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High resolution images of stratified ejecta boulders on the lunar nearside reveal layers of alternating low and high albedo material. We measured the thickness and albedo of each alternating light and dark layer from 29 stratified boulders located in Aristarchus Crater and Mare Undarum. The results were used to test hypotheses to explain the origin of the observed strata in these impact ejected boulders...
We have developed a new method for regional mapping of the lunar magnetic anomalies as the vector field at the surface using the satellite observation, that is the surface vector mapping (SVM). The SVM is based on the inverse boundary value problem with a spherical boundary surface. There are two main procedures for reducing effects of bias and noise on mapping: (1) preprocessing the data to provide...
The present study aims to constrain the composition of the initial lunar magma ocean (LMO) with fluid dynamic and thermodynamic consideration. A plausible range of the initial LMO composition is investigated by developing an incremental polybaric fractional crystallization model with variable fractionation efficiency to satisfy three conditions for the anorthosite crust formation: (1) the amount of...
According to the standard giant impact hypothesis, the Moon formed from a partially vaporized disk generated by a collision between the proto-Earth and a Mars-sized impactor. The initial structure of the disk significantly affects the Moon-forming process, including the Moon’s mass, its accretion time scale, and its isotopic similarity to Earth. The dynamics of the impact event determines the initial...
Bulk surface hydrogen enhancements have been identified within the Moon’s Shackleton crater. Using an analysis of fast and epithermal neutron data from the Lunar Prospector mission, the permanently shadowed region (PSR) within this crater has a surface concentration of 0.72±0.13wt.% water equivalent hydrogen (WEH). In contrast, hydrogen enhancements within other polar PSRs such as Cabeus are likely...
Since early 2012, the Lyman-Alpha Mapping Project (LAMP) far-ultraviolet spectrograph on the Lunar Reconnaissance Orbiter (LRO) spacecraft has carried out a series of limb observations from within lunar shadow to search for the presence of a high altitude dust exosphere via forward-scattering of sunlight from dust grains. Bright “horizon-glow” was observed from orbit during several Apollo missions...
The identification of impact craters on planetary surfaces provides important information about their geological history. Most studies have relied on individual analysts who map and identify craters and interpret crater statistics. However, little work has been done to determine how the counts vary as a function of technique, terrain, or between researchers. Furthermore, several novel internet-based...
A comparative assessment of the mineralogy of young basalts (∼1.2Ga to ∼2.8Ga) from the western nearside, Moscoviense basin, and the Orientale basin of the Moon has been made using Level 2 Moon Mineralogy Mapper (M 3 ) data from the Chandrayaan-1 mission. Spectral data characteristics of the individual units have been generated from fresh small craters to minimize the complications due to...
We report on a multi-year dataset of daily averaged observations of He in the lunar atmosphere by the LAMP UV spectrograph on NASA’s Lunar Reconnaissance Orbiter (LRO). We examine data obtained from the start of the LRO orbital tour in September 2009 to March 2013. We find that the maximum He number density occurs about two hours after local midnight, which is consistent with earlier measurements...
We investigate the possibility that a strong core dynamo of the Moon has magnetized the lunar crust. The magnetic data from two missions, Lunar Prospector and Kaguya, are used and the magnetic fields of two different features are examined: The isolated small magnetic source bodies with almost no topographic signatures, and the impact craters with diameters larger than 100km. Five data sets are examined...
The flashes from meteoroid impacts on the Moon are useful in determining the flux of impactors with masses as low as a few tens of grams. A routine monitoring program at NASA’s Marshall Space Flight Center has recorded over 300 impacts since 2006. A selection of 126 flashes recorded during periods of photometric skies was analyzed, creating the largest and most homogeneous dataset of lunar impact...
In this study, we analyzed the distribution and properties of 146 craters with impact melt deposits exterior to their rims. Many of these craters were only recently discovered due to their unusual radar properties in the near-global Mini-RF data set. We find that most craters with exterior deposits of impact melt are small, ⩽20km, and that the smallest craters have the longest melt flows relative...
The giant impact hypothesis for the origin of the Moon points to the creation of a hot, young Moon, likely with a global magma ocean. Such a magma ocean would produce a flotation crust of plagioclase crystals, or an anorthositic crust. Early calculations of the expected anorthosite content of the lunar highlands crust did not match initial measurements of Apollo samples, and more recently have not...
Historically, topographic profiles provided a quantitative means to investigate the morphology and formation processes for impact craters, although no generic mathematical framework was developed to reduce profiles to morphology descriptors. Only need-specific polynomial expressions were utilized in previous studies, thus no standardized automated comparison of craters exists. We employ a Chebyshev...
Knowing the isotopic composition of Theia, the proto-planet which collided with the Earth in the Giant Impact that formed the Moon, could provide interesting insights on the state of homogenization of the inner Solar System at the late stages of terrestrial planet formation. We use the known isotopic and modeled chemical compositions of the bulk silicate mantles of Earth and Moon and combine them...
The lunar surface is characterized by asymmetric distribution of its volcanic deposits. The nearside contains about 90% of the mare basalts, while there are a few on the farside with some are in the South Pole Aitken (SPA) basin, which is the largest and oldest impact basin on the Moon. Although the mare volcanism on the nearside of the Moon has been very well characterized, our understanding of the...
Radar provides a unique means to analyze the surface and subsurface physical properties of geologic deposits, including their wavelength-scale roughness, the relative depth of the deposits, and some limited compositional information. The NASA Lunar Reconnaissance Orbiter’s (LRO) Miniature Radio Frequency (Mini-RF) instrument has enabled these analyses on the Moon at a global scale. Mini-RF has accumulated...
The lunar nearside large volcanic complexes, such as the Rümker Hills, Aristarchus Plateau, and Marius Hills are likely sites of intense and sustained magmatic activity. These volcanic complexes, recently proposed to be shield volcanoes, are generally located at regionally high elevations and some feature relatively well-localized positive gravity anomalies. Applying localized spectral analyses on...
The Moon has areas of magnetized crust (“magnetic anomalies”), the origins of which are poorly constrained. A magnetic anomaly near the northern rim of South Pole-Aitken (SPA) basin was recently postulated to originate from remnant metallic iron emplaced by the SPA basin-forming impactor. Here, we remotely examine the regolith of this SPA magnetic anomaly with a combination of Clementine and Lunar...
Cryptomaria, lunar volcanic deposits obscured by crater and basin impact ejecta, can provide important information about the thermal and volcanic history of the Moon. The timing of cryptomare deposition has implications for the duration and flux of mare basalt volcanism. In addition, knowing the distribution of cryptomaria can provide information about mantle convection and lunar magma ocean solidification...
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