethora of lunar missions (flown or proposed) reflects a resurgence in interest in the Moon, not only in its own right, but also as a record of the early solar system including the formation of the Earth. Results from recent orbiter missions have shown evidence of ice or at least hydrogen within shadowed craters at the lunar poles.
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According to the history of lunar detection, the relationship between selenodesy and lunar detection is reviewed, and the focus of the lunar detection and the lunar detection plan of China are summarized. The key techniques of sel...
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According to the history of lunar detection, the relationship between selenodesy and lunar detection is reviewed, and the focus of the lunar detection and the lunar detection plan of China are summarized. The key techniques of selenodesy are presented, and the applications of selenodesy to the lunar detection are discussed.
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We present the site selection process and urban planning of a Lunar Base for a crew of 10 (LB10), with an infrared astronomical telescope, based on the concept of the Lunar Liquid Mirror Telescope. LB10 is a base designated for pe...
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We present the site selection process and urban planning of a Lunar Base for a crew of 10 (LB10), with an infrared astronomical telescope, based on the concept of the Lunar Liquid Mirror Telescope. LB10 is a base designated for permanent human presence on the Moon. The base architecture is based on utilization of inflatable, rigid and regolith structures for different purposes. The location for the settlement is identified through a detailed analysis of surface conditions and terrain parameters around the Lunar North and South Poles. A number of selection criteria were defined regarding construction, astronomical observations, landing and illumination conditions. The location suggested for the settlement is in the vicinity of the North Pole, utilizing the geographical morphology of the area. The base habitat is on a highly illuminated and relatively flat plateau. The observatory in the vicinity of the base, approximately 3.5 kilometers from the Lunar North Pole, inside a crater to shield it from Sunlight. An illustration of the final form of the habitat is also depicted, inspired by the baroque architectural form.
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We present improved resolution maps of the Lunar Prospector Neutron Spectrometer thermal, epithermal, and fast neutron data and gamma ray spectrometer Th-line fluxes via global application of pixon image reconstruction techniques....
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We present improved resolution maps of the Lunar Prospector Neutron Spectrometer thermal, epithermal, and fast neutron data and gamma ray spectrometer Th-line fluxes via global application of pixon image reconstruction techniques. With the use of mock data sets, we show that the pixon image reconstruction method compares favorably with other methods that have been used in planetary neutron and gamma ray spectroscopy. The improved thermal neutron maps are able to clearly distinguish variations in composition across the lunar surface, including within the lunar basins of Hertzsprung and Schr?dinger. The improvement in resolution reveals a correlation between albedo and thermal neutron flux within the basins. The consequent increase in dynamic range confirms that Hertzsprung basin contains one of the most anorthositic parts of the lunar crust, including nearly pure anorthite over a region tens of kilometers in diameter. At Orientale, the reconstructed epithermal neutron data show broad overlap with circular polarization ratio but there remains a mismatch between measures of regolith maturity that sample the surface and those that probe the near subsurface, which is consistent with a complex layering scenario.
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Ever since the beginning of the space program, lunar habitation has always been on peoples' minds. Prior researchers have explored habitat building materials - some based on earth-based construction materials, some based on in-sit...
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Ever since the beginning of the space program, lunar habitation has always been on peoples' minds. Prior researchers have explored habitat building materials - some based on earth-based construction materials, some based on in-situ lunar resources. Geopolymer cement is a cementitious binder made of aluminosilicate materials such as lunar regolith. A cementitious binder made of lunar regolith as the main geopolymer precursor, instead of as an added aggregate, is a solution that has not been deeply explored in prior works. This research explores the curing process of lunar regolith based geopolymer cement in an environment that loosely approximates the lunar environment, using the lunar average daytime temperature and a vacuum. The results did not show much promise for the samples cured under both heat and vacuum as the longest-cured data point did not meet compressive strength standards, but another pathway to lunar habitation may be found in a separate set of samples that cured under heat and ambient atmospheric pressure.
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The parameters of various lunar figures are of interest to the scientific community working on lunar exploration. In this study, the size of the geometrically best fitting triaxial and rotational ellipsoids, and spheres, are estim...
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The parameters of various lunar figures are of interest to the scientific community working on lunar exploration. In this study, the size of the geometrically best fitting triaxial and rotational ellipsoids, and spheres, are estimated using the method of condition equations with common unknown parameters from the coordinates of 271,610 control points of the newly available lunar control, ULCN 2005. In the first set of solutions, the origin of the figures is calculated with respect to the center of the mass of the Moon. Their origins are set to coincide with the lunar center of mass in the second set of solutions. The new estimates are the most up-to-date values for the triaxial and rotational ellipsoidal and spherical parameters of the lunar figures and are significantly different up to half a km as compared to the most recent solutions.
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The lunar magma ocean (LMO) model was proposed after the discovery of anorthosite in Apollo 11 samples. However, the chemical and isotopic compositions of lunar anorthosites are not fully consistent with its LMO origin. We have an...
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The lunar magma ocean (LMO) model was proposed after the discovery of anorthosite in Apollo 11 samples. However, the chemical and isotopic compositions of lunar anorthosites are not fully consistent with its LMO origin. We have analyzed major and trace elements in anorthositic clasts from ten lunar feldspathic meteorites, which are related to the solidification of the LMO. The plagioclase rare earth element (REE) abundances and patterns are not correlated with the Mg# of coexisting mafic minerals in anorthosites, implying that mafic minerals and plagioclase may not be in chemical equilibrium, consistent with their textural differences. The REE abundances in plagioclase range approximately fortyfold, which cannot be produced by fractional crystallization of a single magma. Combining plagioclase trace element data from Apollo and meteoritic anorthosites, we propose that plagioclases derived from the LMO floated to the surface to form the primordial crust, which then may have been metasomatized by incompatible-element-rich KREEP (potassium, rare earth element, phosphorus) melts and mantle-derived partial melts. The lunar anorthosites may represent this metasomatized crust rather than solely a derivative from the LMO. Furthermore, silicate melts similar to the metasomatic agents may also have melted the crust to form the Mg-suite rocks. This hypothesis is consistent with overlapping ranges of age and initial ENd between lunar anorthosites and Mg-suite rocks. These events are consistent with an overturn event of the cumulate mantle very early after primordial crust formation to produce the partial melts that metasomatized the crust. (C) 2020 Elsevier B.V. All rights reserved.
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In this study, we investigated how well we can determine the lunar interior structure using available geodetic and seismic data based on the linear inverse method. We also evaluated how we can improve our knowledge of the lunar in...
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In this study, we investigated how well we can determine the lunar interior structure using available geodetic and seismic data based on the linear inverse method. We also evaluated how we can improve our knowledge of the lunar interior structure using geophysical data obtained in future lunar geodetic and seismic explorations. A posteriori errors of the lunar interior parameters determined from geodetic data obtained from the Japanese SELENE mission and seismic data obtained from the Apollo missions indicate that the lunar core size and density cannot be determined with sufficient accuracy to reveal core composition. We quantitatively showed that accuracies of the determination of core parameters will be improved by better determination of the Love number k_2 or h_2. This improvement will be achieved by the analysis of new gravity data obtained by the NASA GRAIL mission or our planned new Very Long Baseline Interferometry experiment on the Japanese SELENE-2 mission. This will enable us to determine the core size with an approximately 10% error and the core density with an approximately 25% error and improve our knowledge of the core. We will also be able to further reduce the errors in core density by applying future seismic network explorations and obtain information on the composition of the lunar core and its inner structure.
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The scientific objective of the Lunar-A, Japanese Penetrator Mission, is to explore the lunar interior by seismic and heat-flow experiments. Two penetrators containing two seismometers (horizontal and vertical components) and heat...
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The scientific objective of the Lunar-A, Japanese Penetrator Mission, is to explore the lunar interior by seismic and heat-flow experiments. Two penetrators containing two seismometers (horizontal and vertical components) and heat-flow probes will be deployed from a spacecraft onto the lunar surface, one on the near-side and the other on the far-side of the moon. The data obtained by the penetrators will be transmitted to the earth station via the Lunar-A mother spacecraft orbiting at an altitude of about 200 km. The spacecraft of a cylindrical shape, 2.2 m in maximum diameter and 1.7 m in height, is designed to be spin-stabilized. The spacecraft will be inserted into an elliptic lunar orbit, after about a half-year cruise during which complex manoeuvering is made using the lunar-solar gravity assist. After lunar orbit insertion, two penetrators will be separated from the spacecraft near perilune, one by one, and will be landed on the lunar surface.
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Lunar sinuous rilles (SRs) are enigmatic features interpreted to have formed as the result of lava erosion into the lunar surface. While specific SRs have been studied in detail over the past few decades, the most recent general s...
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Lunar sinuous rilles (SRs) are enigmatic features interpreted to have formed as the result of lava erosion into the lunar surface. While specific SRs have been studied in detail over the past few decades, the most recent general survey of these features was conducted in 1969 using Lunar Orbiter IV and V photographs. The current global study updates the catalog of SRs, using higher resolution SELENE and LRO image and topography data to provide detailed observations and measurements of the rilles observed across the lunar surface. The new survey catalogs more than 200 SRs that vary in length from 2 km to 566 km (median length 33.2 km), in width from 160 m to 4.3 km (median width 480 m), in depth from 4.8 m to 534 m (median depth 49 m), in slope from -1.4° to 0.5° (median slope -0.2°), and in sinuosity index from 1.02 to 2.1 (median sinuosity 1.19). Oceanus Procellarum contains 48% of the rilles mapped in this survey, and these rilles are typically associated with the known centers of volcanism within the Procellarum-KREEP Terrain, the Aristarchus Plateau and the Marius Hills. The current study also constrains the timing of the formation of lunar SRs, using the assumptions that the incised unit represents an upper age limit and the terminal or embaying unit represents a lower age limit. Results indicate that the distribution of ages of rille formation is highly correlated with the emplacement ages of mare units, where the majority of rilles are observed to have formed between 3.0 Ga and 3.8 Ga ago, though some of the features associated with the Aristarchus Plateau may have formed as recently as 1.0 Ga to 1.5 Ga ago. The documented observations can be used to better understand how SRs formed; for example, the range of slopes observed for all rilles (-1.4° to 0.5°) indicates that thermal erosion is likely dominant during the formation of the 78% of rilles that are observed to have formed in solidified mare basalt material, though mechanical erosion is likely to have been a more significant process during the formation of the 25% of observed rilles that originate in the highlands (20% of the mapped rilles crossed from the highlands into the mare), where a thicker regolith is expected to have been more easily eroded.
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