PS3.4

Introduction:  A plethora of geophysical, geo-chemical, and geodynamical observations indicate that the terrestrial planets have differentiated into silicate crusts and mantles that surround a dense core. The latter consists primarily of Fe and some lighter alloying elements (e.g., S, Si, C, O, and H). There is strong evidence from measurements of the tidal deformation of the planet that the core of Mars is presently liquid.

The InSight mission aims at constraining these numbers via the RISE radio tracking experiment, and the SEIS seismic package. We used data recorded by SEIS for high SNR marsquakes between March 2019 and July 2020. The InSight Marsquake Service located these events in the distance range 27-40 degrees, based on identification of P- and S-body waves. Later studies identified a number of secondary, surface-reflected phases, which were used to constrain the upper mantle. We build upon the velocity models derived from these phase picks to constrain the time window in which to look for shear waves reflected from the core mantle boundary. Since shear waves cannot propagate in a fluid medium, the core mantle boundary (CMB) acts as a polarization filter, which fully reflects horizontally polarized shear waves back into the mantle. Shear waves reflected from the CMB, called ScS, are therefore expected to have a predominantly horizontal polarization at the receiver, with an azimuth orthogonal to the source direction. In this distance range, ScS is separated in time from any other body wave phase and therefore well-observable.

Methods: We follow a two-step approach: 1. Confirm seismic arrivals as ScS, based on existing mantle velocity models. 2. Pick precise arrival times and invert those for mantle profiles and core size, constrained by mineralogy, moment of inertia and average density of the planet.

Results: The inversion of travel times constrains the core radius to the upper end of pre-mission geophysics-based estimates. This value is compatible with estimates from the geodetic experiment RISE onboard and implies that a lower mantle is unlikely to be present. Moreover, a large core has important implications for core composition. Average retrieved core density is 6 g/cm^3, which implies that for a (Fe-Ni)-S composition, a sulfur content in excess of 18% is required. This is above the eutectic composition observed experimentally with potentially profound implications for the future crystallization of the Martian core, subject to further laboratory research of Fe-S data under core conditions.

All ScS candidate phases that were observed show significant seismic energy and a relatively flat spectrum above 0.1 Hz, which implies a low seismic attenuation throughout the mantle. The spectral character of direct S-phases for the distant-most events is consistent with that of the ScS-phases for more nearby events, which supports the identification of the arrivals as core-reflected.

How to cite: Stähler, S. C., Khan, A., Ceylan, S., Duran, A. C., Garcia, R., Giardini, D., Huang, Q., Kim, D., Lognonné, P., Maguire, R., Marusiak, A., Samuel, H., Schmerr, N., Schimmel, M., Sollberger, D., Stutzmann, E., and Banerdt, W. B. and the InSight Core Collaboration: Seismic detection of the Martian core by InSight, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13310, https://doi.org/10.5194/egusphere-egu21-13310, 2021.

Since InSight (the Interior Exploration using Geodesy and Heat Transport) landed 26 months ago and deployed an ultra sensitive broadband seismometer(SEIS) on the surface of Mars, around 500 seismic events of diverse variety have been detected, making it possible to directly analyze the subsurface properties of Mars for the very first time. One of the primary goals of the mission is to retrieve the crustal structure below the landing site. Current estimates differ by more than 100% for the average crustal thickness. Since data from orbital gravity measurementsprovide information on relative variations of crustal thickness but not absolute values, this landing site measurement could serve as a tie point to retrieve global crustal structure models. To do so, we propose using a joint inversion of receiver functions and apparent incidence angles, which contain information on absolute S-wave velocities of the subsurface. Since receiver function inversions suffer from a velocity depth trade-off, we in addition exploit a simple relation which defines apparent S-wave velocity as a function of observed apparent P-wave incidence angles to constrain the parameter space. Finally we use the Neighbourhood Algorithm for the inversion of a suitable joint objective function. The resulting ensemble of models is then used to derive the full uncertainty estimates for each model parameter. Before its application on data from InSight mission, we successfully tested the method on Mars synthetics and terrestrial data from various geological settings using both single and multiple events. Using the same method, we have previously been able to constrain the S-wave velocity and depth for the first inter-crustal layer of Mars between 1.7 to 2.1 km/s and 8 to 11 km, respectively. Here we present the results of applying this technique on our selected data set from the InSight mission. Results show that the data can be explained equally well by models with 2 or 3 crustal layers with constant velocities. Due to the limited data set it is difficult to resolve the ambiguity of this bi-modal solution. We therefore investigate information theoretic statistical tests as a model selection criteria and discuss their relevance and implications in seismological framework.

How to cite: Joshi, R., Knapmeyer-Endrun, B., Mosegaard, K., Bissig, F., Khan, A., Panning, M., Staehler, S., Tauzin, B., Lekic, V., Scholz, J.-R., Davis, P., Widmer-Schnidrig, R., Garcia, R., Pinot, B., Lognonné, P., and Christensen, U.: Joint inversion of receiver functions and apparent incidence angles to investigate the crustal structure of Mars, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9470, https://doi.org/10.5194/egusphere-egu21-9470, 2021.

Historical dike intrusions in the vicinity of volcanic edifices on Earth are known to produce swarms of seismic activity with cumulative seismic moments between 1·10¹² and 1·10²⁰ Nm, equivalent to moment magnitudes between 2 and 7. On Mars, long linear graben systems are likely to host giant dike complexes at depth, which possibly produced significant seismicity during their intrusion. Not only this, but dike intrusions are also candidates to produce crustal seismicity at present day, which may be detected during the lifespan of the InSight mission. In this work we infer the possible geometry of dikes underneath Cerberus Fossae, and make estimations of the energy released during their intrusion.

We used cross section area balancing on topographic profiles orthogonal to several of the Cerberus Fossae graben to estimate proxies for the geometry of the underlying dikes (aperture, height, depth, etc.). This technique has already been used to approximate dike properties at the nearby Elysium Fossae, with successful results. At Cerberus Fossae, the obtained dike aspect ratios are consistent with sublinear scaling, which is characteristic of fluid-induced fractures (as expected for dikes). These results support the presence of giant dikes underneath Cerberus, which may be up to 700 m thick, 140 km long, and have heights of up to 20 km.

Additionally, we used the inferred geometries and assumptions about the host rock mechanical properties to estimate various energy quantities related to dike intrusion, and compared them with the energy releases in terrestrial diking episodes. Two calculations are of special interest; M_d, the energy associated to dike inflation, and M_s, an approximation to the cumulative seismic moment release. The obtained M_d values are between 3.1·10²⁰ and 5.0·10²¹ Nm, and are 1 to 2 orders of magnitude larger than the equivalent moments in terrestrial events. M_s was calculated from M_d with two key assumptions; 1) that all aseismic energy was released by the dike, and 2) values of seismic efficiency (the percentage of seismic relative to the total energy released) based on terrestrial examples. The obtained M_s are between 6.3·10¹⁹ and 2.2·10²¹ Nm, which are equivalent to moment magnitudes of 6.5 and 7.9. These are comparable to, albeit slightly larger than, the cumulative moments of some of the largest terrestrial diking events, such as the first episode in the Manda-Hararo sequence (Ethiopia, 2005, M_s = 6.2) or the Miyake-jima event (Japan, 2000, M_s = 6.8).

The Elysium volcanic province is thought to have been active until very recent times, and possibly even at present day. If this is the case, then intrusions in the lower size of the spectrum investigated at Cerberus, and smaller-sized events, may be detected by InSight as a series of crustal seismic events with cumulative moment magnitudes <6. Further research is needed to fully assess the validity of the comparisons between terrestrial and Martian events, and the possible energy releases of dike-induced marsquakes.

How to cite: Rivas-Dorado, S., Ruiz, J., and Romeo, I.: First approximations to the energy release of giant dikes at Cerberus Fossae, Mars, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13008, https://doi.org/10.5194/egusphere-egu21-13008, 2021.

On the first hundreds of sols in which the InSight lander operated on the surface of Mars, its instrumentation has proven to be particularly suitable to unveil and understand atmospheric variability at all temporal scales, from the synoptic scale (baroclinic waves) to the sub-hour scale (gravity waves, bores) down to the turbulent scale (vortices, gusts, infrasounds). Recently, the InSight lander achieved a complete Martian year of observations of the atmosphere of Mars -- allowing for the seasonal variability of the Martian atmosphere and its phenomena at all scales to be monitored almost continuously, including during several large dust storms episodes. In this presentation, based on this Martian year of InSight observations, we will review the annual CO2 sublimation / condensation cycle, the variability of large-scale meteorology, the statistics of a year of wind observations -- and insightful comparisons with global climate models, the strong seasonal variability of gravity wave and turbulent activity, including a burst of activity of convective vortices in Mars' southern summer. We will also discuss how the atmosphere influences seismic and magnetic signals captured by InSight -- and the search for Martian infrasound.

How to cite: Spiga, A., Banfield, D., Newman, C., Murdoch, N., Lorenz, R., Garcia, R. F., Viúdez‐Moreiras, D., Pla-Garcia, J., Forget, F., Charalambous, C., Baker, M., Martire, L., Perrin, C., Lemmon, M., Stutzmann, É., Mittelholz, A., Stott, A., Mueller, N., Horleston, A., and Ceylan, S. and the InSight & TWINS & SEIS teams: A complete Martian year of atmospheric observations with InSight instruments, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4967, https://doi.org/10.5194/egusphere-egu21-4967, 2021.

The ubiquitous dust aerosol particles in the atmosphere of Mars play a main role on the behaviour and evolution of its climate. By absorbing and scattering the incoming solar radiation, they modify the atmospheric thermal structure and dynamics. Dust radiative forcing calculations are of high relevance to understand Mars' overall atmospheric dynamics. The accuracy in determining internal radiation fields and the resulting atmospheric heating/cooling rates contribute to the uncertainties in these calculations.

Radiative transfer schemes using 2-stream approximations are widely implemented in multiple Mars’ dynamical models and Global Circulation Models (GCMs). The uncertainties associated to this approximation are related to neglecting details of dust particles’ scattering phase function: the higher the number of streams considered, the better the accuracy of the scheme, although there is a persistent trade-off between accuracy and computational cost. The objective of this work is to evaluate the accuracy of dust aerosol radiative forcing estimations in the Martian atmosphere by multiple-stream schemes.

Several scenarios covering the different atmospheric conditions during the Martian Year were simulated with different radiative transfer models, as well as other high-opacity dust storm scenarios. The atmosphere was discretised into 50 levels from 0 to 100 km, with atmospheric variables loaded from LMD’s Mars Climate Database (MCD). The visible and infrared spectral regions were divided into 12 bands, covering from 0.24 to 1,000 μm. Gaseous opacities were calculated with the correlated-k method, with absorption data retrieved from HITRAN. Dust aerosol radiative properties were derived using the wavelength-dependent properties reported by Wolff et al. (2006, 2009), with vertical distributions following a Conrath profile, and assuming a well-mixed dust scenario. Particle size (effective radius) and column dust opacity were given values to characterise every scenario. Finally, the calculated internal radiation fields and heating/cooling rates with the two-stream approximation code were compared with 4, 8, 16 and 32-stream solutions using the discrete ordinates method (DISORT).

The comparison of the results with respect to the 32-stream model shows heating rate underestimations with average differences of about 2.7, 0.3, 0.1, and 0.1 K/sol for the 2-, 4-, 8-, and 16-stream models, respectively. Such differences tend to be larger when there is more dust is loaded into the atmosphere. On the other hand, the average computational times for 1 sol using the 4-, 8-, 16-, and 32-stream schemes are about 15, 25, 40 and 135 times longer than the 2-stream scheme, respectively.

Future research prospects include the implementation of multiple-stream DISORT codes in Mars’ mesoscale dynamical models to investigate the accuracy of simulations of the atmospheric effects generated by local and regional dust storms.

How to cite: Chen-Chen, H., Pérez-Hoyos, S., and Sánchez-Lavega, A.: Comparison of radiative transfer schemes for the calculation of heating rates in the atmosphere of Mars, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12590, https://doi.org/10.5194/egusphere-egu21-12590, 2021.

We investigate a range of atmospheric phenomena concerning their potential to address the Martian methane lifetime discrepancy. This refers to the over-estimate of the modelled lifetimes compared to observations by a factor of up to six hundred. We apply a newly developed atmospheric photochemical model where we vary in a Monte Carlo approach the chemical rate and Eddy mixing coefficients within their current uncertainties. We also investigate the effect of air shower events due to galactic cosmic rays and solar cosmic rays. Our results suggest that the current uncertainty in chemical rates and transport together with seasonal changes in the water column can likely account for up to a factor of about thirty in the Mars methane lifetime discrepancy whereas the air shower effects are likely to be of secondary importance.

How to cite: Grenfell, J. L., Wunderlich, F., Sinnhuber, M., Herbst, K., Scheucher, M., Gebauer, S., and Rauer, H.: Atmospheric phenomena affecting the methane lifetime on Mars, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15442, https://doi.org/10.5194/egusphere-egu21-15442, 2021.

Recent modelling efforts based on MAVEN measurements suggest that the Martian Moon Phobos is affected by a unique space weathering scenario [1]. On rocky bodies in the solar system, mostly solar wind ions cause ion-induced space weathering of their surfaces. Space weathering is an important driver for the alteration of planetary surfaces [2], as well as for the creation of exospheres on, for example, the Moon or Mercury [3, 4]. As a consequence, most analog experiments aim to investigate effects by the impact of solar wind ions [5, 6].

Phobos is not only exposed to the solar wind, but also significantly sputtered by planetary oxygen ions originating from the Martian atmosphere due to its proximity to Mars [7]. O ions at energies of several 100s to several 1000s eV are responsible for the dominant erosion process on the surface of Phobos in the Martian magnetotail [1]. However, there still remain uncertainties as the sputtering by planetary O ions has not yet been investigated experimentally.

Here we present experiments on the sputtering of Phobos analog materials by O⁺ and O₂⁺ ions at different energies [8]. As analog material, thin films of augite (Ca,Mg,Fe)₂Si₂O₆ on a quartz crystal microbalance (QCM) are used. The QCM allows in-situ real-time sputtering experiments by measuring the sample’s mass change [9]. Experimental sputtering yields are compared to simulations with the SRIM package and SDTrimSP [10, 11]. The latter has shown better accuracy for reproducing sputtering yields [6, 12], which is also found in the presented studies [8].

Oxygen ion irradiations of Phobos analog materials show fluence-dependent mass changes, indicating that both sputtering and O ion implantation in the near-surface region occur at the same time. The measurements can be consistently reproduced by dynamic SDTrimSP simulations that include O implantation up to local concentrations of 67%. The new experimental findings show that sputtering by O ions is about 50% lower than previously assumed. However, our measurements still support the importance of sputtering by planetary ions in the Martian tail, where it will dominate over solar wind sputtering by up to a factor of 10 [8].

References

 [1]         Q. Nenon, et al., J. Geophys. Res.: Planets 124 (2019), 3385

[2]          B. Hapke, J. Geophys. Res.: Planets 106 (2001), 10039

[3]          P. Wurz, et al., Icarus 191 (2007), 486

[4]          R.M. Killen, et al., Space Sci. Rev. 132 (2007), 509

[5]          H. Hijazi, et al., J. Geophys. Res.: Planets 122 (2017), 1597

[6]          P.S. Szabo, et al., Astrophys. J. 891 (2020), 100

[7]          A.R. Poppe, S.M. Curry, Geophys. Res. Lett. 41 (2014), 6335

[8]          P.S. Szabo, et al., J. Geophys. Res.: Planets 125 (2020), e2020JE006583

[9]          G. Hayderer, et al., Rev Sci. Instrum., 70 (1999), 3696

[10]        J. Ziegler, et al., NIMB, 268 (2010), 1818

[11]        A. Mutzke, IPP-Report 2019-02 (2019)

[12]        M. Schaible, et al., J. Geophys. Res.: Planets 122 (2017), 1968

How to cite: Szabo, P. S., Biber, H., Jäggi, N., Wappl, M., Stadlmayr, R., Primetzhofer, D., Nenning, A., Mutzke, A., Fleig, J., Mezger, K., Lammer, H., Galli, A., Wurz, P., and Aumayr, F.: Quantifying Space Weathering of Phobos by Martian Planetary Oxygen Ions, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1813, https://doi.org/10.5194/egusphere-egu21-1813, 2021.

Most Noachian-aged craters on Mars have distinctive morphologic characteristics that suggest they were modified by runoff from rainfall in a predominantly warm and wet early Mars climate. However, melting and runoff of frozen water ice (snowmelt) represents a plausible alternative for fluvial erosion in the Noachian. In recent work, we described a "closed-source drainage basin" (CSDB) crater in Terra Sabaea that contained inverted fluvial channel networks and lacustrine deposits. The crater is not breached by fluvial channels and lacks depositional morphologies such as fans or deltas, which sets it apart from previously described open- and closed-basin lakes on Mars that are hydrologically connected to their surroundings. The lack of hydrologic connectivity, along with additional evidence of remnant cold-based glacial morphologies within the crater, led us to hypothesize top-down melting of a cold-based crater wall glacier as the source of runoff and sediment for the fluvial and lacustrine deposits, which produced one or more proglacial lakes within the crater.

Here, we describe the results of a follow-on survey of the region within 500 km of the first CSDB crater. We searched for examples of features that could be interpreted as inverted fluvial channels regardless of their location. Of the 42 inverted channel networks we identified, 19 are located within unbreached craters; 17 are within breached craters with at least one inlet but no outlets; and 6 are located in the intercrater plains. The features are not randomly distributed; rather, they form two distinct groupings, one in the southwest of the study area and another in the east, with very few in the north or west. All but one occurs within an elevation range of 0 to +3 km. There are several previously identified closed-basin lakes within the study area, but none contained inverted channels.

The 42 inverted channel systems represent a wide variety of geologic and hydrologic settings. The region has distinctly low valley network density, and the few mapped valley networks in the region are clustered around +2 km elevation. If the fluvial regime were controlled primarily by elevation, and assuming no significant sequestration, lower elevations should have greater overall runoff production due to the accumulation of flow from upslope. The difference between breached and unbreached craters could therefore represent glacial melting occurring within craters (higher elevation) as opposed to significantly upslope of them (lower elevation), which would instead promote runoff and breaching of craters by valley networks.

We previously described a single CSDB crater that showed evidence for cold-based crater wall glaciation, sedimentation and proglacial lake formation, but this new work adds a significant body of evidence that such processes were operating at much greater regional scales. While runoff from rainfall is usually considered the most likely mechanism of fluvial erosion in the Noachian, the possibility remains that fluvial erosion could have occurred via snowmelt in a subfreezing ambient climate. We have provided compelling evidence that fluvial and lacustrine features could have formed in such a climate and that Noachian Mars may have been colder than previously believed.

How to cite: Boatwright, B., Head, J., and Palumbo, A.: Inverted Fluvial Channels in Terra Sabaea, Mars: Geomorphic Evidence for Proglacial Lakes and Widespread Highlands Glaciation in the Late Noachian, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8504, https://doi.org/10.5194/egusphere-egu21-8504, 2021.

We continue the analysis of HiRISE high resolution images of Mars to understand properties of dust covering the surface. The data on dust devils observed with Mars landers and surface traces of dust devils could be expanded with elongated albedo features imaged near “new” impact sites (“new” means that we have orbital images before and after the meteoroid impact, which give us an estimate of the impact date and the age of a feature). The age of these features is from 0.5 to 12 terrestrial years. From geometric reasons we could assume that the most possible mechanism of this elongated albedo details is the “footprint” of two or more colliding air shock waves, generated at the impact site. Of ~1200 “new” impacts known today, in 18 cases crater pairs or clusters, created with fragments of the same “parent” meteoroid, we recognize 24 thin “parabolas” with a width of 1 to 10 m (0.2 to 10 main crater diameters, D), extended to 100 – 400 m (3 to 100 D) from the impact site. In ~30 cases near a single crater we observe a curved albedo feature nick-named “scimitar”. These features have width, growing with a distance from the impact point. The length varies from 10 to 100 D, the width varies from 1 to 10 D. Our working hypothesis is that “scimitars” are footprints of ballistic and spherical air shock wave collision at the surface. Both “parabolas” and “scimitars” have an exact bilateral symmetry, which allows us to reconstruct the flight direction of projectiles.

We estimate the equivalent energy of spherical air blasts with two different assumptions for “parabolas” and “scimitars” formation. For parabolas we assume a mechanism, similar to dust devil track formation – the negative pressure excurse uplifts the upper fine dust layer. The main assumption is that the dark parabolic strip width corresponds the wave length of the negative pressure phase in the air shock wave. It gives us the minimum energy estimate as in reality the negative phase could be longer. The negative pressures here along the parabola length decay from about 10 to 5 Pa with the phase duration of a few milliseconds. Such a suction pulse is able to mobilize dust particles 50 to 100 microns in size.

For scimitars, which in contrast to “dark” parabolas are typically “brighter” than surrounding area, we have no a good mechanical explanation of origin. However, with limits of our current model, the spherical “explosion” air blast should be enough energetic, to overrun the ballistic shock wave. From non-linear motion of the shock wave front we can estimate the fraction of meteoroid’s kinetic energy, converted to the air blast energy. The model is able to reproduce approximately the scimitar’s curvature.

How to cite: Ivanov, B.: Mars surface dust activation at small meteoroid’s impacts, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10018, https://doi.org/10.5194/egusphere-egu21-10018, 2021.

In 2022, ESA/ROSCOSMOS will launch the ExoMars2022 rover mission to Mars. The selected landing site for the mission is Oxia Planum, a wide, Noachian-age, phyllosilicate-bearing plain located on the SE border of Chryse Planitia. The Fe,Mg-rich clay mineral deposits at Oxia Planum are one of the largest exposures of this type on Mars, with a thickness of more than 10 m. They clearly record complex water-rock interactions and as such are a promising target to answer scientific questions posed by the ExoMars 2022 mission pertaining to the history of water and the geochemical environment in the shallow Martian subsurface, and the ancient and present habitability of the planet.

From the spectral analysis by CRISM and OMEGA, bedrock deposits at Oxia appear to contain vermiculite, a hydrous 2:1 phyllosilicate. But the exact mineralogy of the deposits and their origin is not yet fully understood. To fill this gap, and to better prepare for in-situ analyses by the ExoMars2022 rover, we performed a survey of potential terrestrial analog rocks by determining their mineralogy and NIR spectra for comparison with CRISM and OMEGA spectra of bedrock deposits at Oxia. The study focused on Fe-rich, trioctahedral vermiculite.

Two terrestrial sites were identified and studied: Otago, New Zealand with vermiculitized chlorite-schists that underwent alteration without significant oxidation; and Granby, Massachusetts with basaltic tuffs containing Fe-rich clays of apparent hydrothermal origin filling amygdales. Both analogues have been added to a newly built Planetary Terrestrial Analogue Library (PTAL) collection. The PTAL collection aims to provide the scientific community with analogue rocks to help characterize and define the mineralogy and geochemistry of landing sites on Mars chosen for in-situ analyses (www.ptal.eu).

The analogue comparisons reveal that Oxia bedrock deposits consist of Fe-rich, trioctahedral vermiculite, which is well crystallized and probably mixed with minor saponite. Additionally, NIR data analysis suggests that the deposits were not oxidized, nor illitized after formation. Based on this study, Oxia’s bedrock deposits may have formed from: (1) hydrothermal or magma fractionation-related origin of phyllosilicates and formation as an ash-fall deposits or (2) chlorite-rich sediment transported to a basin where chlorite was subsequently altered to vermiculite under anoxic, reducing conditions. The detailed characterization of the analogues and discussion of processes inferred for the evolution of Oxia Planum will be presented during the meeting.

Vermiculite, with its high surface area and exchange capacity, has great potential to store organic compounds. The mineralogy of the bedrock deposits at Oxia, along with the anoxic, reducing conditions that might have been prevalent during Noachian time would be advantageous for retaining and preserving organic matter and make it a promising site for future analysis.

How to cite: Krzesinska, A., Bultel, B., Loizeau, D., Craw, D., April, R., Poulet, F., and Werner, S.: Mineralogy, aqueous history and biosignature preservation potential of bedrock deposits at Oxia Planum, ExoMars 2022 landing site - Spectral characterization of terrestrial analogues., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-841, https://doi.org/10.5194/egusphere-egu21-841, 2021.

Serpentinization and carbonation have affected ultramafic rocks on Noachian Mars in several places. Among the most prominent systems revealing mineral assemblages characteristic of serpentinization/carbonation is the Nili Fossae region [1]. Jezero crater – the target of the Mars 2020 rover –hosted a paleolake which constitutes a sink for sediments from Nili Fossae [1]. Thanks to the near infrared spectrometer onboard Mars2020 [2], the mission has the potential to offer ground truth measurement for other putative serpentinization/carbonation system documented on Mars. Several important aspects that may be addressed are: Do carbonates result from primary alteration of olivine-rich lithologies or are they derived by reprocessing of previous alteration minerals [3]? What is the composition? and nature of the protolith, which appear to be constituted of considerable amounts of olivine [4]? To reveal critical information regarding the conditions of serpentinization/carbonation, accessory minerals need detailed studies [1; 5]. In case of Jezero Crater, and serpentinization on Mars in general, the main alteration minerals are identified, but little is known about the accessory minerals.

The Nili Fossae-Jezero system has potential analogues in terrestrial serpentinized and carbonated rocks, such as the Leka Ophiolite Complex, Norway (PTAL collection, https://www.ptal.eu). Here, distinct mineral assemblages record different stages of hydration and carbonation of ultramafic rocks [6].

We perform petrological and mineralogical analyses on thin sections to characterize the major and trace minerals and combine with Near Infrared (NIR) spectroscopy measurements. We study the significance of the mineralogical assemblages including solid solution composition and nature of accessory minerals. Effect of the presence of accessory minerals on the NIR signal is investigated and their potential incidence on the amount of H₂/CH₄ production in mafic or ultramafic system is discussed [5; 8]. This could improve our understanding of serpentinization and carbonation processes on Mars, which can guide future in-situ operations and also help for a better interpretation of the remote sensing data acquired on other possible serpentinization/carbonation systems.

 References:

1. Brown, A. J., et al. EPSL297.1-2 (2010): 174-182.

2. Wiens, R.C., et al.  Space Sci Rev217, 4 (2021).

3. Horgan, B., et al. Second International Mars Sample Return. Vol. 2071. 2018.

4. Ody, A., et al. JGR: Planets118.2 (2013): 234-262.

5. Klein, F., et al. Lithos178 (2013): 55-69.

6. Bjerga, A., et al. Lithos227 (2015): 21-36.

7. Bultel, B. (Doctoral dissertation, Lyon). (2016).

How to cite: Bultel, B., Krzesinska, A., Loizeau, D., Poulet, F., Astrheim, H. O., Bjerga, A., Harrington, E. M., Viennet, J.-C., Dypvik, H., and Werner, S. C.: Leka Ophiolite Complex as analogy to the serpentinization-carbonation system on Mars., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12057, https://doi.org/10.5194/egusphere-egu21-12057, 2021.

The Mars organic molecular analyzer (MOMA) of the Rosalind Franklin rover (ExoMars project) will combine laser desorption-ionization mass spectrometry (LDI-MS) and gas-chromatography mass spectrometry (GC-MS) to assess the origin of organic matter on planet Mars. In order to further assess the type of molecular information that can be retrieved with the former technique, we applied high-resolution laser two-step mass spectrometry (L2MS) to fossil organic matter of sedimentary rock from the Jurassic deposit of Orbagnoux, France. Abundant sulfur-rich microbial organic matter has been thoroughly documented in this deposit [1]. This sample has been chosen following the detection of thiophenes at Gale Crater on Mars by the Sample analysis at Mars (SAM) instrument [2]. In our L2MS instrument [3], the samples are irradiated with a pulsed desorption laser (532 or 266 nm), which generates a plume of chemical species that can be further ionized with a second orthogonal laser beam (266 nm). A radiofrequency ion guide is used to carry the ions to an orthogonal time-of-flight mass spectrometer (oToF-MS system by Fasmatech), yielding high-resolution mass spectra (m/Δm ~10000 at 128 m/z). Focusing of the desorption laser using a reflective objective and automated micro-positioning of the sample were used to generate hyperspectral raster mappings. Subsamples included solvent-extracted molecules (bitumen and maltene fractions), insoluble macromolecular organic matter (kerogen), rock powder and a polished slice. Our analyses showed that we can extract chemical information with LDI-MS from both soluble and insoluble organic fractions of the Orbagnoux samples and that various chemical families can be distinguished even in mineralized samples. Carbon clusters, including sulfurated and hydrogenated species could be detected in all subsamples. With the exception of the rock slice, polyaromatic hydrocarbons could be detected in all samples. Oxygenated molecules and alkylbenzenes could only be detected in extracts, which generated rich and intense mass spectra. Various inorganic ions were also generated in all sample fractions. Using focused desorption beams, carbon clusters (including sulfurated clusters) and inorganic species could be detected and mapped in the polished slice with <50 µm lateral resolution. L2MS thus shows great promise for fast screening of organic/inorganic species on Mars, and for microanalyses applied to paleontological questions.

[1] Mongenot, T., Derenne, S., Largeau, C., Tribovillard, N.P., Lallier-Vergès, E., Dessort, D., Connan, J., 1999. Spectroscopic, kinetic and pyrolytic studies of kerogen from the dark parallel laminae facies of the sulphur-rich Orbagnoux deposit (Upper Kimmeridgian, Jura). Org. Geochem. 30, 39–56. 

[2] Eigenbrode, J.L., Summons, R.E., Steele, A., Freissinet, C., Millan, M., Navarro-González, R., Sutter, B., McAdam, A.C., Franz, H.B., Glavin, D.P., Archer, P.D., Mahaffy, P.R., Conrad, P.G., Hurowitz, J.A., Grotzinger, J.P., Gupta, S., Ming, D.W., Sumner, D.Y., Szopa, C., Malespin, C., Buch, A., Coll, P., 2018. Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars. Science (80-. ). 360, 1096–1101. 

[3] A. Faccinetto, P. Desgroux, M. Ziskind, E. Therssen, C. Focsa, High-sensitivitydetection of polycyclic aromatic hydrocarbons adsorbed onto soot particles using laser desorption/laser ionization/time-of-flight mass spectrometry: An approach to studying the soot inception process in low-pressure flames, Combustion and Flame 158 (2011) 227–239. 

How to cite: Thlaijeh, S., Lepot, K., Carpentier, Y., Duca, D., Egorov, D., Riboulleau, A., Tribovillard, N., and Focsa, C.: Multiscale analysis of Jurassic rocks with sulfur-rich organic matter using laser desorption/ionization mass spectrometry, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16158, https://doi.org/10.5194/egusphere-egu21-16158, 2021.

After 17 years in orbit Mars Express remains one of ESA’s most scientifically productive Solar System missions which publication record exceeds 1300 papers. Characterization of the surface geology on a local-to-regional scale by HRSC, OMEGA and partner experiments on NASA spacecraft has allowed constraining land-forming processes in space and time. Recent studies characterized the geology of Jezero crater in great detail and provided Digital Elevation Model (DEM) of several equatorial regions at 50 m/px resolution. New maps and catalogues of surface minerals with 200 m/px resolution were released. MARSIS radar published new observations and analysis of the multiple subglacial water bodies underneath the Southern polar cap. Modelling suggested that the “ponds” can be composed of hypersaline perchlorate brines.

Spectrometers and imagers SPICAM, PFS, OMEGA, HRSC and VMC continued amending the longest record of atmospheric parameters such as temperature, dust loading, water vapor and ozone abundance, water ice and CO₂ clouds distribution and observing transient phenomena. More than 27,000 ozone profiles derived from SPICAM UV spectra obtained in MY#26 through MY#28 were assimilated in the OpenMARS database. A new “scan” mode of the spacecraft was designed and implemented to investigate diurnal variations of the atmospheric parameters. Observations of Tharsis region and Hellas basin contribute to mesoscale meteorology.

ASPERA measurements together with MAVEN “deep dip” data enabled assessment of the conditions that lead to the formation of the dayside ionopause in the regions with and without strong crustal magnetic fields suggesting that the ionopause occurs where the total ionospheric pressure (magnetic + thermal) equals the upstream solar wind dynamic pressure.

In 2020 Mars Express successfully performed two types of novel observations. In egress-only radio-occultations a two-way radio link was locked at a tangent altitude of about 50 km. This is well below the ionospheric peak and would allow perfect sounding of the entire ionosphere thus doubling the number of ionospheric soundings. MEX and TGO performed several test UHF occultations. The dual-spacecraft radio-occultation technique would significantly enhance the missions’ capabilities in atmospheric sounding.  

Mars Express is extended till the end of 2022. A science case for the mission extension till the end of 2025 will be developed and submitted by summer 2021. The talk will give the Mars Express status, review the recent science highlights, and outline future plans including synergistic science with TGO.

How to cite: Titov, D., Bibring, J.-P., Cardesin, A., Carter, J., Duxbury, T., Forget, F., Giuranna, M., González-Galindo, F., Holmström, M., Jaumann, R., Määttänen, A., Martin, P., Montmessin, F., Orosei, R., Pätzold, M., Plaut, J., and Team, M. S.: Mars Express science highlights and future plans, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12956, https://doi.org/10.5194/egusphere-egu21-12956, 2021.

This work takes advantage of the NOMAD spectrometer observations, on board the 2016 ExoMars Trace Gas Orbiter. ExoMars is an ESA-Roscosmos joint mission consisting of a rover and an orbiter (Trace Gas Orbiter - TGO). The Nadir and Occultation for Mars Discovery (NOMAD) is one of the four instruments on board TGO. The instrument is a suite of three spectrometers designed to observe the atmosphere and the surface of Mars in the UV, visible and IR. For this study, the Limb, Nadir and Occultation (LNO) channel, operating in the IR, is selected [1][2].  We focus on specific signatures in the [2.3 - 3.8 μm] range of NOMAD-LNO in order to study the possible detection of clouds at these wavelengths in the infrared.

For this study, we have selected the order 169 ([2611.8 nm - 2632.7 nm]) located in the vicinity of 2.7 µm CO₂/H₂O ices absorption band. We search for the presence of ice clouds in MY 34 (L_S = 150° - 360°) and MY 35 for observations with a solar zenith angle below 80 degrees.  The detection method is adapted from Bellucci et al., 2019 [3] and L. Ruiz Lozano et al., 2020 [4].  The initial results indicate a number of detections in the Tharsis region consistent with the known ‘W’ clouds [6][7].  Finally, these results will be compared with the NOMAD-UVIS observations ([230 nm - 310 nm]) obtained at the same TGO orbits.

Acknowledgements

The NOMAD experiment is led by the Royal Belgian Institute for Space Aeronomy (IASB-BIRA), assisted by Co-PI teams from Spain (IAA-CSIC), Italy (INAF-IAPS), and the United Kingdom (Open University). This project acknowledges funding by the Belgian Science Policy Office (BELSPO), the Belgian Fonds de la Recherche Scientifique – FNRS under grant number 30442502 (ET_HOME) and the FRIA, with the financial and contractual coordination by the ESA Prodex Office (PEA 4000103401, 4000121493), by Spanish Ministry of Science and Innovation (MCIU) and by European funds under grants PGC2018-101836-B-I00 and ESP2017-87143-R (MINECO/FEDER), as well as by UK Space Agency through grants ST/R005761/1, ST/P001262/1, ST/R001405/1 and ST/R001405/1 and Italian Space Agency through grant 2018-2-HH.0.

References
[1] A.C. Vandaele et al., 2015. Optical and radiometric models of the NOMAD instrument part I: the UVIS channel. Optics Express, 23(23):30028–30042.
[2] E. Neefs et al., 2015. NOMAD spectrometer on the ExoMars trace gas orbiter mission: part 1—design, manufacturing and testing of the infrared channels. Applied optics, 54(28):8494–8520.
[3] G. Bellucci et al., 2019. TGO/NOMAD Nadir observations during the 2018 global dust storm event, EPSC-DPS 2019
[4] L. Ruiz Lozano et al., 2020. Use of TGO-NOMAD nadir observations for ice detection, EPSC Abstracts, Vol. 14, Virtual EPSC 2020, EPSC2020-748.
[5] M. Vincendon, et al., 2011. New near‐IR observations of mesospheric CO2 and H2O clouds on Mars, J. Geophys. Res., 116, E00J02, doi:10.1029/2011JE003827.
[6] J. L. Benson, et al., 2003. The seasonal behavior of water ice clouds in the Tharsis and Valles Marineris regions of Mars: Mars Orbiter Camera Observations, Icarus, Volume 165, Issue 1, 2003, Pages 34-52, ISSN 0019-1035, https://doi.org/10.1016/S0019-1035(03)00175-1.

How to cite: Ruiz Lozano, L., Karatekin, Ö., Dehant, V., Bellucci, G., Oliva, F., Altieri, F., Carrozzo, F. G., D'Aversa, E., Daerden, F., Thomas, I., Ristic, B., Willame, Y., Depiesse, C., Mason, J., Patel, M., López Moreno, J. J., and Vandaele, A. C.: Ice clouds detection with NOMAD-LNO onboard ExoMars Trace Gas Orbiter, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14775, https://doi.org/10.5194/egusphere-egu21-14775, 2021.

We will present the vertical distribution of ozone obtained from NOMAD-UVIS solar occultations and we will compare the results of three retrieval schemes.

NOMAD (Nadir and Occultation for MArs Discovery) is a spectrometer composed of 3 channels: 1) a solar occultation channel (SO) operating in the infrared (2.3-4.3 μm); 2) a second infrared channel LNO (2.3-3.8 μm) capable of doing nadir, as well as solar occultation and limb; and 3) an ultraviolet/visible channel UVIS (200-650 nm) that can work in the three observation modes [1,2].

The UVIS channel has a spectral resolution <1.5 nm. In the solar occultation mode it is mainly devoted to study the climatology of ozone and aerosols content [3].

Since the beginning of operations, on 21 April 2018, NOMAD UVIS acquired more than 4000 solar occultations with an almost complete coverage of the planet.

NOMAD-UVIS spectra are simulated using three different retrieval scheme:

1) An onion peeling approach based on [4,5] deriving slant columns at the different altitudes sounded, from which local densities are obtained;

2) The line-by-line radiative transfer code ASIMUT-ALVL developed at IASB-BIRA [6] using the Optimal Estimation Method to derive the local density profile in one go (on all transmittances of one occultation observation);

3) A direct onion peeling method deriving sequentially from top to bottom the local densities in the different layers probed.

We will compare results obtained from the different retrieval methods as well as their uncertainties and we will discuss the advantages and difficulties of each method.

References

[1] Vandaele, A.C., et al., Planetary and Space Science, Vol. 119, pp. 233–249, 2015.

[2] Neefs, E., et al., Applied Optics, Vol. 54 (28), pp. 8494-8520, 2015.

[3] M.R. Patel et al., In: Appl. Opt. 56.10 (2017), pp. 2771–2782. DOI: 10.1364/AO.56.002771.

[4] Quémerais, E.,et al. J.Geophys. Res. (Planets)111, 9, 2006.

[5] Piccialli, A. et al., Planetary and Space Science, 113-114(2015) 321–335

[6] Vandaele, A.C., et al., JGR, 2008. 113 doi:10.1029/2008JE003140.

How to cite: Piccialli, A., Vandaele, A. C., Willame, Y., Aoki, S., Depiesse, C., Trompet, L., Neary, L., Viscardy, S., Daerden, F., Erwin, J., Thomas, I. R., Ristic, B., Mason, J., Patel, M., Khayat, A., Wolff, M., Bellucci, G., and Lopez Moreno, J. J.: Ozone vertical profiles from TGO/NOMAD-UVIS: an inter-comparison of three retrieval schemes, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10062, https://doi.org/10.5194/egusphere-egu21-10062, 2021.

The Emirates Mars Mission (EMM) is the United Arab Emirates’ (UAE) first mission to Mars and is the first Arab mission to another planet. It launched an unmanned observatory called “Hope” into an elliptical orbit around Mars on July 20, 2020  carrying three scientific instruments to study the Martian atmosphere in visible, ultraviolet, and infrared wavelengths. EMM will be the first mission to provide the first truly global picture of the Martian atmosphere, revealing important information about how atmospheric processes drive diurnal variations for a period of one Martian year. This will provide scientists with valuable understanding of the changes to the Martian atmosphere today through the achievement of three scientific objectives:

• Characterize the state of the Martian lower atmosphere on global scales and its geographic, diurnal and seasonal variability.
• Correlate rates of thermal and photochemical atmospheric escape with conditions in the collisional Martian atmosphere.
• Characterize the spatial structure and variability of key constituents in the Martian exosphere.

The mission is led by Emiratis from Mohammed Bin Rashid Space Centre (MBRSC) and is expanding the nation’s human capital through knowledge transfer programs set with international partners from the University of Colorado Laboratory for Atmospheric and Space Physics (LASP), Arizona State University (ASU) School of Earth and Space Exploration, and University of California Berkeley Space Sciences Laboratory (SSL). The presentation will review the status of the mission up to and beyond a successful Mars Orbit Insertion on Feb 9, 2021, including activities from Mars orbit in preparation for the start of mission science in May 2021.

How to cite: Sharaf, O., Amiri, S., Almatroushi, H., AlRais, A., Wali, M., AlShamsi, Z., AlTeneiji, N., McGrath, M., Withnell, P., Brain, D., Ferrington, N., Reed, H., Landin, B., Ryan, S., Pramann, B., Holsclaw, G., Edwards, C., and Wolff, M. and the EMM Team: Emirates Mars Mission (EMM) 2020 Overview and Status, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1906, https://doi.org/10.5194/egusphere-egu21-1906, 2021.

The Mars 2020 Mission was designed  to address four overarching goals [1]: i) investigate the mineralogy and geology of the Jezero crater as representative of the ancient Martian environment, ii) assess the habitability of this ancient environment, iii) identify and cache samples with a high potential of preserving biosignatures, iv) study the current environmental Martian conditions in preparation for human exploration.The SuperCam Instrumental Suite was designed as the primary tool to remotely investigate elemental composition and mineralogy of rock and soil targets. It will also provide sub-mm context color imaging of outcrop textures, search for organics and volatiles, perform atmospheric characterization, and record sounds [2], [3]. To achieve these objectives, SuperCam implements four nested and co-aligned spectroscopic techniques: laser induced breakdown spectroscopy (LIBS), Raman spectroscopy, time-resolved fluorescence spectroscopy, and passive VISIR spectroscopy. Laser-induced breakdown spectroscopy (LIBS) obtains emission spectra of materials ablated from the samples in electronically excited states. The Supercam LIBS instrument comprises three spectrometers covering the UV (245 – 340 nm), the violet (385 – 465 nm), and the visible and near-infrared (VNIR, 536 – 853 nm) ranges encompassing spectral lines of the majority of the elements of interest.  Using a dedicated LIBS database, it is possible to retrieve the composition of the ablated targets. For ChemCam, the first planetary LIBS device on board the Curiosity rover on Mars, this was achieved using multivariate techniques [4] for the major elements and univariate techniques for some minors and traces [5].  A similar procedure has been applied on SuperCam: LIBS measurements of a suite of more than 300 samples covering a wide range of compositions for the major elements has been acquired at a distance of 3m with a representative model of the instrument. The database includes a set of the calibration targets (SCCT) similar to those that are mounted on the Perseverance rover. Measurements of the SCCT were also acquired a 1.5m and 4.2m. Some SCCTs were also analysed using the Flight Model during System Thermal Test (STT). Several steps in the quantification procedure are achieved. i) Identification and removal of outliers ii) Definition of representative five-fold cross-validation for model evaluation. iii) definition of the train set and test set.  iv) training of various multivariate regression methods among them Partial Least Squares (PLS), linear methods (Lasso, Elastic Net, Blended Lasso [6]) or ensemble methods (Random Forest, Gradient Boosting) v) prediction of the test set and SCCT at various distances and on the STT targets. The performances of the methods are evaluated using statistical for both the Cross Validation and Prediction) vi) Selection of the best model for a given element. A specialized pipeline is designed to produce the quantified results at tactical timescales.

[1] Farley et al. (2020), Space Sci. Rev. 216, 142.  [2] Wiens et al. (2020) Space Sci. Rev. 216, in press [3] Maurice et al. (2020) Space Sci. Rev. 216, in press [4] Clegg et al. (2017), SCAB, 129, 64. [5] Payré et al. (2017) JGR, 122, 650. [6] Anderson et al. (2017), SCAB, 129, 49.

How to cite: Forni, O., Anderson, R. B., Cousin, A., Clegg, S. M., Frydenvang, J., Pilleri, P., Legett, C., Wiens, R. C., and Maurice, S.: Supercam Laser Induced Breakdown Spectroscopy Calibration, Data Processing, and First Results, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1081, https://doi.org/10.5194/egusphere-egu21-1081, 2021.

Starting in February 2021, the Perseverance rover 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 RMI (Remote Micro-Imager) provides pictures for local context and site imaging at high-resolution.

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.

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.

References: [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). 

How to cite: Gasnault, O., Virmontois, C., Maurice, S., Wiens, R. C., Le Mouelic, S., Bernardi, P., Forni, O., Pilleri, P., Daydou, Y., Rapin, W., and Cais, P.: A first look at the SuperCam RMI images aboard Perseverance , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16461, https://doi.org/10.5194/egusphere-egu21-16461, 2021.

The NASA Perseverance rover will land on Mars in February 2021, bringing with it a new suite of analytical instruments with which to explore its landing site in Jezero crater. The primary goal of this new mission is to assess the geology and past habitability in order to identify and cache samples with a high likelihood of preserving biosignatures, in preparation for a future sample return mission [1]. As part of its instrument payload, Perseverance will carry the SuperCam instrument [2-3]. SuperCam combines a number of analytical techniques, notably a laser-induced breakdown spectroscopy (LIBS) instrument for chemical analysis that is coupled with a microphone for acoustic studies. The SuperCam microphone is a commercial of-the-shelf electret (based on Knowles EK-23132) and is designed to record sounds in the audible range, from 100 Hz to 10 kHz, during the surface mission. There are three main science investigations of interest for the SuperCam microphone: 1) Analysis of the LIBS acoustic signal; 2) study of atmospheric phenomena; and 3) examination of rover mechanical sounds. Since the atmosphere will be the source of acoustic signals, the microphone may be used to better understand the nature of the atmosphere and related phenomena such as thermal gradient and convective behavior in the rover’s vicinity [4], the behavior of dust devils [5], and to refine current atmospheric attenuation models for Mars [6]. Under atmosphere, LIBS analysis produces an acoustic signal due to the creation of a shock wave during laser ablation of a target. This acoustic signal can provide critical information about a target’s hardness and ablation depth [7-8] and whether there are coatings or thin layers present [9]. Mechanisms on the rover itself will also provide a source of acoustic signal that may be examined by the SuperCam microphone, notably sounds produced by the Mars Oxygen ISRU Experiment (MOXIE, [10]) instrument pumps during oxygen production. By the time of the conference, the SuperCam microphone should have acquired the first sounds on Mars; we will report on these exciting initial results and compare them to our prelanding expectations.

[1] Farley K.A. et al. (2020) SSR 216, 142. [2] Wiens R.C. et al. (2021) SSR 217(4). [3] Maurice, S. et al. (in revision) SSR. [4] Chide, B. et al. (2020) 52^nd LPSC. [5] Murdoch, N. et al. (2021) 52^nd LPSC. [6] Chide, B. et al. (2020) AGU Fall meeting, S007-02. [7] Chide, B. et al. (2019) SAB 153, 50-60. [8] Chide, B. et al. (2020) SAB 174, 106000. [9] Lanza, N.L. et al (2020) 51^st LPSC, no. 2807. [10] Hecht, M. H. et al. (2015) 46^th LPSC, no. 2774.

How to cite: Lanza, N., Chide, B., Mimoun, D., Alvarez, C., Angel, S., Bernardi, P., Beyssac, O., Bousquet, B., Cadu, A., Clave, E., Forni, O., Fouchet, T., Gasnault, O., Jacob, X., Lacombe, G., Laserna, J., Lasue, J., Lorenz, R., Meslin, P.-Y., and Montmessin, F. and the SuperCam Acoustics Working Group: Expected first results from the SuperCam microphone onboard the NASA Perseverance rover, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8505, https://doi.org/10.5194/egusphere-egu21-8505, 2021.

The SuperCam Instrument Suite [1-4], a US-French-Spanish-Danish collaboration, consists of three separate units: the Body Unit (BU) within the Rover [2], the Mast Unit (MU) at the top of the Perseverance Remote Sensing Mast [3], and Calibration Targets [4] located on the rover deck. SuperCam includes a passive visible/near-infrared (VISIR) spectroscopy system that will identify minerals near the rover (mm-scale) to distant outcrops (m-scale) over an extended wavelength range (0.385-0.465 µm, 0.536-0.853 µm, 1.3-2.6 µm) that is diagnostic for most mineral classes.

The infrared spectrometer (IRS) in the MU [5] uses an acousto-optic tunable filter (AOTF) excited by a RF signal to successively diffract up to 256 different wavelengths ranging between 1.3 and 2.6 µm on one of two available photodiodes to produce a single spectrum in about 80 seconds at a spectral resolution of 5-20 nm. The field-of-view (FOV) of the IRS is 1.15 mrad and is co-aligned with the RMI boresight. The visible (VIS) system in the BU comprises three spectrometers covering the UV (245 – 340 nm), violet (385 – 465 nm), and visible and near-infrared (VNIR, 536–853 nm). The spectrometers are fed by light collected by the telescope in the MU through an optical fiber connecting the MU and BU. The violet spectrometer has a spectral resolution of 0.12 nm, and the VNIR transmission spectrometer has a spectral resolution of 0.35 – 0.70 nm. The VIS FOV is 0.74 mrad and co-aligned with the IR FOV.

Several SuperCam calibration targets (SCCT) are dedicated to VISIR spectroscopy, including an AluWhite white target, an Aeroglaze Z307 black target, and red, cyan, and green color targets [4]. Several of the other targets whose primary purpose is for other techniques exhibit useful VISIR spectral features and will be observed [5].

Raw data will be converted to radiance (W/m2/sr/µm) with calibrated wavelengths using the instrument transfer function [6-7]. Relative reflectance spectra will be generated by dividing the calibrated radiance spectrum by either (1) a Mars atmospheric transmission spectrum and then by a modeled solar irradiance spectrum; or (2) a radiance spectrum of the white SCCT taken close in time to the surface observation, as is done with Mastcam-Z calibration [8].

This poster will show initial VISIR data acquired on Mars, compared with test and performance data obtained at Paris Observatory, LANL, and JPL. As of this writing, the planned observations during the first ~30 sols include spectra of the white and black SCCTs, and at least one Mars target spectrum.

[1] Farley et al. (2020), Space Sci. Rev. 216, 142. [2] Wiens et al. (2020) Space Sci. Rev. 216, in press, [3] Maurice et al. (2020) Space Sci. Rev. 216,in press, [4] Manrique et al. (2020) Space Sci. Rev. 216, 8, 1-27; [5] Cousin et al. (2021) this meeting [6] Fouchet et al. (2021) Icarus, in prep. [7] Royer et al. (2020) Rev. Scient. Instrum. 91, 063105. [8] Bell, J.F. et al. (2021), Space Sci. Rev, in press.

How to cite: Johnson, J., Fouchet, T., Forni, O., Reess, J.-M., Bernardi, P., Newell, R., Ollila, A., Legett, C., Beck, P., Cousin, A., Royer, C., Pilorget, C., Poulet, F., Cloutis, E., McConnochie, T., Wiens, R. C., and Maurice, S.: Initial SuperCam Visible/Near-Infrared Spectra from the Mars 2020 Perseverance Rover, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-986, https://doi.org/10.5194/egusphere-egu21-986, 2021.