Micro-imaging VIS-IR spectroscopy of Martian meteorites in support of the future MaMIss spectrometer measurements

In the view of the future ExoMars 2020 mission, an activity of VIS-IR spectral investigations on terrestrial and extraterrestrial Mars Analogues is ongoing, in support of the Ma Miss in situ measurements. Ma_Miss is an imaging spectrometer that works in the range 0.4-2.2 μm with 20nm spectral sampling and that will observe the lateral wall of the borehole generated by ExoMars Rover's drill (Coradini et al., 2001). In this abstract, we describe some results about the spectral properties and characterization of mineral grains of the slabs of two Martian meteorites by means of the SPIM imaging spectrometer. SPIM works in the 0.22-5.05 μm spectral range, with a spatial resolution of 38x38 μm on the sample and represents the spare of the spectrometer on Dawn spacecraft (De Angelis et al., 2015). The meteorites investigated are North West Africa 8657 (NWA8657) and Dar Al Gani 489 (DAG489), basaltic shergottites. The average spectrum of the NWA8657 slab, in comparison with spectral measurements on other martian meteorites (Mcfadden & Cline, 2005) shows low reflectance values and 1 and 2 μm spectral absorptions indicating the strong presence of Ca-pyroxenes. The successive pixel by pixel analyses for the pyroxenes spectral speciation showed a great variability of clinopyroxenes in NWA8657. In fact, the 2 μm absorption at longer wavelength in some pixel does not always correspond to the 1 μm feature at longer wavelength. The average spectrum of DAG 489 is marked by a signature typical of low-Ca pyroxenes. Pixel by pixel analyses of DAG489 shows a more homogeneous composition of the pyroxenes characterized by the two major features centered at 0.98-0.99 and 1.98-2 μm. Further spectral absorptions related to sulfates, phosphates and carbonates were detected that are being validated by SEM-BSD to constrain the formation hystories of these two shergottites

North West Africa 8657 Shergottite Micro-Investigation by Imaging Techniques

In this abstract preliminary results from the comparison of data obtained by the VIS-IR SPIM spectrometer and SEM backscattered images are reported. In particular, for validating spectra interpretation, EDS and WDS spot analyses were collected

Identification of a Ca-Phosphate Grain in North West Africa 8657 Martian Meteorite by VIS-IR Micro-Imaging Spectroscopy

This abstract focuses on the VIS-IR imaging spectroscopy investigation on some grains of merrillite in the North West Africa 8657 shergottite slab

Microimaging VIS-IR spectroscopy comparison between two shergottites

In this abstract we show the preliminary results of the micro-comparison between two basaltic shergottites DAG489 and NWA8657 by means of the Spectral Imager (SPIM)spare of Dawn spectrometer. The spatial resolution of SPIM enable the interpretation of spectra pixel by pixel to obtain a more reliable assignment of endmembers/minerals occurring in these meteorites. The preliminary investigations revealed a difference in pyroxenes composition and variability, and in the occurrence of hydrated phases in DAG489. Further studies are ongoing on these meteorites that will support the interpretation of MaMISS imaging spectrometer onboard of the next ExoMars2020 mission

Hyperspectral Micro-Imaging in the Visible-Infrared Range of Enstatite Chondrite: Preliminary Investigation on Thin Section of Sahara 97072

This abstract describe preliminary interpretation of microimaging hyperspectral data collected on a thin section of the enstatite chondrite EH3 Sahara 97072

Spin Temperatures of Ammonia and Water Molecules in Comets

The nuclear spin temperature, which is derived from the ortho-to-para abundance ratio of molecules measured in cometary comae, is a clue to the formation conditions of cometary materials, especially the physical temperature at which the molecules were formed. In this paper we present new results for the nuclear spin temperatures of ammonia in comets Hale-Bopp (C/1995 O1) and 153P/Ikeya-Zhang based on observations of NH2 at 26 and 32 K, respectively. These results are similar to previous measurements in two other comets, and the nuclear spin temperatures of ammonia in the four comets are concentrated at about 30 K. We emphasize that the nuclear spin temperatures of water measured thus far have also been about 30 K. In particular, the spin temperatures of ammonia and water are equal to each other within ±1 σ error bars in the case of comet Hale-Bopp. These nuclear spin temperatures of ammonia and water were measured under quite different conditions (heliocentric distances and gas production rates). There is no clear trend between the nuclear spin temperatures and the heliocentric distances, the gas production rates, or the orbital periods of the comets. The possibilities of the ortho-to-para conversion in the coma and in the nucleus are discussed. The present data set implies that the ortho-to-para ratios were not altered after the molecules were incorporated into the cometary nuclei. It appears that cometary ammonia and water molecules formed on cold grains at about 30 K

Psychological Distress in Breast Cancer Patients during the Italian COVID-19 Pandemic

Background. The emergency caused by the SARS-CoV-2 pandemic exacerbated psychological distress. Our aim was to investigate the impact of breast cancer on patients' lives during the Italian lockdown. Methods. Sixty-five female breast cancer patients were studied, assessing the level of psychological distress with the Hospital Anxiety and Depression Scale (HADS) and the impact of the cancer diagnosis (Impact of Event Scale-Revised-IES-R). In addition, we compared these data with a matched group of breast cancer patients enrolled in 2019. Results. Patients enrolled in 2020 had statistically higher levels of anxious symptomatology and higher levels of traumatic symptomatology due to the cancer diagnosis. A mediation analysis was performed to determine how the experience of distress due to COVID-19 negatively impacted the level of anxiety and amplified the impact of the diagnosis with a significant increase in traumatic symptoms. Conclusions. Considering the vulnerability of these patients and the serious and novel situation that the healthcare system is currently facing, we would like to point out the importance of structured and organised psychological support for these patients

A study regarding the stability of the primordial crust of asteroid Ceres

Ceres is a particular object of the solar system, since it is a "transition body" between the icy satellites of the outer solar system and the rocky bodies of the inner part. Probably it is differentiated [1,2], i.e. it has a core made of "rock" (silicates) with a weak presence of metals, a large icy mantle and a rocky crust. In particular, it has been proposed the existence on the surface of the ammoniated phyllosilicates, compatible with an outer solar system origin [3]. Also water in clay minerals, brucite, and iron-rich serpentine have been proposed to exist on the surface [4]. Ice directly on the surface regolith seems to be very unstable: numerical simulations of [5] indicate that it can last for very few orbits. A crust made of a mixture of ice and rock is potentially unstable. In the solar system, for example, Callisto has such a crust but its surface temperature is below the critical temperature for the Rayleigh-Taylor instability [6]: this seems not to be the case of Ceres. In this work, we verify the stability of the primordial crust, by assuming a certain initial composition (ice and rock) and thickness. We assume a post-differentiation Ceres, made of three layers (rocky core, icy mantle and crust). The key role is played by the viscosity of the layers, which influenced the survival or not of the primordial crust. We applied the method of the parametrized thermal convection widely diffused in literature. [1] McCord, T.B. and Sotin, C., 2005, JGR 110 [2] Castillo-Rogez, J.C., and McCord, T.B., 2010, Icarus 205, 443-459 [3] De Sanctis, M.C. et al., 2015, doi:10.1038/nature16172 [4] Rivkin, A.S., et al., 2014, Space Sci Rev, 95-116, 163, doi 10.1007/s11214-010-9677-4 [5] Formisano, M., et al., 2016, MRAS 455, 1892-1904 [6] Shoji, D. and Kurita, K., 2014, doi:10.1002/2014JE004695