The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
Shaopeng Huang - One of the best experts on this subject based on the ideXlab platform.
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effects of solar radiation terrestrial radiation and Lunar Interior heat flow on surface temperature at the nearside of the moon based on numerical calculation and data analysis
Advances in Space Research, 2017Co-Authors: Yutian Song, Xueqiang Wang, Shaopeng Huang, Shengshan Bi, Jiangtao WuAbstract:Abstract Surface temperature at the nearside of the Moon ( T s,n ) embraces an abundance of valuable information to be explored, and its measurement contributes to studying Earth’s energy budget. On a basis of a one-dimensional unsteady heat-transfer model, this paper ran a quantitative calculation that how much the T s,n varies with the changes of different heat sources, including solar radiation, terrestrial radiation, and Lunar Interior heat flow. The results reveal that solar radiation always has the most important influence on T s,n not only during Lunar daytime (by means of radiation balance) but also during Lunar nighttime (by means of Lunar regolith heat conduction). Besides, the effect of terrestrial radiation is also unavoidable, and measuring the variation of Lunar nighttime low temperature is exactly helpful in observing Earth outgoing radiation. Accordingly, it is practical to establish a Moon-base observatory on the Moon. For verification, the Apollo 15 mission temperature data was used and analyzed as well. Moreover, other 9 typical Lunar areas were selected and the simulation was run one after another in these areas after proper model amendation. It is shown that the polar regions on the Moon are the best areas for establishing Moon-base observatory.
Wim Van Westrenen - One of the best experts on this subject based on the ideXlab platform.
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Neutral buoyancy of titanium-rich melts in the deep Lunar Interior
Nature Geoscience, 2012Co-Authors: Mirjam Van Kan Parker, Chrystèle Sanloup, Nicolas Sator, Bertrand Guillot, Elodie J. Tronche, Jean-philippe Perrillat, Mohamed Mezouar, Nachiketa Rai, Wim Van WestrenenAbstract:The absence of very deep moonquakes implies that the lower mantle of the Moon is partially molten. An analysis of the density range of Lunar melts at high pressures suggests that only titanium-rich melt is neutrally buoyant deep within the Moon. The absence of moonquakes originating deeper than about 1,100 km (ref. 1 ) implies that the lower mantle of the Moon could be partially molten. Up to 30% melt by volume has been estimated to exist between about 1,200 and 1,350 km depth^ 2 . However, the absence of recent volcanic activity at the Moon’s surface implies that such deep partial melts must be at least as dense as their surroundings. Here we use a combination of in situ synchrotron X-ray absorption techniques and molecular dynamics simulations to determine the density range of primitive Lunar melts at pressures equivalent to those in the Lunar Interior. We find that only melts that contain about 16 wt% titanium dioxide are neutrally buoyant at depths corresponding to the top of the proposed partial melt zone. These titanium-rich melts are formed by deep partial melting of titanium-rich rocks. As such rocks are thought to have formed at shallow levels during crystallization of the Lunar magma ocean, we infer that a significant vertical transport of mass occurred before melt formation. Our measurements therefore provide evidence for a large-scale overturn of the Lunar mantle shortly after crystallization of the magma ocean and point to the continuing influence of a dense, titanium-rich reservoir on Lunar Interior evolution.
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Neutral buoyancy of titanium-rich melts in the deep Lunar Interior
Nature Geoscience, 2012Co-Authors: Mirjam Van Kan Parker, Chrystèle Sanloup, Nicolas Sator, Bertrand Guillot, Elodie J. Tronche, Jean-philippe Perrillat, Mohamed Mezouar, Nachiketa Rai, Wim Van WestrenenAbstract:The absence of moonquakes originating deeper than about 1,100 km (ref. 1) implies that the lower mantle of the Moon couldbepartiallymolten.Upto30%meltbyvolumehas been estimated to exist between about 1,200 and 1,350km depth2. However, the absence of recent volcanic activity at the Moon's surface implies that such deep partial melts must be at least as dense as their surroundings. Here we use a combination of in situ synchrotron X-ray absorption techniques and molecular dynamics simulations to determine the density range of primitive Lunar melts at pressures equivalent to those in the Lunar Interior. We find that only melts that contain about 16 wt% titanium dioxide are neutrally buoyant at depths corresponding to the top of the proposed partial melt zone. These titanium-rich melts are formed by deep partial melting of titanium-rich rocks. As such rocks are thought to have formed at shallow levels during crystallization of the Lunar magma ocean, we infer that a significant vertical transport of mass occurred before melt formation. Our measurements therefore provide evidence for a large-scale overturn of the Lunar mantle shortly after crystallization of the magma ocean and point to the continuing influence of a dense, titanium-rich reservoir on Lunar Interior evolution.
Francis Albarède - One of the best experts on this subject based on the ideXlab platform.
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An intrinsic volatility scale relevant to the Earth and Moon and the status of water in the Moon
Meteoritics and Planetary Science, 2015Co-Authors: Francis Albarède, Emmanuelle Albalat, Cin-ty LeeAbstract:The notion of a dry Moon has recently been challenged by the discovery of high water contents in Lunar apatites and in melt inclusions within olivine crystals from two pyroclastic glasses. The highest and most compelling water contents were found in pyroclastic glasses that are not very common on the Lunar surface. To obtain more representative constraints on the volatile content of the Lunar Interior, we measured the Zn content, a moderately volatile element, of mineral and rock fragments in Lunar soils collected during Apollo missions. We here confirm that the Moon is significantly more depleted in Zn than the Earth. Combining Zn with existing K and Rb data on similar rocks allows us to anchor a new volatility scale based on the bond energy of nonsiderophile elements in their condensed phases. Extrapolating the volatility curve to H shows that the bulk of the Lunar Interior must be dry (
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An intrinsic volatility scale relevant to the Earth and Moon and the status of water in the Moon
Meteoritics & Planetary Science, 2014Co-Authors: Francis Albarède, Emmanuelle Albalat, Cin-ty A. LeeAbstract:The notion of a dry Moon has recently been challenged by the discovery of high water contents in Lunar apatites and in melt inclusions within olivine crystals from two pyroclastic glasses. The highest and most compelling water contents were found in pyroclastic glasses that are not very common on the Lunar surface. To obtain more representative constraints on the volatile content of the Lunar Interior, we measured the Zn content, a moderately volatile element, of mineral and rock fragments in Lunar soils collected during Apollo missions. We here confirm that the Moon is significantly more depleted in Zn than the Earth. Combining Zn with existing K and Rb data on similar rocks allows us to anchor a new volatility scale based on the bond energy of nonsiderophile elements in their condensed phases. Extrapolating the volatility curve to H shows that the bulk of the Lunar Interior must be dry (≤1 ppm). This contrasts with the water content of the mantle sources of pyroclastic glasses, inferred to contain up to approximately 40 ppm water based on H2O/Ce ratios. These observations are best reconciled if the pyroclastic glasses derive from localized water-rich heterogeneities in a dominantly dry Lunar Interior. We argue that, although late addition of 0.015% of a chondritic veneer to the Moon seems required to explain the abundance of platinum group elements (Day et al. 2007), the volatile content of the added material was clearly heterogeneous.
Mirjam Van Kan Parker - One of the best experts on this subject based on the ideXlab platform.
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Neutral buoyancy of titanium-rich melts in the deep Lunar Interior
Nature Geoscience, 2012Co-Authors: Mirjam Van Kan Parker, Chrystèle Sanloup, Nicolas Sator, Bertrand Guillot, Elodie J. Tronche, Jean-philippe Perrillat, Mohamed Mezouar, Nachiketa Rai, Wim Van WestrenenAbstract:The absence of very deep moonquakes implies that the lower mantle of the Moon is partially molten. An analysis of the density range of Lunar melts at high pressures suggests that only titanium-rich melt is neutrally buoyant deep within the Moon. The absence of moonquakes originating deeper than about 1,100 km (ref. 1 ) implies that the lower mantle of the Moon could be partially molten. Up to 30% melt by volume has been estimated to exist between about 1,200 and 1,350 km depth^ 2 . However, the absence of recent volcanic activity at the Moon’s surface implies that such deep partial melts must be at least as dense as their surroundings. Here we use a combination of in situ synchrotron X-ray absorption techniques and molecular dynamics simulations to determine the density range of primitive Lunar melts at pressures equivalent to those in the Lunar Interior. We find that only melts that contain about 16 wt% titanium dioxide are neutrally buoyant at depths corresponding to the top of the proposed partial melt zone. These titanium-rich melts are formed by deep partial melting of titanium-rich rocks. As such rocks are thought to have formed at shallow levels during crystallization of the Lunar magma ocean, we infer that a significant vertical transport of mass occurred before melt formation. Our measurements therefore provide evidence for a large-scale overturn of the Lunar mantle shortly after crystallization of the magma ocean and point to the continuing influence of a dense, titanium-rich reservoir on Lunar Interior evolution.
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Neutral buoyancy of titanium-rich melts in the deep Lunar Interior
Nature Geoscience, 2012Co-Authors: Mirjam Van Kan Parker, Chrystèle Sanloup, Nicolas Sator, Bertrand Guillot, Elodie J. Tronche, Jean-philippe Perrillat, Mohamed Mezouar, Nachiketa Rai, Wim Van WestrenenAbstract:The absence of moonquakes originating deeper than about 1,100 km (ref. 1) implies that the lower mantle of the Moon couldbepartiallymolten.Upto30%meltbyvolumehas been estimated to exist between about 1,200 and 1,350km depth2. However, the absence of recent volcanic activity at the Moon's surface implies that such deep partial melts must be at least as dense as their surroundings. Here we use a combination of in situ synchrotron X-ray absorption techniques and molecular dynamics simulations to determine the density range of primitive Lunar melts at pressures equivalent to those in the Lunar Interior. We find that only melts that contain about 16 wt% titanium dioxide are neutrally buoyant at depths corresponding to the top of the proposed partial melt zone. These titanium-rich melts are formed by deep partial melting of titanium-rich rocks. As such rocks are thought to have formed at shallow levels during crystallization of the Lunar magma ocean, we infer that a significant vertical transport of mass occurred before melt formation. Our measurements therefore provide evidence for a large-scale overturn of the Lunar mantle shortly after crystallization of the magma ocean and point to the continuing influence of a dense, titanium-rich reservoir on Lunar Interior evolution.
Mahesh Anand - One of the best experts on this subject based on the ideXlab platform.
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The hydrogen isotopic composition of Lunar melt inclusions: An interplay of complex magmatic and secondary processes
Geochimica et Cosmochimica Acta, 2020Co-Authors: A. Stephant, Romain Tartese, Mahesh Anand, X. Zhao, G. Degli-alessandrini, Ian A. FranchiAbstract:Abstract Since the discovery of water (a term collectively used for the total H, OH and H2O) in samples derived from the Lunar Interior, heterogeneity in both water concentration and its hydrogen isotopic ratio has been documented for various Lunar phases. However, most previous studies have focused on measurements of hydrogen in apatite, which typically forms during the final stages of melt crystallisation. To better constrain the abundance and isotopic composition of water in the Lunar Interior, we have targeted melt inclusions (MIs), in mare basalts, that are trapped during the earliest stages of melt crystallisation. Melt inclusions are expected to have suffered minimal syn- or post-eruption modification processes, and, therefore, should provide more accurate information about the history of H in the Lunar Interior. Here, we report H-/18O- measurements as calibrated water concentrations, and hydrogen isotope ratios obtained by secondary ion mass spectrometry (SIMS) in a large set of basaltic MIs from Apollo mare basalts 10020, 10058, 12002, 12004, 12008, 12020, 12040, 14072 and 15016. Our results demonstrate that partially crystallised MIs from Lunar basalts and their parental melts were influenced by a variety of processes such as hydrogen diffusion, degassing and assimilation of material affected by solar-wind implantation. Deconvolution of these processes show that Lunar basaltic parental magmas were heterogeneous and had a broadly chondritic hydrogen isotopic composition with δD values varying between -200 and +200 ‰.
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Water in evolved Lunar rocks: Evidence for multiple reservoirs
Geochimica et Cosmochimica Acta, 2016Co-Authors: K. L. Robinson, Mahesh Anand, Ian A. Franchi, Jessica Barnes, Kazuhide Nagashima, Aurélien Thomen, Gary R. Huss, G. Jeffrey TaylorAbstract:We have measured the abundance and isotopic composition of water in apatites from several Lunar rocks representing Potassium (K), Rare Earth Elements (REE), and Phosphorus (P) − KREEP − rich lithologies, including felsites, quartz monzodiorites (QMDs), a troctolite, and an alkali anorthosite. The H-isotope data from apatite provide evidence for multiple reservoirs in the Lunar Interior. Apatite measurements from some KREEP-rich intrusive rocks display moderately elevated δD signatures, while other samples show δD signatures similar to the range known for the terrestrial upper mantle. Apatite grains in Apollo 15 quartz monzodiorites have the lowest δD values measured from the Moon so far (as low as −749‰), and could potentially represent a D-depleted reservoir in the Lunar Interior that had not been identified until now. Apatite in all of these intrusive rocks contains 6500 ppm H2O). Complexities in partitioning of volatiles into apatite make this comparison uncertain, but measurements of residual glass in KREEP basalt fragments in breccia 15358 independently show that the KREEP basaltic magmas were low in water. The source of 15358 contained ∼10 ppm H2O, about an order of magnitude lower than the source of the Apollo 17 pyroclastic glass beads, suggesting potential variations in the distribution of water in the Lunar Interior.
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Determining the source(s) of water in the Lunar Interior
2015Co-Authors: Jessica Barnes, Romain Tartese, Mahesh Anand, Ian A. Franchi, Sara S. Russell, David A. KringAbstract:Recently, there have been numerous studies investigating the amount and isotopic composition of water in Lunar materials. The combined results from these investigations have provided two major insights that have challenged the long-standing paradigm of an anhydrous Moon. The first major insight relates to the new estimates for the water content of the bulk silicate Moon (BSM) ranging from ~ 10 to ~ 400 ppm H 2 O. The second major insight is related to the source of Lunar water, which ranges from Oort cloud comets, to carbonaceous chondrite-like asteroids, or perhaps even from the proto-Earth. Whilst we have some understanding about the flux of asteroids and comets to the Moon during the purported ‘late heavy bombardment’ (LHB; ~ 10 % comets, 90 % asteroids), we have very limited understanding of the flux of these objects during the first ~ 100 Ma of Lunar history (i.e., during Lunar differentiation or Lunar magma ocean (LMO) stage). In this study, we have estimated the mass of water delivered to the Moon in the first 100 Ma of its geological history that satisfies current estimates of water in the BSM, followed by an estimate of the relative proportions of asteroidal and cometary material delivered to the Moon that is consistent with the H-isotopic composition of water in the Lunar Interior.
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Understanding the origin and evolution of water in the Moon through Lunar sample studies
Philosophical transactions. Series A Mathematical physical and engineering sciences, 2014Co-Authors: Mahesh Anand, Romain Tartese, Jessica BarnesAbstract:A paradigm shift has recently occurred in our knowledge and understanding of water in the Lunar Interior. This has transpired principally through continued analysis of returned Lunar samples using modern analytical instrumentation. While these recent studies have undoubtedly measured indigenous water in Lunar samples they have also highlighted our current limitations and some future challenges that need to be overcome in order to fully understand the origin, distribution and evolution of water in the Lunar Interior. Another exciting recent development in the field of Lunar science has been the unambiguous detection of water or water ice on the surface of the Moon through instruments flown on a number of orbiting spacecraft missions. Considered together, sample-based studies and those from orbit strongly suggest that the Moon is not an anhydrous planetary body, as previously believed. New observations and measurements support the possibility of a wet Lunar Interior and the presence of distinct reservoirs of water on the Lunar surface. Furthermore, an approach combining measurements of water abundance in Lunar samples and its hydrogen isotopic composition has proved to be of vital importance to fingerprint and elucidate processes and source(s) involved in giving rise to the Lunar water inventory. A number of sources are likely to have contributed to the water inventory of the Moon ranging from primordial water to meteorite-derived water ice through to the water formed during the reaction of solar wind hydrogen with the Lunar soil. Perhaps two of the most striking findings from these recent studies are the revelation that at least some portions of the Lunar Interior are as water-rich as some Mid-Ocean Ridge Basalt source regions on Earth and that the water in the Earth and the Moon probably share a common origin.
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Tracking secular changes in the "water" content of Lunar Interior using basaltic Lunar meteorites
2012Co-Authors: Mahesh Anand, Romain Tartese, Kentaro Terada, Ian A. Franchi, Natalie A. Starkey, Y. SanoAbstract:Lunar meteorites provide a wider sampling of the Lunar surface compared to the samples collected during the Apollo and Luna Missions. Apatite is the main hydroxyl-bearing (proxy for water) mineral in Lunar samples, especially in basaltic rocks. Apatite is also amenable to in-situ U-Pb age dating studies. The ages of Lunar basaltic meteorites also span over a larger range compared to basaltic samples from Apollo and Luna collections. Thus, by determining the age, the H-content, and the H isotopic composition of apatites from Lunar basaltic meteorites, it is possible to investigate any secular variation in the water contents of the Lunar Interior.
