Near-Earth rubble-pile asteroids Bennu and Ryugu are part of the carbonaceous taxonomic complex (C-complex), and samples returned from both bodies resemble the most aqueously altered carbonaceous chondrites. However, telescopic and spacecraft visible-near infrared (VIS-NIR) reflectance spectra of Ryugu exhibit a red (positive) spectral slope, whereas Bennu has a blue (negative) spectral slope characteristic of the rare B-type subclass of asteroids. The asteroid spectra also suggest different levels of hydration, with Ryugu dominated by OH and Bennu containing spectral evidence of more H2O. To understand what causes these differences, we acquired VIS-NIR reflectance data (similar to 0.3-5 mu m) from a variety of Bennu samples over spatial scales of 100 mu m to several millimeters. No single sample reproduces the average spectral properties of Bennu, but by evaluating samples of different petrology and physical states-groups of particles, isolated particles, and larger stones-we demonstrate that primary composition, and highly hydrated Mg-rich phosphate in particular, plays a strong role in controlling the spectral slope and average hydration absorption strength of Bennu materials. Bennu and Ryugu may be dominated by different lithologies originating from different regions of a common planetesimal, thus explaining their different spectral evolution. The spectral characteristics of B-type asteroids, particularly those with blue slopes at near-infrared wavelengths and broad hydration features at similar to 3 mu m, may indicate the presence of Mg phosphate and thus a history of complex fluid-rock interactions relevant to prebiotic chemistry.

Visible-to-shortwave infrared (VSWIR) reflectance spectroscopy has revolutionized our understanding of planetary surface compositions. However, space-weathering processes on airless bodies complicate quantitative compositional analyses. Here, we present a framework to isolate the signatures of space weathering in VSWIR spectra of lunar maria by leveraging radiative transfer modeling under the assumptions that (i) a space-weathered target can be expressed as a mixture of fresh and fully space-weathered components and (ii) remaining signatures can be modeled by including agglutinates as an end-member component. We first validate this approach against laboratory spectra of space-weathered Apollo mare soils of known mineral compositions using a probabilistic Markov Chain Monte Carlo implementation of the Hapke radiative transfer model. Second, we illustrate how this approach can be applied to orbital Moon Mineralogy Mapper data. The proposed space-weathering correction workflow for lunar maria could be expanded to other lunar lithologies and applied to existing and future data sets.

The NASA MESSENGER mission revealed that lavas on Mercury are enriched in sulfur (1.5-4 wt%) compared with other terrestrial planets (<0.1 wt%) due to high S solubility in silicate melt under its very low oxygen fugacity (& fnof;O-2). However, the speciation of that S remains poorly constrained. In this study, we evaluate the role of pressure, temperature, and melt composition on S solubility and speciation in reduced magmas relevant to Mercury. Sulfur speciation was determined by S K-edge XANES spectra collected in 60 experiments that span a range of pressure (0.1 to 5 GPa), temperature (1225 to 1850 degrees C), and & fnof;O-2 (IW-0.8 to IW-8.6). Data were analysed using new relevant XANES standards and XANES spectral unmixing techniques. Stepwise forward regression was used to develop empirical equations for S species (MgS, CaS, and TiS). We found that fO(2), P/T, and S content in the silicate melt at sulfide saturation (SCSS) exert the main controls on MgS content (wt.%) in the silicate melt, and that fO(2) and MgS content in the silicate melt exert the main controls on SCSS. MgS(liq)wt.%=a+(bP)(T)+clogfO(2)+d[Swt.%](SCSS )(1) We find that as & fnof;O-2 decreases from IW-2 to IW-7, S speciation in silicate melt goes through two major changes. Between IW-2 and IW-4, FeS and FeCr2S4 species are destabilized, and CaS becomes the dominant S species with minor TiS. Below IW-4, MgS is the dominant S species with minor CaS. At low fO(2), S bonding with Fe, Mg, Ca, Ti, Na, and Mn affect the activities of SiO2, MgO, CaO, TiO, Na2O, and MnO in the silicate melt. This stabilizes enstatite at the expense of forsterite, destabilizes the Ca-bearing minerals plagioclase and clinopyroxene, and shifts plagioclase chemistry from the Ca-rich endmember anorthite to the Na-rich endmember albite as understand by reprojecting silicate ternary diagrams incorporating S speciation data. At the expense of MgS, CaS is more stable in the silicate melt at higher pressures at fO(2) below IW-4 creating a pathway for CaS to be carried in the silicate melt from depth to the surface before oldhamite (CaS) crystallization. These S speciation changes have substantial impacts on physicochemical properties of silicate melt such as viscosity, melting temperature, and mineral stability, which led to the distinct evolution of Mercury and other reduced planetary interiors.

The cause of Mars’s loss of surface habitability is unclear, with isotopic data suggesting a ‘missing sink’ of carbonate 1 . Past climates with surface and shallow-subsurface liquid water are recorded by Mars’s sedimentary rocks, including strata in the approximately 4-km-thick record at Gale Crater 2 . Those waters were intermittent, spatially patchy and discontinuous, and continued remarkably late in Mars’s history 3 —attributes that can be understood if, as on Earth, sedimentary-rock formation sequestered carbon dioxide as abundant carbonate (recently confirmed in situ at Gale 4 ). Here we show that a negative feedback among solar luminosity, liquid water and carbonate formation can explain the existence of intermittent Martian oases. In our model, increasing solar luminosity promoted the stability of liquid water, which in turn formed carbonate, reduced the partial pressure of atmospheric carbon dioxide and limited liquid water 5 . Chaotic orbital forcing modulated wet–dry cycles. The negative feedback restricted liquid water to oases and Mars self-regulated as a desert planet. We model snowmelt as the water source, but the feedback can also work with groundwater as the water source. Model output suggests that Gale faithfully records the expected primary episodes of liquid water stability in the surface and near-surface environment. Eventually, atmospheric thickness approaches water’s triple point, curtailing the sustained stability of liquid water and thus habitability in the surface environment. We assume that the carbonate content found at Gale is representative, and as a result we present a testable idea rather than definitive evidence.

RationaleExtraterrestrial amines and ammonia are critical ingredients for the formation of astrobiologically important compounds such as amino acids and nucleobases. However, conventional methods for analyzing the composition and isotopic ratios of volatile amines suffer from lengthy derivatization and purification procedures, high sample mass consumption, and chromatographic interferences from derivatization reagents and non-target compounds.MethodsHere we demonstrate a highly efficient method to analyze the composition and compound specific isotopic ratios of C1 to C6 amines as well as ammonia based on solid phase micro-extraction (SPME) on-fiber derivatization. 2,3,4,5,6-pentafluorobenzyl chloroformate (PFBCF) adsorbed on a solid phase SPME fiber is subsequently exposed to the headspace of the water extract of the Murchison meteorite to selectively extract, derivatize and concentrate volatile amines and ammonia. PFBCF does not directly contact the aqueous solution containing other soluble organics.ResultsAn aliquot of volatile amines and ammonia in the headspace are selectively derivatized on the SPME fiber and subsequently thermally desorbed onto the GC injector for analysis. Only the amounts of amines required for either compositional or isotopic analysis are derivatized and consumed in the process, preserving the bulk fraction of amines and ammonia for other analyses, and the process does not affect other volatile compound classes. Carbon and hydrogen isotopic ratios of amines are obtained by isotopic mass balance.ConclusionsThe exceptional selectivity and sensitivity of SPME on-fiber derivatization of volatile amines in carbonaceous chondrite extracts allow minimization of sample consumption. Carbon and hydrogen isotopic values of individual amines in the Murchison meteorite are consistent with their extraterrestrial origin, with a substantial fraction inherited from interstellar molecular clouds. SPME on-fiber derivatization is well suited for analyzing extraterrestrial materials, especially precious asteroid return samples.

CM carbonaceous chondrites are complex brecciated meteorites that exhibit significant chemical, mineralogic, and petrographic diversity both between and within individual samples. As most reflectance spectroscopy studies of carbonaceous chondrites are performed on bulk powders, important questions remain about the true spectral diversity of these complex breccias and the degree to which lab‐based meteorite spectra can be reliably related to remotely acquired spectra of primitive asteroids. The Aguas Zarcas meteorite is a unique CM chondrite in that it has been found to exhibit at least five chemically and isotopically distinct lithologies that are all associated with a single fall event. Here, we describe a coordinated petrographic and spectroscopic study to further investigate the thermochemical and collisional history of the Aguas Zarcas parent body and to better understand how to interpret remotely acquired spectra of primitive asteroids. Four intact sections of the Aguas Zarcas meteorite, which together represent at least three to four distinct lithologies, were analyzed using microscope FT‐IR (μFT‐IR) spectroscopy and electron probe microanalysis (EPMA) elemental mapping. Our study found significant variations in spectral features, particularly in the mid‐infrared (MIR) wavelength region, that can be linked to petrographic diversity between lithologies. The relative abundance of matrix phyllosilicates and pyroxene appears to have the strongest influence on the shape, position, and strength of MIR spectral features. Linear spectral unmixing models as a method for compositional interpretation showed varying accuracy when compared to EPMA‐based estimates, with integrated μFT‐IR spectral maps showing better results compared to unmixing of bulk (larger spot size) FT‐IR spectra. A notable discovery in two sections of the Aguas Zarcas meteorite was the presence of carbonate veins along the boundary of chemically and petrographically separate lithologies, which provide important constraints on the nature and timing of pre‐ and post‐brecciation aqueous alteration.

The scarcity of olivine-rich mantle material in meteorite collections and asteroid spectra, known as the "Missing Mantle Conundrum," challenges our understanding of planetesimal differentiation. Current models suggest that numerous planetesimals underwent melting and differentiation early in Solar System history, yet little evidence of olivine- and pyroxene-rich mantles is found. We explore the hypothesis that mantle material maybe present in the asteroid belt but is spectrally masked by dark, primitive carbonaceous chondrite material. To test this, we mixed laboratory analogs of CM and CV chondrite mantle compositions with natural CM2 and CV3 meteorites, examining how particle size and chondritic material abundance affect the detectability of diagnostic silicate absorption features. Visible-near infrared (VNIR) reflectance spectra demonstrate that even small amounts of carbonaceous material can suppress olivine and pyroxene absorption bands. The suppression of absorption features and spectral darkening is highly nonlinear, with this effect being most notable for the finer particles and the CM chondrites. At mantle abundances below 20 wt%, spectral features for all mixtures become virtually indistinguishable from those of the chondrite meteorites. Simulated noise levels typical of ground-based telescopic observations reveal that mantle material can be masked at even higher abundances, potentially obscuring similar to 30-65 wt% of mantle material. These findings suggest that significant amounts of olivine- and pyroxene-rich mantle material may be present in near-Earth and main-belt asteroids, currently classified as primitive bodies. Rubble pile asteroids, which are widespread, may be particularly susceptible to misinterpretation due to their complex regolith, where differentiated mantle material can be mixed with primitive, undifferentiated components. This mixing, which arises naturally through the Solar System's ongoing collisional evolution, complicates spectral interpretations and highlights the potential for underestimating the extent of differentiation in these bodies.

Chloride salt-bearing deposits are widely distributed across the southern highlands of Mars. Because chloride salts are highly water-soluble, these deposits may be representative of the last significant period of stable liquid water at the Martian surface. Therefore, these deposits are key to understanding the fate and evolution of surface waters on Mars. However, little consensus exists about the formation conditions of these deposits, and their origins remain enigmatic. This is due in part because remote spectroscopic detection and quantification of many anhydrous chlorides is hampered by a lack of easily discernible diagnostic absorption features. To address this issue, we present a novel Hapke radiative transfer model-based method to estimate hydration states and salt abundances of Martian chloride salt-bearing deposits using visible/near-infrared (VNIR) reflectance spectra. VNIR laboratory spectra are used to derive water abundances of analog chloride-bearing materials, establishing an experimental basis for application of these methods to Mars. These methods are then applied to orbital Compact Reconnaissance Imaging Spectrometer for Mars data to create maps of the hydration state and modeled salt abundance of chloride-bearing deposits. When overlain onto high resolution 3D digital terrain models, these methods produce the highest resolution site-specific salt abundance maps currently available, enhancing our understanding of chloride deposit geologic context. As an example, deposits in the Terra Sirenum region are observed to have higher estimated salt abundances than previously recognized, exhibiting spatial variations in both abundance and surface morphology.

On Mars, phyllosilicate ("clay") minerals are often associated with older terrains, and sulfate minerals are associated with younger terrains, and this dichotomy is taken as evidence that Mars' surface dried up over time. Therefore, in situ investigation of the Mount Sharp strata in Gale crater, which record a shift from dominantly clay -bearing to sulfate -bearing minerals, as seen in visible- near -infrared orbital reflectance spectra, is a key science objective for the Mars Science Laboratory (MSL) Curiosity rover mission. Here, we present regional (orbiter -based) and in situ (rover -based) evidence for a lowangle erosional unconformity that separates the lacustrine and marginal lacustrine deposits of the Carolyn Shoemaker formation from the dominantly eolian deposits of the lower Mirador formation within the orbitally defined clay -sulfate transition region. The upsection record of wetter (Carolyn Shoemaker formation) to drier (lower Mirador formation) depositional conditions is accompanied by distinct changes in diagenesis. Clay minerals occur preferentially within the Carolyn Shoemaker formation and are absent within the lower members of the Mirador formation. At and above the proposed unconformity, strata are characterized by an increase in diagenetic nodules enriched in X-ray amorphous Mg -sulfate. Early clay formation in the Carolyn Shoemaker formation may have created a hydraulic barrier such that later migrating magnesium- and sulfur -rich fluids accumulated preferentially within the lower members of the Mirador formation. The proposed unconformity may have also acted as a fluid conduit to further promote Mg -sulfate nodule formation at the Carolyn Shoemaker-Mirador formation boundary. These results confirm an association of the clay -sulfate transition with the drying of depositional environments, but they also suggest that at least some orbital sulfate signatures within the region are not time -congruent with the environmental signals extracted from primary sedimentology. Our findings highlight that complex interactions among primary depositional environment, erosion, and diagenesis contribute to the transition in clay -sulfate orbital signatures observed in the stratigraphy of Mount Sharp.

On 24 September 2023, the NASA OSIRIS-REx mission dropped a capsule to Earth containing approximately 120 g of pristine carbonaceous regolith from Bennu. We describe the delivery and initial allocation of this asteroid sample and introduce its bulk physical, chemical, and mineralogical properties from early analyses. The regolith is very dark overall, with higher-reflectance inclusions and particles interspersed. Particle sizes range from sub-micron dust to a stone about 3.5 cm long. Millimeter-scale and larger stones typically have hummocky or angular morphologies. A subset of the stones appears mottled by brighter material that occurs as veins and crusts. Hummocky stones have the lowest densities and mottled stones have the highest. Remote sensing of the surface of Bennu detected hydrated phyllosilicates, magnetite, organic compounds, carbonates, and scarce anhydrous silicates, all of which the sample confirms. We also find sulfides, presolar grains, and, less expectedly, Na-rich phosphates, as well as other trace phases. The sample composition and mineralogy indicate substantial aqueous alteration and resemble those of Ryugu and the most chemically primitive, low-petrologic-type carbonaceous chondrites. Nevertheless, we find distinct hydrogen, nitrogen, and oxygen isotopic compositions, and some of the material we analyzed is enriched in fluid-mobile elements. Our findings underscore the value of sample return, especially for low-density material that may not readily survive atmospheric entry, and lay the groundwork for more comprehensive analyses.

Accurate information regarding the surface composition is crucial for understanding the for-mation and evolution history of planetary bodies.Visible and near-infrared remote sensing spectroscopic techniques have long been used for the detection of surface composition.However,in the thermal in-frared spectral range,various types of planetary surface materials exhibit richer spectral features.With the development of thermal emission spectroscopic techniques,it has been increasingly used in planetary exploration.Particularly,in the ongoing and planned asteroid exploration missions,thermal emission spectrometers are employed as key payloads.In order to better interpret the thermal emission spectral data to be obtained in the future,it is essential to establish scientifically reasonable data processing and calibration schemes.This paper provides a comprehensive overview on the design of thermal emission spectral measurement devices for planetary science research,the measurement process,and data reduc-tion methods.To obtain accurate emissivity spectra data,the challenge of distinguishing sample radia-tion signals from instrument radiation during thermal emission measurements must be properly ad-dressed first.Especially,for measurements conducted under low-temperature and vacuum conditions that are similar to the surface conditions of the Moon and asteroids.This paper proposes and demonstrates a data reduction method based on interferograms,which are the original signals measured by FTIR spec-trometer.This method can effectively separate the actual radiation signal from the samples,thus yield-ing more accurate emissivity spectra data.The insights derived from this study can serve as valuable refe rences for the development and construction of thermal emission measurement devices and can facilitate the processing and scientific interpretation of data from future missions such as Tianwen-2.

Spectral variations due to the removal of surface adsorbed H2O at 3 and 6 mu m in reflectance spectra on lunar soils and relevant minerals (olivine, pyroxene, and plagioclase) have been assessed. This study characterizes variations in hydration features as a function of lunar relevant surface temperatures, to further understand current (i. e., M-3, HRI-IR, VIMS) and future (i.e., Lunar Trailblazer) observations of diurnal changes in surface hydration. Additionally, we explore the utility of using the 6 mu m H2O feature to discern the speciation of surface hydration at 3 mu m. We perform controlled temperature measurements (25-200 C-degrees) in a Linkam THMS600 Environmental Stage fixed to a Bruker LUMOS Microscope Fourier Transform IR (mu FTIR) spectrometer. We observe clear and systematic changes in the strength of the 3 mu m H2O/OH feature associated with the thermal removal of adsorbed H2O, in addition to changes in the overall shape and band position of the feature in both the terrestrial and lunar samples. The strength of the 3 mu m feature for the compositionally distinct and relatively brighter Apollo highland soil (62231) is stronger and more symmetric than the 3 mu m feature observed for the darker mare soil (10084). While several silicate related absorption features are identified near 6 mu m, neither a distinguishable hydration feature nor any changes in reflectance that could be attributed to the presence or a change in the amount of surface adsorbed H2O were observed at 6 mu m.

Introduction: Ryugu is a second-generation C-type asteroid formed by the reassembly of fragments of a previous larger body in the main belt. While the majority of Ryugu samples returned by Hayabusa2 are composed of a lithology dominated by aqueously altered minerals, clasts of a more pristine olivine-pyroxene lithology remain in the least-altered samples [1]. These clasts are objects of prime interest for revealing the composition of the original building blocks of Ryugu’s parent asteroid and of the dust from which they formed.We used infrared hyperspectral imaging to analyze four mm-sized sections of Ryugu samples extracted from Chamber A (A0026) and Chamber C (C0002, C0023, C0025). We compare the Ryugu IR spectra to observations of asteroids, comets, meteorites and interplanetary dust particles (IDPs), to study the potential links between the original building blocks of Ryugu’s parent asteroid and objects that retained dust from the outer Solar System.Methods: We used different FTIR microscopes at the SMIS beamline of synchrotron SOLEIL [2]: (1) a synchrotron-radiation-fed microscope equipped with a large mid-IR range MCT/B-detector, (2) a far-IR bolometer-equipped microscope, (3) an imaging microscope equipped with a 128×128 pixels focal plane array detector. For (1) and (2), different apertures were used from 5 to 100 µm. For (3), we used a field of view of ~420 µm and pixel size of 3.3 µm, and several IR tiles were accumulated in mosaic IR hyperspectral images, to analyze mm-sized areas in Ryugu stones. Complementary point-to-point micro-IR measurements were performed at Tohoku University (globar source), with spots of ~100-200 µm.Results and discussion: While a large fraction of the matrix of C0002 shows the 10-µm feature of phyllosilicates similar to aqueously altered chondrites, very different silicate spectral features are observed at some clasts detected by Nakamura et al. [1], because of the presence of anhydrous inclusions. Most of these inclusions have a double-peak structure, due to the intimate mixture of hydrated and anhydrous silicates, in particular olivine with a band at ~880 cm-1 (11.36 µm). Some of them show the signature of pure olivine, while others show a strong spectral contribution of pyroxene at ~1075 cm-1 (9.3 µm). A very few grains have a large spectral profile indicating a significant contribution of amorphous phases. Several olivine grains are also observed in C0023 and C0025, in the less-altered lithologies. These features are absent from A0026.In a principal component analysis, spectra of Ryugu samples, CI chondrites and hydrated IDPs reveal a pattern that correlates with increasing alteration, from the least altered clasts of Ryugu stones, to weakly altered Ryugu clasts, and then major (most altered) lithology of Ryugu, Alais, Tagish-Lake, Orgueil, and the hydrated IDPs.Some grains enriched in amorphous silicates discovered in C0002 have IR spectra similar to D-type asteroid Hektor (a Jupiter Trojan) [3], to comet Hale-Bopp [4], and to anhydrous chondritic porous IDPs of cometary origin [5]. They can be identified with anhydrous grains rich in GEMS (Glass with Embedded Metal and Sulfides) [1], which in turn are similar in texture and composition to the GEMS found in IDPs of probably cometary origin, formed in the protoplanetary disk.Conclusions: The amorphous-rich grains in C0002 are one of the most interesting reservoirs of anhydrous “cometary-like” dust found in Ryugu. Their IR spectra suggest a possible link between at least one of the reservoirs from which Ryugu’s parent asteroid originated and the reservoir that formed comets and D-type asteroids in the outer protoplanetary disk [6].Acknowledgments: This work is part of the multi-analytical sequence of the Hayabusa2 “Stone” MIN-PET group, led by T. Nakamura. It was supported by the Centre National d’Etudes Spatiales (CNES-France, Hayabusa2 mission) and by the ANR project LARCAS (Grant ANR-22-CE49-0009-01) of the French Agence Nationale de la Recherche. The micro-spectroscopy measurements were supported by grants from Region Ile-de-France (DIM-ACAV) and SOLEIL.References: [1] Nakamura T. et al. (2022). Science doi:10.1126/science.abn8671. [2] Rubino S. et al. (2023). Earth, Planets and Space 75. doi:10.1186/s40623-022-01762-8. [3] Emery J.P. et al. (2006). Icarus, 182, 496–512. [4] Crovisier J. et al. (1997) Science, 275, 1904. [5] Brunetto R. et al. (2011). Icarus, 212, 896–910. [6] Brunetto R. et al. (2023). ApJL, 951:L33. doi:10.3847/2041-8213/acdf5c.

The Curiosity rover explored the region between the orbitally defined phyllosilicate-bearing Glen Torridon trough and the overlying layered sulfate-bearing unit, called the "clay-sulfate transition region." Samples were drilled from the top of the fluviolacustrine Glasgow member of the Carolyn Shoemaker formation (CSf) to the eolian Contigo member of the Mirador formation (MIf) to assess in situ mineralogical changes with stratigraphic position. The Sample Analysis at Mars-Evolved Gas Analysis (SAM-EGA) instrument analyzed drilled samples within this region to constrain their volatile chemistry and mineralogy. Evolved H2O consistent with nontronite was present in samples drilled in the Glasgow and Mercou members of the CSf but was generally absent in stratigraphically higher samples. SO2 peaks consistent with Fe sulfate were detected in all samples, and SO2 evolutions consistent with Mg sulfate were observed in most samples. CO2 and CO evolutions were variable between samples and suggest contributions from adsorbed CO2, carbonates, simple organic salts, and instrument background. The lack of NO and O2 in the data suggest that oxychlorines and nitrates were absent or sparse, and evolved HCl was consistent with the presence of chlorides in all samples. The combined rover data sets suggest that sediments in the upper CSf and MIf may represent similar source material and were deposited in lacustrine and eolian environments, respectively. Rocks were subsequently altered in briny solutions with variable chemical compositions that resulted in the precipitation of sulfates, carbonates, and chlorides. The results suggest that the clay-sulfate transition records progressively drier surface depositional environments and saline diagenetic fluid, potentially impacting habitability.

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Accurate interpretation of the martian sedimentary rock record-and by extension that planet's paleoenvironmental history and potential habitability-relies heavily on rover-based acquisition of textural and compositional data and researchers to properly interpret those data. However, the degree to which this type of remotely sensed information can be unambiguously resolved and accurately linked to geological processes in ancient sedimentary systems warrants further study. In this study, we characterize Mars-relevant siliciclastic-evaporite samples by traditional laboratory-based geological methods (thin section petrography, X-ray diffraction [XRD], backscattered electron imaging, microprobe chemical analyses) and remote sensing methods relevant to martian rover payloads (visible-near-mid infrared reflectance spectroscopy, X-ray fluorescence mapping, XRD). We assess each method's ability to resolve primary and secondary sedimentologic features necessary for the accurate interpretation of paleoenvironmental processes. While the most dominant textures and associated compositions (i.e., bedded gypsum evaporite) of the sample suite are readily identified by a combination of remote sensing techniques, equally important, although more subtle, components (i.e., interbedded windblown silt, meniscus cements) are not resolved unambiguously in bulk samples. However, rover-based techniques capable of coordinating spatially resolved compositional measurements with textural imaging reveal important features not readily detected using traditional assessments (i.e., subtle clay-organic associations, microscale diagenetic nodules). Our findings demonstrate the improved generational capacity of rovers to explore ancient sedimentary environments on Mars while also highlighting the complexities in extracting comprehensive paleoenvironmental information when limited to currently available rover-based techniques. Complete and accurate interpretation of ancient martian sedimentary environments, and by extension the habitability of those environments, likely requires sample return or in situ human exploration.