Nicolas Mangold's research while affiliated with French National Centre for Scientific Research and other places

Planetary exploration relies considerably on mineral characterization to advance our understanding of the solar system, the planets and their evolution. Thus, we must understand past and present processes that can alter materials exposed on the surface, affecting space mission data. Here, we analyze the first dataset monitoring the evolution of a known mineral target in situ on the Martian surface, brought there as a SuperCam calibration target onboard the Perseverance rover. We used Raman spectroscopy to monitor the crystalline state of a synthetic apatite sample over the first 950 Martian days (sols) of the Mars2020 mission. We note significant variations in the Raman spectra acquired on this target, specifically a decrease in the relative contribution of the Raman signal to the total signal. These observations are consistent with the results of a UV-irradiation test performed in the laboratory under conditions mimicking ambient Martian conditions. We conclude that the observed evolution reflects an alteration of the material, specifically the creation of electronic defects, due to its exposure to the Martian environment and, in particular, UV irradiation. This ongoing process of alteration of the Martian surface needs to be taken into account for mineralogical space mission data analysis.

This 1:30,000 scale geological map describes Oxia Planum, Mars, the landing site for the ExoMars Rosalind Franklin rover mission. The map represents our current understanding of bedrock units and their relationships prior to Rosalind Franklin’s exploration of this location. The map details 15 bedrock units organised into 6 groups and 7 textural and surficial units. The bedrock units were identified using visible and near-infrared remote sensing datasets. The objectives of this map are (i) to identify where the most astrobiologically relevant rocks are likely to be found, (ii) to show where hypotheses about their geological context (within Oxia Planum and in the wider geological history of Mars) can be tested, (iii) to inform both the long-term (hundreds of metres to ∼1 km) and the short-term (tens of metres) activity planning for rover exploration, and (iv) to allow the samples analysed by the rover to be interpreted within their regional geological context.

Early observations from the Perseverance rover suggested a deltaic origin for the western fan of Jezero crater only from images of the Kodiak butte. Here, we use images from the SuperCam Remote Micro-Imager and the Mastcam-Z camera to analyze the western fan front along the rover traverse, and further assess its depositional origin. Outcrops in the middle to lower half of hillslopes are composed of planar, inclined beds of sandstone that are interpreted as foresets of deltaic deposits. Foresets are locally structured in ~20-25 m thick, ~80-100 m long, antiformal structures interpreted as deltaic mouth bars. Above these foresets are observed interbedded sandstones and boulder conglomerates, interpreted as fluvial topset beds. One well-preserved lens of boulder conglomerate displays rounded clasts within well-sorted sediment deposited in fining upward beds. We interpret these deposits as resulting from lateral accretion within fluvial channels. Estimations of peak discharge rates give a range between ~100 and ~500 m3.s-1 consistent with moderate to high floods. By contrast, boulder conglomerates exposed in the uppermost part of hillslopes are poorly sorted and truncate underlying beds. The presence of these boulder deposits suggests that intense, sediment-laden flood episodes occurred after the deltaic foreset and topset beds were deposited, although the origin, timing, and relationship of these boulder deposits to the ancient lake that once filled Jezero crater remains undetermined. Overall, these observations confirm the deltaic nature of the fan front, and suggest a highly variable fluvial input.

Within Jezero crater, the Perseverance rover currently explores the lowermost-exposed scarp of the delta (Fig. 1) [1,2]. Here we: (1) present the distribution of light-toned veins currently observed via the rover along its route in Jezero crater; (2) introduce compositional results of veins as analyzed via Perseverance’s SuperCam instrument, and place them into the context of results from the other instruments.

For two years, the Perseverance rover has been exploring the Jezero crater floor. A lot of remote observations have been made on the delta front and its remnants, and notably toward the Kodiak butte, situated about 1 km south of the main delta front (Fig. 1). There, morphologies typical of a Gilbert-type delta have been identified [1] using long-distance observations carried out by SuperCam’s Remote Micro-Imager (RMI) and Mastcam-Z (Fig. 2). In this work, we use high-resolution 2D images, as well as 3D Digital Outcrop Models [2;3], to document and characterize the sedimentary succession observed up the cliffs of Kodiak. We divide the Kodiak butte into 3 units (0 to 2) with further sub-facies divisions described below.

During the first scientific campaign, Perseverance explored the Jezero crater floor and found two main igneous formations: the basaltic Máaz unit, and Séítah, consisting of an olivine-rich cumulate. Then the rover did a rapid traverse towards the second campaign region, Jezero’s delta. Just before reaching the lowest part of the delta, Perseverance encountered the Séítah formation again, with some variability in the degree of alteration. Here, we use the data obtained by the SuperCam instrument to document the structure and texture of rocks at the transition between Séítah and the delta front, its geochemistry and its primary and secondary mineralogy. Then, we discuss the simi-larities/differences between these rocks and discuss a geological scenario to account for these observations.

The Apollo 17 manned mission land-ed in the Taurus Littrow valley on the Moon in De-cember 1972. The geology of this site was thoroughly investigated during extra vehicular activities performed during three days spent at the surface [1, 2]. A total of 111 kg of well-documented rock and soil samples were collected and brought back to Earth. Among several waypoints of interest, astronauts spent more than one hour to investigate five large boulder fragments at Sta-tion 6, lying at the base of the North Massif. Schmitt et al.’s [2] analysis indicates that original single boulder originated in Crisium-age melt breccia ejecta overlain by Serenitatis-age melt breccia ejecta. Earlier photoge-ologic interpretations had suggested that the North Massif was largely Serenitatis in age [3, 4]. In a previ-ous study [5], we used scanned photographs taken in situ with astronaut’s Hasselblad film cameras to recon-struct a 3D model of each of the boulders using Struc-ture-from-Motion photogrammetry techniques. In addi-tion to the 3D reconstruction of the boulders them-selves reported in [5], we have now reconstructed in 3D several rock samples hammered from the boulders, using archived photographs from the Lunar Receiving Lab facility in Houston.

In February 2021, the Perseverance rover landed in Jezero crater, Mars. The crater floor was found to be composed of lava flows and cumulate rocks [1-5]. These magmatic rocks appear to have undergone some limited aqueous alteration; however, it is not clear whether this alteration is related to the lacustrine phase of the crater [1,3,6,7]. After completing its exploration of the crater floor, Perseverance reached the foot of the Jezero western fan in late April 2022 (sol ~422). Long-distance images acquired earlier in the mission had already confirmed the deltaic nature of the fan [8], which had long been suspected from orbital observations [9,10]. Between April and December 2022, Perseverance investigated the basal layers of the delta at two locations named Hawksbill Gap and Cape Nukshak, which are ~400 m apart [11]. Here, we present an overview of the geo-chemistry and mineralogy of the delta rocks as observed by SuperCam, and show that these rocks record a diver-sity of past aqueous alteration environments.