Three-dimensional features of chondritic meteorites : applying micro-computed tomography to extraterrestrial material

This work examines the application of X-ray computed tomography (XCT) in meteoritics. This powerful technique uses the attenuation of X-rays passing through a sample to map it in three dimensions, allowing for the imaging and quantification of phases and features without the need for destructive sampling. XCT is a novel method with its applications to planetary science only recently recognised and not extensively explored. As such, this study presents two examples of using XCT to both elucidate its potential, and better understand the constituents of chondritic meteorites and the processes experienced on their parent bodies. To test the reliability of XCT, the data are conjoined with standard analytical techniques. Firstly, the 3D fabric and textural properties of 17 L chondrites of varying petrological type and shock stage are described. Specifically, porosity is imaged, quantified and compared with pycnometry data. For each chondrite, the size distribution and orientations of metal grains are reconstructed and correlated with the degree and direction of anisotropy of magnetic susceptibility in the sample. Both porosity and metal grain fabrics reveal trends with progressive thermal and shock metamorphism. The mechanisms accounting for such correlation are explored. Secondly, XCT is used to survey fragments of the Barwell L6 meteorite to identify and locate igneous inclusions. From this data, several inclusions were then subsampled and further geochemically investigated, including oxygen isotopic compositions, hafnium-tungsten systematics, and trace element analysis. Studied inclusions are found to be similar in composition and age to chondrules, but depleted in metal. A possible formation scenario is proposed and the potential link to chondrule formation is discussed. Using these examples, the factors influencing the accuracy of XCT data acquisition and processing are described. The benefits and limitations of the technique, with respect to the analysis of extraterrestrial material and implications for future use, are also considered

Marshall Space Flight Center Research and Technology Report 2019

Today, our calling to explore is greater than ever before, and here at Marshall Space Flight Centerwe make human deep space exploration possible. A key goal for Artemis is demonstrating and perfecting capabilities on the Moon for technologies needed for humans to get to Mars. This years report features 10 of the Agencys 16 Technology Areas, and I am proud of Marshalls role in creating solutions for so many of these daunting technical challenges. Many of these projects will lead to sustainable in-space architecture for human space exploration that will allow us to travel to the Moon, on to Mars, and beyond. Others are developing new scientific instruments capable of providing an unprecedented glimpse into our universe. NASA has led the charge in space exploration for more than six decades, and through the Artemis program we will help build on our work in low Earth orbit and pave the way to the Moon and Mars. At Marshall, we leverage the skills and interest of the international community to conduct scientific research, develop and demonstrate technology, and train international crews to operate further from Earth for longer periods of time than ever before first at the lunar surface, then on to our next giant leap, human exploration of Mars. While each project in this report seeks to advance new technology and challenge conventions, it is important to recognize the diversity of activities and people supporting our mission. This report not only showcases the Centers capabilities and our partnerships, it also highlights the progress our people have achieved in the past year. These scientists, researchers and innovators are why Marshall and NASA will continue to be a leader in innovation, exploration, and discovery for years to come

Extracting Martian Meteorite Mineral Spectra for Remote Sensing of the Surface Geology of Mars

The source craters of the Martian meteorites remain unknown. This PhD extracted pyroxene mid-infrared spectra directly from the shergottites to supplement the current spectral libraries in modelling the geology of the Martian surface. Models using planet-representative spectral end members improves the spectral fit of the modelling, and the accuracy of the mineral abundance determination

Abstracts to Be Presented at the 2015 Supercomputing Conference

Compilation of Abstracts to be presented at the 2015 Supercomputing Conferenc

Program and abstract volume

The workshop will focus on why sample return science is important to the future of solar system science and exploration, including the implications for NASA as it plans and implements future missions to a variety of solar system locations.Lunar and Planetary Institute, National Aeronautics and Space Administration, Planetary Science Division, Mars Exploration Programconveners Deborah Bass NASA Mars Program Office, David Beaty NASA Mars Program Office, Catharine Conley NASA Planetary Protection, Clive Neal University of Notre Dame, Meenakshi Wadhwa CAPTEM ChairPARTIAL CONTENTS: Curating NASA's Extraterrestrial Samples — Past, Present, and Future / C. Allen, J. Allton, G. Lofgren, K. Righter, and M. Zolensky--Sample Return Missions Where Contamination Issues are Critical: Genesis Mission Approach / J. H. Allton and E. K. Stansbery--Analysis of the End to End Science of the Potential Mars Sample Return Campaign / A. C. Allwood, C. Herd, D. W. Beaty, and E2E-iSAG Team--Sample Return Propulsion Technology Development Under NASA's ISPT Project / D. J. Anderson, J. Dankanich, D. Hahne, E. Pencil, T. Peterson, and M. M. Mun

Investigation and Classification of Planetary Materials and Surfaces using Novel Methods to Analyze Large Compositional Datasets: Quantitative X-ray Compositional Mapping and Lunar Reconnaissance Orbiter Narrow Angle Camera Photometric Analysis

Our understanding of planetary bodies and their surfaces originates from measurements made by spacecraft instruments and laboratory analysis of extraterrestrial materials. Integration of these datasets can significantly advance the fields of planetary geology and geochemistry. The goal of my dissertation research has been to develop novel methods for interrogating extraterrestrial samples and planetary regoliths, with an emphasis on integrating these complementary datasets. Additionally, my research has focused on utilizing ‘big data’ within the geoscience and planetary science communities, whether that data be geospatial or geochemical in nature. My dissertation research involves two separate, but related projects: (1) coupling Apollo 17 sample analyses with orbital observations from the Lunar Reconnaissance Orbiter Camera (LROC); and (2) development of quantitative compositional mapping (QCM) and lithologic mapping (LM) techniques using the electron microprobe, with specific applications demonstrated using vestan and lunar meteorites. For the Apollo 17 photometry research, the effects of composition, surface maturity, mineralogy, and glass content on the photometric properties of the lunar surface were investigated using Apollo 17 soil compositions as ground truth. A regional Hapke photometric parameter map of Taurus-Littrow Valley (TLV) on the Moon was produced and provides information about the photometric properties of the lunar regolith at a pixel scale of ~5 mpp. Finally, an empirical calibration was developed to relate the photometric properties (e.g., single scattering albedo) of the surface to the mafic content of Apollo 17 soils (wt.% MgO+FeO+TiO2). This relationship was used to generate a regional, topography-corrected compositional map of the TLV at high-resolution (~5 meters per pixel; mpp). Specifically, LROC Narrow Angle Camera (NAC) images were combined with NAC-derived digital terrain models to solve for photometric parameters by taking local illumination geometry into account, and thus allowing photometric parameters to be determined at a pixel scale of NAC DTMs (~5 meters per pixel). Locations of the Apollo samples and Lunar Roving Vehicle (LRV) stations, along with physiochemical information of soils collected from those stations, were used to precisely located each sample in NAC images, and to determine the correlation between the single scattering albedo and various measures of composition such as the alumina (Al2O3) content, which corresponds to high-albedo anorthositic components, or the mafic index (FeO+MgO+TiO2), which corresponds to the low-albedo mafic mineral components. The strongest correlation was observed for the mature soils, presumably because the soil maturation process breaks rocks and minerals down to a similar fine grain size. Additionally, the photometric data are self-consistent for incidence angles less than ~60 degrees. Using Bear Mountain as a test case, we describe a very effective method for removing slope effects, except for the steepest slopes where immature regolith occurs, by using the photometric parameters determined from NAC DTM data to account for local illumination geometry. Finally, we make inferences about the local geology, where for example, we examine the photometric characterization of Tycho impact melt at Apollo 17 and discuss the potential for Tycho impact melt in Station 2 soils. For the project on vestan and lunar meteorites, my dissertation research involved developing data processing protocols, multivariate statistical classification routines, and data interpretation workflows for QCM and LM. These methods, along with standard geochemical analyses (e.g., electron probe microanalysis and instrumental neutron activation analysis), were used to quantitatively characterize the mineralogic and lithologic heterogeneity (modal abundance and mineral compositions) of vestan and lunar meteorite samples using non-destructive techniques. For example, six paired howardites, collected from the Dominion Range, Antarctica, during the 2010 ANSMET field season, were extensively characterized using petrography, electron probe microanalysis (EPMA), laser ablation ICP-MS, instrumental neutron activation analyses (INAA), and fused-bead (FB) analysis by EPMA. These howardites contain abundant lithic clasts of eucritic and diogenitic compositions, as well as atypical lithologies only recently recognized (dacite and Mg-rich harzburgite). Additionally, we identified secondary material (breccia-within-breccia and impact melt) derived from multiple impact events. We describe the characteristics of the howardites, and the lithic clasts they contain, to (1) establish the range and scale of petrologic diversity, (2) recognize inter- and intra-sample mineralogical and lithological heterogeneity, (3) confirm the initial pairing of these stones, and (4) demonstrate the magmatic complexity of Vesta, and by inference, early formed planetesimals. We identified a minimum of 21 individual lithologies represented by lithic clasts \u3e1 mm, based on textural and geochemical analysis; however, more lithologies may be represented as comminuted mineral fragments. Large inter- and intra-sample variations exist between the howardites, with distinct diogenite:eucrite and basaltic eucrite:cumulate eucrite ratios, which may be identifiable in Dawn data. We conclude that these meteorites are fragments of the megaregolith and have the potential to represent the largest sample of the vestan surface and are therefore ideal for remote sensing calibration studies. In summary, the results from my dissertation projects are used to: (1) correlate the photometric properties of the lunar regolith to physiochemical characteristics of Apollo 17 soil samples and address outstanding science questions at the Apollo 17 landing site (e.g., characterization of impact melt from Tycho crater); and (2) assess the extent of magmatic differentiation in the vestan crust, and by inference early planetesimals. This dissertation offers new methods for investigating small-scale compositional variations on the Moon; and provides new, highly effective methods for petrologic investigations of complex samples for which only limited quantities exist (e.g., returned lunar and asteroid samples)

Abstracts of the 1st GeoDays, 14th–17th March 2023, Helsinki, Finland

Non peer reviewe

Commissioning and First Science Results of the Desert Fireball Network: a Global-Scale Automated Survey for Large Meteoroid Impacts

This thesis explores the first results from the Desert Fireball Network, a distributed global observatory designed to characterise fireballs caused by meteoroid impacts. To deal with the >50 terabytes of data influx per week, innovative data reduction techniques have been developed. The science topics investigated in this work include airbursts caused by large meteoroids impacting the Earth's atmosphere, the recovery of a meteorite and its orbital history, and the structure of a meteor shower

Nanoscale geochemistry and geochronology of xenotime: application to Earth sciences

The PhD project titled ‘Nanoscale geochemistry and geochronology of xenotime: application to Earth sciences’ aims at identifying and understanding mineralogical mechanisms that impact geochronometers at the nanoscale. The project focuses on the nanoscale geochemical behaviour of xenotime and their implications in geochronology, using a multi-scale study approach. The thesis presents nanogeochronology method of xenotime dating using atom probe tomography and detailed case studies of xenotime from three different geological conditions