^1,2Zoltán Váci,^1,2Carl B. Agee,³Munir Humayun,^1,2Karen Ziegler,²Yemane Asmerom,²Victor Polyak,⁴Henner Busemann,⁴Daniela Krietsch,⁵Matthew Heizler,⁶Matthew E. Sanborn,⁶Qing‐Zhu Yin
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13456]
¹Institute of Meteoritics, University of New Mexico, Albuquerque, New Mexico, 87131 USA
²Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico, 87131 USA
³National High Magnetic Field Laboratory, Department of Earth Ocean & Atmospheric Science, Florida State University, Tallahassee, Florida, 32310 USA
⁴Institute of Geochemistry and Petrology, ETH Zürich, 8092 Zurich, Switzerland
⁵New Mexico Bureau of Geology, New Mexico Institute of Mining and Technology, Socorro, New Mexico, 87801 USA
⁶Department of Earth and Planetary Sciences, University of California, Davis, Davis, California, 95616 USA
Published by arrangement with John Wiley & Sons

Northwest Africa (NWA) 11042 is a heavily shocked achondrite with medium‐grained cumulate textures. Its olivine and pyroxene compositions, oxygen isotopic composition, and chromium isotopic composition are consistent with L chondrites. Sm‐Nd dating of its primary phases shows a crystallization age of 4100 ± 160 Ma. Ar‐Ar dating of its shocked mineral maskelynite reveals an age of 484.0 ± 1.5 Ma. This age coincides roughly with the breakup event of the L chondrite parent body evident in the shock ages of many L chondrites and the terrestrial record of fossil L chondritic chromite. NWA 11042 shows large depletions in siderophile elements (<0.01×CI) suggestive of a complex igneous history involving extraction of a Fe‐Ni‐S liquid on the L chondrite parent body. Due to its relatively young crystallization age, the heat source for such an igneous process is most likely impact. Because its mineralogy, petrology, and O isotopes are similar to the ungrouped achondrite NWA 4284 (this work), the two meteorites are likely paired and derived from the same parent body.

¹Cosette M. Gilmour,¹Christopher D. K. Herd
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13436]
¹Department of Earth and Atmospheric Sciences, University of Alberta, 1‐26 Earth Sciences Building, Edmonton, AB, T6G 2E3 Canada
Published by arrangement with John Wiley & Sons

Platinum group element (PGE) concentrations have been determined in situ in ordinary chondrite kamacite and taenite grains via laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS). Results demonstrate that PGE concentrations in ordinary chondrite metal (kamacite and taenite) are similar among the three ordinary chondrite groups, in contrast to previous bulk metal studies in which PGE concentrations vary in the order H < L < LL. PGE concentrations are higher in taenite than kamacite, consistent with preferential PGE partitioning into taenite. PGE concentrations vary between and within metal grains, although average concentrations in kamacite broadly agree with results from bulk studies. The variability of PGE concentrations in metal decreases with increasing petrologic type; however, variability is still evident in most type six ordinary chondrites, suggesting that equilibration of PGEs does not occur between metal grains, but rather within individual metal grains via self‐diffusion during metamorphism. The constant average PGE concentrations within metal grains across different ordinary chondrite groups are consistent with the formation of metal via nebular condensation prior to the accretion of ordinary chondrite parent bodies. Post‐condensation effects, including heating during chondrule‐formation events, may have affected some element ratios, but have not significantly affected average metal PGE concentrations.

^1,2J. S. New,^1,3R. A. Mathies,²M. C. Price,²M. J. Cole,^1,3M. Golozar,²V. Spathis,²M. J. Burchell,¹A. L. Butterworth
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13448]
¹Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, California, 94720 USA
²School of Physical Sciences, University of Kent, Canterbury, Kent, CT2 7NH UK
³Department of Chemistry, University of California, Berkeley, California, 94720 USA
Published by arrangement with John Wiley & Sons

The presence and accessibility of a sub‐ice‐surface saline ocean at Enceladus, together with geothermal activity and a rocky core, make it a compelling location to conduct further, in‐depth, astrobiological investigations to probe for organic molecules indicative of extraterrestrial life. Cryovolcanic plumes in the south polar region of Enceladus enable the use of remote in situ sampling and analysis techniques. However, efficient plume sampling and the transportation of captured organic materials to an organic analyzer present unique challenges for an Enceladus mission. A systematic study, accelerating organic ice‐particle simulants into soft inert metal targets at velocities ranging 0.5–3.0 km s⁻¹, was carried out using a light gas gun to explore the efficacy of a plume capture instrument. Capture efficiency varied for different metal targets as a function of impact velocity and particle size. Importantly, organic chemical compounds remained chemically intact in particles captured at speeds up to ~2 km s⁻¹. Calibration plots relating the velocity, crater, and particle diameter were established to facilitate future ice‐particle impact experiments where the size of individual ice particles is unknown.