¹Elizabeth A. Lymer,¹Michael G. Daly,²Kimberly T. Tait,²Veronica E. Di cecco,¹Emmanuel A. Lalla
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13580]
¹Centre for Research in Earth and Space Science, York University, 4700 Keele St, Toronto, Ontario, M3J 1P3 Canada
²Department of Natural History, Centre for Applied Planetary Mineralogy, Royal Ontario Museum, 100 Queen’s Park, Toronto, Ontario, M5S 2C6 Canada
Published by arrangement with John Wiley & Sons

Here, we discuss the merits of non‐destructive UV laser‐induced fluorescence spectroscopy (LIF) as a flight or laboratory instrument to analyze organic and mineral material in samples on or returned from carbon‐rich asteroids such as (101955) Bennu by NASA’s OSIRIS‐REx mission. LIF is a unique instrument that is non‐destructive while acquiring data, and allows for no sample preparation, crushing, or cutting. This method provides spectral data indicative of specific minerals and organics in less time than Raman spectroscopy, and can be set up to produce 2‐D raster images of areas of interest. Furthermore, if an LIF system is set up with a gated CCD camera, time‐resolved fluorescence spectroscopy can be performed, providing a unique identification tool for organic and mineral contents using fluorescence decay over several nanoseconds. This technique was used to analyze millimeter‐sized chondrules and calcium‐aluminum‐rich inclusions on four carbonaceous chondrite samples provided by the Royal Ontario Museum: Murchison (CM2), Allende (CV3), NWA 11554 (CV3), and NWA 12796 (CK3). The LIF 2‐D maps, point spectra, and time‐resolved fluorescence data and mineral identifications using LIF were compared to that of well‐known techniques such as Raman spectroscopy and SEM/EDS.

¹Jon D. Tandy,²Mark C. Price,²Penny J. Wozniakiewicz,²Mike J. Cole,²Luke S. Alesbrook,³Chrysa Avdellidou
Meteoritics & Planetary Science (in Press) Libk to Article [https://doi.org/10.1111/maps.13581]
¹School of Human Sciences, London Metropolitan University, London, N7 8DB UK
²Centre for Astrophysics and Planetary Science, School of Physical Sciences, Ingram Building, University of Kent, Canterbury, CT2 7NH UK
³Laboratoire Lagrange, Boulevard de l’Observatoire, CS 34229, Nice, 06304 France
Published by arrangement with John Wiley & Sons

The wavelength dependence and temporal evolution of the hypervelocity impact self‐luminous plume (or “flash”) from CO2 ice, water ice, and frozen Martian and lunar regolith simulant targets have been investigated using the Kent two‐stage light‐gas gun. An array of 10 band‐pass filtered photodiodes and a digital camera monitored changes in the impact flash intensity during the different phases of the emitting ejecta. Early‐time emission spectra were also recorded to examine short‐lived chemical species within the ejecta. Analyses of the impact flash from the varied frozen targets show considerable differences in temporal behavior, with a strong wavelength dependence observed within monitored near‐UV to near‐IR spectral regions. Emission spectra showed molecular bands across the full spectral range observed, primarily due to AlO from the projectile, and with little or no contribution from vaporized metal oxides originating from frozen regolith simulant targets. Additional features within the impact flash decay profiles and emission spectra indicate an inhomogeneity in the impact ejecta composition. A strong correlation between the density of water ice‐containing targets and the impact flash rate of decay was shown for profiles uninfluenced by significant atomic/molecular emission, although the applicability to other target materials is currently unknown. Changes in impact speed resulted in considerable differences in the temporal evolution of the impact flash, with additional variations observed between recorded spectral regions. A strong correlation between the impact speed and the emission decay rate was also shown for CO2 ice targets. These results may have important implications for future analyses of impact flashes both on the lunar/Martian surface and on other frozen bodies within the solar system.