Equatorial locations of water on Mars: Improved resolution maps based on Mars Odyssey Neutron Spectrometer data

We present a map of the near subsurface hydrogen distribution on Mars, based on epithermal neutron data from the Mars Odyssey Neutron Spectrometer. The map’s spatial resolution is approximately improved two-fold via a new form of the pixon image reconstruction technique. We discover hydrogen-rich mineralogy far from the poles, including  ∼10 wt.% water equivalent hydrogen (WEH) on the flanks of the Tharsis Montes and  >40 wt.% WEH at the Medusae Fossae Formation (MFF). The high WEH abundance at the MFF implies the presence of bulk water ice. This supports the hypothesis of recent periods of high orbital obliquity during which water ice was stable on the surface. We find the young undivided channel system material in southern Elysium Planitia to be distinct from its surroundings and exceptionally dry; there is no evidence of hydration at the location in Elysium Planitia suggested to contain a buried water ice sea. Finally, we find that the sites of recurring slope lineae (RSL) do not correlate with subsurface hydration. This implies that RSL are not fed by large, near-subsurface aquifers, but are instead the result of either small ( < 120 km diameter) aquifers, deliquescence of perchlorate and chlorate salts or dry, granular flows

Wake-induced pressure fluctuations on the Mars2020/SuperCam microphone inform on Martian wind properties

The SuperCam Mars 2020 Microphone, a collabora- tion between ISAE-SUPAERO, IRAP in Toulouse and the Los Alamos National Laboratory (LANL), will record sounds from the surface of Mars in the audible range. It will support SuperCam Laser-Induced Breakdown Spectroscopy (LIBS) investigation by recording LIBS shock waves but it will also record aeroacoustic noise generated by wind flowing past the microphone. Here we use Computational Fluid Dynamics to study the interaction between the wind and SuperCam, by means of Direct Numerical Simulations. The goal is to understand how the microphone signal can be used to determine the wind speed and direction on Mars

Productivity, family planning and reproductive health in Burkina Faso: PopDev qualitative data

The PopDev study is a prospective cohort study of pregnant and/or postpartum women who were between seven months gestation and three months postpartum at recruitment and followed-up over an up to nine month period. The cohort is a population-representative sample of parturient women in the commune of Bobo-Dioulasso, Burkina Faso. This deposit presents the qualitative data - French transcripts of 56 in-depth interviews and 3 focus group discussions - from a nested cohort of women recruited from within PopDev, and their husband/partners. Key themes discussed in these qualitative data are women’s work, use of family planning, and the factors that facilitated or were challenging during their return to work during the postpartum period

Centimeter to decimeter hollow concretions and voids in Gale Crater sediments, Mars

Voids and hollow spheroids between ∼1 and 23 cm in diameter occur at several locations along the traverse of the Curiosity rover in Gale crater, Mars. These hollow spherical features are significantly different from anything observed in previous landed missions. The voids appear in dark-toned, rough-textured outcrops, most notably at Point Lake (sols 302-305) and Twin Cairns Island (sol 343). Point Lake displays both voids and cemented spheroids in close proximity; other locations show one or the other form. The spheroids have 1-4 mm thick walls and appear relatively dark-toned in all cases, some with a reddish hue. Only one hollow spheroid (Winnipesaukee, sol 653) was analyzed for composition, appearing mafic (Fe-rich), in contrast to the relatively felsic host rock. The interior surface of the spheroid appears to have a similar composition to the exterior with the possible exceptions of being more hydrated and slightly depleted in Fe and K. Origins of the spheroids as Martian tektites or volcanic bombs appear unlikely due to their hollow and relatively fragile nature and the absence of in-place clearly igneous rocks. A more likely explanation to both the voids and the hollow spheroids is reaction of reduced iron with oxidizing groundwater followed by some re-precipitation as cemented rind concretions at a chemical reaction front. Although some terrestrial concretion analogs are produced from a precursor siderite or pyrite, diagenetic minerals could also be direct precipitates for other terrestrial concretions. The Gale sediments differ from terrestrial sandstones in their high initial iron content, perhaps facilitating a higher occurrence of such diagenetic reactions

Design, development, and scientific performance of the Raman Laser Spectrometer EQM on the 2020 ExoMars (ESA) Mission

The Raman Laser Spectrometer (RLS) is one of the three Pasteur Payload instruments located within the rover analytical laboratory drawer (ALD), for ESA’s Aurora exploration programme, ExoMars 2020 mission. The instrument will analyse the crushed surface and subsurface samples that are positioned below the Raman optical head by the ALD carousel. The RLS engineering and qualification model (EQM) was delivered to ESA at the end of 2017, after a wide technical and scientific test characterization campaign. The scientific campaign comprised instrument calibration and detailed evaluation of the scientific requirements and overall performance. For spectral calibration, continuous emission standard lamps (such as Hg-Ar, Ne, and Xe) were utilized, as well as Raman spectra of pure liquids typically used as standards (cyclohexane and carbon tetrachloride (CCl4)). In addition, Raman spectra of the RLS calibration target (CT), a small disc of polyethylene terephthalate (PET) were obtained at various temperatures. This target, placed inside the rover, will be used for both Instrument health checks and calibration activities throughout Mars operations. For the scientific requirements and performance evaluations, several liquid and solid samples were analysed under a wide range of ambient conditions. The obtained spectral band parameters (peak position, relative peak intensity, peak width, and peak profile) were evaluated. Also, the instrument response (in terms of SNR) was characterized at different integration times and detector operating temperatures. In this paper, we provide a description of the development, verification, functional test, and overall scientific performance of the RLS instrument developed for ExoMars. Particular attention is placed on the performance of the EQM, which is the most representative instrument, in terms of engineering and functionality, of the flight model (FM) and in addition is used for performing all the mechanical, thermal, and radiation tests necessary for space qualification (for planetary applications). The data presented and analysed here, comprise part of the overall dataset obtained during the full instrument characterization campaign conducted at INTA before and during delivery and integration of the EQM in the rover ALD at TAS-I facilities (Torino, Italy). The results obtained confirm that the full functionality and scientific performance of the RLS instrument was maintained after integration.Proyecto MINECO Retos de la Sociedad. Ref. ESP2017-87690-C3-1-

In situ detection of boron by ChemCam on Mars

We report the first in situ detection of boron on Mars. Boron has been detected in Gale crater at levels Curiosity rover ChemCam instrument in calcium-sulfate-filled fractures, which formed in a late-stage groundwater circulating mainly in phyllosilicate-rich bedrock interpreted as lacustrine in origin. We consider two main groundwater-driven hypotheses to explain the presence of boron in the veins: leaching of borates out of bedrock or the redistribution of borate by dissolution of borate-bearing evaporite deposits. Our results suggest that an evaporation mechanism is most likely, implying that Gale groundwaters were mildly alkaline. On Earth, boron may be a necessary component for the origin of life; on Mars, its presence suggests that subsurface groundwater conditions could have supported prebiotic chemical reactions if organics were also present and provides additional support for the past habitability of Gale crater

Semi‐quantification of binary saline solutions by Raman spectroscopy: Implications for Europa

Producción CientíficaThe Europa lander is a concept for a potential future planetary exploration mission which purpose is to characterize the icy shell of Europa and to search for organics. To achieve this objective, the current concept of the lander includes a Raman spectrometer, such as RLS instrument, that could be able to analyze (sub) surface targets in their solid and liquid form. Knowing that ice and brines of Europa are potentially enriched by sulfate and chlorides, this work seeks to evaluate if Raman spectroscopy could be used to semi quantify the saline content of water solutions using space-like instrumentation. To do so, MgSO4 and MgCl2 were used to prepare three sets of water solutions. Raman analyses were then performed by the laboratory simulator of the ExoMars Raman Laser Spectrometer (RLS), which has been defined as the threshold system for the Europa Lander. After data analysis, two different semi-quantification approaches were tested, and their results compared. Although univariate calibration curves proved to successfully quantify the content of SO42− and Cl− anions dissolved in mono-analyte water solutions, this strategy provided very poor results when applied to binary saline mixtures. Overcoming this issue, the non-linearity prediction ability of Artificial Neural Networks (ANNs) in combination with bandfitting allows to successfully resolve the complexity of the vibrational perturbation suffered by the OH region, which is caused by the cross interaction of H2O molecules with different anions.Ministerio de Economía y Competitividad, Grant/Award Number: PID2019-107442RBC31

Characteristics of stand-off detection of geological samples at MARS atmospheric pressure using laser-induced breakdown spectroscopy (LIBS).

LIBS has been proposed as a new method for stand-off detection of geological samples for use on landers and rovers to Mars and studies are on-going to determine capabilities. Because of the severe size, weight, ruggedness and power requirements for space instrumentation and the need to maximize scientific return, it is important to benchmark capabilities with parameters representative of compact instrumentation likely to be used in a flight instrument. Some of these issues are addressed here

Analysis of water ice and ice/dust mixtures using laser-induced breakdown spectroscopy (LIBS).

In 1992, LIBS was proposed as a new method for stand-off detection of geological samples for use on landers and rovers to Mars. Recently, there has been increased interest in the technique for this and other space applications and studies have determined some of the characteristics and capabilities of the method under the conditions that these measurements will have to be made. In addition to rocks and soils, there is interest in using LIBS to analyze ices and dusts entrained in ice . This is especially true for missions to the Mars polar regions . Of particular interest is determining the nature of polar layered deposits, the geochemistry of polar surface materials, detection of water ice and the distribution of ice, and the presence of possible organics in these materials (via C/N ratios