^1,2Louise Alexander,^2,3Joshua F. Snape,⁴Katherine H. Joy,^1,2Hilary Downes,^1,2Ian A. Crawford
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.12689]
¹Department of Earth and Planetary Science, Birkbeck College, University of London, London, UK
²The Centre for Planetary Sciences at UCL-Birkbeck, London, UK
³Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden
⁴School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester, UK
Published by arrangement with John Wiley & Sons

¹Rebecca Winkler,¹Michael H. Poelchau,²Stefan Moser,¹Thomas Kenkmann
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.12694]
¹Institute of Earth and Environmental Sciences—Geology, Albert-Ludwigs-Universität Freiburg (ALU), Freiburg, Germany
²Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach Institut, EMI, Efringen-Kirchen, Germany
Published by arrangement with John Wiley & Sons

Hypervelocity impact experiments on porous tuff targets were carried out to determine the effect of porosity on deformation mechanisms in the crater’s subsurface. Blocks of Weibern Tuff with about 43% porosity were impacted by 2.5 mm and 12.0 mm diameter steel spheres with velocities between 4.8 km s−1 and 5.6 km s−1. The postimpact subsurface damage was quantified with computer tomography as well as with meso- and microscale analyses of the bisected crater subsurface. The intensity and style of deformation in mineral clasts and the tuff matrix were mapped and their decay with subsurface depth was determined. Subsurface deformation styles include pore space compaction, clast rotation, as well as microfracture formation. Evaluation of the deformation indicates near-surface energy coupling at a calculated depth of burial of ~2 projectile diameters (dp), which is in conflict with the crater shape, which displays a deep, central penetration tube. Subsurface damage extends to ~2 dp beneath the crater floor in the experiments with 2.5 mm projectiles and increases to ~3 dp for 12 mm projectiles. Based on overprinting relationships and the geometrical orientation of deformation features, a sequence of subsurface deformation events was derived (1) matrix compaction, (2) intragranular crack formation in clasts, (3) deformation band formation in the compacted matrix, (4) tensile fracturing.

¹Carles E. Moyano-Cambero,¹Josep M. Trigo-Rodriguez,²Jordi Llorca,³Sonia Fornasier,³Maria A. Barucci,⁴Albert Rimola
Meteoritics & Planetary Science (in Press)  Link to Article [DOI: 10.1111/maps.12703]
¹Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, Barcelona, Spain
²Institut de Tècniques Energètiques i Centre de Recerca en Nanoenginyeria, Universitat Politècnica de Catalunya, ETSEIB, Barcelona, Spain
³LESIA, Observatoire de Paris, PSL Research University, CNRS, Univ. Paris Diderot, Sorbonne Paris Cité, UPMC Univ. Paris 06, Sorbonne Universités, Meudon Principal Cedex, France
⁴Departament de Química, Universitat Autònoma de Barcelona, Bellaterra, Spain
Published by arrangement with John Wiley & Sons

A crucial topic in planetology research is establishing links between primitive meteorites and their parent asteroids. In this study, we investigate the feasibility of a connection between asteroids similar to 21 Lutetia, encountered by the Rosetta mission in July 2010, and the CH3 carbonaceous chondrite Pecora Escarpment 91467 (PCA 91467). Several spectra of this meteorite were acquired in the ultraviolet to near-infrared (0.3–2.2 μm) and in the midinfrared to thermal infrared (2.5–30.0 μm or 4000 to ~333 cm−1), and they are compared here to spectra from the asteroid 21 Lutetia. There are several similarities in absorption bands and overall spectral behavior between this CH3 meteorite and 21 Lutetia. Considering also that the bulk density of Lutetia is similar to that of CH chondrites, we suggest that this asteroid could be similar, or related to, the parent body of these meteorites, if not the parent body itself. However, the apparent surface diversity of Lutetia pointed out in previous studies indicates that it could simultaneously be related to other types of chondrites. Future discovery of additional unweathered CH chondrites could provide deeper insight in the possible connection between this family of metal-rich carbonaceous chondrites and 21 Lutetia or other featureless, possibly hydrated high-albedo asteroids.

¹Lingzhi Sun, ^1,2Zongcheng Ling, ¹Jiang Zhang, ¹Bo Li, ¹Jian Chen, ¹Zhongchen Wu, ³Jianzhong Liu
Icarus (in Press) Link to Article [doi:10.1016/j.icarus.2016.07.010]
¹School of Space Science and Physics, Shandong Provincial Key Laboratory of Optical Astronomy & Solar-Terrestrial Environment, Shandong University, Weihai 264209, China
²Key Laboratory of Lunar and Deep Space Exploration, Chinese Academy of Sciences, Beijing 100012, China
³Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China
Copyright Elsevier

Iron and optical maturity (OMAT) are two key geological marks of the Moon that closely related to its geochemical evolution and interactions between surface and space environment. We apply Partial Least Squares (PLS) regression to Chang’E-1 Imaging Interferometer (IIM) (32 bands between 480 and 960 nm) in mapping lunar global FeO and OMAT, and the FeO and OMAT values are derived based on reasonable spectral parameters (absorbance, band ratios, TiO2 and maturity sensitive parameters, etc.). After been calibrated by the FeO map from Lunar Prospector Gamma-Ray Spectrometer (LP-GRS), the global FeO map derived from PLS modeling shows a quantitatively more reasonable result consistent with previous remote sensing results (LP) as well as lunar feldspathic meteorite studies and Chang’E-3 landing site. Based on the new FeO map by Chang’E-1, we discover a compositional inhomogeneity across lunar highland regions, which has not been suggested by previous datasets (e.g., Clementine UVVIS). Furthermore, we suggest that at least part of the FeO enrichments in highlands would be caused by mixing of highland and mare materials. The IIM derived OMAT map does not suggest a dichotomy of the lunar highlands and mare regions, implying the compositional differences between those two terrains have been suppressed. We further check the maturity effect for the young mare basalts (20 wt.%) and ultrahigh-TiO2 (>10 wt.%) tend to have greater OMAT values and vary little with ages; (3) this may be due to the distinct optical maturity effects of ultramafic minerals (i.e., ultrahigh Fe and Ti) and/or the spectral blue shifts of abundant ilmenite.