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Although Mars today does not have a core dynamo, magnetizations in the Martian crust and in meteorites suggest a magnetic field was present prior to 3.7 billion years (Ga) ago. However, the lack of ancient, oriented Martian bedrock samples available on Earth has prevented accurate estimates of the dynamo's intensity, lifetime, and direction. Constraining the nature and lifetime of the dynamo are vital to understanding the evolution of the Martian interior and the potential habitability of the planet. The Perseverance rover, which is exploring Jezero crater, is providing an unprecedented opportunity to address this gap by acquiring absolutely oriented bedrock samples with estimated ages from ∼2.3 to >4.1 Ga. As a first step in establishing whether these samples could contain records of Martian paleomagnetism, it is important to determine their ferromagnetic mineralogy, the grain sizes of the phases, and the forms of any natural remanent magnetization. Here, we synthesize data from various Perseverance instruments to achieve those goals and discuss the implications for future laboratory paleomagnetic analyses. Using the rover's instrument payload, we find that cored samples likely contain iron oxides enriched in Cr and Ti. The relative proportions of Fe, Ti, and Cr indicate that the phases may be titanomagnetite or Fe‐Ti‐Cr spinels that are ferromagnetic at room temperature, but we cannot rule out the presence of non‐ferromagnetic ulvöspinel, ilmenite, and chromite due to signal mixing. Importantly, the inferred abundance of iron oxides in the samples suggests that even <1 mm‐sized samples will be easily measurable by present‐day magnetometers. Mars today does not have a magnetic field, but laboratory studies of Martian meteorites and spacecraft observations of the Martian crust indicate that Mars's metallic core once generated a magnetic field, known as a core dynamo. Although the dynamo seems to have been active prior to ∼3.7 billion years ago, its strength, direction and lifetime are largely unknown. Determining these characteristics is important for understanding the evolution of the Martian core and to test the theory that the magnetic field played a key role in making ancient Mars habitable. The Perseverance rover is providing a unique opportunity to answer these questions by acquiring bedrock samples that may span the full lifetime of the field. However, to establish whether these samples could tell us about the ancient dynamo, it is important to show they contain minerals with a special property known as ferromagnetism that allows them to record and retain records of the ancient magnetic field. Here, we present evidence the samples contain iron oxide minerals, many of which are known to be ferromagnetic. As such, we expect that future laboratory studies of these samples following their return to Earth will provide powerful constraints on the history of Mars's magnetic field. Iron oxides with titanium and chromium components are present in lithologies sampled by the Perseverance rover on MarsThese iron oxides may contain magnetizations from ancient Martian magnetic fieldsReturned samples of these lithologies will constrain the history and characteristics of the Martian dynamo Iron oxides with titanium and chromium components are present in lithologies sampled by the Perseverance rover on Mars These iron oxides may contain magnetizations from ancient Martian magnetic fields Returned samples of these lithologies will constrain the history and characteristics of the Martian dynamo

The Mars 2020 Perseverance rover has explored fluvio‐lacustrine sedimentary rocks within Jezero crater. Prior work showed that igneous crater floor Séítah and Máaz formations have mafic mineralogy with alteration phases that indicate multiple episodes of aqueous alteration. In this work, we extend the analyses of hydration to targets in the Jezero western fan delta, using data from the SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) Raman spectrometer. Spectral features, for example, sulfate and hydration peak positions and shapes, vary within, and across the crater floor and western fan. The proportion of targets with hydration associated with sulfates was approximately equal in the crater floor and the western fan. All hydrated targets in the crater floor and upper fan showed bimodal hydration peaks at ∼3,200 and ∼3,400 cm−1. The sulfate symmetric stretch at ∼1,000 cm−1coupled with a hydration peak at ∼3,400 cm−1indicate that MgSO4·nH2O (2 < n≤ 5) is a likely hydration carrier phase in all units, perhaps paired with low‐hydration (n≤ 1) amorphous Mg‐sulfates, indicated by the ∼3,200 cm−1peak. Low‐hydration MgSO4·nH2O (n= 1–2) are more prevalent in the fan, and hydrated targets in the fan front only had one peak at ∼3,400 cm−1. While anhydrite co‐occurs with hydrated Mg‐sulfates in the crater floor and fan front, hydrated Ca‐sulfates are observed instead at the top of the upper fan. Collectively, the data imply aqueous deposition of sediments with formation of salts from high ionic strength fluids and subsequent aridity to preserve the observed hydration states. The Mars 2020 Perseverance rover has explored a fan delta deposit in the Jezero crater where a lake was present in the past. In this work, we use the SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) Raman spectroscopy instrument on the rover to determine the minerals that contain water in the form of H2O and/or OH. These hydrated minerals are indicators of interactions of rock with water and inform us how the environmental conditions and the habitability of Jezero crater evolved over time. Hydrated Mg‐sulfates MgSO4·nH2O (2 < n≤ 5) are observed in both the crater floor and the western fan. Mg‐sulfates of lower hydration degree (n= 1–2) are more commonly found in the western fan, particularly the fan front. Hydrated Ca‐sulfate is found only close to the top of the fan. These changes in sulfate degree of hydration and/or cations from the floor to the fan are evidence of multiple past fluid events and chemistries at Jezero crater. MgSO4·nH2O (2 < n≤ 5) are found in the Jezero fan and floor while low‐hydration MgSO4·nH2O (n= 1–2) are more commonly found in the fanHydrated Ca‐sulfates are found only in the upper fanThe diverse phases imply salt formation from high ionic strength fluids and subsequent aridity to preserve the observed hydration states MgSO4·nH2O (2 < n≤ 5) are found in the Jezero fan and floor while low‐hydration MgSO4·nH2O (n= 1–2) are more commonly found in the fan Hydrated Ca‐sulfates are found only in the upper fan The diverse phases imply salt formation from high ionic strength fluids and subsequent aridity to preserve the observed hydration states

The first samples collected by the Perseverance rover on the Mars 2020 mission were from the Maaz formation, a lava plain that covers most of the floor of Jezero crater. Laboratory analysis of these samples back on Earth would provide important constraints on the petrologic history, aqueous processes, and timing of key events in Jezero crater. However, interpreting these samples requires a detailed understanding of the emplacement and modification history of the Maaz formation. Here we synthesize rover and orbital remote sensing data to link outcrop‐scale interpretations to the broader history of the crater, including Mastcam‐Z mosaics and multispectral images, SuperCam chemistry and reflectance point spectra, Radar Imager for Mars' subsurface eXperiment ground penetrating radar, and orbital hyperspectral reflectance and high‐resolution images. We show that the Maaz formation is composed of a series of distinct members corresponding to basaltic to basaltic‐andesite lava flows. The members exhibit variable spectral signatures dominated by high‐Ca pyroxene, Fe‐bearing feldspar, and hematite, which can be tied directly to igneous grains and altered matrix in abrasion patches. Spectral variations correlate with morphological variations, from recessive layers that produce a regolith lag in lower Maaz, to weathered polygonally fractured paleosurfaces and crater‐retaining massive blocky hummocks in upper Maaz. The Maaz members were likely separated by one or more extended periods of time, and were subjected to variable erosion, burial, exhumation, weathering, and tectonic modification. The two unique samples from the Maaz formation are representative of this diversity, and together will provide an important geochronological framework for the history of Jezero crater. The Perseverance rover on the Mars 2020 mission is collecting samples from Jezero crater for potential return to Earth via Mars Sample Return, and the first samples collected by the rover were from the Maaz formation, a lava plain that covers much of the crater floor. These igneous samples can be used to date when the lavas crystallized and to better understand their subsequent interactions with water, both of which will be important for reconstructing the history of habitable environments in Jezero crater. In this study we use images and reflectance spectra from the rover and orbiters, along with ground penetrating radar from the rover, to determine the history of the Maaz formation lavas. We find evidence for significant erosion and weathering in between successive flows, suggesting that they were emplaced over a long period of time. Some of the lavas underlie the Jezero delta, and so their age will provide limits on the timing of lake activity in Jezero crater, while others retain craters, so their age will help to better understand crater density‐based age estimates for surfaces across Mars. The Maaz formation is a series of pyroxene‐ and plagioclase‐dominated lava flows on the Jezero crater floor with variable morphologiesSignificant erosion and tectonism occurred during at least one flow hiatus, suggesting emplacement over an extended period of timeThe crystallization ages of Maaz formation samples will help constrain the timing of delta activity and the global cratering chronology The Maaz formation is a series of pyroxene‐ and plagioclase‐dominated lava flows on the Jezero crater floor with variable morphologies Significant erosion and tectonism occurred during at least one flow hiatus, suggesting emplacement over an extended period of time The crystallization ages of Maaz formation samples will help constrain the timing of delta activity and the global cratering chronology

As part of the Bagnold Dune campaign conducted by Mars Science Laboratory rover Curiosity, visible/near‐infrared reflectance spectra of dune sands were acquired using Mast Camera (Mastcam) multispectral imaging (445–1013 nm) and Chemistry and Camera (ChemCam) passive point spectroscopy (400–840 nm). By comparing spectra from pristine and rover‐disturbed ripple crests and troughs within the dune field, and through analysis of sieved grain size fractions, constraints on mineral segregation from grain sorting could be determined. In general, the dune areas exhibited low relative reflectance, a weak ~530 nm absorption band, an absorption band near 620 nm, and a spectral downturn after ~685 nm consistent with olivine‐bearing sands. The finest grain size fractions occurred within ripple troughs and in the subsurface and typically exhibited the strongest ~530 nm bands, highest relative reflectances, and weakest red/near‐infrared ratios, consistent with a combination of crystalline and amorphous ferric materials. Coarser‐grained samples were the darkest and bluest and exhibited weaker ~530 nm bands, lower relative reflectances, and stronger downturns in the near‐infrared, consistent with greater proportions of mafic minerals such as olivine and pyroxene. These grains were typically segregated along ripple crests and among the upper surfaces of grain flows in disturbed sands. Sieved dune sands exhibited progressive decreases in reflectance with increasing grain size, as observed in laboratory spectra of olivine size separates. The continuum of spectral features observed between the coarse‐ and fine‐grained dune sands suggests that mafic grains, ferric materials, and air fall dust mix in variable proportions depending on aeolian activity and grain sorting. Visible/near‐infrared spectra of Bagnold Dunes sands indicate variable mixtures of olivine and ferric materialsObserved spectral variations with grain size are consistent with laboratory spectra of olivineCoarse‐grained fractions enriched in mafic components compared to more ferric, fine fractions, likely related to aeolian/kinematic sorting

The Curiosityrover conducted the first field investigation of an active extraterrestrial dune. This study of the Bagnold dunes focuses on the ChemCam chemical results and also presents findings on the grain size distributions based on the ChemCam Remote Micro‐Imager and Mars Hand Lens Imager images. These active dunes are composed of grains that are mostly <250 μm. Their composition is overall similar to that of the aeolian deposits analyzed all along the traverse (“Aeolis Palus soils”). Nevertheless, the dunes contain less volatiles (Cl, H, and S) than the Aeolis Palus soils, which appear to be due to a lower content of volatile‐rich fine‐grained particles (<100 μm) or a lower content of volatile‐rich amorphous component, possibly as a result of (1) a lower level of chemical alteration, (2) the removal of an alteration rind at the surface of the grains during transport, (3) a lower degree of interaction with volcanic gases/aerosols, or (4) physical sorting that removed the smallest and most altered grains. Analyses of the >150 μm grain‐size dump piles have shown that coarser grains (150–250 μm) are enriched in the mafic elements Fe and Mn, suggesting a larger content in olivine compared to smaller grains (<150 μm) of the Bagnold dunes. Moreover, the chemistry of soils analyzed in the vicinity of the dunes indicates that they are similar to the dune material. All these observations suggest that the olivine content determined by X‐ray diffraction of the <150 μm grain‐size sample should be considered as a lower limit for the Bagnold dunes. Bagnold Dunes Campaign corresponds to the first in situ characterization of active dune fieldBagnold dunes lack <100 μm and > 1mm grainsBagnold dunes are overall similar to Aeolis Palus soils in composition but are depleted in volatile‐rich amorphous component and present slightly more olivine The Curiosity rover, which is exploring the Gale Crater on Mars, has been investigating a dune field. This is the first time an active and extensive dune field is explored by a rover on Mars, and therefore, Curiosity used all the instruments on board in order to better understand how the dunes can form and with what processes and also to assess their chemistry. This in situ investigation was a great opportunity to compare with orbital data. Our work is focusing on chemical data from the ChemCam instrument, as well as on grain size distributions from the image analyses of two cameras. We show that, overall, the dunes are similar in chemistry to the soils analyzed along the traverse, but they are depleted in H, Cl, and S, suggesting that they contain less fine‐grained particles or less amorphous component (which is known to be enriched in such elements). This could be due to several processes that we try to investigate. Also, we show that the coarser grains of the dunes (150–250 µm) are enriched in Fe and Mn, probably due to an enrichment in olivine.

The Mars 2020 Perseverance rover landed in Jezero crater on 18 February 2021. After a 100‐sol period of commissioning and the Ingenuity Helicopter technology demonstration, Perseverance began its first science campaign to explore the enigmatic Jezero crater floor, whose igneous or sedimentary origins have been much debated in the scientific community. This paper describes the campaign plan developed to explore the crater floor's Máaz and Séítah formations and summarizes the results of the campaign between sols 100–379. By the end of the campaign, Perseverance had traversed more than 5 km, created seven abrasion patches, and sealed nine samples and a witness tube. Analysis of remote and proximity science observations show that the Máaz and Séítah formations are igneous in origin and composed of five and two geologic members, respectively. The Séítah formation represents the olivine‐rich cumulate formed from differentiation of a slowly cooling melt or magma body, and the Máaz formation likely represents a separate series of lava flows emplaced after Séítah. The Máaz and Séítah rocks also preserve evidence of multiple episodes of aqueous alteration in secondary minerals like carbonate, Fe/Mg phyllosilicates, sulfates, and perchlorate, and surficial coatings. Post‐emplacement processes tilted the rocks near the Máaz‐Séítah contact and substantial erosion modified the crater floor rocks to their present‐day expressions. Results from this crater floor campaign, including those obtained upon return of the collected samples, will help to build the geologic history of events that occurred in Jezero crater and provide time constraints on the formation of the Jezero delta. The Mars 2020 Perseverance rover, along with the Ingenuity Helicopter technology demonstration, landed in Jezero crater, Mars on 18 February 2021. Here, we detail results from the first science campaign of the mission, the purpose of which was to explore the enigmatic Jezero crater floor. By the end of the campaign, Perseverance traversed more than 5 km, created seven abrasion patches, and sealed a total of nine samples and a witness tube for return to Earth. Analysis of the rocks in the crater floor revealed two distinct geologic formations, named the Máaz and Séítah formations. Both formations were determined to be igneous in origin, the former likely from a series of lava flows and the latter formed from a slowly cooling melt or magma body. The composition of the Máaz and Séítah formation rocks also indicate that they experienced significant alteration from water in the past, consistent with Jezero crater having once been filled with water. Results from Perseverance's Jezero crater floor campaign, including those obtained upon return of the collected samples to Earth, will help build the geologic history of Jezero crater and reveal its past habitability. The Máaz and Séítah formations are igneous, with Séítah representing olivine‐rich cumulates and Máaz representing separate lava flowsCrater floor rocks have been variably altered to produce carbonates and other alteration minerals during multiple aqueous episodesPost‐emplacement processes tilted these rocks near the Máaz‐Séítah contact, and erosion produced varied textures and olivine‐rich regolith The Máaz and Séítah formations are igneous, with Séítah representing olivine‐rich cumulates and Máaz representing separate lava flows Crater floor rocks have been variably altered to produce carbonates and other alteration minerals during multiple aqueous episodes Post‐emplacement processes tilted these rocks near the Máaz‐Séítah contact, and erosion produced varied textures and olivine‐rich regolith

We utilize SuperCam's Mars microphone to provide information on wind speed and turbulence at high frequencies on Mars. To do so, we first demonstrate the sensitivity of the microphone signal level to wind speed, yielding a power law dependence. We then show the relationship between the microphone signal level and pressure, air and ground temperatures. A calibration function is constructed using Gaussian process regression (a machine learning technique) taking the microphone signal and air temperature as inputs to produce an estimate of the wind speed. This provides a high rate wind speed estimate on Mars, with a sample every 0.01 s. As a result, we determine the fast fluctuations of the wind at Jezero crater which highlights the nature of wind gusts over the Martian day. To analyze the turbulent behavior of this wind speed estimate, we calculate its normalized standard deviation, known as gustiness. To characterize the behavior of this high frequency turbulent intensity at Jezero crater, correlations are shown between the evaluated gustiness statistic and pressure drop rates/sizes, temperature and energy fluxes. This has implications for future atmospheric models on Mars, taking into account turbulence at the finest scales. The NASA Perseverance mission sent microphones to the surface of Mars. This microphone has recorded signals due to the wind. We examine how these recorded signals vary with other sensor data from Perseverance, which shows a link between the microphone signal, the dedicated wind speed sensor and air temperature. Based on this finding, we develop a way to predict the wind speed from the microphone data using a machine learning technique. The microphone records data at a very high rate compared with sensors so far sent to Mars. This means that the wind speed predicted from the microphone data can be used to study the chaotic and variable wind behavior on Mars to a level never seen before. We show that this chaotic and variable behavior has links to temperature and the number of whirlwinds observed. This will lead us to better weather models for Mars. Wind‐induced noise is observed by the SuperCam Mars microphone on PerseveranceMicrophone and air temperature data are used to estimate the wind speed at high frequencies, using a machine learning modelThe wind speed estimate is used to examine the relationships between turbulent intensity, pressure drops, temperature, and energy flux Wind‐induced noise is observed by the SuperCam Mars microphone on Perseverance Microphone and air temperature data are used to estimate the wind speed at high frequencies, using a machine learning model The wind speed estimate is used to examine the relationships between turbulent intensity, pressure drops, temperature, and energy flux

A multi‐instrument study of the regolith of Jezero crater floor units by the Perseverance rover has identified three types of regolith: fine‐grained, coarse‐grained, and mixed‐type. Mastcam‐Z, Wide Angle Topographic Sensor for Operations and eNgineering, and SuperCam Remote Micro Imager were used to characterize the regolith texture, particle size, and roundedness where possible. Mastcam‐Z multispectral and SuperCam laser‐induced breakdown spectroscopy data were used to constrain the composition of the regolith types. Fine‐grained regolith is found surrounding bedrock and boulders, comprising bedforms, and accumulating on top of rocks in erosional depressions. Spectral and chemical data show it is compositionally consistent with pyroxene and a ferric‐oxide phase. Coarse‐grained regolith consists of 1–2 mm well‐sorted gray grains that are found concentrated around the base of boulders and bedrock, and armoring bedforms. Its chemistry and spectra indicate it is olivine‐bearing, and its spatial distribution and roundedness indicate it has been transported, likely by saltation‐induced creep. Coarse grains share similarities with the olivine grains observed in the Séítahformation bedrock, making that unit a possible source for these grains. Mixed‐type regolith contains fine‐ and coarse‐grained regolith components and larger rock fragments. The rock fragments are texturally and spectrally similar to bedrock within the Máazand Séítahformations, indicating origins by erosion from those units, although they could also be a lag deposit from erosion of an overlying unit. The fine‐ and coarse‐grained types are compared to their counterparts at other landing sites to inform global, regional, and local inputs to regolith formation within Jezero crater. The regolith characterization presented here informs the regolith sampling efforts underway by Perseverance. We used multiple instruments on the Perseverance rover to describe three populations of loose sediments found on the floor of Jezero crater by their grain sizes and chemical compositions. The smallest population has grains that are small sand‐sized (80–530 μm) and a mixture of minerals commonly found on Mars, including pyroxene that is present in local rocks and airborne dust found globally. These grains are the easiest to move by wind, so could have distal regional sources as well. Larger gray grains that are 1–2 mm in size and rounded contain olivine. These grains move along the surface, pushed by the impacts of smaller grains that are lifted by the wind. Their size and composition are very similar to olivine grains found in nearby in‐place rocks, indicating that they may have a more local source. Finally, there are larger pieces of rocks that have broken down from the erosion of local in‐place rocks over time and mix with the other types of grains. Loose sediments within the Jezero crater described here can be compared to loose sediments studied at other landing sites on Mars to help understand how Jezero sediments are formed and transported. Textural, spectroscopic, and chemical analyses of regolith in Jezero crater reveal details of fine, coarse, and mixed grain componentsCompositional information and physical grain characteristics from those analyses inform transport history and possible source materialRegolith components are compared to their counterparts at other landing sites to inform global versus local inputs to regolith formation Textural, spectroscopic, and chemical analyses of regolith in Jezero crater reveal details of fine, coarse, and mixed grain components Compositional information and physical grain characteristics from those analyses inform transport history and possible source material Regolith components are compared to their counterparts at other landing sites to inform global versus local inputs to regolith formation

Laser‐induced breakdown spectroscopy, as utilized by the ChemCam instrument onboard the Curiosity rover, detected enhanced abundances of the element copper. Since landing in Gale crater (6 August 2012), 10 enhancements in copper abundance were observed during 3007 Martian days (sols) of rover operations and 24 km of driving (as of 20 January 2021). The most prominent ones were found in the Kimberley area on the crater floor (Aeolis Palus) and in Glen Torridon (GT) on the lower flanks of Aeolis Mons (Mt. Sharp). Enhancements in copper record the former existence of modestly acidic and oxidizing fluids, which were more oxidizing in Kimberley than in GT. Of the two main types of bedrock in the lowest part of GT, Mg‐rich “coherent” and K‐rich “rubbly” (named based on their outcrop expression), copper was detected only in coherent, not in rubbly bedrock. The difference between these two types of bedrock may be due to difference in provenance. Alternatively, based on a recently developed lacustrine‐groundwater mixing model, we suggest that rubbly bedrock was altered by modestly acidic, shallow‐subsurface lake water that leached out both copper and manganese, while coherent bedrock was affected by dominantly alkaline fluids which would be consistent with its mineralogical composition (including siderite) as returned by the CheMin instrument onboard the rover. Higher up in GT, ChemCam data indicated significant gradients in the copper concentration in coherent bedrock on a local scale of only a few meters, which suggests a different alteration style and possibly different types of diagenetic fluids. Gale crater, Mars, about 152‐km in diameter and 3.6 Ga in age, has a central mound that is partly of sedimentary origin. To date (July 2022), the NASA rover Curiosity has been exploring the crater floor and the lower‐most 600 m (in elevation) of sediments of that mound. ChemCam, an instrument mounted on top of the remote‐sensing mast utilizing Laser‐Induced Breakdown Spectroscopy, has been measuring chemical composition and specifically copper abundances along the rover traverse. We identified 10 areas of copper enhancement along Curiosity's traverse. In the Kimberley formation on the crater floor, copper was identified in a manganese‐rich sandstone. Later on, some 350 m above Kimberley, high copper abundances were detected in magnesium‐rich mudstone and in iron‐rich sandstone in the Jura and Knockfarril Hill member, respectively. Following earlier work about copper in Gale crater (Payré et al., 2019, https://doi.org/10.1016/j.icarus.2018.12.015), we postulate a copper‐rich source region north of Gale crater and suggest that copper‐rich detrital material delivered to these areas in Gale crater. Taking into account the chemical and mineralogical composition of these types of bedrock, we conclude that copper was mobilized by later acidic and oxidizing fluids. High copper abundances (200–400 ppm) are found in specific areas along the rover traverseIn the Jura member in Glen Torridon (GT), copper is detected only in coherent bedrock, not in rubbly bedrockIn the Knockfarril Hill member in GT, there is evidence for the redistribution of copper and iron by acidic, oxidizing fluids High copper abundances (200–400 ppm) are found in specific areas along the rover traverse In the Jura member in Glen Torridon (GT), copper is detected only in coherent bedrock, not in rubbly bedrock In the Knockfarril Hill member in GT, there is evidence for the redistribution of copper and iron by acidic, oxidizing fluids

The Mars Science Laboratory (MSL) Curiosity rover completed a detailed investigation at the Kimberley waypoint within Gale crater from sols 571–634 using its full science instrument payload. From orbital images examined early in the Curiosity mission, the Kimberley region had been identified as a high‐priority science target based on its clear stratigraphic relationships in a layered sedimentary sequence that had been exposed by differential erosion. Observations of the stratigraphic sequence at the Kimberley made by Curiosity are consistent with deposition in a prograding, fluvio‐deltaic system during the late Noachian to early Hesperian, prior to the existence of most of Mount Sharp. Geochemical and mineralogic analyses suggest that sediment deposition likely took place under cold conditions with relatively low water‐to‐rock ratios. Based on elevated K2O abundances throughout the Kimberley formation, an alkali feldspar protolith is likely one of several igneous sources from which the sediments were derived. After deposition, the rocks underwent multiple episodes of diagenetic alteration with different aqueous chemistries and redox conditions, as evidenced by the presence of Ca‐sulfate veins, Mn‐oxide fracture fills, and erosion‐resistant nodules. More recently, the Kimberley has been subject to significant aeolian abrasion and removal of sediments to create modern topography that slopes away from Mount Sharp, a process that has continued to the present day. Mars Science Laboratory explored the Kimberley waypoint from sols 571–634 using its full science instrument payloadThe stratigraphic sequence most likely formed at the margins of a lake within Gale crater, prior to the existence of Mount SharpThe sediments at the Kimberley were derived from several igneous sources, including an alkali feldspar protolith

Glen Torridon is a topographic trough located on the slope of Aeolis Mons, Gale crater, Mars. It corresponds to what was previously referred to as the “clay‐bearing unit,” due to the relatively strong spectral signatures of clay minerals (mainly ferric smectites) detected from orbit. Starting in January 2019, the Curiosityrover explored Glen Torridon for more than 700 sols (Martian days). The objectives of this campaign included acquiring a detailed understanding of the geologic context in which the clay minerals were formed, and determining the intensity of aqueous alteration experienced by the sediments. Here, we present the major‐element geochemistry of the bedrock as analyzed by the ChemCam instrument. Our results reveal that the two main types of bedrock exposures identified in the lower part of Glen Torridon are associated with distinct chemical compositions (K‐rich and Mg‐rich), for which we are able to propose mineralogical interpretations. Moreover, the topmost stratigraphic member exposed in the region displays a stronger diagenetic overprint, especially at two locations close to the unconformable contact with the overlying Stimson formation, where the bedrock composition significantly deviates from the rest of Glen Torridon. Overall, the values of the Chemical Index of Alteration determined with ChemCam are elevated by Martian standards, suggesting the formation of clay minerals through open‐system weathering. However, there is no indication that the alteration was stronger than in some terrains previously visited by Curiosity, which in turn implies that the enhanced orbital signatures are mostly controlled by non‐compositional factors. In early 2019, the Curiosityrover embarked on a multi‐year exploration of the Glen Torridon region, a topographic trough on the flank of Aeolis Mons, the sedimentary mound inside Gale crater, Mars. Orbital instruments have detected clay minerals over Glen Torridon, making it a primary target for Curiosity, because clay minerals are indicators of past interactions with water, and provide a medium favorable to the preservation of organic compounds. Understanding the context of formation of the clay minerals, and determining how much the sediments have been altered by water were among the objectives of the Glen Torridon campaign. Based on the chemical compositions measured by the ChemCam instrument, we show that the amount of water that interacted with the sediments was high enough to take away part of the most soluble elements. Nonetheless, similar levels of alteration have been observed in other parts of Gale, which implies that the signal observed from orbit is not controlled solely by the abundance of clay minerals in the rocks. Finally, in the highest part of Glen Torridon, we analyzed an area of light‐toned rocks with distinct chemical compositions, which likely result from further modification by groundwater long after the main phase of alteration. The Curiosityrover explored Glen Torridon, a section of Aeolis Mons previously referred to as the “clay‐bearing unit” of Gale craterBedrock compositions measured by ChemCam show variations correlated with changes in outcrop expression and with diagenetic overprintThe relatively strong clay mineral signatures detected from orbit over Glen Torridon are not caused by a greater intensity of alteration The Curiosityrover explored Glen Torridon, a section of Aeolis Mons previously referred to as the “clay‐bearing unit” of Gale crater Bedrock compositions measured by ChemCam show variations correlated with changes in outcrop expression and with diagenetic overprint The relatively strong clay mineral signatures detected from orbit over Glen Torridon are not caused by a greater intensity of alteration

The clay‐rich Glen Torridon region of Gale crater, Mars, was explored between sols 2300 and 3007. Here, we analyzed the diagenetic features observed by Curiosity, including veins, cements, nodules, and nodular bedrock, using the ChemCam, Mastcam, and Mars Hand Lens Imager instruments. We discovered many diagenetic features in Glen Torridon, including dark‐toned iron‐ and manganese‐rich veins, magnesium‐ and fluorine‐rich linear features, Ca‐sulfate cemented bedrock, manganese‐rich nodules, and iron‐rich strata. We have characterized the chemistry and morphology of these features, which are most widespread in the higher stratigraphic members in Glen Torridon, and exhibit a wide range of chemistries. These discoveries are strong evidence for multiple generations of fluids from multiple chemical endmembers that likely underwent redox reactions to form some of these features. In a few cases, we may be able to use mineralogy and chemistry to constrain formation conditions of the diagenetic features. For example, the dark‐toned veins likely formed in warmer, highly alkaline, and highly reducing conditions, while manganese‐rich nodules likely formed in oxidizing and circumneutral conditions. We also hypothesize that an initial enrichment of soluble elements, including fluorine, occurred during hydrothermal alteration early in Gale crater history to account for elemental enrichment in nodules and veins. The presence of redox‐active elements, including Fe and Mn, and elements required for life, including P and S, in these fluids is strong evidence for habitability of Gale crater groundwater. Hydrothermal alteration also has interesting implications for prebiotic chemistry during the earliest stages of the crater's evolution and early Mars. The NASA Curiosityrover explored the ancient lakebed rocks within the Glen Torridon region of Mars from January 2019 to January 2021. The rover observed many signs that the bedrock was changed by groundwater, especially in the higher elevations along the rover's path. We used data from the rover's ChemCam instrument to record chemistry, and images from four cameras on the rover to look for physical changes to the rocks. When the rock in Glen Torridon was altered by groundwater, it introduced a variety of physical and chemical changes to the rock, and the amount of some elements (sodium, calcium, iron, magnesium, or manganese) increased in the rocks in association with these physical changes to the rocks. We can use these changes in the rock's characteristics to determine the type of water that changed these rocks on Mars (its chemical composition, its temperature, acidic vs. basic, oxidizing vs. reducing) at the time that the changes occurred. We found that many types of groundwater mixed at different times to cause changes to the rocks. At least one of the groundwater types was warmer than what was previously expected and could be related to the impact that formed the crater. Glen Torridon in Gale crater underwent multiple generations of diagenesis of the bedrock that widely varies in chemistry and morphologyOne hypothesis suggests an initial enrichment of elements occurred during the Gale's post‐impact hydrothermal alteration phase of evolutionWe estimate that at least one type of vein in Glen Torridon required warm temperatures, and highly reducing and alkaline fluid to form Glen Torridon in Gale crater underwent multiple generations of diagenesis of the bedrock that widely varies in chemistry and morphology One hypothesis suggests an initial enrichment of elements occurred during the Gale's post‐impact hydrothermal alteration phase of evolution We estimate that at least one type of vein in Glen Torridon required warm temperatures, and highly reducing and alkaline fluid to form

We analyze spatially pervasive, light‐toned “halos” associated with fractures in a sedimentary unit (Stimson) of Gale crater, Mars, and report a similar network of halos discovered in a separate geologic group (Bradbury). Through a dedicated active neutron measurement campaign, we provide independent confirmation of the water‐rich nature of these features. Together with mineralogical and geochemical data, these features are consistent with abundant hydrated amorphous silica (opal‐A). We suggest that the mineral and amorphous assemblages are indicative of formation under low‐temperature and predominantly low‐pH conditions (passive silica enrichment) with minor contribution of silica (active silica enrichment) from adjacent units. We show that there is significant amorphous silica in the array of sedimentary rocks in Gale crater, allowing them to play a role in an active silica enrichment phase of halo formation. We suggest that the involved alteration event was short lived and our finding of vast halo networks in a distant, older unit implies a more vast network of hydrologic subsurface conduits than previously known. This relatively recent subsurface hydrologic system was present long after the transition from a warm and wet to a cold and dry Martian environment, extending the habitability conditions on Mars to an epoch that is generally considered not favorable for life on the surface. Finally, our bulk H quantification of these features, which ranges from ∼3–6 wt% H2O‐equivalent‐H, suggests that the amorphous material in halos hosts ample supplies of readily released water, making them a considerable resource at the otherwise dry Martian equator. Light‐toned opaline silica features found throughout rocks along Curiosity rover's traverse are the exposed roots of a vast fluid event in recent Martian geologic history. Using data collected from several instruments on Curiosity rover, we find evidence that the event was short lived and was followed by consistently cold and dry Mars climate conditions. This water‐rich subsurface network was shielded from modern harsh surface conditions, allowing for a potentially habitable environment on Mars in a more recent era. These light‐toned features are also ideal for follow‐up investigation or sample return as similar opal‐rich deposits on Earth are known to preserve traces of microbial life. Additionally, the features themselves contain a considerable amount of readily released water, making them an ideal resource at the otherwise dry Martian equator. We demonstrate that water‐rich, opal‐A‐bearing light‐toned halos are more prevalent in Gale crater, Mars than previously understoodHalos are associated with the conduits of a large‐scale hydrologic system in Gale craterHalos provided a subsurface habitable environment during a modern epoch of otherwise relatively uninhabitable surface conditions We demonstrate that water‐rich, opal‐A‐bearing light‐toned halos are more prevalent in Gale crater, Mars than previously understood Halos are associated with the conduits of a large‐scale hydrologic system in Gale crater Halos provided a subsurface habitable environment during a modern epoch of otherwise relatively uninhabitable surface conditions

Between January 2019 and January 2021, the Mars Science Laboratory team explored the Glen Torridon (GT) region in Gale crater (Mars), known for its orbital detection of clay minerals. Mastcam, Mars Hand Lens Imager, and ChemCam data are used in an integrated sedimentological and geochemical study to characterize the Jura member of the upper Murray formation and the Knockfarril Hill member of the overlying Carolyn Shoemaker formation in northern GT. The studied strata show a progressive transition represented by interfingering beds of fine‐grained, recessive mudstones of the Jura member and coarser‐grained, cross‐stratified sandstones attributed to the Knockfarril Hill member. Whereas the former are interpreted as lacustrine deposits, the latter are interpreted as predominantly fluvial deposits. The geochemical composition seen by the ChemCam instrument show K2O‐rich mudstones (∼1–2 wt.%) versus MgO‐rich sandstones (>6 wt.%), relative to the average composition of the underlying Murray formation. We document consistent sedimentary and geochemical data sets showing that low‐energy mudstones of the Jura member are associated with the K‐rich endmember, and that high‐energy cross‐stratified sandstones of the Knockfarril Hill member are associated with the Mg‐rich endmember, regardless of stratigraphic position. The Jura to Knockfarril Hill transition therefore marks a significant paleoenvironmental change, where a long‐lived and comparatively quiescent lacustrine setting progressively changes into a more energetic fluvial setting, as a consequence of shoreline regression due to either increased sediment supply or lake‐level drop. Between January 2019 and January 2021, the Mars Science Laboratory team explored the Glen Torridon region in Gale crater. This region is also known as the “clay‐bearing unit” after the previous observation of strong spectral signatures of such minerals from orbit. As this indicates the presence of wetter conditions during the Martian past, this area was a main objective of the mission. There, sedimentary strata show a major change from fine‐grained mudstones, characteristic of the underlying Murray formation (lake deposits), toward coarser‐grained cross‐stratified sandstones of the Knockfarril Hill member (river deposits). This change is also identified in the geochemical signal, by the ChemCam instrument. ChemCam data show higher magnesium and lower potassium in the coarse‐grained fraction compared to the fine‐grained sediment. We also observe a progressive transition with interbedding of both lithologies across the region. We interpret these strata to record a progressive transition from a quiet lake toward a more energetic lake shore to river plain, consequently to shoreline migration, due to either sedimentary fill of the basin and/or a drop in lake level. Sedimentary facies observed by Curiositysuggest lacustrine and fluvial environments preserved in the Glen Torridon (GT) stratigraphyA paleoenvironmental transition is observed across the Jura/Knockfarril Hill members boundary, suggesting onset of fluvial conditionsThis transition is progressive, and consistent within both the sedimentary and geochemical signals in the GT region Sedimentary facies observed by Curiositysuggest lacustrine and fluvial environments preserved in the Glen Torridon (GT) stratigraphy A paleoenvironmental transition is observed across the Jura/Knockfarril Hill members boundary, suggesting onset of fluvial conditions This transition is progressive, and consistent within both the sedimentary and geochemical signals in the GT region

Aeolian processes have shaped and contributed to the geological record in Gale crater, Mars, long after the fluviolacustrine system existed ∼3 Ga ago. Understanding these aeolian deposits, particularly those which have been lithified and show evidence for aqueous alteration, can help to constrain the environment at their time of deposition and the role of liquid water later in Mars' history. The NASA Curiosity rover investigated a prominent outcrop of aeolian sandstone within the Stimson formation at the Greenheugh pediment as part of its investigation of the Glen Torridon area. In this study, we use geochemical data from ChemCam to constrain the effects of aeolian sedimentary processes, sediment provenance, and diagenesis of the sandstone at the Greenheugh pediment, comparing the Greenheugh data to the results from previous Stimson localities situated 2.5 km north and >200 m lower in elevation. Our results, supported by mineralogical data from CheMin, show that the Stimson formation at the Greenheugh pediment was predominately sourced from an olivine‐rich unit that may be present farther up the slopes of Gale crater's central mound. Our results also suggest that the Greenheugh pediment Stimson formation was cemented by surface water runoff such as that which may have formed Gediz Vallis. The lack of alteration features in the Stimson formation at the Greenheugh pediment relative to those of the Emerson and Naukluft plateaus suggests that groundwater was not as available at this locality compared to the others. However, all sites share diagenesis at the unconformity. We use geochemical data from the Curiosity rover's ChemCam instrument to investigate the geological history of the Greenheugh pediment capping unit. The Greenheugh pediment is a geologic feature that has a gently sloping top, forming a broad plain extending from the base of the valley, Gediz Vallis. The Greenheugh pediment is capped by a unit of broadly uniform thickness which represents the remains of the Stimson dune field that existed <2.5 Ga (mid‐to late‐Hesperian). ChemCam geochemical data shows that the sands deposited at the Greenheugh capping unit were largely sourced from a nearby olivine‐rich unit. Surface waters then cemented the windblown sand deposits, ponding at the unconformity with the underlying mudstone unit, creating concretions toward the base. Episodes of groundwater circulation did not affect the rocks at Greenheugh as much as they did at other Stimson localities, though both sites share evidence of acid‐sulfate alteration along the unconformity. These results suggest that the ancient Stimson dune field was a dynamic environment, incorporating grains from the surrounding geological units on Mt Sharp. Furthermore, liquid water was stable at the surface in the Hesperian and was available for multiple diagenetic events along bedrock weaknesses. ChemCam geochemical results support that the Greenheugh pediment capping unit was deposited within the Stimson sand sea in the HesperianThe Greenheugh pediment capping unit was sourced from olivine‐rich sands, potentially recycled from units farther up Mt SharpGreenheugh experienced less interaction with groundwaters than Stimson at the Emerson and Naukluft plateaus, but shared diagenesis at the unconformity ChemCam geochemical results support that the Greenheugh pediment capping unit was deposited within the Stimson sand sea in the Hesperian The Greenheugh pediment capping unit was sourced from olivine‐rich sands, potentially recycled from units farther up Mt Sharp Greenheugh experienced less interaction with groundwaters than Stimson at the Emerson and Naukluft plateaus, but shared diagenesis at the unconformity

The lowermost exposure of the Murray formation in Gale crater, Mars, was interpreted as sediment deposited in an ancient lake based on data collected by the Curiosityrover. Constraining the stratigraphic extent and duration of this environment has important implications for the paleohydrology of Gale. Insights into early Martian environments and paleofluid flow velocity can be obtained from grain size in rocks. Visual inspection of grain size is not always available for rocks investigated at field sites on Mars due to limited image coverage. But grain sizes can also be estimated from the Gini Index Mean Score, a grain‐size proxy that uses point‐to‐point chemical variations in ChemCam Laser Induced Breakdown Spectroscopy data. New Gini Index Mean Score results indicate that the Murray formation is dominated by mudstones with grains smaller than the spatial resolution of all rover cameras. Intervals of fine to coarse sandstone also are present, some of which are verified using observations of grain size and sedimentary structures in associated images. Overall, results demonstrate that most of the Murray consists of mudstone, suggesting settling of grains from suspension in low energy depositional environments such as lakes. Some of the mudstones contain desiccation cracks indicating periods of drying with a lowering of lake water level. However, beds and lenses of cross‐bedded sandstones are common at specific intervals, suggesting episodes of fluvial and possibly eolian deposition. The persistence of lacustrine deposits interspersed with fluvial deposits suggests that liquid water was sustained on the Martian surface for tens of thousands to millions of years. The lowest exposed rocks of the Murray formation in Gale crater, Mars, are interpreted as ancient lake deposits based on Curiosityrover data. However, the duration and temporal variability of this ancient lake is still an open question. Here we characterize the vertical distribution of deposits within the entire Murray formation using new grain size information. Characterizing grain size in rocks provides information about the speed of past fluid flows, which is crucial for interpreting depositional environments. However, measuring grain size in images is rarely possible for Martian rocks. Thus, we estimate grain sizes with the Gini Index Mean Score, a grain‐size proxy that uses ChemCam Laser Induced Breakdown Spectroscopy data. Gini Index Mean Score results indicate that the Murray formation is dominated by rocks with mud‐sized grains (i.e., mudstones), suggesting mud‐sized grains settled in a low energy lake environment. Mud cracks occur in some of the mudstones, indicating drying periods in a lake. Rocks with sand‐sized grains (i.e., sandstones) and cross bedding occur at specific intervals, suggesting episodes with stream channels and wind‐blown sand dunes. The dominance of lake deposits interspersed with stream deposits suggests that liquid water was present in Gale crater for tens of thousands to millions of years. A detailed record of inferred rock grain size was produced for the Murray formation using ChemCam laser induced breakdown spectroscopy dataInferred grain sizes in the Murray formation include mudstones and sandstones, with mudstones being the dominant lithologyGrain size variations suggest changing environments and sustained liquid water in Gale crater for tens of thousands to millions of years