Orals: Thu, 1 May | Room 0.94/95
Since February 2021, the Mars 2020 rover ‘Perseverance’ has been exploring Jezero crater on Mars to characterize the geology, assess the potential for rocks to represent ancient habitable environments and/or preserve biosignatures, and collect a suite of scientifically compelling samples for return to Earth (Farley et al., 2020). From 2021 to September 2024, Perseverance explored the interior of Jezero impact crater, and consequently the geological unit post-dating its formation. In September 2024, Perseverance has started the ascent of Jezero crater rim, the first step of a long campaign through Jezero crater rim and the rocks outside of the crater. The expectation of this campaign is to encounter rock types that are not included in the current sample cache typically representing materials from Mars most ancient crust (Pre-Jezero and even pre-Isidis crust).
The crater rim campaign started by the investigation of the inner part of the crater rim from Jezero margin unit to the summit of the Crater rim. During this ascent, the rover investigated a complex of NW/SE aligned buttes (Curtis ridge, Mist Park and Eagle cliff). The inner part of the crater rim exploration ended by the investigation the back part of Pico Turquino butte. An exceptional diversity of rocks in terms of primary composition and alteration has been observed. Pyroxenites, Gabbros, Olivine bearing rocks and high Si rocks have been docmuented very close to each other suggesting a complex stratigraphy due either to Jezero impact itself or due to older impact events that have shaped the Noachian basement in the region. In terms of alteration, non-altered rocks have been observed, as well as Mg/Fe clays, Al-clays and hydrated silica. It reveals complex and diverse alteration histories.
At time of this abstract writing, no samples have been collected yet. The notional sample cache for this campaign based on orbital data investigation includes: Noachian basement materials (including both stratified Fe-Mg smectites and “blue-fractured” low-calcium-pyroxene-bearing materials); megabreccia (including potentially kaolinite-bearing megabreccia); an in-situ example of the regional olivine-carbonate-bearing unit; hydrothermal features; and impact melt/breccia. Many of these targets are common on a regional to global scale but have never been studied with a rover, or sampled. The Crater Rim campaign promises to expand the already compelling sample suite onboard the Perseverance rover.
This presentation will discuss the up-to-date results from the Crater Rim campaign, the current and future sampling opportunities for the campaign, and the implications for Mars Sample Return.
How to cite: Quantin-Nataf, C., Mayhew, L., Ravanis, E., Herd, C., Farley, K., Stack, K., Simon, J., Kronyak, R., Deahn, M., Horgan, B., Bedford, C., Wiens, R., Klidara, A., Jones, A., Barnes, R., Johnson, J., Crumpler, L., and Calef, F.: First Science Results from the Mars 2020 Perseverance Rover Crater Rim Campaign, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15817, https://doi.org/10.5194/egusphere-egu25-15817, 2025.
Home to a lake around 4 billion years ago, Jezero crater is a unique location to study the interplay between igneous processes and aqueous alteration on ancient Mars. The Perseverance rover, which landed on Mars in 2021, can be used to study the history of the Jezero ancient lake system to better understand the duration of time liquid water was present on the surface of Mars. The Máaz formation, rich in basaltic rock, is the highest stratigraphic unit in the crater floor and hosts a diversity of alteration phases that indicate multiple aqueous episodes may have affected the crater floor rocks. Manganese alteration phases can give us insight into aqueous alteration since manganese is sensitive to changes in redox conditions and so variations in manganese concentrations in the crater can indicate shifts in redox levels in the ancient lake. The Curiosity rover in Gale crater and the Opportunity rover in Endeavor crater have also discovered manganese enrichments, which have been used to infer the presence of more highly oxidizing conditions on Mars over its history than previously thought. Manganese is typically a minor component in igneous minerals, with concentrations often below 1 wt% in most terrestrial rocks. Using data from the PIXL (Planetary Instrument for X-Ray Lithochemistry) instrument aboard the Perseverance rover, we investigated alteration products in the Máaz formation with anomalous MnO (much greater than 1 wt%). Our analysis reveals two anomalously high Mn regions in the Guillaumes and Alfalfa abrasion patches. The first has been identified as despujolsite (Ca₃Mn⁴⁺(SO₄)₂(OH)₆·3H₂O), discovered in the Guillaumes abrasion at a low stratigraphic unit within Máaz, which forms from either hydrothermal or lacustrine deposition in Earth analogs. In the Alfalfa abrasion patch, in a high stratigraphic unit in Máaz, we identified Mn-rich magnetite and a Mn-Fe hydrated sulfate in the solid solution series between szomolnokite (Fe2+SO4·H2O) and szmikite (MnSO4·H2O), suggesting a history of serpentinization followed by uplift and exposure to oxidizing acidic fluids. These findings underscore the complexity of aqueous alteration over the course of Jezero history. Future sample return missions could refine mineralogical interpretations and provide more information to refine our understanding of aqueous conditions and habitability in the crater.
How to cite: Sinclair, K., Clark, B., Catling, D., Elam, W., and Liu, Y.: The Possible Aqueous Origins of Manganese Alteration Minerals in the Máaz Formation of Jezero Crater, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3027, https://doi.org/10.5194/egusphere-egu25-3027, 2025.
Phyllosilicate and sulfate-bearing units are ubiquitous on Mars, indicating past water-rich planetary environments that likely transitioned from neutral-to-alkaline pH conditions (phyllosilicate formation) to more acidic pH conditions (sulfate deposition). Thus, sediments with mixed mineralogy dominated by phyllosilicates and sulfates, informally referred to as the “clay-sulfate units”, may reflect planetary changes in ancient climate with implications on its habitability. Yet, the specific processes and surface conditions that led to the formation of the clay-sulfate units have remained uncertain.
In this study, we investigated the alteration of Mars-analog phyllosilicates (hereafter “clays”) with acidic, sulfate-rich solutions by performing laboratory batch (closed system) and field (open system) experiments to characterize dissolution processes and catalogue diagnostic alteration features produced under a wide range of conditions. Two Fe-rich smectites (nontronites), NAu-1 and NAu-2, and one silicon (IV) oxide (silica), which was used as control, were reacted with two types of acidic, sulfate-rich solutions that were prepared with (1) natural acid rock drainage labelled ARD, and (2) synthetic sulfuric acid (H2SO4) labelled ASf. The initial solutions were adjusted at four pH values (1, 3, 5, and 7) and reacted at 4, 30, and 80°C for up to 6 months. At the end of the experiments, the filtered supernatants were analyzed by ICP-MS while the solids were characterized by X-ray diffraction (XRD), energy-dispersive X-ray fluorescence analyses (ED-XRF), Raman spectroscopy and thermal analysis data, including thermal gravimetry (TG), differential scanning calorimetry (DSC) and evolved gas analysis (EGA).
Results show that structural changes of the acid-treated nontronite clays were detected under all experimental conditions, as evidenced by multiple methods. However, the dissolution of clays was limited even under the most extreme conditions (i.e., NAu-1 reacted with ARD at a pH of 1, at the highest temperature (80°C) and for an extended duration). These results contradict previous studies that suggest that Fe-rich nontronite clays break down easily and dissolve when exposed to highly acidic and high-temperature conditions. Further investigations showed that the dissolution processes were ubiquitous and accompanied by changes in solutions composition and the precipitation of secondary phases, which included Fe(III) oxyhydroxides, a wide range (i.e., Fe(III), Al, Mg, Mn, and Ca) of sulfate minerals, and, in one instance, traces of dioctahedral mica (i.e., illite). These precipitates formed coatings on reacting nontronite clays, thus protecting them from aggressive dissolution. Significantly, the composition of the acid-sulfate solutions plays an essential role in the system evolution, including the geochemical characteristics of the reacting solution and the amount and identity of post-alteration mineralogical assemblages.
Application of our results to Mars reveals that acidic, sulfate-rich fluids were essential for producing clay-sulfate assemblages, such as those found at Gale Crater. Specifically, highly acidic solutions could have induced widespread disintegration of primary clay units and the formation of secondary sulfate deposits. The combined results of our study may allow us to produce a catalogue of alteration features to relate the mineralogical assemblages mapped on Mars to specific solution attributes and environmental conditions in which clays reacted with acidic solutions.
How to cite: Lefticariu, L., Lewinski, M. G., Specht, J. F., Pentrak, M. P., Peretyazhko, T. S., and Jakubek, R. S.: Formation of clay-sulfate sedimentary units on Mars via phyllosilicate alteration by acid-sulfate fluids, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3835, https://doi.org/10.5194/egusphere-egu25-3835, 2025.
Lithium behaves uniquely in different geological environments, making it an excellent tracer element. It is moderately incompatible and is most prominent in highly evolved pegmatites and granites. However, its small ionic radius makes it susceptible to substitute, typically for Mg, and incorporate in a range of major rock-forming minerals and secondary phyllosilicates. Moreover, Li is highly soluble and can concentrate in late-stage brines and rare Li salts, and rocks typically preserve Li signatures related to the latest fluid alterations. The ChemCam instrument onboard NASA’s Mars Science Laboratory Curiosity rover uses laser-induced breakdown spectroscopy (LIBS) to quantify Li concentration through a dedicated Li calibration. It is currently one of only three science instruments (the others being the LIBS instruments SuperCam on the Perseverance rover and MarSCoDe on the Zhurong rover) on Mars able to do so. The Curiosity rover landed at the Bradbury Rise landing site in the ~155 km diameter impact crater, Gale, in August 2012 to search for past habitable environments in the more than 5 km tall Mount Sharp composed of sedimentary rocks. Since then, Curiosity has traversed more than 33 km through fluvio-deltaic sandstone and conglomerates, lacustrine mudstones, lake-margin sandstone, and aeolian dunes. We present Li concentrations where a majority of the stratigraphic members are enriched relative to terrestrial and martian basalts (~5 ppm in mid-ocean ridge basalts and ~3 ppm in shergottites) and with local enrichments up to 158 ppm. Furthermore, Li abundance and the correlations between Li and other elements detected by ChemCam vary systematically between the main chemostratigraphic groups encountered in Gale crater, alluding to the fact that Li is likely hosted in various mineral phases and that these vary between groups. The lowermost Bradbury group rocks have slightly elevated Li abundances relative to basaltic compositions (8-14 ppm, 25th-75th percentiles) with local enrichments up to 118 ppm and most likely reflect an igneous signature with Li hosted in multiple mineral phases such as feldspar, mica, and pyroxene. The lower Murray formation and the orbitally defined clay-rich Glen Torridon region are both enriched in Li (10-20 ppm and 11-18 ppm, respectively), which is best explained by Li uptake in secondary phyllosilicates as variations in Li content in these areas mirror the detected abundances of secondary clay minerals. This relationship breaks down in the clay-sulfate transition region, which is very poor in phyllosilicates but retains elevated Li concentrations (10-18 ppm), though Li decreases with increasing member elevation as Mg-sulfates become increasingly pervasive. This is best interpreted as an igneous source rock signature, more evolved than a typical basalt alining with geochemical and mineralogical evidence of dry deposition and a minimal amount of late aqueous alteration. The sulfate unit continues the trend of decreasing Li with increasing elevation observed in the clay-sulfate transition region, which demonstrates that Li is not associated with Mg-sulfates in the region. The younger Stimson formation exhibits slightly enriched Li abundances with local enrichments up to 158 ppm. It is interpreted as a primarily igneous signature potentially affected by post-depositional fluid alteration.
How to cite: Nikolajsen, K., Frydenvang, J., Dehouck, E., Gasda, P., Bedford, C., Le Diet, L., Ollila, A., Cousin, A., Wiens, R., Maurice, S., Gasnault, O., and Lanza, N.: Lithium Content in Sedimentary Rocks in Gale Crater, Aeolis Mons, Measured by ChemCam as a Tracer for Aqueous Alteration and Source Rock Geochemistry , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6717, https://doi.org/10.5194/egusphere-egu25-6717, 2025.
Phosphate minerals are present in multiple martian meteorites and have been detected on the surface of Mars by several rover missions and have important implications for astrobiology [1]. We initiated a study of the spectral properties of phosphate minerals two decades ago [2] to support identification of phosphates on Mars using Thermal-IR (TIR), Visible/Near-Infrared (VNIR) and Mössbauer spectroscopy and have been updating our collections [3, 4, 5]. Phosphate minerals form in a wide variety of structures built around PO4 tetrahedra, similar to the mineral structures containing SiO4 and SO4 tetrahedra and many of these could be present on Mars. Nanophase materials characterized at Gale crater may also contain phosphates [6].
Primary phosphates that crystallize from a fluid include apatite (Ca5(PO4)3OH) and triphylite (LiFe2+PO4), while strengite (FePO4•2H2O) and vivianite (Fe2+Fe2+2(PO4)2•8H2O) are secondary phosphates that form in low temperatures aqueous environments. Whitlockite (Ca9(MgFe)(PO4)6PO3OH) can be found in chondrites within meteorites. TIR emissivity spectra in the mid-IR region (Figure 1-A, 200-1500 cm-1) are dominated by the vibrational modes of the (PO4)3- tetrahedra including stretching vibrations near 1000-1200 cm-1 and bending vibrations near 600-700 cm-1 [5, 7].
Phosphates exhibit multiple spectral features in the VNIR region (Figure 1-B, 0.3-5 µm) due to vibrations of H2O, OH, and PO4 groups in the structure as well as excitation absorptions due to Fe [e.g., 4]. Fe bands typically occur near 0.6-1.2 µm, OH bands near 1.45, 2.2 and 2.8 µm, H2O bands near 1.45, 1.95, and 2.9-3 µm, and phosphate bands near 4.5-5 µm. Kulanite (BaFe22+Al2(PO4)3(OH)3), childrenite-eosphorite (Fe2+,Mn2+)AlPO4(OH)2·H2O), and gormanite (Fe32+Al4(PO4)4(OH)6·2H2O) are OH-bearing phosphates and their spectra have strong OH bands near 1.44-1.50, 2.17-2.47, and 2.76-2.87 µm, respectively due to an OH stretching overtone, an OH stretch plus bend combination band, and an OH fundamental stretching vibration. Apatite also includes OH and its spectra include a fundamental stretching vibration at 2.83 µm as well as a triplet near 3.37-3.48 µm and a doublet at 3.98 and 4.02 µm.
Mössbauer spectroscopy of ferric and ferrous phosphates provide a range of isomer shifts and quadrupole splitting values that can be used to identify specific minerals [3]. The Mössbauer parameters, TIR spectra, and extended visible region spectra collected by the Mars Exploration Rovers were used to constrain potential ferric phosphate minerals present along with sulfates at Paso Robles in Gusev Crater [8]. We are currently investigating the presence of phosphates at Gusev and Jezero Craters, especially Ca- and Fe-bearing phosphates including vivianite [9].
References: [1] Hausrath et al. (2024) Minerals, 14, 591. [2] Lane et al. (2007) LPSC, #2210. [3] Dyar et al. (2014) American Miner., 99, 914–942. [4] Bishop (2019) Chapter 4, in Remote Compositional Analysis ... (Cambridge) 68-101. [5] Lane & Bishop (2019) Chapter 3, in Remote Compositional Analysis ... (Cambridge) 42-67. [6] Rampe et al. (2016) American Miner., 101, 678-689. [7] Stutman et al. (1965) Trans. NY Academy Sci., 27, 669-675. [8] Lane et al. (2008) American Miner., 93, 728-739. [9] Kizovski et al. (2024) LPSC, #2615.
How to cite: Bishop, J. L., Lane, M. D., and Dyar, M. D.: The Spectroscopic Properties of Phosphates and Identifying Them on Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14637, https://doi.org/10.5194/egusphere-egu25-14637, 2025.
Visible-to-near-infrared imaging is an efficient way to explore a planet, but the material diversity of a scene is not always expressed in the standard browse products of a multiband imager. We present progress in the development of a new method, Supervised Spectral Parameter Learning (SSPL), that seeks optimal ways of stretching and combining multispectral bands to enhance contrast between pre-selected material groups [1, 2]. We report on empirical developments of the method through application to the Jezero Crater region, the landing sight of the Mars 2020 Perseverance rover, as explored pre-landing [e.g. 3]. We use the publicly available end-member profiles of the composition identified by [3] to investigate how the associated spectral diversity is sampled by the 4 spectral channels of the ESA Trace Gas Orbiter CaSSIS imager [4]. We compute all ratio, slope, band-depth and shoulder-height spectral parameters afforded by the 4 CaSSIS channels and fit a Linear Discriminant to each paired combination of these spectral parameters. The Linear Discriminant finds the line that maximises the separation, quantified by the Fisher Ratio, between the defined target class, in this study carbonates, against the background phyllosilicates and mafic silicates hypothesized by [3]. We use the Fisher Ratio score and linear discriminant classification accuracy (over 500 repeat trials with 80/20 train/test splitting) to rank the success of the spectral parameter paired combinations (SPCs). We apply the top ranking SPCs to the I/F calibrated MY37 027246 019 CaSSIS observation of Jezero Crater, and report on the success and limitations in sorting carbonates from phyllosilicates and basalts, in comparison to overlapping CRISM hyperspectral orbital data.
[1] Stabbins et al, 2024, ESS, doi:10.1029/2023EA003398
[2] Stabbins et al, 2024, sptk, doi:10.5281/zenodo.10692531
[3] Horgan et al, 2020, Icarus, doi:10.1016/j.icarus.2019.113526.
[4] Thomas et al, 2017, Space Sci. Rev., doi:10.1007/s11214-017-0421-1
How to cite: Stabbins, R. and Grindrod, P.: Supervised Spectral Parameter Learning over Jezero Crater with the ESA ExoMars TGO CaSSIS Multiband Imager, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8773, https://doi.org/10.5194/egusphere-egu25-8773, 2025.
We are conducting a coordinated effort to investigate the sulfate-bearing deposits within several different chaos terrains on Mars, including Aram Chaos, Iani Chaos, Aureum Chaos, Aurorae Chaos, and Arsinoes Chaos. Previous studies focused on sulfate deposits at three locations within the equatorial chaos regions were all conducted prior to 2014 using different data sets [1-8]. Improved CRISM image processing using Map-Projected Targeted Reduced Data Record (MTRDR) images [9] have enabled more precise identification and discrimination of sulfates, as well as the acquisition of numerous additional CTX, HRSC, and HiRISE images that provide additional coverage of the morphologies and locations of sulfates within the equatorial chaos regions. We also used the lower resolution but larger spatial coverage of the CRISM mapping data to produce indicator vector maps [10] across the chaos region which allowed us to identify polyhydrated (PHS) and monohydrated (MHS) sulfate outcrops in between locations of targeted CRISM images. Orbital data that we are analyzing include: CRISM MTRDR images and mapping-data-derived mineral indicator GIS vectors specific to the sulfates; HiRISE images and derived Digital Terrain Models (DTMs); CTX images and mosaics; and HRSC images and DTMs.
HiRISE and CTX images that cover the chaos regions were used to identify deposits that are generally brighter and smoother relative to the darker, hilly chaos terrain in which they occur. We mapped out the distribution of these light-toned deposits (LTDs) in ArcPro and determined they are more extensive than previously mapped. CRISM images were analyzed of the LTDs using spectral parameter maps corresponding to diagnostic mineralogies which indicate the presence of different types of sulfates. We identified sulfate-bearing units at all five chaos regions in association with the larger LTDs, with signatures of polyhydrated and monohydrated sulfates. At Aram Chaos, we identified ferric hydroxysulfate outcrops (FHS; Fe3+SO4OH) beyond what was mapped previously.
There are both similarities and differences between the sulfates within the chaos regions. Similarities include the identification of PHS at all five chaos locations and MHS at four, with stratigraphic relationships showing the PHS are always above the MHS where they occur together. Differences include variations in the brightness and surface textures of each type of sulfate. By comparing the distribution, mineralogy, stratigraphy, and morphology of the sulfates within each of the five chaos regions, we hope to evaluate how the geologic setting of each chaos region may have affected the characteristics of each sulfate deposit that formed within it.
References: [1] Glotch, T., and P. Christensen (2005), JGR doi:10.1029/2004JE002389; [2] Glotch, T., and A. Rogers (2007) JGR doi:10.1029/2006JE002863; [3] Masse, M. et al. (2008) JGR doi:10.1029/2008JE003131. [4] Noe Dobrea, E.Z. et al. (2008) Icarus doi:10.1016/ j.icarus. 2007.06.029; [5] Lichtenberg, K. A., et al. (2010) JGR doi:10.1029/2009JE003353; [6] Warner, N.H. et al. (2011) JGR doi/ 10.1029/2010JE003787; [7] Sefton-Nash, E. et al. (2012) Icarus, 221, 20-42; [8] Sowe, M. et al. (2012) Icarus, 218, 406-419; [9] Seelos, F. et al. (2024) Icarus, 419, 115612; [10] Cartwright, S. F. A. and F. P. Seelos (2023) AGU Mtg, Abs. #P51B-01.
How to cite: Weitz, C., Sheppard, R., Bishop, J., Cartwright, S., and Seelos, F.: Analyses of Sulfate Deposits in the Martian Equatorial Chaos Regions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11889, https://doi.org/10.5194/egusphere-egu25-11889, 2025.
The High Resolution Imaging Science Experiment (HiRISE) onboard the Mars Reconnaissance orbiter has been acquiring images of the Martian surface at scales of ~25-50cm/px since 2006 [1]. The dataset has been instrumental in helping understand a variety of past and present geologic processes (e.g., [2,3]), and support landing site safety certification and science exploration for future missions (e.g., [4,5]). Apart from high-resolution panchromatic information provided by 10 overlapping CCDs with a broadband RED filter (~690nm), HiRISE also acquires colour infrared information along a central strip with two additional filters (BG: ~500 nm and IR: ~870 nm). While this colour swath is narrow and limited in coverage (and has recently become narrower still), it has provided crucial information for characterizing several colour-associated surface changes (e.g., [6,7]).
Most compositional information of Mars is provided at relatively medium-to-coarse resolution (10s to 100s of m/px) by Observatoire pour la Minéralogie, l’Eau, les Glaces et l’Activité (OMEGA) and the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). With the loss of CRISM’s L-detector in 2018, and subsequent decommissioning of the instrument in 2022 [8], it is important for us to understand the spectral capabilities of presently operational higher-resolution multispectral instruments in orbit like HiRISE and the Colour and Stereo Surface Imaging System (CaSSIS; ~4m/px). Recent studies (e.g., [7]) have demonstrated that HiRISE products available through the PDS, which are subject to cosmetic clipping of the values at extremes of the image histogram, may not be ideal for quantitative spectral analysis. Alternatively, generation of unfiltered data products, free from such cosmetic modifications, have been shown to be beneficial for spectral characterization of surface materials like pure water-ice [7,9].
We attempt to further explore this capability, to assess the spectral sensitivity of the three HiRISE colour channels to help characterise a variety of surface minerals that have been identified on Mars. We have been acquiring dedicated HiRISE colour observations at all CRISM mineral/phase type-locality sites identified by [10]. In this work, we describe how the three HiRISE colour wavelengths resolve each mineral/phase, and the extent to which HiRISE colour may be able to discriminate between them. We also provide band ratios and spectral parameters that are useful for mitigating the effects of the variable atmospheric opacity and illumination. Altogether, HiRISE colour products will be useful for future surface characterization studies, and permit co-analysis with other operational multispectral datasets like CaSSIS [11] and the High Resolution Stereo Camera (HRSC) [12].
References:
[1] McEwen et al., (2007), JGR, E05S02, https://doi.org/10.1029/2005JE002605
[2] Dundas et al., (2021), JGR 126(8), https://doi.org/10.1029/2021JE006876
[3] Daubar et al., (2022), JGR 127, https://doi.org/10.1029/2021JE007145
[4] Mandon et al., (2021), Astrobiology 21(4), https://doi.org/10.1089/ast.2020.2292
[5] Fawdon et al., (2024), Journal of Maps 20(1), https://doi.org/10.1080/17445647.2024.2302361
[6] Dundas et al. (2023), GRL 50(2), https://doi.org/10.1029/2022GL100747
[7] Rangarajan et al. (2024a), Icarus 419, https://doi.org/10.1016/j.icarus.2023.115849
[8] Seelos et al. (2024), Icarus 419, https://doi.org/10.1016/j.icarus.2023.115612
[9] Rangarajan et al. (2024b), 10th Mars Conf., https://www.hou.usra.edu/meetings/tenthmars2024/pdf/3224.pdf
[10] Viviano et al. (2014), JGR 119(6), https://doi.org/10.1002/2014JE004627
[11] Tornabene et al. (2024), EPSC2024-1231, https://doi.org/10.5194/epsc2024-1321
[12] Jaumann et al. (2007), PSS 55, https://doi.org/10.1016/j.pss.2006.12.003
How to cite: Rangarajan, V. G., Tornabene, L. L., Hauber, E., Adeli, S., Russell, P. S., Wray, J. J., Delamere, A. W., and Seelos, F. P.: Assessing the Spectral Capability of the HiRISE Colour Channels: A Re-Visit to the CRISM Type-Locality Sites on Mars at Higher Resolution, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18947, https://doi.org/10.5194/egusphere-egu25-18947, 2025.
Martian meteorites offer insights into Martian magmatic processes and impact history, critical for understanding terrestrial planet evolution. Among over 100 identified Martian meteorites (4.4 Ga-165 Ma; Nyquist et al., 2001; Moser et al., 2013), shergottites are the most common, resembling terrestrial basalts (McSween, 2015; Kizovski et al., 2019) but showing strong shock metamorphism. Key shock features include plagioclase-to-maskelynite transitions, olivine and pyroxene mosaicism, and planar fractures in olivine (Stöffler et al., 1986; Walton & Herd, 2006; Jones, 2014). However, deformation history interpretations using shock and post-shock features remain ambiguous due to limited quantitative constraints and direct observation at a mesoscale. This study analyzes olivine microstructures in poikilitic shergottite NWA 7721 using electron backscatter diffraction (EBSD) and dark-field X-ray microscopy (DFXM). We discovered a bimodal morphological subgrain distribution in the large olivine grain: (1) almost strain-free recrystallized crystallites (<5 µm) forming rims and filling fractures and (2) irregular subgrain fragments (>15 µm) with strong alignment and low-angle boundaries (< 15º). With DFXM, it further revealed two dislocation distributions in the 3D grain volume that 1) “dislocation network” formed by very-low-angle misorientation boundaries (<0.1º) and 2) incipient subdomain walls formed by low-angle misorientation boundaries (> 0.3º). These textures suggest a complex deformation-recovery process for the emplacement of shergottite on Mars. The small crystallites formed via shock-induced heterogeneous nucleation at olivine grain edges and fractures (Walton & Herd, 2006), facilitated by eutectic melting followed by recrystallization during brief post-shock heating that is less than 0.2 hours of 1600-2000K (Takenouchi et al., 2017; Speciale et al., 2020). The irregular subgrain fragments are preserved olivine relics, isolated by very-low-angle boundary networks developed during compressive shock wave passage, migrating to form low-angle boundaries during rapid quenching. This records the final deformation episode before meteorite delivery to the Earth, shedding light on shock metamorphism and recovery processes in Martian rocks.
How to cite: Li, Y., Kalacska, S., Yildirim, C., Detlefs, C., Zhao, B., Hetherington, C. J., Flemming, R. L., and McCausland, P.: Microstructure Decoding the Deformation history of the highly shocked Martian Shergottite NWA 7721, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13953, https://doi.org/10.5194/egusphere-egu25-13953, 2025.
Background
Meteorites originating from Mars represent the only tangible samples that allow us to investigate the geologic history of this planet, including its potential early habitability. The discovery of the polymict regolith breccia NWA 7034 meteorite and its pairs, informally known as Black Beauty, provides, for the first time, a direct time window into the earliest crustal processes on Mars [1,2]. Analyses of the crustal fragments from this meteorite indicates that water was present on the Martian surface 4450 million years ago [3].
Neutron tomographic imaging is a method for non-destructively characterising samples in 3D and as neutrons are sensitive to H it is possible to directly locate H-rich phases. When combined with X-ray tomographic imaging it is possible to confirm the identification of H and determine which minerals are hosting the H [4].
Methods
Two pieces of the Martian meteorite NWA 7034 have been analysed using neutron and X-ray tomography. High-resolution neutron CT was performed at ICON at the Paul Scherrer Institute in Switzerland. X-ray CT was performed at the B05 beamline at European Synchrotron Radiation Facility in France by Phil Cook. The 3D volumes from each measurement were co-registered and high attenuation phases were segmented and identified.
Results
Comparison to theoretical attenuation values of minerals in the sample shows that high X-ray attenuation stems from Fe-oxides and high neutron attenuation stems from hydrous phases. There are more high attenuation X-ray spots than high attenuation neutron spots, which shows that not all Fe-oxides contain H. Segmentation also shows that all hydrous phases overlap with the Fe-oxide phases. As such, this data suggests that the water-related H in the meteorite is stored in Fe-oxides.
References
[1] M. Humayun et al., Nature 503 (2013), 513–516
[2] A. Goodwin et al., Astrobiology 22 (2022), 755-767
[3] Z. Deng et al., Science Advances 6 (2020), eabc4941
[4] J. Martell et al., Science Advances 8 (2022), eabn3044
How to cite: Naver, E., Nikolajsen, K. W., Carøe, M. S., Frydenvang, J., Bizzarro, M., Jørgensen, J. S., Poulsen, H. F., and Theil Kuhn, L.: Combined neutron and X-ray tomography of Martian meteorite NWA 7034 to locate hydrous phases, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17926, https://doi.org/10.5194/egusphere-egu25-17926, 2025.
The composition of Mars' crust is crucial for reconstructing the internal structure and geological evolution of the planet. Recent observations based on high-resolution near-infrared spectral data have identified plagioclase-bearing geological units on the Martian surface, appearing in multiple distant locations [1],[2]. The spectral characteristics imply extremely low content of basic minerals, indicating the potential lithology of ferroan anorthosites [1] or felsic rocks [2], challenging the classic view that the Martian crust is primarily basaltic. However, thermal infrared spectra suggest that the silica content of previously identified plagioclase outcrops does not match that of felsic rocks on Earth [3]. In addition, the characteristic absorption of plagioclase at ~1.25µm has been found in the bulk spectra of rocks containing 30-80 wt% plagioclase, corresponding to a range of feldspar-bearing lithologies [4]. The plagioclase-bearing lithology on Mars identified with the characteristic spectral absorption feature remains unclear.
In this study, we analyzed both the visible-near-infrared point spectra and hyperspectral images of a set of Martian meteorites, specifically the basaltic shergottites, which are so far the most representative samples from the Martian crust. An integrated BSE and EDX analysis (TIMA) which characterized the mineralogy, grainsize and texture was performed on the same sample set. We found that all the point spectra of basaltic shergottites contain the ~1.25 µm band, with the potential contribution from the electronic transition of iron in either plagioclase or olivine. Martian olivine, being more iron-rich, is expected to show stronger and wider bands at around 1 µm, with greater contribution from the 0.85 and 1.25 µm band due to Fe2+ in the M1 site [5], which overlaps with the distinctive absorption of Fe-bearing plagioclase. Based on the analysis of amplitude ratio and area ratio at 1 µm and 1.25 µm after Gaussian fitting, the olivine-phyric basaltic shergottites have systematically stronger ~1.25 µm band than those without olivine phenocrysts. Meanwhile, the abundances of plagioclase in the samples varying from 9.2% to 36.5% do not correlate with the strength of the ~1.25 µm band. We derived the distinct spectral characteristics of Martian ferroan plagioclase from the hyperspectral image cubes co-registered to the mineral phase maps. Our results suggest that the presence and abundance of iron-bearing plagioclase in the samples cannot be determined solely based on the absorption band centered at ~1.25 µm. Further investigation into the spectral variability of plagioclase would reveal its correlation with composition, grain size and crystallinity. The analysis can be used to reinterpret the orbital spectroscopy data of key areas and provide valuable references for future interpretations of Martian surface remote sensing data.
Reference：
[1] Carter J, Poulet F. (2013), Nature Geoscience, 6(12): 1008-1012;[2] Wray J J et al. (2013), Nature Geoscience, 6(12): 1013-1017;[3] Rogers et al. (2015), Geophysical Research Letters 42.8: 2619-2626;[4] Barthez M et al. (2023), Journal of Geophysical Research: Planets,128(8): e2022JE007680; [5] Isaacson Peter J. et al. (2014), American Mineralogist 99: 467 - 478.
How to cite: Xing, G., Pan, L., Chen, J., and Zhao, Y.: Investigation of near-infrared spectroscopic characteristics of plagioclase in the Martian crust, implications from Martian meteorites, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7877, https://doi.org/10.5194/egusphere-egu25-7877, 2025.
*Email: alka.rani@nasa.gov
The Elysium Volcanic Province (EVP), including Cerberus Fossae (CF), is a geologically young and tectonically active region, notable for recent volcanic and seismic activity [1]. It is a great region of interest for investigating Martian mantle dynamics and volcanic evolution. The broader aim is to explore the interconnected dynamics of mantle heterogeneity, lithospheric evolution, and surface processes within a stagnant-lid framework, thereby enhancing our understanding of Mars's thermal and geodynamic evolution. Therefore, we employ a comprehensive approach by integrating geochemical, thermoelastic, and seismic analyses to explore the spatiotemporal evolution of volcanism in the studied province.
The geochemical investigations of EVP, using elemental datasets from Mars Odyssey's Gamma-Ray Spectrometer (GRS) [2-3], reveal igneous compositions with minimal alteration, preserving the primary signatures of volcanic processes in the study region. Pressure-temperature analyses [4-5] indicate variations from 1.3 to 2.2 GPa and 1350 to 1500°C, transitioning spatially from the Northwest to Southeast of the EVP. These variations align with differences in lithospheric thickness and mantle potential temperature, suggesting an evolution of localized magmatic activity. Furthermore, we developed a geophysical model using BurnMan [6-7] to deduce corresponding elastic properties, incorporating the Birch-Murnaghan Equation of State and temperature profiles [8]. Elastic properties were derived for various bulk silicate Mars compositions, revealing features like the olivine-wadsleyite transition, thermal boundary layers, and crustal thickness variations. These findings align with recent geophysical investigations [9-10], highlighting the influence of thermal and compositional variation on Mars’s interior. Additionally, to further constrain the subsurface structures, we have used seismic analyses, incorporating data from NASA’s InSight mission, to validate thermoelastic models by comparing differential travel times near Cerberus Fossae with derived ray paths. This multidisciplinary approach provides a robust framework for unraveling the geodynamic evolution of EVP. Integrating geochemical, thermoelastic, and seismic analyses ensures a comprehensive understanding of the mantle’s thermal and compositional state, advancing our knowledge of volcanic processes on Mars and their implications for planetary evolution.
References: [1] Vaucher J., et al., (2009), Icarus 204, 418–442. [2] Boynton W. et al., (2007) JGR: Planets, 112. [3] Rani A. et al., (2022) GRL, 49. [4] Putrika K.D. (2005) GGG, 6. [5] Lee C.T.A. et al., (2009) EPSL 279, 20–33. [6] Cottaar, S., et al., (2014), Geochemistry, Geophysics, Geosystems, 15.4, 1164–1179. [7] Cottaar, S., et al., (2016), BurnMan v0.9.0. Zenodo. [8] Plesa et al., (2018), GRL, 45(22), 12-198. [9] Khan, et al., (2023), Nature, 622 (7984), 718-723. [10] Samuel, et al., (2023) Nature, 622 (7984), 712-717.
How to cite: Rani, A., F. Haviland, H., M. Bremner, P., Byul Woo, H., Roy, A., Mallik, A., Basu Sarbadhikari, A., and Karunatillake, S.: Geochemical and Geophysical Insights into the Elysium Volcanic Province: Unravelling the Spatiotemporal Evolution of Martian Volcanic Province , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14678, https://doi.org/10.5194/egusphere-egu25-14678, 2025.
Fluvial and sedimentary deposits on Mars provide key evidence of surface water activity in geologic times. On the contrary, the distribution and characteristics of Mars’ past groundwater activity remain poorly understood, limiting our ability to reconstruct the early Mars climate regimes. Eberswalde crater, known for hosting the most well-preserved deltaic deposit on Mars, exhibits meandering lobes of inverted channels [1,2], as evidence for sustained fluvio-lacustrine activity in a standing body of water [2-4]. In this study, we present a detailed analysis of the morphology, mineralogy, and stratigraphy of vein-like structures within Eberswalde crater using high-resolution imagery data (HiRISE and CTX). We identified three major morphological types of vein-like structures. Type II structures showed varying widths between 1.5 m and 4 m. Through manual co-registration to the CRISM data, we identified a correlation between the high-albedo linear feature and a clay-bearing spectral signature which matches well with the spectral features in Eberswalde delta sediment. We propose that these features were clastic dikes formed due to groundwater activity, before or at the same time as the formation of the deltaic deposits. Stratigraphic relationships between the identified structures and the mapped geologic units [5-6] suggest the top unit of the delta is relatively young. The morphometry and spatial distribution of the clastic dikes offer valuable constraints on the flux and velocity of ancient groundwater in this region.
References: [1] Moore, J. M., & Howard, A. D. (2005). Journal of Geophysical Research: Planets, 110(E4). [2] Wood, L. J. (2006). Geological Society of America Bulletin, 118(5–6), 557–566. [3] Lewis, K. W., & Aharonson, O. (2006). Journal of Geophysical Research: Planets, 111(E6). [4] Pondrelli, M et al. (2008). Icarus, 197(2), 429-451. [5] Mangold, N., et al. (2012). Icarus, 220(2), 530-551. [6] Rice, M. S., et al. (2013). International Journal of Mars Science and Exploration, 8, 15–57.
How to cite: Pan, L., Xing, G., and Qi, C.: Groundwater activity inferred from potential clastic dikes in Eberswalde crater, Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16086, https://doi.org/10.5194/egusphere-egu25-16086, 2025.
The Japan Aerospace Exploration Agency (JAXA) is undertaking the Martian Moons Exploration Mission which presents a valuable opportunity to understand Phobos’ surface environments by landing spacecraft on its regolith to collect surface soil samples. Several Phobos simulations have been developed, such as the UTPS-TB (University of Tokyo Phobos Simulant, Tagish Lake based) to aid engineering and scientific evaluation experiments. This study evaluates the accuracy of the UTPS-TB by comparing its organic and elemental composition to that of planetary bodies spectrally similar to Phobos. UTPS-TB was not initially created to simulate organic content, but this study assesses its potential suitability for use in organic analysis. A comparative analysis is conducted based on previous literature detailing spectroscopic signatures at the visible-to-near-infrared and mid-infrared wavelengths of Phobos and other planetary bodies. It is concluded that its reflectance spectrum is overall most similar to that of CM2 chondrites, Tagish Lake meteorite, and D-type asteroids. Key characteristics are discussed in depth, such as a reduced hydrated band at 2.7 µm, an anhydrous nature, olivine and pyroxene content, as well as a dark component containing pyrite, magnetite, and iron-nickel content. The UTPS-TB exhibits characteristics of a pristine planetary body. Thermogravimetric mass loss experiments reveal low grade metamorphic profiles similar to that of Tagish Lake and CM chondrites. Derived ratios between molecular water, organic and hydroxide, phyllosilicate, and carbonate content are comparable to CM chondritic ratios, with a dominant phyllosilicate component. Elemental analysis of carbon, hydrogen, nitrogen, and sulphur content indicates that H and C content are consistent with expected low levels of alteration. The organic content ratio is notably very similar to that of CM2 Murchison. UTPS-TB, by this assessment, is a reliable simulation of Phobos. Amino acid analysis via ultra-performance liquid chromatography fluorescence detection and quadruple time-of-flight hybrid mass spectrometry (UPLC-FD/QToF-MS) of the UTPS-TB is currently being conducted.
How to cite: Munday, B. P., Chan, Q. H. S., and Kebukawa, Y.: Determining a good Phobos simulant: An organic analysis based on spectral similarities between Phobos, Tagish Lake, and CM chondritic meteorites, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12293, https://doi.org/10.5194/egusphere-egu25-12293, 2025.
The possibility of life on Mars is a subject of interest in astrobiology due to the planet's proximity and similarities to Earth. Mars may thus hold the best record of the prebiotic conditions leading to life, even if life does not or has never existed there. Following the confirmation of the past existence of surface liquid water, the Curiosity, Perseverance and Opportunity rovers started searching for evidence of past life. A significant portion of astrobiology studies focus on analyzing the (micro)biology of analog sites across the globe, as well as detecting evidence for the presence of life in such locations. These studies are essential for an increased understanding of the limits of life, biodiversity, resilience and adaptation of microorganisms being exposed to multiple extremes of relevance for Astrobiology, as well as long term viability of cells and their signatures under Mars-like settings [1]. Therefore search for evidence of habitability, taphonomy (related to fossils), and organic compounds on Mars is now a primary objective for space agencies. To support the scientific output of these missions and to go further on the search of life on Mars, Martian environmental investigations are necessary to study the survival potential and the short- and long-term stability of biosignatures, at space missions and at ground simulation beds, with extremophile organisms. We have selected at different Mars analog areas in Spain, volcanic-, clayey soils-, and gypsum areas, different lichen species. These samples were exposed to Mars-like environmental parameters, as there are Mars-like UV-Radiation, Mars composition of 95% CO2 and Mars-like pressure of 8-10 mB, at DLR [2], INTA-CAB [1], and on the EXPOSE facility, at the International Space Station [3, 4]. To study the vitality of the samples, we analyzed the metabolic activity, the metabolites, as well as the biomolecular changes before and after exposure. Ultrastructure- and morphological changes were analyzed by microscopic techniques. For the identification of biomarkers we used RAMAN spectroscopy. These studies are relevant as contribution for an urgent need to create a database of reference biosignatures, an European “biosignature data base”, and for analogue environments for future space exploration programs whose objective is the search for extraterrestrial life.
References
[1] Antunes, A., Lau Vetter, M., Flannery, D., Li, Y. (2023). Editorial: Mars analogs: Environment, habitability and biodiversity. Front. Astron. Space Sci., Sec. Astrobiology 10 – 2023: Doi.org/; 10.3389/fspas.2023.1208367
[2] de Vera, J.-P., Schulze-Makuch, D., Khan, A., Lorek, A., Koncz, A., Möhlmann, D. and Spohn, T. (2014). Adaptation of an Antarctic lichen to Martian niche conditions can occur within 34 days. Planetary and Space Science 98, 182-190. DOI: 10.1016/j.pss.2013.07.014
[3] De la Torre, R., Ortega-García, M.V., Miller, A.Z., and de Vera, J.P. (2020). Lichen Vitality After a Space Flight on Board the EXPOSE-R2 Facility Outside the International Space Station: Results of the Biology and Mars Experiment. Astrobiology 20-5:583-600. DOI: 10.1089/ast.2018.1959.
[4] Baqué, M., Backhaus, T., Meeßen, J., and de Vera, J.P. (2022). Biosignature stability in space enables
their use for life detection on Mars. Science Advances, 8 (36), eabn7412 (1-12). DOI:
10.1126/sciadv.abn7412
How to cite: de la Torre Noetzel, R.: Impact of extreme Martian environmental conditions on the limits of life and detection of biosignatures, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11122, https://doi.org/10.5194/egusphere-egu25-11122, 2025.
The NASA InSight mission operated on Mars from November 2018 to May 2022, primarily aimed at investigating the planet’s interior structure using seismology, geodesy, and heat flow measurements. Among its instruments was the InSight Fluxgate magnetometer, IFG, part of an auxiliary sensor suite, which provided environmental monitoring data. The IFG captured the first surface measurements of Mars’ crustal magnetic field, as well as time-varying magnetic fields. These data enable electromagnetic (EM) sounding, a technique that uses interactions between time-varying magnetic fields and the subsurface to infer electrical conductivity. Electrical conductivity is in turn linked to subsurface mineralogy, temperature, and volatile content, offering complementary insights to other geophysical methods.
Previous attempts to use InSight IFG data for EM sounding were unsuccessful due to contamination from spacecraft-generated signals and limited data coverage. Here, we report the first successful EM sounding results from InSight data. By focusing on time periods of 100–1000 seconds, where coherence between horizontal and vertical magnetic field components is high, we compute transfer functions. Further, we derive the corresponding C-response under the assumption of an inducing field geometry and invert those for electrical subsurface elctrical conductivity.
Because the largest scale inducing field detectable at the equator (n=m=1) provides a maximum penetration depth and a lower limit of crustal conductivity, we evaluate the effect of a range of inducing field geometries. Irrespective of inducing field geometry, our results reveal conductivity profiles, characterized by a high-conductivity crust (>~10⁻² S/m) underlain by more resistive material. This contrasts with expectations of a cold, dry Martian crust and suggests elevated volatile content, high iron concentrations, and / or increased temperatures.
Our findings demonstrate the utility of EM sounding on Mars and underscore the scientific potential of magnetometer data in planetary exploration. They also highlight the need for further investigation of Martian electrical conductivity at longer periods and therfore at larger depths, which may reveal new insights into the planet’s thermal evolution and volatile inventory.
How to cite: Mittelholz, A., Grayver, A., Johnson, C. L., and Munch, F.: Electromagnetic Sounding on Mars with InSight, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3289, https://doi.org/10.5194/egusphere-egu25-3289, 2025.
Previous results of global mapping have shown that Mars crustal magnetism is generally stronger south of the crustal dichotomy boundary (where the crust is thicker) and is strongest in one-third of the Southern Hemisphere. It is generally weak over ancient impact basins (e.g., Hellas, Argyre,) and is weakest over young volcanic provinces (Tharsis, Elysium). However, a lack of clear correlations of orbital anomalies with surface geology has inhibited a full understanding of the nature of crustal magnetic field sources. Here, we present preliminary regional mapping results for the Claritas Fossae region south of Tharsis that shows a more detailed correlation than found before of magnetic anomalies with areas of ancient magmatic activity and uplift. The possible existence of a magnetic anomaly over Claritas Fossae was first reported by Dohm et al. (2009), based on MGS magnetometer data at higher altitudes. However, the correlation of anomalies with the Claritas rise is much clearer using the MAVEN data. The simplest interpretation is that the anomaly sources consist of magmatic intrusions magnetized thermoremanently in the Mars core dynamo magnetic field during the Noachian. By extension, most or all crustal magnetic anomaly sources on Mars may consist of magmatic intrusions.
While it is accepted that a Mars core dynamo existed during the Early to Middle Noachian when the southern highlands formed and did not exist during the Late Hesperian and Amazonian when the younger volcanic constructs formed, the timing of the final termination of dynamo generation (Middle Noachian, Late Noachian, or Early Hesperian) remains uncertain. Preliminary regional mapping of anomalies over volcanic constructs whose final eruptions occurred in Late Hesperian or later times confirms that crustal fields are relatively weak over the main calderas. Hadriacus Mons, with a Late Noachian or Early Hesperian model age, has previously been reported to have a magnetization signature based on MGS electron reflectometry data (Lillis et al., 2006). Preliminary ESD mapping of MAVEN data confirms that an anomaly is present over the central caldera of Hadriacus Mons and its southern flank. It extends southwestward along the direction of pyroclastic flows into the outer Hellas basin. Formation of the large valley that dissects Hadriacus Mons’ flanks (Dao Vallis) has been attributed to melting of subsurface ice by magmatic heat, producing a large ‘’outburst flood’’. This interpretation is consistent with the hypothesis that acquisition of strong thermoremanence in Fe-rich volcanic materials occurred mainly in an oxidizing environment. It is proposed here that this region is a good candidate for future low-altitude magnetometer data acquisition. If such measurements confirm that anomalies are associated with the pyroclastic flow deposits, which have a model age of 3.7 to 3.9 Gyr, it would follow that dynamo activity continued into the Late Noachian or Early Hesperian.
How to cite: Hood, L., Matlock, T., Williams, D., Crown, D., Oliveira, J., Halekas, J., Langlais, B., and Lillis, R.: Regional Mapping of MAVEN Orbital Magnetometer Data: Implications for the Nature of Crustal Field Sources and the Duration of the Mars Dynamo, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6974, https://doi.org/10.5194/egusphere-egu25-6974, 2025.
Mars possesses a strong remanent crustal field, indicative of an ancient magnetic dynamo which is now inactive. We address the problem of modelling this field using magnetometer measurements from two orbiters, MGS (1997 – 2006) and MAVEN (since 2014).
A substantial amount of additional low-altitude data has been collected by MAVEN since the most recent and highest resolution global model was published, thereby necessitating a new model to be computed. Two approaches were formally used for this: Spherical Harmonics (SH) and Equivalent Source Dipoles (ESD). We propose to solve this regression problem with an ensemble of Physics-Informed Neural Networks (PINN). With this approach, (1) the generalization performance of our model is monitored while relying solely on the data for this purpose; (2) the entire datasets are used without the need to down-sample; (3) the resolution varies with respect to the nonuniform data coverage; and (4) model uncertainty is estimated.
The input of each network is the observer coordinates in the Mars body-fixed reference frame, and the output is a scalar potential. The predicted magnetic field is computed from this scalar potential with automatic differentiation before updating the free parameters with back-propagation. As such, the conservative nature of the magnetic field is encoded as a hard constraint. The estimation of prediction uncertainties relies on an implicit regularization scheme based on bootstrap aggregating and early stopping. From predicted values of the magnetic field and corresponding variances, a spherical harmonics expansion was performed with a weighted least-squares.
The corresponding spherical harmonics degree spectrum at orbit altitude is stable up to degree 160 and has more energy than previous models. The improved resolution of this model opens doors for future research and has potential for scientific inferences regarding the crustal magnetism of Mars and its interactions with the induced magnetosphere.
How to cite: Delcourt, T.: A New Model of the Crustal Magnetic Field of Mars Using Physics-Informed Neural Networks, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6628, https://doi.org/10.5194/egusphere-egu25-6628, 2025.
How to cite: Karatekin, Ö., Okada, T., Sakatani, N., Blommaert, J., Henry, G., Lozano, L. R., Temel, O., Ritter, B., Nuyts, D., Tavares, J. L., Kanamaru, M., Shimaki, Y., Arai, T., Senshu, H., Demura, H., Sekiguchi, T., Kouyama, T., Tanaka, S., Michel, P., and Küppers, M. and the TIRI Team: First Results from Thermal Infra-Red Imager (TIRI) during Hera’s Mars Swing-By, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19582, https://doi.org/10.5194/egusphere-egu25-19582, 2025.
We perform an observational event from Mars Atmosphere and Volatile Evolution (MAVEN) instruments that magnetosonic waves and penetrating solar wind H+ are simultaneously observed in Martian magnetic pileup region, accompanied by large reflected H+ flux. Combined with the observations, we use test particle simulations to quantify wave-particle interactions between the waves and H+ and the resulting H+ reflection. The results show that there is a strong Landau resonance for 101–104 eV H+ on time scale of ~12 s, with pitch-angle scattering at <(Δα)2> = 10-2–10-1 rad2 and energy diffusion at <(ΔEk/Ek0)2> = ~10-2. Surprisingly, the non-resonance effect can also affect the H+ with lower energy 100–101 eV. Landau resonance makes the reflection efficiency of penetrating H+ reach 12.30% with high energy (103–104 eV) and large pitch-angle (45°–90°), which provides a new way for reflecting the penetrating H+ to space.
How to cite: Yun, X., Fu, S., Ni, B., Cui, J., and Ge, Y.: Reflection of Martian Penetrating Solar Wind Protons due to Wave-particle Interactions with Magnetosonic Waves, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18700, https://doi.org/10.5194/egusphere-egu25-18700, 2025.
Water vapour on Mars has long been an important target for exploration, as its detection revealed that Mars was home to an active water cycle fuelled by exchanges between ice on the surface and the atmosphere. From its first spectroscopic identification in 1963 to the most recent studies carried out by the many spacecrafts that have orbited Mars, our understanding of the water cycle on Mars has made considerable progress. Here we present a climatology of water vapour column abundances over 11 Martian years (MY), observed by the “Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars” (SPICAM) instrument on the European Space Agency's Mars Express mission. Despite uneven spatial coverage due to the orbital configuration of Mars Express, SPICAM succeeded in monitoring the abundance of water vapour in daylight at almost all latitudes and seasons. As its water vapour measurements are based on sunlight reflected by Mars in the near infrared, SPICAM has not been able to observe during the polar night, where water vapour is predicted to be anyway present in almost undetectable quantities.
The 11MY-climatology encompasses two years with a Global Dust Event (GDE), allowing us to perform an initial exploration of the differences between years with and years without a GDE. We have also compared our measurements with those of past and present missions, a topic that has long resisted reconciliation attempts. Furthermore, we attempted to fill observation gaps with the well-known kriging (a Gaussian process regression) technique to allow better appraisal of the year-to-year variations. Finally, we propose a reference water vapor annual cycle based on averaging all the years of observations.
How to cite: Montmessin, F., Verdier, L., Korablev, O., Lefèvre, F., Trokhimovskiy, A., Fedorova, A., Baggio, L., and Lacombe, G.: Mars water cycle: an 11 Mars year climatology of water vapour column abundances by SPICAM on Mars Express, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10068, https://doi.org/10.5194/egusphere-egu25-10068, 2025.
The "Mars Magnetosphere ATmosphere Ionosphere and Space-weather SciencE (M-MATISSE)" mission is an ESA Medium-class (M7) candidate currently in Phase A study by the European Space Agency (ESA). M-MATISSE's main scientific goal is to unravel the complex and dynamic couplings of the Martian Magnetosphere, Ionosphere, and Thermosphere (M-I-T coupling) with relation to the solar wind (i.e., space weather) and the lower atmosphere, and the processes leading to this coupling, which are highly entangled between several regions of the system. The M-I-T coupling controls the dissipation of incoming energy from the solar wind, and therefore, the evolution of Mars' atmosphere and climate (including atmospheric escape, auroral processes, and incoming radiation). Moreover, understanding the behavior of Mars' M-I-T system and of the chain of processes that control space weather and space climate at Mars, as well as the radiation environment, is essential for exploration as it leads to accurate space weather forecasts and, thus, prevents hazardous situations for spacecraft and humans.
M-MATISSE consists of two orbiters with focused, tailored, high-heritage payloads to observe the plasma environment from the surface to space through coordinated simultaneous observations. It will utilize a unique multi-vantage point observational perspective, with the combination of in-situ measurements by both orbiters and remote observations of the lower atmosphere and ionosphere by radio crosstalk between them. The father-ship, called Henri, has a periapsis below 270 km and an apoapsis of 3000 km with an inclination of 60°. It is intended to spend most of its time within the Martian plasma system. The daughter-ship, called Marguerite, also has an inclination of 60°, a periapsis below 270 km and an apoapsis of 10,000 km. It is intended to spend most of its time in the solar wind and/or far tail of Mars (a region barely explored before). M-MATISSE has a nominal mission duration of 1 Martian year, and the launch date is identified for July 2037.
The M-MATISSE mission has three main goals:
Characterizing the global dynamics of the M-I-T coupling by unravelling its temporal and spatial variabilities. This will be done with simultaneous observations of the solar wind (energy input) and ionosphere-magnetosphere (energy sink), and also, via investigating the coupling of the mesosphere with the ionosphere and solar energetic particles.
Characterizing the radiation environment by determining how the M-I-T system absorbs the energy that reaches the planet and forecasting near-real time planetary space weather.
Characterizing the ionosphere/lower-atmosphere coupling, which is a region barely explored but essential for solar energetic particles related phenomena as well as for communications in HF wavelengths.
In addition, M-MATISSE will significantly contribute to the understanding of Mars climate and the lower atmosphere as two remote instruments have dedicated instrumentation to monitor dust, clouds, and to obtain temperature and density profiles from the surface up to about 50 km. Moreover, the heliophysics community will be involved in the mission with a full-package solar wind monitor at Mars' distances, contributing to the understanding of solar wind and the propagation of solar transients in the inner solar system.
How to cite: Andert, T., Sanchez-Cano, B., and Leblanc, F. and the M-MATISSE team: The M-MATISSE mission: Mars Magnetosphere ATmosphere Ionosphere and Space weather SciencE. An ESA Medium class (M7) candidate in Phase-A, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11867, https://doi.org/10.5194/egusphere-egu25-11867, 2025.
This paper introduces a new mixing formalism for non-orographic gravity waves (GWs) that integrates with the stochastic GW scheme previously developed by \cite{liu2023surface}. The formalism extends the parameterization to turbulence-induced mixing from the surface to the exosphere, derived in terms of the eddy diffusion coefficient. Sensitive tests with the Mars Planetary Climate Model reveal eddy diffusivities of 104 -109 cm2 s-1 ,varying with altitude and season. While the induced mixing has minor temperature effects consistent with Mars Climate Sounder observations, it significantly enhances middle-upper atmosphere tracer transport, revealing the critical role of non-orographic GWs in regulating upper atmospheric dynamics and influencing processes like tracer escape.
How to cite: Liu, J., Forget, F., Millour, E., and Lott, F.: Integrating Non-Orographic Gravity Wave Mixing into the Mars Planetary Climate Model: Impacts on Upper Atmospheric Dynamics and Tracer Transport, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3864, https://doi.org/10.5194/egusphere-egu25-3864, 2025.
Suspended aerosols may have a direct impact in atmospheric processes, such as photochemical reactions and atmospheric radiative balance and dynamics. On Mars, the most common aerosols are composed of mineral dust particles and/or water ice. This last one is known to affect both the radiative balance [2] and the water cycle [1], whereas suspended mineral dust is the prevalent aerosol component on the planet.
The instrument Nadir and Occultation for Mars Discovery (NOMAD) is a suite of three spectrometers on board the Trace Gas Orbiter (TGO) which has been observing the Martian atmosphere routinely since April 2018, i.e., for almost 3 full Martian Years. [5] Data from its solar occultation channel (SO), combining several sets of diffraction orders, or wavelengths, are used in this work to retrieve the aerosol properties and distribution during that period with a very fine resolution in the vertical from the ground up to the thermosphere. Our aerosol retrieval strategy follows a three-step process [4]. Firstly, we perform a "cleaning" of the NOMAD observations, in the form of transmittance spectra at the tangent altitudes, using an in-house pre-processing algorithm developed at IAA/CSIC. This is intended to eliminate residual imperfections in the calibrated transmittances, like spectral shifts and bendings. Secondly, the cleaned spectra are used to retrieve the aerosol extinction vertical profiles following a global fit approach. Finally, we apply a fitting algorithm to compare the retrieved extinctions (spectral ratios of the retrieved extinctions) with the extinction ratios simulated with a Lorenz-Mie code [3]. The aerosol properties inferred are size (effective radius and effective variance), nature (mineral dust and water ice proportions), number density and mass of the particles, as well as their vertical distribution and variability over time.
In this talk we will review the obtained results analyzing more than three full Martian Years. This is a significant extension of a previous first analysis by our team [4] focused in the 1st year of NOMAD data. We have also improved a couple of aspects from the previous work, like vertical sampling and wavelength coverage. We will describe the dataset and the major results obtained on the distribution and properties of the aerosols, splitting between dust and water ice.
References:
[1] Montmessin, F. et. al, Journal of Geopysical Research, 2004, doi: 1029/2004JE002284
[2] Wilson, R.J, et. al, Geophysical Research Letter, 2008, doi: 1029/2007GL032405
[3] Mishchenko, M.I et. al, Cambridge University Press, 2002.
[4] Stolzenbach, A. et. al, Journal of Geophysical Research: Planets, 2023, doi: 1029/2023JE007835
[5] Vandaele, A. C. et al., 2018, Space Science Reviews, doi: 10.1007/s11214-018-0517-2
How to cite: Gamonal García-Galán, M. Á., López-Valverde, M. Á., Brines, A., Stolzenbach, A., Modak, A., González-Galindo, F., Funke, B., López-Moreno, J. J., Rodríguez-Gómez, J., Sanz-Mesa, R., Bellucci, G., Patel, M., and Thomas, I.: Martian atmospheric aerosol composition and distribution over 3 full MYs from Nomad/TGO solar occultation measurements, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12204, https://doi.org/10.5194/egusphere-egu25-12204, 2025.
Gravity waves are a phenomenon that has been observed in several planetary atmospheres, including Earth, Venus, and Mars. They are formed when air is stably stratified and are triggered by wind flow over topography (orographic) or by weather events such as frontal systems, jet streams and convection (non-orographic). As a parcel of air is forced up by one of these mechanisms in stable air, buoyancy acts as a restoring force on the parcel causing oscillations. As the resulting wave propagates upward where the atmosphere is less dense, the amplitude grows and energy and momentum are transferred from the lower to the upper atmosphere. On Mars, gravity-wave induced density and temperature fluctuations have been observed by orbiting platforms (e.g. [1-5]) and during aerobraking [6-7] and from the surface [8]. Their effects are also seen in airglow imagery [9].
While the waves are relatively small, ranging in wavelength from tens to hundreds of kilometres, their impact through thermal and dynamical forcing on the climate can be quite large and therefore need to be accounted for in atmospheric models. Global models typically do not resolve these waves so their impact on the large-scale flow must be parameterised. These parameterisation schemes are poorly constrained (see [10] for an overview).
We present the first analysis of density and temperature perturbations in the ExoMars Trace Gas Orbiter (TGO) Nadir Occultation for MArs Discovery (NOMAD) Solar Occultation (SO) observations [11] to help constrain the GEM-Mars Global Climate Model (GCM) [12, 13].
The GEM-Mars GCM uses two parameterisations for orographic [14] and non-orographic gravity waves [15-17], originating from the terrestrial version of the model [18-20]. By comparing temperatures, mapping the perturbations and analysing the derived potential energy and gravity wave drag from the observations, we can then adjust the schemes’ tuning parameters to better match the NOMAD temperatures. For example, in the non-orographic scheme, the lower bound vertical wavenumber, which limits the maximum vertical wavelength of the spectrum allowed, can be adjusted.
We show that by adjusting the parameters in the schemes, we can better reproduce the temperatures in the 70-100 km altitude range, especially in the midlatitude to polar regions.
References :
1 England, S. L. et al., 2017
2 Vals, M. et al., 2019
3 Heavens, N. G. et al., 2020
4 Starichenko, E. D. et al., 2021
5 Starichenko, E. D. et al., 2024
6 Creasey, J. E. et al., 2006
7 Fritts, D. C. et al., 2006
8 Guzewich, S. D. et al., 2021
9 Altieri, F. et al., 2012
10 Medvedev, A. S. and Yiğit, E., 2019
11 Vandaele A. C. et al., 2018
12 Neary, L. and Daerden, F. , 2018
13 Daerden, F. et al., 2019
14 McFarlane, N. A., 1987
15 Hines, C. O., 1997a
16 Hines, C. O., 1997b
17 Charron, M. et al., 2002
18 Côté, J. et al., 1998
19 Côté, J. et al., 1998
20 Yeh, K.-S. et al., 2002
How to cite: Neary, L., Trompet, L., Daerden, F., Thomas, I., Ristic, B., and Vandaele, A. C.: Using ExoMars TGO/NOMAD observations to help constrain the GEM-Mars GCM gravity wave parameterisations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17409, https://doi.org/10.5194/egusphere-egu25-17409, 2025.
We report new cases of extremely long and narrow clouds similar to the cloud formed at Arsia Mons (AMEC) (Hernández-Bernal et al, 2021) that form at mid-temperate and subpolar latitudes in both hemispheres of the planet.
For this study, we use the images obtained by the VMC camera on board the Mars Express mission. Given Mars Express’ advantageous polar elliptical orbit, we are able to characterize these clouds at different local times (during morning hours when these clouds develop) and spatial resolutions.
We study the properties of the orographic elongated clouds that form in three regions with different topography: The volcanic region of Alba Patera (250°E, 40°N), the rugged mountain range of Thaumasia Highlands and Lyot crater (29.3°E, 50.4°N). The elongated clouds at Alba Patera form during the northern fall and winter between Ls = 170° - 330° and can reach lengths of up to 2600 km with widths of 250 km. Similarly, the elongated clouds at Lyot crater form during Ls = 180° - 340° and can have lengths of up to 3000 km and widths of 300 km. Lastly, the elevated region of Thaumasia Highlands forms many elongated clouds. However, the longest clouds form at 269.5°E, 39°S and can have lengths of up to 2700 km and widths of 200 km. These clouds form during the southern fall and winter during solar longitudes Ls = 0° - 60° and Ls = 110° - 165°.
How to cite: Larsen, E., Sánchez-Lavega, A., del Río-Gaztelurrutia, T., and Hernández-Bernal, J.: Extremely long and narrow orographic clouds on Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20451, https://doi.org/10.5194/egusphere-egu25-20451, 2025.
Dust and water vapor are key components influencing radiative processes in the Martian atmosphere. We identify a distinct barrier mechanism driven by the planetary-scale Hadley circulation (HC), which plays a significant role in controlling the global spatial distribution of dust and water vapor. Using six years of output data from the Ensemble Mars Atmosphere Reanalysis System (EMARS), we analyze the behavior of these components during northern winter. Our results reveal contrasting spatial patterns: dust is predominantly confined within the HC, while water vapor accumulates outside it. This differentiation is attributed to the distinct source regions of dust and water vapor. We demonstrate that the HC not only constrains these source regions but also acts as a barrier to their mixing. These findings highlight the critical role of HC dynamics in modulating the distribution of dust and water vapor in the Martian atmosphere and provide new insights into the complexity of Martian material cycle.
How to cite: Fan, C.-S., Sun, C., Xie, Z., and Fan, S.: Insulation of Dust and Water Vapor by Martian Hadley Circulation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4106, https://doi.org/10.5194/egusphere-egu25-4106, 2025.
Isotopic analysis serves as a critical tool in understanding the complexities of the water cycle and quantifying the influence of distinct atmospheric processes.This research focuses on the spatio-temporal distribution of the HDO/H2O ratio in water vapor on Earth and Mars, identifying the processes that control these variations.Utilizing isotopic data from General Circulation Model LMDZ simulations for Earth and Planetary Climate Model (PCM) simulations for Mars, we investigate the similarities and differences in water vapor transport and phase changes within each planet's atmosphere. Key findings include a marked isotopic enrichment from ice sublimation in both planets, with a stronger effect observed on Mars due to longer crystal residence times. In contrast, Earth exhibits a buffering effect by the near-surface ocean not present on Mars. Our hypothesis that a unified conceptual framework can interpret isotopic distributions on both planets is supported, suggesting shared fundamental processes with adaptations to each planet's unique conditions.This comparative analysis not only highlights the similarities and differences in the water cycles of Earth and Mars, but also demonstates the adaptability of our conceptual framework to various planetary environments. These insights enhance our comprehension of planetary hydrological cycles and contribute to a deeper understanding of their underlying microphysical mechanisms.
How to cite: Wang, D., Risi, C., Montmessin, F., Tian, L., Bowen, G. J., Vals, M., Gourion, E., Fan, S., Petzold, G., and Sun, C.: Comparing Tropospheric Water Vapor Isotopic Distribution and Controls on Earth and Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16607, https://doi.org/10.5194/egusphere-egu25-16607, 2025.
Light atmospheric species such as helium (He) serve as tracers of global circulation in Mars' upper atmosphere (>100 km). Due to its low mass and large scale-height, He exhibits unique behaviour, including the formation of He bulges, their spatiotemporal variations, and their response to Global Dust Storm (GDS). The significant variability observed during nominal dust conditions (i.e., in the absence of a GDS) highlights helium's sensitivity to global circulation across different locations and seasons on Mars. In recent years, seminal studies have explored the small- and large-scale variabilities in He bulges during nominal dust conditions using data from the Neutral Gas and Ion Mass Spectrometer (NGIMS) onboard NASA's Mars Atmosphere and Volatile Evolution (MAVEN) mission. These observations were supplemented by simulations from the Mars Global Ionosphere-Thermosphere Model (M-GITM). However, no other Global Climate Models (GCMs) simulations have been compared with NGIMS He observations, despite notable discrepancies between NGIMS data and M-GITM outputs. Consequently, He climatology under nominal dust conditions using a GW-parameterized GCMs remains unexplored.
MAVEN dataset, spanning Mars Years (MY) 32–37, excluding the period of MY34 GDS, Solar Longitude (Ls) ~ 180-290°, obtained through the NGIMS instrument onboard MAVEN, provides sufficient global coverage and a rare opportunity to study the long-term climatology of He in the Martian upper atmosphere. We use this dataset at an altitude of ~200 km to understand the latitudinal, seasonal, and local-time variability of He bulges in the upper atmosphere during nominal dust conditions on Mars. Additionally, we compare these observations with simulations from a GW-parameterized version of Mars-PCM, which is prescribed with a ‘climatology’ dust scenario. This scenario uses column dust opacity derived by averaging dust opacities observed during MY 24 to 35, excluding MY 25, 28, and 34, to enable an unbiased investigation of He bulges independent of the effects of GDS. In addition, a comparative analysis of NGIMS observations and Mars-PCM simulations, with gravity waves turned on will allow us to study discrepancies between observations and simulations reported in previous studies. The result of this study shows a stronger agreement between NGIMS observed He bulges with those simulated by Mars-PCM as compared to the models used previously. Particularly, the latitudinally extended He bulges shown in this study discard the anonymity of their presence in the high latitude regions (>50°) of Mars, as suggested in previous studies. Furthermore, the sol-to-sol simulations from Mars-PCM for a typical Martian year provides an insight on the seasonal migration of He bulges throughout the year. The He bulges shift toward the southern hemisphere around Ls of ~50° as Mars transitions from the northern spring equinox to northern summer. Conversely, they migrate to the northern hemisphere around Ls ~183° as Mars moves from the northern autumn equinox to northern winter. Thus, the results of this study further our understanding of spatiotemporal variability and migration of He bulges, highlighting the significance of gravity waves induced changes, particularly at the high latitude regions in the upper atmosphere of Mars.
How to cite: Gupta, N., Kumar Guha, B., Gebhardht, C., Al Daheri, S., Sharma, B., Bougher, S., Young, R. M. B., Millour, E., Montabone, L., Rao, N. V., and Sharma, P.: Helium Bulges in the Upper Atmosphere of Mars: Seasonal and Latitudinal Variations in Helium Densities from NGIMS Observations and Mars-PCM Simulations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18562, https://doi.org/10.5194/egusphere-egu25-18562, 2025.
Whistler mode waves are a common type of electromagnetic waves in the Martian induced magnetosphere. Using high‐resolution magnetic field data from the Magnetometer (MAG) instrument onboard Mars Atmosphere and Volatile Evolution (MAVEN) from October 2014 to November 2022, we perform a detailed analysis of the statistical distribution of the occurrence rate, averaged amplitude, peak frequency, wave normal angle and ellipticity of left‐hand and right‐hand polarized whistler mode waves in the Martian induced magnetosphere. Our results show that whistler mode waves are mainly observed in the subsolar and magnetic pileup region, with the occurrence rate of right‐hand mode waves higher than that of left‐hand mode waves. The averaged wave amplitude ranges from 0.02 to 0.13 nT and peak wave frequency ranges from 2 to 9 Hz. We also find that the wave normal angles for both left‐hand and right‐hand polarized whistler waves are relatively larger in the subsolar region and magnetic pileup region where the corresponding wave ellipticity is closer to the linear polarization. Our results are valuable to in‐depth understanding of the generation mechanism of whistler mode waves as well as their contributions to the electron dynamics in the Martian induced magnetosphere.
How to cite: Du, H., Cao, X., Ni, B., Fu, S., Jin, T., Yun, X., Long, M., and Pang, S.: Statistical Distribution of Whistler Mode Waves in the Martian Induced Magnetosphere Based on MAVEN Observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18577, https://doi.org/10.5194/egusphere-egu25-18577, 2025.
Posters on site: Wed, 30 Apr, 16:15–18:00 | Hall X4
Introduction: Numerous detections by the Mars Reconnaissance Orbiter spacecraft’s CRISM instrument have established that the mineral kieserite (MgSO4·H2O) is an important component of many sulfate deposits on Mars 1–4. These orbital detections were enabled by the distinct infrared absorption fingerprint of kieserite. Most recently the Curiosity rover’s CheMin instrument has detected the mineral kieserite in situ at Gale crater5, resulting in a renewed interest in the formation of this mineral. Wang et al. (2018)6 and Kong et al. (2014)7 reported intriguing Raman spectra of an enigmatic ‘low-humidity kieserite’ phase occurring at Dalangtan Playa, an arid salt deposit in China. The maximum temperature at this field site barely exceeds 30 °C during summer, thus starkeyite (MgSO4·4H2O) should be the stable phase under these conditions8. Wang et al. (2018)6 hypothesize that the formation of kieserite outside of its stability field was enabled via the formation of a transient amorphous phase that then crystallized to form kieserite. Higher hydrates (epsomite and hexahydrite) readily turn amorphous under dry, low-pressure conditions9 and amorphous magnesium sulfate hydrates are likely present in many samples analyzed by the MSL Curiosity rover 5,10. Therefore, the Wang et al. (2018)6 results suggest that kieserite formation potentially facilitated by an intermediate amorphous phase might explain the widespread occurrence of kieserite on Mars. To test this hypothesis, we have studied recrystallisation of amorphous magnesium sulfate both under simulated terrestrial and Martian environmental conditions.
Results: No indications of the presence of kieserite were found in our experiments, thus our preliminary results do not lend support to the hypothesis that kieserite may form via an intermediate amorphous phase. The kieserite occurrences on Mars and at Dalangtan Playa remain enigmatic and additional experiments at higher and lower temperatures, at varied RH, and on longer timescales are in progress.
Acknowledgments: JMM’s research was supported by an appointment to the NASA Postdoctoral Program at the NASA Ames Research Center, administered by Oak Ridge Associated Universities under contract with NASA.
References:
1 Bishop, J. L. et al. Journal of Geophysical Research: Planets 114, (2009)
2 Roach, L. H. et al. Icarus 207, 659–674 (2010)
3 Roach, L. H. et al. Icarus 206, 253–268 (2010)
4 Sheppard, R. Y. et al. Journal of Geophysical Research: Planets 126, e2020JE006372 (2021)
5 Chipera, S. J. et al. Journal of Geophysical Research: Planets 128, e2023JE008041 (2023)
6 Wang, A. et al. Astrobiology 18, 1254–1276 (2018)
7 Kong, W. G. et al. American Mineralogist 99, 283–290 (2014)
8 Chipera, S. J. et al. Geochimica et Cosmochimica Acta 71, 241–250 (2007)
9 Vaniman, D. T. et al. Nature 431, 663–665 (2004)
10 Smith, R. J. et al. Journal of Geophysical Research: Planets 123, 2485–2505 (2018)
11 Trainer, M. G. et al. Journal of Geophysical Research: Planets 124, 3000–3024 (2019)
How to cite: Meusburger, J. and Bristow, T.: Recrystallization of amorphous magnesium sulfate hydrates: A low-temperature formation pathway for kieserite (MgSO4·H2O) on Mars?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12749, https://doi.org/10.5194/egusphere-egu25-12749, 2025.
The remote sensing observation of ices and cryospheres in planets and satellites in our Solar System have been accompanied by studies on field analogs (e.g., Antarctica Cianfarra et al. 2022; Svalbard, Preston et Dartnell 2024;) and spectroscopy analysis of dusty ice mixtures in laboratory (e.g., Stephan et al. 2021, Yoldi et al. 2021).
In this project, we used the Mars Global (MGS-1) High-Fidelity Martian Dirt Simulant (Cannon et al. 2019) to create artificial ice mixtures similar to the layer of the North Polar Cap on Mars and we acquired their spectra at low temperature. The spectral acquisitions were performed with the aim to compare the synthetic ice spectra with the ones collected by the NASA Compact Reconnaissance Imaging Spectrometer for Mars (CRISM; Zurek and Smrekar 2007) in the polar regions in order to quantify the content and understand the composition of the dust entrapped in the North polar deposits.
The finest part (0-32 µm) of the simulant MGS-1 (Cannon et al. 2019) is spectrally representative of the atmospheric dust included in the polar strata.
We mixed the simulant with deionized water in different ice/dust ratio to obtain mixtures from 0% to 35% dust. We cooled the mixtures at 193 K in a refrigerator or using liquid nitrogen and varying the freezing time from 1.30 h to 1 minute. Then, using Headwall Photonics Nano/Micro-Hyperspec cameras we acquired the reflectance spectra of different mixtures in a nitrogen controlled environment to avoid moisture and using a cooled sample-holder and a thermocouple to monitor the temperature increase during the acquisitions.
Both the slabs created with slow and fast cooling show absorptions at 1500 and 2000 nm due to water ice and at 500 nm due to the iron content. However, the fast cooling slabs has well-defined absorption bands and shoulders whereas the slow cooling slabs show shallower bands. As expected with the increase of the simulant amount in the mixtures, the 500 nm-band deepens while the 1500 and 2000 nm-bands get shallower. The rise of the sample temperature resultes in an increase of the whole reflectance. The overall results are consistent with previous works on the granular icy mixtures (e.g., Stephan et al. 2021, Yoldi et al. 2021) although some relevant differences are recorded such as the shapes of the absorption bands and the reflectance.
In conclusion, we developed a new set-up to acquire hyperspectral cubes of icy slabs that better represent the condition of exposed ice along Martian polar rupes as well as cuts, cliffs and walls of icy crust of planetary and small bodies of the outer Solar System.
References:
Cannon K. M. et al. (2019) Icarus, 317, 470–478, https://doi.org/10.1016/j.icarus.2018.08.019.
Cianfarra, P. et al. (2022) Tectonics, 4, 6, https://doi.org/10.1029/2021TC007124.
Hauber, E. et al. (2011) Geol. Soc. Spec., 356, 111-131, https://doi.org/10.1144/SP356.7.
Lalich D. E. et al. (2019) J. Geophys. Res. Planets, 124, 7, 1690-1703, https://doi.org/10.1029/2018JE005787.
Spilker L. (2019) Science, 364, 6445, 1046-1051, https://www.science.org/doi/abs/10.1126/science.aat3760.
Stephan, K. et al. (2021) Minerals, 11, https://doi.org/10.3390/min11121328.
Yoldi, Z. et al. (2021) Icarus, 358, 114-169, https://doi.org/10.1016/j.icarus.2020.114169.
Zurek R. W. and Smrekar S. E. (2007) J. Geophys. Res. Planets, 112, 5, 1-22, https://doi.org/10.1029/2006JE002701.
How to cite: Costa, N., Bonetto, A., Ferretti, P., Casarotto, B., Massironi, M., Bohleber, P., and Altieri, F.: Hyper-spectral acquisitions of ice mixtures with Martian simulant at low temperatures, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-447, https://doi.org/10.5194/egusphere-egu25-447, 2025.
Detailed soil characterization at Gale crater based on in-situ observations has revealed compositional trends within soils, while the physical and chemical processes underlying the compositional trends remains to be evaluated. Here we use the grain-morphometrical and geochemical trends across the Wentworth-classes of 48 in-situ soil targets at Gale crater to evaluate underlying pedological processes and potential chemical weathering signatures. The concentration of olivine minerals within the ~ 250 μm to ~ 500 μm size range indicates the prevalence of heavy mineral sorting on a granulometric sense in Gale soils that surpasses the possible effect of the cratering-induced mixing processes. The extent of olivine sorting in soils varies spatially, influenced by the targets’ aeolian setting. The finest portion of Gale soils (< 125 μm) is likely a mixture of allochthonous sediment, globally sourced from atmospheric suspension, and autochthonous counterparts from the weathering of local rocks, while the coarser soils (> 125 μm ) are mostly sourced from local rocks, with possible inputs from both the unaltered parent rock of the Stimson formation and the bedrocks that have undergone diagenetic alteration. If applicable globally, this would reinforce prior inferences that even dust-mantled regions are geochemically heterogeneous owing to a substantial fraction of soils derived from underlying lithology. The low chemical weathering intensity and coupling of mobile elements in soils suggest localized, low pH, low water-to-rock ratio aqueous weathering condition under predominantly cold and arid climate, which may occur either during post-pedogenetic alteration in soils or during the acidic alteration of source rocks.
How to cite: Shi, Y., Zhao, S., Karunatillake, S., Cousin, A., Zhao, J., and Xiao, L.: Sorting and weathering trends of soil at Gale Crater, Mars: Implications for regional pedological processes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4420, https://doi.org/10.5194/egusphere-egu25-4420, 2025.
Using the Planum Boreum and Planum Australe Mars Reconnaissance Orbiter (MRO) Shallow Radar (SHARAD) 3D radargrams (Foss et al., 2017, 2024; Putzig et al., 2018, 2022), we have mapped the subsurface radar stratigraphy in the vicinity of six large craters in the North and South Polar Layered Deposits (PLD) – which exhibit striking cross-circumpolar similarities. For example, both Crotone crater in the North PLD and Crater S3 in the South PLD show an almost complete lack of subsurface radar layering. In contrast, Boola crater in the North PLD and McMurdo crater in the South PLD each exhibit significant subsurface stratigraphy below well-preserved surface features (a sizable ejecta blanket and a large secondary field, respectively). Similarly, the regions around both Udzha crater in the North PLD and Elim crater in the South PLD reveal extensive subsurface layering proximal to possible intra-crater deposition. We will estimate columnar radar dielectric properties in the vicinity of all six of these North and South PLD craters to constrain the effects of possible bulk composition variations upon surface crater preservation and subsurface layer stratigraphy. We will then input our subsurface stratigraphic mapping and dielectric radar property estimates into MARSSIM landform evolution modeling (Howard, 2020) of the modification history in and around these craters to assess the origins of the North and South PLD – could these circumpolar deposit complexes share a common genesis that dates back more than several hundred million or perhaps even over a billion years?
References:
Foss, F.J. et al., 2017, 3D imaging of Mars' polar ice caps using orbital radar data, The Leading Edge, 36(1), 43-57.
Foss, F.J. et al., 2024, Producing 3D radargrams from orbital radar sounding data at Mars: History, results, methods, lessons and plans. Icarus, 419, 115793
Howard, A.D., 2020, Evolution of glacial landscapes of the Martian mid-latitudes, GSA Meeting, Abs #355189, 249-10.
Putzig, N.E. et al., 2018, Three-dimensional radar imaging of structures and craters in the Martian polar caps, Icarus, 308, 138-147.
Putzig, N.E. et al., 2022, New views of the internal structure of Planum Boreum from enhanced 3D imaging of Mars Reconnaissance Orbiter Shallow Radar data, The Planetary Science Journal, 3(11), 259.
How to cite: Pathare, A., Russell, A., Morgan, G., Howard, A., Perry, M., and Putzig, N.: The Modification History of Large Craters in the Martian Polar Layered Deposits, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12355, https://doi.org/10.5194/egusphere-egu25-12355, 2025.
The Martian dynamo evolution is critical for understanding the interior properties and climate change of Mars. It has been referred to shut down at ~4.1-4.0 Ga based on the magnetic signatures of large impact craters but be present at ~3.9 Ga and ~3.7 Ga from the paleomagnetic studies and magnetic fields above volcanic units. Here, we investigate the magnetic signatures of the Iota crater, located inside the CT3-G crater with central strong magnetic fields. The Iota crater shows a weak central magnetic field with an inside-outside magnetic field ratio of 0.29. A forward model is established and the results show that the magnetization strength of the retained materials beneath the Iota crater is about 40% of the surrounding, indicating that the dynamo strength at that time became weak. The different magnetic signatures of Iota and CT3-G reveal that the Martian dynamo changed at ~4.1 Ga, but did not stop completely.
How to cite: zhang, K. and du, A.: Martian Dynamo Change at ~4.1 Ga: Evidence from the Magnetic Measurements of the Iota Crater, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5334, https://doi.org/10.5194/egusphere-egu25-5334, 2025.
Growing evidence supports the existence of subsurface water ice on Mars, though direct evidence of groundwater remains scarce. Using seismic data from seasonal marsquakes, we provide compelling evidence for groundwater within approximately 2 meters of the surface, restricted to localized regions in the northern mid-latitudes. The observed rapid seasonal variability in seasonal marsquake activity suggests that changes in subsurface pore pressure, driven by water ice melting during warmer seasons, play a critical role in triggering these events. This mechanism explains key characteristics of seasonal marsquakes, including their spatial clustering, elevated b-values, and shallow focal depths. Our findings offer new insights into the present-day water cycle on Mars, shedding light on the dynamic interplay between seasonal temperature changes and shallow subsurface hydrological processes.
How to cite: Shi, J., Li, J., Meng, H., Sun, C., Fan, S., Qi, C., Zhang, L., and Wang, T.: Seasonal Marsquakes Reveal Shallow Groundwater Activity on Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4315, https://doi.org/10.5194/egusphere-egu25-4315, 2025.
Our study, employing deep-learning-based polarization estimation to locate low-frequency family marsquakes, has detected seven marsquakes in the vicinity of Hesperia Planum. Among these, Marsquake s1197a is the largest event, with a magnitude of 3.6. The high signal-to-noise ratio (SNR) of the data has facilitated an in-depth investigation into its focal mechanism. We have determined the relative arrival time between the sS and S phases in the tangential component, which is approximately 15 seconds. This measurement, in conjunction with the previous Martian crustal model, has led to an estimated depth of 30 km for the marsquake. This depth was held constant throughout our subsequent focal mechanism analysis. To characterize the source of the marsquake, we utilized a double-couple focal mechanism model and calculated synthetic waveforms using the FK method. The focal mechanism was constrained by three components of the S wave and the vertical P wave. Our preferred focal mechanism is a thrust mechanism. Notably, non-extensional focal mechanisms are also included among our top 200 focal mechanisms. The consistency between our preferred focal mechanism and the older compressional structures near Hesperia Planum suggests that the region may have experienced marsquakes at present. This finding implies that the seismic activity on Mars is more active than previously thought.
How to cite: Hao, J., Li, Q., Xiao, Z., and Li, J.: The focal mechanism of Marsquake s1197a near Hesperia Planum, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15813, https://doi.org/10.5194/egusphere-egu25-15813, 2025.
The deployment of the seismometer on Mars has recorded thousands of marsquakes. Accurately locating these events is crucial for understanding Mars' internal structure and geological evolution. With only a single station, determining the location, especially the accurate back-azimuth, is more challenging than on Earth. Deep learning, being data-driven, can learn patterns of complex noise that are difficult for traditional methods to model, making it promising for improving back-azimuth estimation of marsquakes. However, challenges arise when applying deep learning to estimate marsquake polarization due to the limited quantity and low quality of the data. In this study, we assumed the background noise remains relatively stable around the P-wave arrivals and trained a deep learning model to learn noise patterns preceding marsquakes. Then we combined the trained model with Sliding Window Inference and Featured-Training (SWIFT) to handle the high uncertainty in P phase picking to predict polarizations of low frequency family marsquakes. As a result, we have further improved the localization of marsquakes by relocating 56 events, including 7 Quality C events with epicentral distances over 90°. For two Martian impact events with ground-truth locations, S1000a and S1094b, our deviations are only ~5° and ~3°. Our results reveal a new clustered seismicity zone around compressional structures in Hesperia Planum, including 7marsquakes with magnitudes from 2.5 to 3.6. Marsquakes are also widely distributed along the northern lowlands, dichotomy boundary, and higher latitude southern highlands, suggesting a globally distributed character. Our renewed marsquake location brings new insight to the tectonic interpretation of marsquakes.
How to cite: Li, Q., Xiao, Z., Hao, J., and Li, J.: Global Distribution of Low Frequency Family Marsquakes From Deep Learning-Based Polarization Estimation , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5680, https://doi.org/10.5194/egusphere-egu25-5680, 2025.
Satellite gravimetry data from Mars offers a unique glimpse into the planet's interior structure. Combined with topography data of the planet's surface, measurements of the gravitational field can be used to probe the lateral density variations in the planet's upper layers. Due to inherent degeneracies between the effects of density anomalies in the mantle and the crust on gravity, and incomplete isostasy models, previous efforts for global gravity inversion to decouple the two planetary layers were unsuccessful. This study aims to aid these inversion efforts by providing constraining information about the scale and magnitude of the lateral density fluctuations. In this simulation-based approach, a two-layer planetary model is applied and the Matérn covariance function is used to simulate physically viable density distributions. The simulations are used as an input to an inference method applying Normalising Flow neural networks to infer which Matérn parameters closest align with real observations. The results can provide constraints for future inversion attempts and inform us about the sensitivity of gravimetry data to the subsurface densities.
How to cite: Rakoczi, H., Root, B., Messenger, C., and Hammond, G.: Application of Satellite Gravimetry and AI to Map the Density Distributions of Mars’s Upper Layers, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20213, https://doi.org/10.5194/egusphere-egu25-20213, 2025.
Several orbiters and landers at Mars have allowed to unravel valuable knowledge about its surface and interior. Tracking of the satellites MGS, MRO, and Odyssey have provided us with detailed knowledge about the gravitational field of Mars, revealing the presence of subsurface structures in crust and mantle. With the InSight mission, seismic waves have indicated the presence of more frequent Marsquakes than assumed before the mission. This raises questions regarding the planet's formation and why Mars is more geologically active than was expected. Another important milestone in studying the interior of Mars is not only the recovery of static gravity field models but addition the seasonal variations, providing information on the periodic behavior of the polar ice caps. With the longer time-period of gravity variation could the secular time varying gravity field be linked to the solid deformation of the planet?
In this study, we focus on a new method for estimating the secular variations of Mars' gravity field using available Deep Space Network (DSN) tracking data with an open-source orbit estimation tool called TUDAT (TU Delft Astrodynamics Toolbox). We have constructed an orbit simulation, including realistic environmental models like the Mars-DTM atmosphere model, that has an orbital accuracy within 2 meters of SPICE kernels.
With this orbital simulator, we conduct sensitivity analyses to study the decoupling of secular gravity variations from other disturbing acceleration signals. These analyses incorporate all relevant dynamic forces acting on the satellite. We perform covariance analysis for various estimation parameters, including the satellite's initial state, atmospheric drag, static, periodic, as well as global versus arc-wise secular gravity coefficients.
By evaluating the formal errors of the estimated parameters and the correlations between them, we aim to identify scenarios where we can effectively separate the atmospheric signal from the gravitational changes of solid Mars. This investigation will contribute to addressing the unresolved question of Martian interior activity.
How to cite: Alkahal, R. and Root, B.: Satellite gravity-rate observations to uncover Martian plume-lithosphere dynamics, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16183, https://doi.org/10.5194/egusphere-egu25-16183, 2025.
Introduction: To accommodate all the payloads onboard MRO and mitigate electromagnetic interferences with the other spacecraft payloads, the SHARAD’s antenna was installed on the zenith deck of the spacecraft bus — on the opposite side of MRO relative to the Martian surface. This configuration causes the SHARAD antenna to be affected by the conductive structure of the solar arrays, leading to a reduction of the signal strength received at the nadir [1]. Modest roll maneuvers (up to 28°) have regularly been executed to compensate for the sub-optimal antenna placement thereby enhancing the signal-to-noise ratio (SNR) of SHARAD surface returns by several decibels [2].
SHARAD Very-Large Rolls Observations: Recent EM simulations of the spacecraft effects on the antenna pattern [3] reveal larger roll angles up to 120°, which could yield SNR improvements of up to 10 dB. Following these findings, the MRO Project and SHARAD team planned a series of very-large-roll (VLR) maneuvers during eclipse periods to minimize ionospheric interference while managing energy and instrument constraints. The first test in May 2023, targeting the sedimentary deposits of Eumenides Dorsum in Medusae Fossae (ID 7858301), confirmed the modeling predictions. The radargram revealed significant improvements in SNR and penetration capabilities compared to standard roll observations (0° or 28°). The VLR technique facilitated a clearer identification of the basal interface at ~800 m depth, where sedimentary deposits typically exhibited high radar transparency (i.e., low-loss tangent). Additional tests were performed at the polar deposits and mid-latitude targets including ground ice, sediments, and volcanics in Arcadia, Amazonis, and Elysium Planitiae.
Super-Resolution Techniques Applied to VLR Observations: To further maximize the scientific value of VLR observations, we applied advanced signal processing algorithms properly designed to enhance the range resolution of sounder data [4,5]. Comparative analyses of radargrams acquired at 0° and 120° roll angles highlight the remarkable improvement in signal clarity and depth achieved when VLR maneuvers are combined with super-resolution techniques. At this conference, we will present quantitative assessments of SNR gains of VLR products versus standard products, demonstrating the superior performance of super-resolution algorithms when applied to VLR data. All these efforts aim to enhance radargram product quality and to refine the understanding of sedimentary and glacial terrains on Mars, which are of high scientific interest to the SHARAD community. While opportunities for VLR observations remain limited due to the operational complexity of these large maneuvers, planned observations over mid-latitude and polar terrains will offer further opportunities to exploit advanced signal processing algorithms [6,7] and improve clutter discrimination [8].
Acknowledgments: This work was supported by ASI contract 2023-9-HH.0 – CUP: F83C23000120005.
References: [1] Croci et al. (2007), 4th International Workshop on, Advanced Ground Penetrating Radar, pp. 241-245. [2] Campbell et al (2021), Icarus, 10.1016/j.icarus.2021.114358; [3] DiCarlofelice et al. (2024), Icarus, 10.1016/j.icarus.2023.115802. [4] Raguso et al. (2018), 5th IEEE MetroAeroSpace, pp. 242-246, 10.1109/MetroAeroSpace.2018.8453529. [5] Raguso et al. (2024), Icarus, 10.1016/j.icarus.2023.115803. [6] Pastina et al. (2003), Signal Processing, 83(8), pp.1737-1748, 10.1016/S0165-1684(03)00072-0. [7] Pastina et al. (2007), IEEE TGRS, 45 (11), 10.1109/TGRS.2007.905309. [8] Raguso et al. (2022), IEEE GRSL, pp. 1-5, 10.1109/LGRS.2022.3223882.
How to cite: Raguso, M., Mastrogiuseppe, M., Lombardo, P., and Pastina, D.: Enhancing SHARAD Subsurface Imaging on Mars through a combination of Very-Large Roll (VLR) Maneuvers and Super-Resolution Techniques., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20114, https://doi.org/10.5194/egusphere-egu25-20114, 2025.
The ExoMars Rosalind Franklin Rover exobiology mission is now scheduled for launch in 2028 to search for traces of past or present life in the shallow subsurface of Oxia Planum. The rover is equipped with a drill that can take samples down to 2m, where organic molecules and possible biosignatures are likely to be preserved. The WISDOM GPR has been designed specifically for the objectives of the ExoMars mission. It will provide scans of the Martian subsurface down to a few meters, which, together with the other rover instruments, will help to understand the geological context of the landing site.
Rover-based GPR systems typically use antennas mounted at some distance from the ground. Over the large signal bandwidth, this fixed antenna-to-ground distance varies from a fraction of a wavelength to several wavelengths and can cause strong frequency-dependent coupling with the rover structure. Even with careful instrument design, additional coupling in the receiver chain cannot be avoided. These types of coupling, as well as the frequency-dependent main lobe response of the antenna, depend on the environment in which the rover is located (e.g. the dielectric properties of the ground), so that existing pre-calibrations of the radar system, e.g. in the laboratory, are of limited validity.
The algorithms we developed for data processing and system calibration can help to analyze and mitigate frequency-dependent coupling effects, separate the instrument transfer function and increase resolution, and thus improve the interpretation of surface and subsurface echoes. They will eventually be implemented in the pipeline that will be used to calibrate and interpret Martian data.
The proposed signal and data processing algorithms are validated on simulated data, on data collected during indoor measurement campaigns and on data collected during field tests. This paper focuses on the application of data processing algorithms to data collected during a field campaign in glacier and permafrost regions on Svalbard.
How to cite: Plettemeier, D., Laabs, M., Lu, Y., Benedix, W.-S., Zakutin, E., Geißler, F., Ciarletti, V., Legall, A., and Brighi, E.: WISDOM GPR calibration and data processing methods applied to field test data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9766, https://doi.org/10.5194/egusphere-egu25-9766, 2025.
NOMAD [1] (Nadir and Occultation for MArs Discovery) is a multi-channel spectrometer onboard the ExoMars 2016 Trace Gas Orbiter (TGO), operating from Martian orbit since April 2018. Among other two, the Solar Occultation (SO) channel covers the infrared (IR) spectrum from 2.3 to 4.3 µm (2320 to 4350 cm−1). The design of NOMAD SO allows for a vertical sampling of typically 1 km. Its high spectral resolution (λ/∆λ∼17000) and its relatively high signal to noise ratio (∼2500), make this instrument suitable for the detection of trace species in the Martin atmosphere such as water vapor (H2O) or hydrogen chloride (HCl).
Here we present vertical profiles of H2O and HCl obtained during six continuous Earth years of NOMAD SO observations. The retrievals have been performed with an inversion scheme combining pairs of diffraction orders in the case of water vapor, following up and improving several previous studies [2]. In the case of HCl, we used multiple detector bins, retrieving an independent vertical profile form each bin in order to obtain robust detection of this species. This set up allowed us sounding water vapor up to about 120 km altitude and HCl up to 60 km. This study presents the most extended data set of water vapor measurements from the NOMAD instrument to date, and an ambitious data set of HCl observations. Covering three full and consecutive Martian Years, observations from April 2018 to December 2023 were analyzed, making a total of more than 7000 H2O and more than 2500 HCl vertical profiles ranging from the perihelion of Mars Year (MY) 34 to the aphelion of MY 37. We show consistent seasonal and latitudinal water vapor patterns, with H2O systematically being more vertically extended during the perihelion season than during the aphelion. In addition, we present an analysis of the water vapor local time variability, confirming overall larger abundances during the evenings than during mornings, and an extensive comparison of our NOMAD results with other water vapor data sets from TGO and with the Mars Planetary Climate Model (MPCM), applying clustering analysis techniques to water vapor vertical profiles for the first time on Mars. Regarding HCl, although until now considered to be a negligible compound in the Martian atmosphere [3, 4], it has been detected systematically by two instruments onboard TGO: the Atmospheric Chemistry Suite (ACS) [5] and more recently NOMAD [6]. Here we present the latest HCl vertical profiles and the seasonal variability of this species from a climatological point of view, revealing possible links with water vapor and dust.
References:
[1] Vandaele, A. C. et al. 2018, Space Science Reviews 214, 1–47. https://doi.org/10.1007/s11214-018-0517-2
[2] Brines, A. et al. 2023, Journal of Geophysical Research: Planets 128, e2022JE007273. https://doi.org/10.1029/2022JE007273
[3] Hartogh, P et al. 2010, Astronomy & Astrophysics 521, L49. https://doi.org/10.1051/0004-6361/201015160
[4] Villanueva, G. et al. 2013, Icarus 223, 11–27. https://doi.org/10.1016/j.icarus.2012.11.013
[5] Korablev, O. et al. 2021, Science Advances 7, eabe4386. https://doi.org/10.1126/sciadv.abe4386
[6] Aoki, S. et al. 2021, Geophysical Research Letters 48, e2021GL092506. https://doi.org/10.1029/2021GL092506
How to cite: Brines, A., Lopez-Valverde, M. A., González-Galindo, F., Funke, B., Gamonal, M. A., Modak, A., Lopez-Moreno, J. J., Sanz-Mesa, R., Aoki, S., Vandaele, A. C., Daerden, F., Thomas, I., Erwin, J., Trompet, L., Villanueva, G., Liuzzi, G., Patel, M., and Bellucci, G.: Water Vapor and HCl Vertical Distribution in Mars as Measured by TGO/NOMAD Solar Occultations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11667, https://doi.org/10.5194/egusphere-egu25-11667, 2025.
Linear instability analyses are performed to investigate the influence of solar wind parameters on instabilities driven by a cool pickup ion beam distribution, which is believed to excite the proton cyclotron waves upstream of Mars. Our analysis reveals that both parallel and oblique waves are excited, with parallel waves showing right-hand polarization and oblique waves exhibiting quasi-perpendicular, quasi-electrostatic characteristics at higher solar wind velocities. The growth rates of both wave types increase with solar wind velocity, while solar wind temperature primarily enhances oblique wave growth, leaving parallel waves unaffected. Quasi-linear theory indicates that parallel waves induce pitch-angle scattering of pickup ions, amplifying wave energy, while oblique waves increase the ion's perpendicular velocity, converting wave energy into ion kinetic energy. These findings advance our understanding of wave-particle interactions and their role in atmospheric escape at Mars.
How to cite: Cheng, K., Shen, C., and Liu, K.: Influence of solar wind parameters on pickup ion beam instabilities upstream of Mars: Linear analysis, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9007, https://doi.org/10.5194/egusphere-egu25-9007, 2025.
The molecular dication, CO2++, was detected in the ionosphere of Mars by the Neutral Gas and Ion Mass Spectrometer (NGIMS) on the Mars Atmosphere and Volatile Evolution (MAVEN) mission [1]. This marked the first detection of a molecular dication in a planetary atmosphere. Results from photochemical models were compared with the observations with the modeled densities being significantly lower than the densities inferred from the observations. Here we show that a much better agreement between model results and observations is obtained when incorporating in the model the assumption that the ion is stable against unimolecular decay. We argue that this assumption not necessarily conflict with results from a storage ring experiment by Mathur et al. (1995) [Ref. 2]. Several modeling studies that cite [2] use a CO2++ lifetime against unimolecular decay of 4 s. This is, however, only a lower limit of the lifetime in question as the removal of the ions in the storage ring may have been strongly dominated by high energy collisions with residual gases. An experiment at a facility offering better (or variable) vacuum conditions could possible constraint the stability/longevity of CO2++.
[1] Gu, H., Cui, J., Niu, D. D., et al. 2020, E&PP, 4, 396
[2] Mathur, D., Andersen, L. H., Hvelplund, P., Kella, D., & Safvan, C. P. 1995, J Phys B At Mol Opt Phys, 28, 3415
How to cite: Cheng, L., Vigren, E., Persson, M., Gu, H., and Cui, J.: Insights from model-observation comparisons of CO2++ concentrations in the Martian Ionopshere, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9054, https://doi.org/10.5194/egusphere-egu25-9054, 2025.
Due to the absence of an Earth-like dipole magnetic field, the impact of coronal mass ejections (CMEs) on the Martian nightside ionosphere differs from that on Earth and is still not well understood. This study investigates the responses in the Martian nightside ionosphere to a CME event occurred on August 30, 2022 using observations from Tianwen-1 and MAVEN. It is found that the ion density in the upper Martian nightside ionosphere between 200 and 500 km decreases when two successive CMEs hit the induced Martian magnetosphere, with a brief density recovery between the two CMEs. This suggests that the ion density in the Martian nightside ionosphere between 200 and 500 km decreases as the intensity of CME increases. The primary cause of the observed decrease in the nightside ion density is likely due to the enhanced magnetic field pressure above the Martian ionosphere during CMEs, which facilitates ion escape from the dayside ionosphere and subsequently reduces the amount of ions transported to the nightside ionosphere, thereby leading to a decrease in ion density on nightside. Furthermore, hemispheric asymmetry is found in the ionospheric response, which indicates that the crustal magnetic fields in the southern hemisphere may play a role in slowing down the reduction of ion density. This study expands the comprehensive description of the impact of a CME event on different regions of Mars and its underlying mechanisms.
How to cite: Liu, L., Qiu, X., Yu, Y., Luo, W., Wang, X., Cao, J., Li, C., Wang, Y., and Zhang, T.: Revealing the CME Impact on the Martian Nightside Ionosphere Based on MAVEN and Tianwen-1 Observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5823, https://doi.org/10.5194/egusphere-egu25-5823, 2025.
The idea of using balloons for planetary surface and atmospheric exploration has been under discussion for many years. Balloons could complement missions of orbiters, landers, and rovers, and enable unique atmospheric or remote sensing investigations with various payloads. Our study deals with the flight behaviour of planetary balloons over the surface of Mars. We studied trajectories for different types of balloons in terms of size, shape and materials starting from different launch points at various diurnal/seasonal launch times. The motion of a balloon is determined by a system of differential equations (Palumbo, 2008), which we solved numerically. The atmospheric parameters applicable to the current location, such as wind speed, temperature and air density, are queried from the Mars Climate Database (Forget et al., 1999; Millour et al., 2022) and used to calculate the gross inflation and the drag (Farley, 2005). At the conference we will present general flight characteristics of various balloon types and different mission scenarios. The results are presented graphically and numerically. In further work, we will consider different properties of carrier gas and related permeability of the balloon’s skin. In addition, we aim at maximizing science opportunities and finding optimal composition of the variables with the help of an optimisation or machine learning algorithm.
References:
Farley, R. (2005, September 26). BalloonAscent: 3-D Simulation Tool for the Ascent and Float of High-Altitude Balloons. AIAA 5th ATIO And16th Lighter-Than-Air Sys Tech. and Balloon Systems Conferences. AIAA 5th ATIO and16th Lighter-Than-Air Sys Tech. and Balloon Systems Conferences, Arlington, Virginia. https://doi.org/10.2514/6.2005-7412
Forget, F., Hourdin, F., Fournier, R., Hourdin, C., Talagrand, O., Collins, M., Lewis, S. R., Read, P. L., & Huot, J. (1999). Improved general circulation models of the Martian atmosphere from the surface to above 80 km. Journal of Geophysical Research: Planets, 104(E10), 24155–24175. https://doi.org/10.1029/1999JE001025
Millour, E., Forget, F., Spiga, A., Pierron, T., Bierjon, A., Montabone, L., Vals, M., Lefèvre, F., Chaufray, J.-Y., Lopez-Valverde, M., Gonzalez-Galindo, F., Lewis, S., Read, P., Desjean, M.-C., Cipriani, F., & MCD Team. (2022, September 23). The Mars Climate Database (Version 6.1). https://doi.org/10.5194/epsc2022-786
Palumbo, R. (2008). A simulation model for trajectory forecast, performance analysis and aerospace mission planning with high altitude zero pressure balloons [Application/pdf]. https://doi.org/10.6092/UNINA/FEDOA/1839
How to cite: Nöding, F., Ziese, R., and Oberst, J.: Analysis of Balloon Missions and Flight Trajectories on Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17677, https://doi.org/10.5194/egusphere-egu25-17677, 2025.
For ten days, a post-mining heap from the coal mine in Bytom was transformed into an analog space base. This place became a hub of scientific activity as young researchers from the Scientific Club of Geophysics at the University of Warsaw embarked on an innovative project to simulate Martian conditions. The mission, named RAF-Analog Space Mission, aimed to replicate space conditions, test behaviors and principles applicable in outer space, and conduct essential scientific research.
The mission team comprised three students: Natalia Godlewska, an astronomy student and co-leader of the project; Norbert Nieścior, a physics student; and Piotr Lorek, a student of biotechnology and medical chemistry. These "astronauts" spent ten days living and working in a specially designed analog space base on the heap. The mission's primary objective was to conduct various scientific studies, including geophysical, geological, psychological, and astrobiological research.
The central phase of the project involved setting up a mobile base composed of a camper (serving as the living quarters) and a delivery van (serving as the scientific laboratory), connected by an airlock. This setup, located on approximately 30 square meters, provided a controlled environment simulating Martian conditions. The participants followed strict protocols, leaving the base only in space suits to maintain the illusion of being on Mars.
Analog space bases are terrestrial simulations of space conditions—in this case, Martian conditions. Analog astronauts strive to live and operate under space-like rules and constraints. The base allowed the team to experience and adapt to the challenges of life on Mars.
How to cite: Godlewska, N., Zawadzki, M., Nieścior, N., Kaczorowski, F., and Lorek, P.: RAF - Analog Space Mission - The first analog space base on mining heaps, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9427, https://doi.org/10.5194/egusphere-egu25-9427, 2025.
The Tumbleweed mission is a swarm-based mission using a large set of wind-driven spheroidal rovers, providing large spatio-temporal datasets on the Martian surface. Development of the scientific use-cases requires proof of feasibility on the Tumbleweed rover and simultaneously of individual instruments aboard it. Although several prototypes have been developed to some success, the ability of the Tumbleweed Rovers to produce environmental data both statically and dynamically, and, more importantly, both conjointly, needs to be proven.
Over the last few months we have been developing a reusable platform that enables the proposed suite of instruments to be tested on the so-called ‘Tumbleweed Science Testbed’. The testbed is a sub-scale rover prototype, equipped with a cuboid payload bay which provides modular interfaces to a variety of COTS and bespoke payloads. In addition to the payload bay, modestly sized sensors can also be incorporated on the structure, providing opportunities for contact-based measurements and vertical profiling relevant for atmospheric sciences.
The science testbed is a 2.7-meter-diameter prototype Tumbleweed rover equipped with a 1U-capacity payload bay. Phase 1 of development focuses on integrating simple, chip-based instruments and plug-and-play sensors with a commercially available single-board computer. For this first iteration, ten sensors have been integrated and subjected to functional tests. In accordance with the science objectives of the Martian Tumbleweed mission, these include a wind sensor, magnetometer, camera, temperature & humidity sensor, pressure sensor, dust/particle sensor, and gas sensor. These instruments will be tested on the mobile science testbed in the Netherlands to understand the influence of Tumbleweed rover dynamics on instrument collection and processing. The testbed will enable evaluation of operational strategies of the tumbling rover as well as the various sensors on-board. Subsequently, the testbed will be used for systematic evaluation of navigation, data compression, noise removal and communication algorithms which are currently under development.
Success criteria of this test includes the following:
- The payload remains stable and successfully stabilises the rover while the overall structure remains intact.
- Data collection from all instruments is achieved for the entirety of the test run and while idle.
- Detailed observation and characterization of the rover’s tumbling dynamics.
The next phase of development of the science testbed will involve the integration of more sophisticated, custom-built instruments such as a radiation spectrometer, soil-permittivity sensor, electric field sensor and hand-lens imager.
Subsequently, the testbed will be used in Mars analog environments to test and develop novel, miniaturized payloads for swarm-based mission architectures. The testbed will be expanded with the addition of identical rovers, to simulate collaborative exploration and the execution of collocated measurements on Mars-like terrain.
How to cite: Kingsnorth, J., Pikulić, L., Shanbhag, A., de Pinto Balsemão, M., Moisuc, C., Bounova, G., Molhuijsen, D., Ilegitim, S., Osman, A., Placke, B., and Rothenbuchner, J.: The Tumbleweed Science Testbed: Rolling Out Theory into Action, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18773, https://doi.org/10.5194/egusphere-egu25-18773, 2025.
