PS4.5

We will investigate the impact of day-night temperature and compositional gradients at the Martian terminator on the retrieval of vertical profiles of ozone obtained from NOMAD-UVIS solar occultations. 

Rapid variations in species concentration at the terminator have the potential to cause asymmetries in the species distributions along the line of sight of a solar occultation experiment. Ozone, in particular, displays steep gradients across the terminator of Mars due to photolysis [1]. Nowadays, most of the retrieval algorithms for solar and stellar occultations rely on the assumption of a spherically symmetrical atmosphere. However, photo-chemically induced variations near sunrise/sunset conditions need to be taken into account in the retrieval process in order to prevent inaccuracies.

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 [2,3]. 

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 [4,5,6].

Since the beginning of operations, on 21 April 2018, NOMAD-UVIS acquired more than 8000 solar occultations with an almost complete coverage of the planet.

NOMAD-UVIS spectra are simulated using the line-by-line radiative transfer code ASIMUT-ALVL developed at IASB-BIRA [7]. In a preliminary study based on SPICAM-UV solar occultations (see [8]), ASIMUT was modified to take into account the atmospheric composition and structure at the day-night terminator. As input for ASIMUT, we used gradients predicted by the 3D GEM-Mars v4 Global Circulation Model (GCM) [9,10]. 

References
[1] Lefèvre, F., Bertaux, J.L., Clancy, R. T., Encrenaz, T., Fast, K., Forget, F., Lebonnois, S., Montmessin, F., Perrier, S., Aug. 2008. Heterogeneous chemistry in the atmosphere of Mars. Nature 454, 971–975.
[2] Vandaele, A.C., et al., Planetary and Space Science, Vol. 119, pp. 233–249, 2015. 
[3] Neefs, E., et al., Applied Optics, Vol. 54 (28), pp. 8494-8520, 2015.
[4] M.R. Patel et al., In: Appl. Opt. 56.10 (2017), pp. 2771–2782. DOI: 10.1364/AO.56.002771. 
[5] M.R. Patel et al., In: JGR (Planets), Vol. 126, Is. 11, 2021.
[6] Khayat, Alain S. J., et al., In: JGR (Planets), Vol. 126, Is. 11, 2021.
[7] Vandaele, A.C., et al., JGR, 2008. 113 doi:10.1029/2008JE003140.
[8] Piccialli, A., Icarus, submitted.
[9] Neary, L., and F. Daerden (2018), Icarus, 300, 458–476, doi:10.1016/j.icarus.2017.09.028.
[10] Daerden et al., 2019, Icarus 326, https://doi.org/10.1016/j.icarus.2019.02.030

How to cite: Piccialli, A., Vandaele, A. C., Neary, L., Willame, Y., Aoki, S., Trompet, L., Depiesse, C., Viscardy, S., Daerden, F., Erwin, J., Thomas, I. R., Ristic, B., Mason, J. P., Patel, M., Khayat, A., Wolff, M., Bellucci, G., and Lopez-Moreno, J. J.: Impact of gradients at the Martian terminator on the retrieval of ozone from TGO/NOMAD-UVIS, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12125, https://doi.org/10.5194/egusphere-egu22-12125, 2022.

The Mars 2020 Perseverance rover landed in Mars in February 2021 in Jezero crater at 18.4ºN. One of its instruments is MEDA, the Mars Environmental Dynamics Analyzer, which measures among other properties air pressure, air temperature at different levels, surface temperature from its infrared emission, and the presence of dust. The latter is provided by a set of photodiodes pointing in different directions that constitute the Remote Dust Sensor or RDS. MEDA data are acquired with a frequency of 1 or 2 Hz in data sessions that cover about 50% of a full sol allowing a full characterization of daily and seasonal cycles.

Predictions before landing indicated that Jezero should be a location favoring the formation of intense vortices and dust devils in Spring to Summer. These expectations were fulfilled with frequent observations of vortices and dust devils observed with MEDA and the rover cameras. A systematic analysis of MEDA’s pressure sensor shows the close passage of convective vortices. These are detected as events that range from short and sharp pressure drops to long and deep pressure drops. Wind measurements during the vortex passage, combined with their duration, give information about the size and distance of the vortex. Many of the most intense events in terms of the pressure drop and peak winds detected have simultaneous drops of light measured with the RDS and are dust devils equivalent to those observed at much higher distances with Perseverance cameras. The combination of pressure, wind and RDS measurements largely constrain the geometry effects associated to these close passing dust devils. Some of them also have additional clear counterparts in other MEDA sensors including temperatures, which allows for an in-depth investigation of the physical properties of selected dust devils. Some events might also be captured by the SuperCam microphone, that records pressure fluctuations in the audible domain. The acoustic signal can provide insights into the short term behavior of vortices, and can contribute to the determination of the vortex physical properties. Statistics of vortices allow us to determine the probability of finding these events with the SuperCam microphone.

We present results for over one Earth year (Ls=6; Feb. 2021, Northern Hemisphere Spring – Ls=180; Feb. 2022; Northern Autumn Equinox). We show the daily cycle of vortex and dust devil activity and how this has evolved from early Spring until the start of the dust storms season. We present results of the distribution of sizes of vortices and dust devils and a selection of some remarkable events. These include direct hits of dust devils passing right through Perseverance, tangential passes in which one wall of the vortex passes over Perseverance, and more distant passages of very dusty events whose diameter in some cases largely exceed 100 m. A comparison of the vortex convective activity observed at Jezero with results from a Large-Eddy-Simulations (LES) using the MarsWRF model helps us to gain insight into how the detected vortices and their properties can constrain other general properties of the atmospheric dynamics at Jezero crater.

How to cite: Hueso, R., Newman, C., Munguira, A., Sánchez-Lavega, A., Lemmon, M., del Río-Gaztelurrutia, T., Richardson, M., Apestigue, V., Toledo, D., Vicente-Retortillo, Á., de la Torre-Juarez, M., Rodríguez-Manfredi, J. A., Tamppari, L., Arruego, I., Murdoch, N., Martínez, G., Navarro, S., Gómez-Elvira, J., Baker, M., and Lorenz, R. and the Mars 2020 Atmosphere Team: Seasonal variation of vortex and dust devil activity on Jezero and physical characterization of selected events, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6027, https://doi.org/10.5194/egusphere-egu22-6027, 2022.

We study a young (~ 4.5 Ma), 3.4 km long landslide located in the floor of Simud Vallis, a large outflow channel that together with Tiu Vallis once connected the Valles Marineris with the Chryse Planitia on Mars (1). Multiple teardrop-shaped islands are present on Simud Vallis’ floor, all elongated in the S–N direction of the flow (2) that incised the Mid-Noachian plateau (3). The Simud Vallis (SV) landslide is located on the western side of one of such landforms. It is characterized by numerous boulders on its deposits (4). By making use of the 2 m-scale HiRISE DEM of (4) we reconstruct the terrain surface before the SV landslide. We thereby estimate the release and deposition heights and volumes related to the rotational slide of the landslide, called stage 1, and of the subsequent flow, called stage 2. Using the r.avaflow software (5) we simulate the mass movement of stage 2 and obtain simulated deposits that are comparable to the current landslide deposit in terms of both horizontal extent and thickness (6). Through two 0.25 m-scale HiRISE images we identify and manually count >130,000 boulders that are located along the landslide, deriving their size-frequency distribution and spatial density per unit area for boulders with an equivalent diameter ≥1.75 m. Our analyses (6) shows that the distribution is of a Weibull-type (7), which commonly results from sequential fragmentation and it is often used to describe the particle distribution derived from grinding experiments (8,9). This suggests that the rocky constituents of the SV landslide fractured and fragmented progressively during the course of the mass movement, consistent with our proposed two-stage model of landslide motion.

References:

 (1) Pajola, M. et al., 2016. Icarus, 268, 355. (2) Carr, M.H. & Clow, G.D., 1981. Icarus, 48 (1), 91. (3) Tanaka, K.L. et al., 2014. US Geological Survey. (4) Guimpier, A., et al., 2021. PSS, 206, 105303. (5) Mergili, M., et al., 2017. Geosci. Model Dev. 10, 553. (6) Pajola, M. et al., 2022. Icarus, 375, 114850. (7) Weibull, W., 1951. J. Appl. Mech., 18, 837. (8) Brown, W.K. & Wohletz, K.H., 1995. J. Appl. Phys. 78, 2758. (9) Turcotte, D.L., 1997. Cambridge University Press, Cambridge.

How to cite: Pajola, M., Mergili, M., Cambianica, P., Lucchetti, A., Brunetti, M. T., Guimpier, A., Mastropietro, M., Munaretto, G., Conway, S., Beccarelli, J., and Cremonese, G.: Mass movement reconstruction and boulder size-frequency distribution of the Simud Vallis landslide, Mars, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3118, https://doi.org/10.5194/egusphere-egu22-3118, 2022.

Many cones on Isidis Planitia form subparallel chains several kilometers in length. This region have characteristic pattern of cones or cone chains- called a “fingerprint” [1]. Our analysis of chains of cones indicates that they can be grouped in larger systems. We considered one of these systems in the northwestern part of Isidis (central location: 14.235°N; 83.096°E).

We selected one standout spectrum that comes from the CRISM FRT00009260 scene but is typical for the entire image area. The scene just comes from the northwestern part of Isidis, where the characteristic chains of cones are visible. The types of cones from our division [2], belong to the group of chains of separate cones and without a furrow. The spectrum shows the minima 1.49; 1.98; 2.04 µm which we assigned to individual minerals. Additionally, the ~ 2 µm range is disturbed by Martian CO₂ influences, which is caused by the imperfect separation of the atmosphere by the “volcano - scan algorithm” (by the atmosphere above Olympus Mons). Gypsum appears to be the most suitable mineral for these minima, although alunites can also be considered. The clay minerals widespread on Mars do not resemble in the observed minima. From the generated endmembers, it can be seen that minerals are accumulated around the cones.

Gypsum is a mineral formed in the process of evaporation and crystallizes from salty, drying water reservoirs. Because Isidis might once have been a highly saline reservoir, gypsum crystallization could occur under such conditions, especially in depressions. Alunites, on the other hand, are products of volcanic exhalation, which would explain the origin of the cones. Common alunites have been found on the La Fossa Crater Volcano, Aeolian Islands [3] as volcanic exhalations and in the vicinity of Las Vegas, Nevada, where alunites with gypsum were mapped based on aerial photos [4]. On Mars in the northeast of Hellas Basin, gypsum and ammonioalunites were interpreted on the basis of the PFS and OMEGA (MEX) spectra [5], [6]

These are our preliminary comparisons that still require further evaluation. The next stage of the work will be to explain the mechanism of the formation of these forms, based on known geological phenomena but in relation to Mars. We want to clarify whether the designated areas were created in the same geological processes, or whether a different mechanism is responsible for the differences in these forms. We take the phenomenon into account that instability of water in the upper layers of the regolith could cause rapid degassing of the regolith [7].

References: [1] Guidat, T. et al. (2015) Earth and Planet. Sci. Let . 411, 253-267. [2] Zalewska N. et al. (2021) LPS 52nd, Abstract # 2710. [3] Parafiniuk J. (2012) Bulletin of the Polish Geolog. Instit. 452, 225-236. [4] Kirkland E. et al. (2007) LPS XXXVIII, Abstract # 2232. [5] Zalewska N. (2013) Planet. Space Sci. 78, 25-32. [6] Zalewska N. (2014) GeoPl. Earth and Planet. Sci. 65-76. [7] Czechowski L. et al. (2021) LPS 52nd, Abstract # 2740.

How to cite: Zalewska, N., Czechowski, L., and Ciążela, J.: Mineralogy of cones in the western part of Isidis Planitia, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10765, https://doi.org/10.5194/egusphere-egu22-10765, 2022.

Passive radar sounding has been proposed as a low-cost, low-risk way to enrich the scientific return of planetary radar sounders, especially in the vicinity of bright radio sources such as Jupiter [Romero-Wolf et al. (2015), Icarus, 248:463-477], whose moons will be studied by radar sounders in the late 2020's and 2030's. To predict what passive radargrams may look like as a function of parameters such as the noise source spectrum and the surface/subsurface roughness, analytical and empirical models have been proposed in the literature [Schroeder et al. (2016), PSS, 134:52-60], and proof-of-concept hardware has been tested on Earth [Peters et al. (2018), TGRS, 56(12) 7338-7349]. To cement our understanding of passive sounding, we searched for traces of passively-acquired radar echoes in existing SHARAD radargrams. Such signals can be uncovered if the incoming noise was captured in one acquisition and its reflection by surface or subsurface features in the next one. Cross-correlating the two uncompressed rangelines could then reveal possible present Martian features using only the signals of opportunity. We started from the engineering parameters of SHARAD, such as its orbit, Rx window length, and PRF, to work out all the geometric configurations where Jovian emissions and their reflection from the surface could have been intercepted if such emissions were present. We made the assumption that waves must be specularly-reflected off the surface of Mars at a given angle, and looked for the angles at which the delay of the reflected noise matches the PRI of SHARAD. We have determined that, for the range of altitudes SHARAD operates at, the (Jupiter-Mars, Mars-SHARAD) angle must lie between 35° and 52°. Based on Friis-like arguments, we believe the SNR of such signals could reach 10 dB in the case of a smooth surface such as Elysium Planitia. We then cross-correlated this database of SHARAD radargrams with that of a model of Jovian noise occurrence at Mars using ExPRES [Hess et al. (2008), GRL, 35.13], and extracted a list of potential candidates. Preliminary analysis of these candidates shows that some of them may indeed contain passively-acquired signals that may be exploited scientifically. We have additionally conducted passive Stratton-Chu simulations [Gerekos et al. (2019), TGRS, 58(4) 2250-2265] of these cases to support interpretation.

How to cite: Gerekos, C., Steinbrügge, G., Donini, E., and Romero-Wolf, A.: Exploitation of SHARAD data from a passive sounding perspective: a preliminary analysis, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3191, https://doi.org/10.5194/egusphere-egu22-3191, 2022.

In 2022, ESA/ROSCOSMOS will launch ExoMars2022 rover mission to Mars. The selected landing site for the mission is Oxia Planum, a Noachian, phyllosilicate-bearing plain located between Mawrth Vallis and Ares Vallis. The Fe,Mg-rich clay mineral detected at Oxia Planum are one of the largest exposures of this type on Mars. They clearly record past water-rock interactions and as such are promising target to answer scientific questions that are the objectives of the ExoMars 2022 mission in terms of past water-rich environment and both ancient and present habitability of the planet.

NIR spectral features of the phyllosilicates at Oxia suggest some kind of Fe-rich vermiculite and/or saponite. Survey of Fe-rich terrestrial vermiculite-bearing rocks and characterization by powder near-infrared and X ray diffraction analyses (Krzesinska et al, 2021) showed that the best spectral analogy is shown by the basaltic tuffs from Granby, Massachusetts, USA. The tuffs have been altered and Fe-rich clays resides in amygdales of supposedly hydrothermal origin (April and Keller, 1991).

The analogue was incorporated to the Planetary Terrestrial Analogue Library (PTAL) collection (Dypvik et al., 2021, www.ptal.eu). As a part of collection, it is further characterized for purposes of supporting the ExoMars mission science.

As shown by bulk analysis of powdered samples, Granby tuffs represent fine-scale mixture of phyllosilicates (Krzesinska et al., 2021). Based on bands between 2.3 and 2.5µm in NIR, vermiculite and saponite are intergrowing with various proportions. For Oxia Planum, better spectral match is shown by samples dominated by vermiculite rather than mixed with saponite.

Here we report an in-situ, micron-scale combined analysis on the same sample by the instrument of MicrOmega (NIR), RLS (RAMAN) completed by sub-micron EDX analysis. Such analysis allows a more detailed characterization of phyllosilicate constituents and understanding their spectral manifestation. This is important to prepare the future in situ scientific investigations on Mars and will also bring a better understanding of the Granby clays that could represent a unique bridge of solid solution between chlorite and saponite (April and Keller, 1991).

How to cite: Bultel, B., Krzesinska, A., Veneranda, M., Loizeau, D., Pilorget, C., Hamm, V., Lourit, L., Lequertier, G., Bibring, J.-P., and Werner, S. C.: Micro-scale characterization of vermiculite-rich sample from Granby Tuff, an analogue to Oxia Planum clays, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11272, https://doi.org/10.5194/egusphere-egu22-11272, 2022.

The Emirates Mars Ultraviolet Spectrometer (EMUS) instrument is one of three science instruments on board the “Hope Probe” of the Emirates Mars Mission (EMM). EMM arrived at Mars on February 9 2021, in order to explore the global dynamics of the Martian atmosphere, while sampling on both diurnal and seasonal timescales. The EMUS instrument is a far-ultraviolet imaging spectrograph, jointly developed by the Mohammed Bin Rashid Space Centre (MBRSC) in Dubai, UAE and the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder, which measures emissions in the spectral range 100-170 nm. Using a combination of its one-dimensional imaging and spacecraft motion, it makes two-dimensional far-ultraviolet images of the Martian disk and near-space environment including the Lyman beta and alpha atomic hydrogen emissions (102.6 nm and 121.6 nm), two atomic oxygen emissions (130.4 nm and 135.6 nm), and the carbon monoxide fourth positive group band emission (140-170 nm). Measurements of radiance at these wavelengths are used to derive the column abundance of atomic oxygen and carbon monoxide in the Martian thermosphere, and the density of atomic oxygen and atomic hydrogen in the Martian exosphere both with spatial and sub-seasonal variability. We will present a survey of results from EMM/EMUS including observed variability in atomic oxygen and carbon monoxide emission, two kinds of aurora, and the status of atmospheric retrievals.

How to cite: Chaffin, M., Almazmi, H., Chirakkil, K., Correira, J., Deighan, J., England, S., Evans, J. S., Fillingim, M., Holsclaw, G., Jain, S., Lillis, R., Lootah, F., Raghuram, S., and Al Matroushi, H.: Key Results from the Emirates Ultraviolet Spectrometer on the Emirates Mars Mission, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10731, https://doi.org/10.5194/egusphere-egu22-10731, 2022.

The Emirates Mars Mission (EMM) – Hope Probe – has commenced its one-Martian-year science phase on May 23rd 2021. The goals of the mission aim to understand the Martian atmosphere, its processes, dynamics, and circulation using three scientific instruments observing Mars' different atmospheric layers simultaneously. 

Hope Probe is studying the lower atmosphere of Mars using the Emirates eXploration Imager (EXI) and the Emirates Mars Infrared Spectrometer (EMIRS). While EXI measures the distribution of water ice and ozone using ultraviolet bands, EMIRS measures the optical depth of dust, ice clouds and water vapor in the atmosphere, in addition to the temperature of the surface and the atmosphere using infrared bands. On the other hand, the Emirates Mars Ultraviolet Spectrometer (EMUS) is studying the upper atmosphere of Mars through extreme and far ultraviolet bands to measure the distribution of carbon monoxide and oxygen in the thermosphere, and oxygen and hydrogen in the exosphere of Mars.

The scientific observations are taken from a unique high-altitude orbit with dimension 20,000 x 43,000 km that offers unprecedented local and seasonal time coverage over most of the planet. This presentation will highlight key atmospheric and surface results from the Hope Probe since it started collecting scientific data on the Martian atmosphere upon arrival to Mars on February 9th 2021. The data returned from the mission is enabling us to improve our understanding of the weather circulation in the lower atmosphere, the mechanisms behind the upward transport of energy and particles, and the subsequent escape of atmospheric particles from the gravity of Mars.

How to cite: Almatroushi, H., Deighan, J., Edwards, C., Holsclaw, G., and Wolff, M. and the EMM Science Team: Results from the Emirates Mars Mission (EMM) - Hope Probe, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3727, https://doi.org/10.5194/egusphere-egu22-3727, 2022.

Thermal tides are planetary-scale harmonic responses driven by diurnal solar forcing and influenced by planetary topography. Excited by solar heating absorbed by the atmosphere and energy exchange with surface, thermal tides grow in Martian atmosphere. These tides usually have large amplitudes due to the low heat capacity of Martian atmosphere, and dominate its diurnal variations. In this talk, we present results of the analysis of thermal tides in Martian atmosphere using temperature profiles retrieved using infrared spectra obtained by the Emirates Mars InfraRed Spectrometer (EMIRS) instrument onboard the Emirates Mars Mission (EMM) Hope spacecraft. The first set of data obtained during the mission science phase is selected, covering a solar longitude (L_S) range 60° - 80° of Martian Year (MY) 36, which is a clear season without large dust storms. The novel orbit design of the spacecraft allows a full local time coverage to be reached within 10 Martian days, approximately ~5° of L_S. It enables the analysis of diurnal temperature variations without the interference of seasonal changes, which was shown to be significant in previous studies. Wave mode decomposition is also applied to these diurnal variations, and amplitudes of other tide modes are derived. The results show good agreements with predictions derived using the Laboratoire de Météorologie Dynamique (LMD) Mars Global Circulation Model (GCM), except for a noticeable phase difference of the dominant diurnal thermal tide. This work provides valuable information on understanding diurnal variations in Martian atmosphere and inspires future advances of Mars GCMs.

How to cite: Fan, S., Forget, F., Smith, M., Guerlet, S., Badri, K., Atwood, S., Edwards, C., Christensen, P., Deighan, J., Al Matroushi, H., Bierjon, A., Liu, J., and Millour, E.: Thermal tides in Martian atmosphere observed by EMIRS onboard the Hope spacecraft, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4208, https://doi.org/10.5194/egusphere-egu22-4208, 2022.

The Emirates Mars Mission (EMM) Emirates Mars Infrared Spectrometer (EMIRS) currently around Mars is acquiring remote measurements of the martian surface (temperature and composition) and lower atmosphere. EMIRS is a FTIR spectrometer covering the range from 6.0-100 µm (1666-100 cm^‑1) with a spectral sampling as high as 5 cm^-1 with a 5.4-mrad IFOV. The EMIRS optical path includes a flat 45˚ pointing mirror to enable one degree of freedom while the spacecraft provides the other to build up a 2-dimensional array of observations. The primary goals of EMIRS are to characterize the geographic and diurnal variability of key atmospheric constituents (water ice, water vapor, and dust) along with temperature profiles and surface temperature on sub-seasonal timescales

EMIRS acquires data of the full martian disk and thus provides an integrated view of the martian surface and atmosphere in every spectrum. These observations include complete diurnal, seasonal, and geographic coverage of atmospheric properties, surface temperature, and also surface composition/mineralogy at wavelengths not regularly acquired of the martian surface. Due to the unique nature of the EMM orbit, EMIRS also collects data that spans the full local solar time range (all solar incidence angles), at multiple emission angles. These unique observations permit the interrogation of diurnal surface ices/frost, thermophysics (including sub-surface layering from both a seasonal and diurnal skin depth), surface roughness, and rock abundance in addition to the primary science goals.

In this presentation, we provide an overview of the first surface observations, atmospheric retrieval algorithm, and first atmospheric science results from the aphelion-season observations taken by EMIRS over the first several months of EMM Science Phase operations.

How to cite: Edwards, C., Smith, M., Atwood, S., Badri, K., Christensen, P., Wolff, M., Osterloo, M., Al Tunaiji, E., Al Mheiri, N., Yousuf, M., Wolfe, C., Smith, N., and Anwar, S.: The Atmosphere and Surface of Mars as Revealed by the Emirates Mars Infrared Spectrometer (EMIRS), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6039, https://doi.org/10.5194/egusphere-egu22-6039, 2022.

The EXI instrument is a camera onboard the EMM spacecraft, with a field a view capable capturing the full disk of Mars throughout its nominal science orbit.   Though the use of its multiple band passes (220, 260, 320, 437, 546, 635 nm) and the effective spatial resolution (2–4 km per native pixel), EXI’s primary goal is to provide both regional and global imaging of the Martian atmosphere with diurnal sampling over much of the planet on a time scale of approximately 10 days.  This presentation will provide an overview of EXI’s on-orbit instrument performance, a brief description of the observation strategy employed with the start of Science Operations (23-May-2021, Ls=49°), and the retrieval results of the ice optical depth and their diurnal behavior for the period of mid-spring through late-summer in the northern hemisphere.  More specifically, the presentation will cover:

• Status of the instrument calibration and plans for on-going on-orbit monitoring of instrument performance, including radiometric errors. Plus, some guidance on interpreting the metadata of the EXI publicly released raw and calibrated images;

• Illustration of the various disk geometries sampled during an EMM orbit of Mars, and how such observations are combined to provide diurnal coverage of the illuminated portion of the disk/atmosphere;

• Overview of the ice optical depth retrieval algorithm, and its application to the data obtained since the start Science Operations with an emphasis on the behavior of the aphelion cloud belt; including the formation and decay phases.

How to cite: Wolff, M., Jones, A. R., Osterloo, M., Shuping, R., Edwards, C., Al Shamsi, M., Espejo, J., Fisher, C., Jeppesen, C., and Knavel, J.: The Emirates eXploration Imager (EXI) onboard the Emirates Mars Mission (EMM): Overview of In-flight Performance, and Water Ice Cloud Retrievals, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4991, https://doi.org/10.5194/egusphere-egu22-4991, 2022.

Raman spectroscopy is an excellent tool for the detection and discrimination of biomolecules e.g. pigments. The highest relevance of Raman spectroscopy in astrobiology has been well-established. The miniaturized, dedicated Raman spectrometers are currently a part of the experimental payload within rovers in the frame of Martian missions Mars 2020 (NASA) and ExoMars (ESA). Finding biomolecules in the rocky environments (for example, detecting carotenoids) would be an amazing outcome of Mars missions. On Earth, semi-translucent or translucent minerals such as gypsum are ideal habitats for endoliths, especially phototrophs. The mineral environment participates in protecting them against harsh superficial environments. Cyanobacteria colonize gypsum, halite, ignimbrite in the Atacama extremely dry zones with high UV flux. Pigments of endoliths encountered there and detected using Raman spectroscopy include mainly UV-screening pigments such as carotenoids and scytonemin. Selenitic gypsum outcrops of Messinian age commonly harbour cyanobacteria and algae also in less harsh environments: in Sicily (annual precipitation 400-600 mm) [1], Poland (600 mm) and Northern Israel (400 mm). Details on the distribution of pigments (including scytonemin) from several gypsum sites in southern Sicily and eastern Poland are presented [2]. Raman investigations using 780, 532 and 445 nm lasers show more detail on the distribution of UV-screening pigments in the dark zones. These dark zones are colonized dominantly by cyanobacteria, mostly by black-bluish Gloeocapsa compacta and yellow-brown Nostoc sp. Raman analysis allows to discriminate between these cyanobacterial taxa. Raman bands of scytonemin at 1593, 1552, 1438 and 1173 cm^-1 were detected in colonies of Nostoc sp. Gloeocapsin, a pigment specific for Gloeocapsa sp, shows characteristic Raman bands similar to anthraquinone-based parietin of lichens: at 1665, 1575, 1378, 1310 and 465 cm^-1 [2]. Both pigments can be used as biomarkers in geobiological and astrobiological studies. Other photosynthetic and protective pigments were also detected: carotenoids, chlorophylls and phycobiliproteins. Deciphering the presence of biomolecules (including pigments) using Raman spectroscopy helps to understand endoliths. Deploying miniature Raman spectrometers at terrestrial Mars analogue localities as well as in depth investigations of colonised gypsum through laboratory microspectrometric investigations is of the highest relevance for the current Martian missions.

References

[1] J. Jehlička, A. Culka, J. Mareš, (2019) Raman spectroscopic screening of cyanobacterial chasmoliths from crystalline gypsum—The Messinian crisis sediments from Southern Sicily, Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy 51, 1802-1812. [2] K. Němečková, A. Culka, I. Němec, H.G.M. Edwards, J. Mareš, J. Jehlička (2021) Raman spectroscopic search for scytonemin and gloeocapsin in endolithic colonisations in large gypsum crystals. Journal of  Raman Spectroscopy 52, 2633-2647.

How to cite: Jehlicka, J., Němečková, K., and Culka, A.: Detecting Raman spectra of pigments from gypsum endoliths: is this a useful training for Martian missions?, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5120, https://doi.org/10.5194/egusphere-egu22-5120, 2022.

The ExoMars Programme will send a rover to Mars in 2022 equipped with a 2 m drill which will search for evidence of extinct life below the surface. This project is focused on the stereo vision systems of the rover, and how better 3-D information can be extracted from the camera images. This is explored through both experimental and simulation-based approaches. The experimental approach was to build a hardware emulator of the three stereo pairs: the Wide-Angle Cameras (WACs) from the Panoramic Camera instrument (PanCam), and the Navigation Camera (NavCam) and Localisation Camera (LocCam) systems. Point clouds were generated from the emulator data and compared against a (LIDAR) generated point cloud to determine which combination of cameras yields the best point clouds. The comparison methods were as follows: the number of tie points, the number of dense cloud points, coordinate extent, surface density, nearest neighbour distance (NND) to the LIDAR cloud, and measurement of a known target. One set of experiments compared the four mast head stereo cameras (WACs and NavCams) and the second set compared all six stereo cameras (WACs, NavCams, and LocCams). The six-view point cloud was the closest match to the LIDAR in terms of mean NND to the LIDAR point cloud, but it was only marginally better than the five-view point clouds and the four-view point cloud made of the WACs and NavCams. The conclusions from both sets of experiments are that the three stereo camera pairs do not contribute equally to improvements in the point clouds generated through photogrammetry. The emulator WACs are the most suited to photogrammetric reconstruction, followed by the emulator NavCams and finally the emulator LocCams.

How to cite: Bohacek, E.: The 3-D capability of science and engineering cameras on the ExoMars rover, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12935, https://doi.org/10.5194/egusphere-egu22-12935, 2022.

The Mars Moon eXploration (MMX) mission by the Japan Aerospace Exploration Agency, JAXA, which is going to explore the Martian Moons Phobos and Deimos and also return samples from Phobos back to Earth will also deliver a small (about 25 kg) Rover to the surface of Phobos.

The payload of this rover consists of a Raman spectrometer (RAX) to measure the mineralogical composition of the surface material, a stereo pair of cameras looking affront (NavCam, also used for navigation) to provide the properties of the investigated area, a radiometer (miniRAD) to measure the surface brightness temperature and determine thermal properties of both regolith and rocks, and two cameras looking at the wheel-surface interface (WheelCam) to investigate the properties and dynamics of the regolith. The cameras will, thus, serve for both, technological and scientific needs.
After the Rover has been delivered by the main spacecraft, it shall upright itself and operate for about 100 days on the surface of Phobos to investigate terrain and mineralogy along its path.
The measurements are going to provide ground truth by studying in-situ properties such as the physical properties and heterogeneity of the surface material.

MMX is planned to be launched in September 2024, the Rover delivery is currently planned for 2027.
The Rover is a contribution by the Centre National d’Etudes Spatiales (CNES) and the German Aerospace Center (DLR) with additional contributions from INTA (Spain) and JAXA.

How to cite: Ulamec, S., Michel, P., Grott, M., Böttger, U., Hübers, H.-W., Cho, Y., Rull, F., Murdoch, N., Vernazza, P., Biele, J., Tardivel, S., and Miyamoto, H.: Phobos Surface Science with the MMX Rover, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4033, https://doi.org/10.5194/egusphere-egu22-4033, 2022.

A search for water on Mars is an important part of a space program. Water is likely to be contained not only in the polar caps but also deposited further away from the polar regions, specifically in the so called “fretted terrain” (near dichotomy boundary between the lowlands and highlands), in the northern lowlands, and elsewhere.  Here we attempt to reconstruct a northern paleo-ocean, using the gravity aspects and locations of features of the fretted terrain as constraints for paleo-seashore. Valles Marineris would contain water that would flow into this ocean. We use recent data on the gravity and magnetic fields of Mars and create from them the gravity aspects and magnetic field proxies computed from the recent gravity and magnetic models JGMRO_120F (Konopliv et al., 2020) and (Connerney et al., 2005; Langlais et al., 2019). We discovered that Isidis, based on gravity aspects, has many volcano-like characteristics despite the traditional view of this structure being an impact related. We note asymmetric positions of Martian polar caps that seem to be related to the magnetic field distribution and we propose a new hypothesis that polar cap accumulation relates to a plasmasphere interaction with the solar wind.  Analysis of the detection of direction of the impactor arrival for Hellas impact basin along with the gravity aspects (namely the strike angles) suggested  that not only the impact likely generated a reset of the global plum activity (that changed the overall unicellular convection pattern into the bicellular convection) but also note the possibility that the magnetic maxima in the polar region could be paleoindicators of the offset by this impact event so that the rotational poles have an offset from the magnetic poles.

How to cite: Klokocnik, J., Kletetschka, G., Kostelecky, J., Bezdek, A., and Karimi, K.: Gravity and magnetic fields of Mars - new findings, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1708, https://doi.org/10.5194/egusphere-egu22-1708, 2022.

We report here the results of more than 2 years of monitoring the rotation of Mars with the RISE instrument on InSight. Small periodic variations of the spin axis orientation, called nutations, can be extracted from the Doppler data with enough precision to identify the influence of the Martian fluid core.  For the first time for a planetary body other than the Earth, we can measure the period of the Free Core Nutation (FCN), which is a rotational normal mode arising from the misalignment of the rotation axes of the core and mantle. In this way, we confirm the liquid state of the core and estimate its moment of inertia as well as its likely size.

The FCN period depends on the dynamical flattening of the core and on its ability to deform. Since the shape and gravity field of Mars deviate significantly from those of a uniformly rotating fluid body, deviations from that state can also be expected for the core. Models accounting for the dynamical shape of Mars can thus be tested by comparing core shape predictions to nutation constraints. The observed FCN period can be accounted for by interior models having a very thick lithosphere loaded by degree-two mass anomalies at the bottom.

The combination of nutation data and interior structure modeling allows us to deduce the radius of the core and to constrain its density, and thus, to address the nature and abundance of light elements alloyed to iron. The inferred core radius agrees with previous estimates based on geodesy and seismic data. The large fraction of light elements required to match the core density implies that its liquidus is significantly lower than the expected core temperature, making the presence of an inner core highly unlikely. Besides, the existence of an inner core would lead to an additional rotational normal mode the signature of which has not been detected in the RISE data.

How to cite: Le Maistre, S., Rivoldini, A., Caldiero, A., Yseboodt, M., Baland, R.-M., Beuthe, M., Van Hoolst, T., Dehant, V., Folkner, W., Buccino, D., Kahan, D., Marty, J.-C., Antonangeli, D., Badro, J., Drilleau, M., Konopliv, A., Peters, M.-J., Plesa, A.-C., Samuel, H., and Tosi, N. and the InSight/RISE team: The deep interior of Mars from nutation measured by InSight RISE, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12428, https://doi.org/10.5194/egusphere-egu22-12428, 2022.

We report the analysis of pressure measurements at Jezero crater, Mars by the MEDA instrument [1] onboard the rover Perseverance following its landing and covering the period from March 5, 2021 up to this meeting presentation (approximately from solar longitudes 15° to 200°). We identify a variety of atmospheric phenomena, spanning from local to global spatial and temporal scales that leave their imprint in the pressure data [2]. These comprises: Local turbulence (high frequency fluctuations), waves (short period oscillations 12-24 minutes), local vortices (sudden pressure drops from seconds to a minute), baroclinic waves (oscillation periods 4-5 sols) and up to six Fourier components of the thermal tides. The normalized amplitude of the diurnal and semidiurnal tides show a large variability along the studied period, but smaller changes are also noted in tidal components 3 to 6.  We report on the effects of the presence of water ice clouds and dust from storms on the tidal components. Finally, we present the main parameters that characterize each of the phenomena studied, their variability throughout this period, and a preliminary interpretation for all of them.

References:

[1] Rodríguez-Manfredi J. A. et al., Space Sci. Rev., 217.3, 1-86 (2021)

[2] Sánchez-Lavega A. et al., Perseverance/Mars2020 measurements of the daily pressure cycle at Jezero, P25A-03, AGU Fall Meeting (2021)

How to cite: Sanchez-Lavega, A., del Rio-Gaztelurrutia, T., Hueso, R., de la Torre, M., Harri, A.-M., Genzer, M., Hieta, M., Polkko, J., Rodríguez-Manfredi, J. A., Tamppari, L. K., Newman, C., Munguira, A., Martínez, G., Vicente-Retortillo, A., Lemmon, M., Pla-Garcia, J., Guzewich, S., Toledo, D., Apéstigue, V., and Viúdez-Moreiras, D. and the Additional Team members: Weather at Jezero, Mars from pressure measurements by the rover Perseverance, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5796, https://doi.org/10.5194/egusphere-egu22-5796, 2022.

NASA’s Mars 2020 Perseverance rover landed in Jezero Crater (~18.4ºN, 77.6ºE) on February 2021 at L_s~5º, just after the northern spring equinox. Perseverance carries the Mars Environmental Dynamics Analyzer (MEDA) instrument [1], which includes a wind sensor that is a heritage from previous sensors sent to Mars as part of the Mars Science Laboratory (MSL) and InSight missions. Those sensors allowed the characterization of the near-surface wind patterns at Gale Crater [2] and Elysium Planitia [3,4]. The wind sensor of MEDA is allowing near-surface wind patterns to be characterized at Perseverance’s landing site, thus complementing the data acquired by previous missions on the surface of Mars.

Previous missions at different locations on the Martian surface observed a contribution by several mechanisms from different scales involved in the near-surface winds, including the effect of local and regional slope winds induced by topography, thermal tides, baroclinic waves and the Hadley cell, each one with a variable weight on the resulting wind patterns as a function of location, season and the presence of dust storms (e.g. [2-4] and references therein). The near-surface wind data acquired by Mars 2020 show a complex dynamics at Jezero Crater, as predicted by models (e.g. [5]). Preliminary interpretation suggests that the diurnal cycle of winds is dominated by the regional circulation mainly forced by slope winds in the Isidis basin region, which interact with the local scale circulation at Jezero and Hadley cell flows. The potential contribution by these mechanisms on the resulting wind patterns measured at Mars2020’s landing site will be presented, with a further focus on the observed wind variability supported by probabilistic models.

References:

[1] Rodriguez-Manfredi et al. (2021), SSR, 217(48). [2] Viúdez-Moreiras et al. (2019), Icarus, 319, 909-925. [3] Banfield et al. (2020), Nat.Geo, 13, 190-198. [4] Viúdez-Moreiras et al. (2020) JGR-Planets, 125, e2020JE006493. [5] Newman et al. (2021) SSR, 217(20).

How to cite: Viúdez-Moreiras, D., Newman, C. E., Gómez-Elvira, J., Harri, A.-M., Genzer, M., Tamppari, L., de la Torre, M., Sánchez, A., Hueso, R., Guzewich, S., Sullivan, R., Pla, J., Navarro, S., Munguira, A., Lorenz, R., Herkenhoff, K., Rodríguez-Manfredi, J. A., and MEDA team, T.: The near-surface wind patterns as observed by NASA Mars 2020 Mission at Jezero Crater, Mars, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6325, https://doi.org/10.5194/egusphere-egu22-6325, 2022.

The Mars Environmental Dynamics Analyzer (MEDA) is a meteorological station onboard Mars 2020 that characterizes the near surface atmosphere. Among other sensors MEDA has 5 Air Temperature Sensors (ATS) at two altitudes: 0.85m, in the front of the rover, and 1.45m around the Remote Sensing Mast, which are azimuthally distributed so that at least one sensor is located upwind. This configuration ensures that, for most environmental conditions, the thermal contamination caused by the rover can be set apart. Local air temperatures are read with a frequency of 1 or 2 Hz, and ATS data can characterize timescales from atmospheric turbulence to the daily temperature cycle and its seasonal evolution. 

Here we show the daily temperature cycle at Jezero and an analysis of its seasonal evolution over the first half Martian year of the mission from Spring (Ls=6) to Autumn Equinox (Ls=180). Simultaneous ATS and winds from MEDA’s wind sensors show that, for most rover orientations, solar irradiation and winds clean environmental measurements are obtained at the 1.45m level. However, clean measurements at the 0.85m level are not always fully achieved, and a small residual thermal contamination is found at this level in many measurement sessions. The daily temperature cycle reflects the daily cycle of convection and turbulence. Strong and fast thermal oscillations start a few hours after sunrise, peak near noon, and collapse before sunset. The seasonal evolution shows a progressive increase of temperatures as summer advances, but less steep than what is retrieved at other Martian locations by previous missions. At the 0.85m level, changes in atmospheric temperatures with time-scales of a few sols correlate well with variations in local terrain properties. At the 1.45m level, similar temperature changes with timescales of a few sols are also found. We investigate whether these changes at 1.45m can be associated with changing atmospheric opacity due to dust and clouds, which are measured by other MEDA sensors and additional instruments in Perseverance. From the two altitudes sampled with ATS, and additional data from the MEDA Thermal InfraRed Sensors (TIRS), which measure ground temperature and air temperature at 40m, we can obtain the near-surface vertical temperature profile for specific sols in which thermal contamination is moderate in all sensors. This allows us to study the evolution of the diurnal convective cycle and the vertical temperature gradient. In addition, the Supercam microphone can also deduce the average air temperature from the ground up to 2.1m high thanks to sound speed measurements during Supercam’s laser zapping rocks. Therefore, it gives an additional hint into the thermal gradient. Furthermore, the amplitude of the thermal oscillations characterizes the thermal turbulence and we present the spectra of turbulence for convective and non convective hours on different moments of the mission. Finally, we will show how the measured thermal data compares with model predictions of the daily cycle of temperatures, expected magnitude of thermal oscillations, and the seasonal evolution.

How to cite: Munguira, A., Hueso, R., Sánchez-Lavega, A., de la Torre-Juarez, M., Chavez, Á., Martínez, G., Newman, C., Banfield, D., Vicente-Retortillo, Á., Lepinette, A., Pla-García, J., Rodríguez-Manfredi, J. A., Chide, B., Bertrand, T., Sebastián, E., Gómez-Elvira, J., Lemmon, M., Tamppari, L., Lorenz, R., and Viudez-Moreiras, D. and the additional MEDA team members: Mars 2020 MEDA ATS Measurements of Near Surface Atmospheric Temperatures at Jezero, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7047, https://doi.org/10.5194/egusphere-egu22-7047, 2022.

The Planetary Instrument of X-ray Lithochemistry (PIXL), onboard the Mars 2020 rover Perseverance, is designed to measure the chemical composition of Martian materials with a spatial resolution of around 100 µm. The surface of Mars is notoriously dusty and even thin layers of dust within the measurement frame will impact the instrument signal, potentially leading to misinterpretation of an underlying chemical composition if not appropriately accounted for. Therefore, knowledge about the dust composition, concentration and distribution is important, both when deciding where to perform measurements and in data analyses.

Herein we present methods for generating high precision dust profiles of Martian surfaces by utilizing the Optical Fiducial System (OFS) component of the PIXL instrument. The OFS consist of a Micro Context Camera (MCC) and a FloodLight Illuminator (FLI). The MCC captures images with a resolution better than 50 µm/pixel at the instrument’s nominal distance of 25 mm, directly enabling the optical characterization of dust, and other components, on these surfaces. The FLI is equipped with a total of 24 light emitting diodes (LEDs), in four groups centered at UV (385 nm), Blue (450 nm), Green (530 nm), and NIR (735 nm), enabling multispectral capabilities. This multispectral floodlight capability directly facilitates dust detection by the MCC, and utilizing the precision of the MCC, the spatial distribution of dust is better constrained.

We present dust profile maps acquired by the PIXL OFS on Martian surfaces and present similar results derived from the rover-mounted calibration targets. In demonstrating the quality of the maps produced, we can improve future scientific analyses while furthermore improving the operational efficiency and data quality of the Perseverance mission through the potential future implementation of a closed-loop autonomous dust-avoidance routine, utilizing the macro capabilities of the PIXL OFS.

The author recognises the great contribution made by the PIXL Team and the broader Mars 2020 Team.

How to cite: Henneke, J., Pedersen, D. A. K., Jørgensen, J. L., Liu, Y., Allwood, A. C., Hurowitz, J., Schmidt, M. E., and VanBommel, S. J.: Profiling Martian Dust Using PIXL Images, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11769, https://doi.org/10.5194/egusphere-egu22-11769, 2022.

The Micro Context Camera (MCC) of PIXL onboard Perseverance has successfully completed commissioning. It meets all requirements and has led to the first proximity science using the PIXL instrument. This abstract presents the inflight system performance.

The pre-launch calibration of the MCC system has been verified on the surface of Mars. Distance measurements to Martian Rock surfaces are performed at with an accuracy better than 100 µm. This is accomplished utilizing Structured Light over the full diurnal thermal environment on the surface of Mars. The PIXL sensor unit is mounted on the turret of the Mars Perseverance rover arm. This autonomous navigation capability has enabled safe approaches of rugged surfaces, without ground intervention or interaction with e.g. a touch plate. It has also enabled proximity science of the Martian surface at unprecedented accuracy. The autonomy further enables PIXL to capture high resolution XRF scans while continuously maintaining optimal distance and focus of the X-ray beam. The system’s performance is robust enough for PIXL to navigate relative to both abraded and natural surfaces.

The MCC also has the capability of multispectral imaging. This has provided information for the interpretation of surface lithology and it also provides additional information for the XRF measurements interpretation due to its high resolution.

The MCC’s Terrain Relative Navigation (TRN) autonomous functionality has also been demonstrated in the Martian environment. This capability is essential for PIXL to maintain the planned scan trajectory relative to the rock surface – as PIXL’s longer duration scans (up to 10 hours) is relying on stability and capability to compensate for the diurnal thermal environment causing position drift relative to the Martian rock surface. We present the measured performance on Mars. This show that the system performs reliably on both high and low topography rock surfaces with and without dust coverage. This has enabled PIXL to autonomously track and self-correct for any drift away from the planned scan trajectory.

How to cite: Pedersen, D., Henneke, J., Jørgensen, J. L., Benn, M., Denver, T., Timmermann, L., Liebe, C. C., Denise, R., Elam, T., Wade, L., Foote, M., Hurowitz, J., and Allwood, A.: PIXL’s Micro Context Camera performance on the surface of Mars, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11234, https://doi.org/10.5194/egusphere-egu22-11234, 2022.

On February 18, 2021, NASA’s Mars 2020 Perseverance rover landed successfully in Jezero crater. Several geological and compositional units were previously identified from orbital data analysis : a dark pyroxene-bearing floor unit; an olivine-bearing unit exposed in erosional windows and partially altered into phyllosilicates and carbonates ; a deltaic complex and its possible erosional remnants and a marginal carbonate-bearing unit. As of Sol 300 (December 2021), the rover has visited two geological units in situ: the dark pyroxene-bearing floor unit and the olivine-bearing floor unit. Others investigations of geological units of interest have been carried out using long distance (up to several kilometers) observations.

The SuperCam instrument contains a suite of techniques including passive spectroscopy in the 0.40-0.85 (VIS) and 1.3-2.6 microns (IR) wavelength ranges, and a color camera (RMI- Remote Micro-Imager) providing high resolution context images. Since the landing, SuperCam has acquired thousands of VISIR spectra of nearby rocks (including both natural and abraded surfaces), as well as hundreds of spectra of distant targets (from 10s of m to 20 km). The VISIR field of view of each individual spectrum ranges from a few mm for the rock of the workspace to 20 m to 20 km. The aim of this contribution is to summarize the main results of VISIR spectra up to Sol 300.

The two geological units investigated in situ have distinct spectra. The crater floor rough unit (Cf-fr)  has a pervasive 1.9 µm absorption indicative of hydration. Additional absorption at 2.28 µm indicate the presence of iron-rich phyllosilicates. Correlations between 1.9 µm and 2.4 µm absorption bands or between 2.1 µm and 2.4 µm bands suggest the presence of both poly and monohydrated sulfates. Spectra similar to oxy-hydroxides have also been observed in some rocks. Unmixing methods such as factor analyses highlight a high calcium pyroxene component. To sum up, the Cf-fr is an altered pyroxene rich unit. The second unit investigated in situ is a region called Seitah, which is dominantly olivine-rich from orbital analyses. Supercam VISIR data confirm the strong signature of olivine of the unit and display a complex suite of absorptions in the 2.3 µm - 2.4 µm region suggesting the presence of iron and magnesium phyllosilicates and/or carbonates. The alteration signature seems to be associated with olivine grains. 

Distant observations were acquired on the western delta front, several remote mesas and hills, on Jezero floor unit (the unit on which Perseverance landed on and investigated in situ), on Seitah before being visited by the rover, and on even more distant targets such as the crater rim or the marginal carbonate-bearing unit. The observed spectral signatures form different clusters depending on the type of target, highlighting the spectral diversity of Jezero geological units.  Remarkably, the long distance observations of Seitah region are in perfect agreement with the in situ measurements confirming the relevance of long distance observations to assess the geological/mineralogical context of Perseverance’s future traverses.

How to cite: Quantin-Nataf, C., Mandon, L., Royer, C., Beck, P., Montmessin, F., Forni, O., Le Mouelic, S., Poulet, F., Johnson, J., Fouchet, T., Dehouck, E., Brown, A., Tarnas, J., Pilleri, P., Gasnault, O., Mangold, N., Maurice, S., and Wiens, R.: Infrared Reflectance of Jezero geological units from Supercam/Mars2020 Observations, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5969, https://doi.org/10.5194/egusphere-egu22-5969, 2022.