Spectral diversity of rocks and regolith at Jezero crater, Mars, as seen by the SuperCam VISIR spectrometer onboard Perseverance - Observatoire de Paris Access content directly
Conference Papers Year : 2021

Spectral diversity of rocks and regolith at Jezero crater, Mars, as seen by the SuperCam VISIR spectrometer onboard Perseverance

Lucia Mandon
Thierry Fouchet
Franck Montmessin

Abstract

The Perseverance rover (Mars 2020 mission, NASA) landed in the ancient lakebed of Jezero crater, Mars on February 2021. The payload includes the SuperCam instrument, which combines various remote-sensing techniques to investigate elemental and mineralogical composition. In particular, the near-infrared spectrometer of SuperCam is a novel instrument on the Martian surface. The spectra, together with data from additional visible spectrometers, cover the 0.390.85 m (VIS) and 1.32.6 m (IR) ranges, allowing the identification of a wide variety of minerals. Here, we present the spectral diversity in the VISIR of rocks and soils in the vicinity of the rovers traverse. As of sol 130, most of the rocks analyzed so far are dark-toned rocks in the crater floor (Cf-fr unit) with variable dust cover. Some variability in reflectance levels and absorption bands is observed within and among the rocks, but overall, they share similar spectral characteristics. In particular, most rocks exhibit an absorption near 1.9 m (indicating the presence of water). This band is usually observed weakly or is absent in local regolith but is detected with a depth up to ~20% in the rocks, indicating probably several wt.% of bound water. While mixing of different phases occurs in the few mm of the field of view of the spectrometer, the following candidates were identified: dust, an oxy-hydroxide (e.g., ferrihydrite), an iron-rich phyllosilicate (e.g., nontronite or hisingerite) and an AlOH-bearing phase. Contrary to what have been inferred from the orbit, no unequivocal mafic mineral signature has yet been identified in a rock target in the VISIR implying low mafic minerals content or small associated grain size. However, the soils exhibit a signature of olivine mixed with pyroxene (intermediate Ca content). Portions of sand ripples are strongly dominated by the olivine signature. The detection of widespread hydration features supports that some pervasive water-rock interactions occurred in the past near the Perseverance landing site. From CRISM orbital data, it is likely that the rover will be driving through areas exhibiting progressively increasing hydration throughout its traverse: future measurements on these potentially more hydrated and diverse rocks are expected to bring new insights into the past environment at Jezero crater.
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obspm-03903818 , version 1 (16-12-2022)

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Lucia Mandon, Clement Royer, Pierre Beck, Cathy Quantin-Nataf, Thierry Fouchet, et al.. Spectral diversity of rocks and regolith at Jezero crater, Mars, as seen by the SuperCam VISIR spectrometer onboard Perseverance. AGU Fall Meeting 2021, Dec 2021, New Orleans, United States. pp.id. P22B-04. ⟨obspm-03903818⟩
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