The SuperCam Instrument Suite on the Mars 2020 Rover: Science Objectives and Mast-Unit Description

On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2-7 m, while providing data at sub-mm to mm scales. We report on SuperCam's science objectives in the context of the Mars 2020 mission goals and ways the different techniques can address these questions. The instrument is made up of three separate subsystems: the Mast Unit is designed and built in France; the Body Unit is provided by the United States; the calibration target holder is contributed by Spain, and the targets themselves by the entire science team. This publication focuses on the design, development, and tests of the Mast Unit; companion papers describe the other units. The goal of this work is to provide an understanding of the technical choices made, the constraints that were imposed, and ultimately the validated performance of the flight model as it leaves Earth, and it will serve as the foundation for Mars operations and future processing of the data.In France was provided by the Centre National d'Etudes Spatiales (CNES). Human resources were provided in part by the Centre National de la Recherche Scientifique (CNRS) and universities. Funding was provided in the US by NASA's Mars Exploration Program. Some funding of data analyses at Los Alamos National Laboratory (LANL) was provided by laboratory-directed research and development funds

Olivine composition and reflectance spectroscopy relationship revisited from advanced mgm deconvolution based on synthetic samples.

International audienceWe revisit the behavior of the three primary olivine absorptions near 1 m (referred to as M1-1, M2, M1-2) and their interelationships by means of an advanced version of MGM analysis. We build on the previous works carried out [e.g.,1, 2] to document at best the compositional variation of olivine from di-agnostic absorption features across the visible and near-infrared wavelengths due to electronic transitions of Fe2+ in the crystal structure

OLIVINE DETECTION AND COMPOSITION DETERMINATION AT COPERNICUS AND ERATOSTHENES CRATERS

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Discrimination between maturity and composition of lunar soils from integrated Clementine UV-visible/near-infrared data: Application to the Aristarchus Plateau

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Advanced mgm deconvolution on powder versus slab of olivine natural samples : a test with nwa 5400

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Advanced mgm deconvolution on powder versus slab of olivine natural samples : a test with nwa 5400

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Thick sections of layered ultramafic cumulates in the Oman ophiolite revealed by an airborne hyperspectral survey : petrogenesis and relationship to mantle diapirism

Using the HyMap instrument, we have acquired visible and near infrared hyperspectral data over the Maqsad area of the Oman ophiolite (~ 15 x 60 km). This survey allowed us to identify and map the distribution of clinopyroxene-rich cumulates (inter-layered clinopyroxenites and wehrlites) whose occurrence was previously undocumented in this area. The cumulates reach several hundred meters in thickness and crop out at distances exceeding 15 km on both sides of the Maqsad former spreading centre. They occur either in mantle harzburgites, as km-sized layered intrusions surrounded by fields of pegmatitic dykes consisting of orthopyroxene-rich pyroxenite and gabbronorites, or at the base of the crustal section where they are conformably overlain by cumulate gabbros. These ultramafic cumulates crystallized from silica- and Mg-rich melts derived from a refractory mantle source (e.g. high Cr#, low [Al₂O₃], low [TiO₂]). These melts are close to high-Ca boninites, although, strictly speaking, not perfect equivalents of present-day, supra-subduction zone, boninites. Chemical stratigraphy reveals cycles of replenishment, mixing and fractional crystallization from primitive (high Mg#) melts, typical of open magma chambers and migration of inter-cumulus melts. The TiO₂ content of clinopyroxene is always low (≤ 0.2 wt.%) but quite variable compared to the associated pegmatites that are all derived from a source ultra-depleted in high field strength elements (HFSE). This variability is not caused by fractional crystallization alone, and is best explained by hybridization between the ultra-depleted melts (parent melts of the pegmatites) and the less depleted mid-ocean ridge basalts (MORB) parent of the dunitic-troctolitic-gabbroic cumulates making up the crustal section above the Maqsad diapir. We propose that, following a period of magma-starved spreading, the Maqsad mantle diapir, impregnated with tholeiitic melts of MORB affinity, reached shallow depths beneath the ocean ridge. This diapir induced melting of the formerly accreted and hydrothermally altered lithosphere. At this stage, these boninitic-like lithospheric melts crystallized as pegmatitic dykes. As the diapir continued to rise, the amount of MORB reaching shallow depths increased, together with the surrounding temperature, leading to the formation of magma chambers where the crystallization of layered cumulates became possible. These cumulates remained rich in pyroxene and devoid of plagioclase as long as the contribution of MORB-derived melts was moderate relative to the lithospheric-derived melts. As the contribution of MORB to the refilling of the magma chamber increased, gabbroic cumulates started to crystallize.17 page(s

Tracing Carbonate Formation, Serpentinization, and Biological Materials With Micro‐/Meso‐Scale Infrared Imaging Spectroscopy in a Mars Analog System, Samail Ophiolite, Oman

International audienceVisible-shortwave infrared (VSWIR) imaging spectrometers map composition remotely with spatial context, typically at many meters-scale from orbital and airborne data. Here, we evaluate VSWIR imaging spectroscopy capabilities at centimeters to sub-millimeter scale at the Samail Ophiolite, Oman, where mafic and ultramafic lithologies and their alteration products, including serpentine and carbonates, are exposed in a semi-arid environment, analogous to similar mineral associations observed from Mars orbit that will be explored by the Mars-2020 rover. At outcrop and hand specimen scales, VSWIR spectroscopy (a) identifies cross-cutting veins of calcite, dolomite, magnesite, serpentine, and chlorite that record pathways and time-order of multiple alteration events of changing fluid composition; (b) detects small-scale, partially altered remnant pyroxenes and localized epidote and prehnite that indicate protolith composition and temperatures and pressures of multiple generations of faulting and alteration, respectively; and (c) discriminates between spectrally similar carbonate and serpentine phases and carbonate solid solutions. In natural magnesite veins, minor amounts of ferrous iron can appear similar to olivine's strong 1-μm absorption, though no olivine is present. We also find that mineral identification for carbonate and serpentine in mixtures with each other is strongly scale-and texture-dependent; ∼40 area% dolomite in mm-scale veins at one serpentinite outcrop and ∼18 area% serpentine in a calciterich travertine outcrop are not discriminated until spatial scales 1 μm are required to identify most organic materials and distinguish most mineral phases

A systematic mapping procedure based on the Modified Gaussian Model to characterize magmatic units from olivine/pyroxenes mixtures: Application to the Syrtis Major volcanic shield on Mars

Clenet et al. (2011) have developed an adapted version of the Modified Gaussian Model (MGM). The improvements allow the characterization of spectra of olivine-pyroxene(s) mixtures, addressing both modal composition and individual minerals chemical composition. This version of MGM is fully automated and operational with large amounts of hyperspectral imaging data. Two natural cases are considered. The first one is the Sumail massif in the Oman ophiolite (Earth). Based on our approach applied to HyMap data, two contrasted lithologic units are mapped: the mantle, which is harzburgite dominated, and the crust made of gabbros and clinopyroxene-rich cumulates, with spectral variations interpreted in terms of pyroxenes chemical compositions. Once this new MGM mapping approach has been validated on a controlled natural situation, we map the distribution of mafic assemblages across the Syrtis Major volcano on Mars using a visible and near-infrared (VNIR) - short wave infrared (SWIR) Observatoire pour la mineralogie, l'eau, les glaces et l'activite (OMEGA) / Mars Express (MEx) mosaic. Our results are in agreement with previous work but olivine appears to be more abundant than previously estimated in the central part of the volcanic edifice, especially in ternary mafic assemblages (augite, olivine, enstatite). Based on these results, we propose a possible scenario for the igneous (and thus thermal) evolution of the Syrtis Major region. Surrounding terrains have formed first and local heterogeneity can be observed between northern and southern areas of the Noachian crust. We also observe variations in the mineral assemblages within Syrtis Major lavas, which can be interpreted in terms of differentiation from a common parent melt and/or of a progressive evolution of the mantle source composition and temperature. Key Points MGM systematic mapping on Syrtis Major to characterize mafic minerals mixtures Olivine and pyroxenes mixture is detected in the central lavas of the volcano Pyroxenes have chemical compositions spanning the enstatite-augite rang

A first look at the SuperCam RMI images aboard Perseverance

International audience<p>Starting in February 2021, the <strong>Perseverance rover</strong> will characterize a new landing site, the Jezero crater on Mars, and assemble a returnable cache of samples [1]. Among the remote sensing instruments, SuperCam combines chemical, mineralogical and organic spectroscopy, sound recording and imaging [2, 3, 4]. SuperCam’s <strong>RMI (Remote Micro-Imager)</strong> provides pictures for local context and site imaging at high-resolution.</p><p><br>The 110-mm SuperCam telescope with a focal length of 563 mm allows to take color images of 2048x2048 pixels with a CMOS camera on a bandwidth from ~375 to ~655 nm. The images will be divided by a reference flat-field to correct the attenuation factor of ~5 due to vignetting. The diameter of the circular field-of-view is ~18.8 mrad. The angular size of the RMI pixels is slightly less than 10 microrads, and the effective image resolution is better than 80 microrads, which represents 0.24 mm at 3 m.</p><p><br>Images will be taken at the start and end of the SuperCam raster observations [3] and assembled into annotated mosaics, which will provide information on the nature of the targets at the scale of the SuperCam investigation. Images will also be taken to study remote outcrops. At the time of the conference, Perseverance will have been on Mars for 2 months. Although the first images of the RMI will be used to check the health of the instrument, we also hope to have a first view of the landing site by then.</p><p><br><strong>References:</strong> [1] Farley K.A. et al. (2020) SSR, 216, 142. [2] Maurice S. et al. (in revision) SSR. [3] Wiens R.C. et al. (2021) SSR, 217, 4. [4] Maurice S. et al. (this issue). </p&gt