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The Perseverance rover continues to make progress on the task of collecting and documenting a set of Martian samples for future return to Earth by the Mars Sample Return program [1]. Near the end of 2022 the rover had acquired, sealed, and stored onboard a total of 15 rock cores, 2 regolith samples, 1 ambient atmosphere sample, and 3 witness tubes [2]. Of these 21 sealed tubes, 10 have been selected for inclusion in a first depot located in the Three Forks region on the floor of Jezero crater near an outflow basin [3]. In December of 2022 the rover began the construction of this depot. The Three Forks region was chosen for the depot location because it is an area with flat terrain, no large rocks, and enough area for the Perseverance rover and potential future robotic vehicles to maneuver around the depot without disturbing the sample tubes [4]. The individual sample core tips are imaged by the Mastcam-Z [5] and Cachecam [6] cameras prior to tube sealing and subsequent storage. These images document the texture and color of the samples and form an important component of the overall sample documentation data set [7]. After the sample tubes are dropped in the depot at pre-designated zones, images of the tubes are acquired with the Front Hazcam, Navcam cameras, and optionally the WATSON camera [8]. These images serve two purposes: a) to provide confirmation of the tube state to the operations team during sample depot construction and b) formally record the location of the tubes within the Three Forks region for the potential retrieval of the tubes by later missions. At the time of this writing, construction of the Three Forks sample depot by the rover operations team was underway, with depot completion expected by February 2023. References: [1] Farley, K.A., Space Sci Rev 216, 142 (2020). [2] Herd, C.D.K, et al., LPSC 2023. [3] September 2022 - MSR/M2020 Sample Depot Science Community Workshop. [4] N. Williams, Golombek, LPSC 2023. [5] Bell, J.F. III, Maki, J.N., et al. Space Sci Rev 217, 24 (2021). [6] Maki, J.N.. et al. Space Sci Rev 216, 137 (2020). [7] Maki et al., LPSC 2022. [8] Bhartia, R., et al., Space Sci Rev 217, 58 (2021).

Background: Visualizing Mastcam-Z Stereo Reconstructions on Global-to-Local Scale Mars 2020 Mastcam-Z [1] 3D products enable the visualization and analysis of rocks, outcrops, and other geological and aeolian features. The Planetary Robotics Vision Processing framework PRoViP [2], among others, generates panoramas, textured meshes and derived products from Mastcam-Z sequences on tactical (Sol-by-Sol) time frame. OPCs (Ordered Point Clouds) [3] georeferenced by the cm-level accurate tactical rover localization provided by the Mapping Specialists on the Mars 2020 science team, are loaded in PRo3D (Planetary Robotics 3D Viewer; [4]) for interactive 3D exploration, measurement and annotation. A “scene” contains several OPCs, overlaid to textured HiRISE [5] Digital Terrain Models – DTMs – again OPCs – for large-scale spatial context (Figure 1). Figure 1: Mastcam-Z Sol 369 OPCs on HiRISE OPC. NASA/JPL/CalTech/USGS/ASU/MSSS/JR/VRVis Narrative Videos for Immersive Story Telling of Scientific Rationales A typical workflow to explain physical processes on a planetary surface based on its 3D virtual representation incorporates the following steps: A spatial and thematic overview shows the environment in large-scale context, typically in km-scale, involving also the mission progress such as Rover trajectory, local landmark features and scale bars. The latter is true of all steps to follow Moving towards a specific region, zooming-in, letting new surface layers appear, or annotating a target of interest attracts attention to a more focused part of the landscape Speed & timing of virtual motion (“Navigation” in the scene) varies tension, or allows time for spoken or annotated explanations Different viewpoints and smoothly transiting between them highlights specific features. PRo3D’s Sequenced Bookmarks: Key for Efficient Video Production PRo3D implements such a workflow in a repeatable way. “Bookmarks” define 3D viewpoints, their sequence, duration and the transition times between them (Figure 2). Disabling/enabling the display of scale bars, individual surfaces and annotations, rover tracks and stations, dip-and-strike annotations, measurements and sky projections of annotations, in conjunction with the embedding of photospheres and multi-temporal surface layers, realizes a comfortable production of highly informative yet ergonomic video stories launched by a “play” button. Up to 8k resolution offline rendering produces smooth videos even on low-budget graphics cards. Figure 2: PRo3D Sequenced Bookmarks user interface (Mastcam-Z Sol 422) ASU/MSSS/JR/VRVis Science Case 1: Explaining the 3D Assessment of Soil Crust Understanding the Martian soil is critical for future human exploration, and samples that will be returned [6]. 3D observations of cracks, fractures and tracks sheds important light on the crust’s characteristics and extent of induration [7]. Figure 3 shows key frames from a PRo3D video explaining a soil crust assessment process. Important building blocks are the Rover tracks’ depth or the steepness of micro slopes. The viewing direction should be parallel to the rills of the rover tracks, the viewing distance from the Rover and the virtual viewing distance shall be small. Figure 3: Soil crust evaluation stages documented using PRo3D’s Sequenced Bookmarks video-rendering. a) Environment, b) approaching the rover tracks, c) side view parallel to track rills with numeric assessments, d) close-range numeric assessments of a micro slope. Two Mastcam-Z OPCs from Sol 329 (zcam07106) and Sol 333 (zcam08354) overlain on HiRISE DTM/Ortho OPC. NASA/JPL/CalTech/ASU/MSSS/ÖAW/JR/VRVis Science Case 2: Explaining the Result of a Geologic Annotation A Digital Outcrop Model’s nature can be difficult to convey in simple 2D images, due to the different types of data collected – interpreting layering characteristics by lines, the orientation or dip and strike of exposed layers and bedding, thickness of layers, variation in thickness (up and down as well as laterally), and locations to build the interpretation on the spatial distribution of key textural and geometrical characteristics [4]. Collating such measurements carried out over multiple outcrops further increases the complexity of concisely sharing observations. Sequenced bookmarks allow for accessible visualisation of such multifaceted data presentation. This is highlighted in the interpretation of the Mure outcrop imaged by Mastcam-Z on Sols 168-169 (sequences 8180/8182/8183, Figure 4). Figure 4: PRo3D’s Sequenced Bookmarks video rendering documenting geologic workflow stages. a. – Initial approach and (scaled) assessment of outcrop. b. – Layer contacts’ interpretation and annotation, visualizing geometry and dimensions. c. – Dip and strike of key surfaces. d. –Layer true thickness. Outlook: Dynamically Adapting the Scene and Further Exploitation Cases Functions for dynamic change of the scene whilst animating, sequenced toggling of surfaces, annotations and scale bars, and additional features such as color change in a predefined sequence are presently implemented. Such way, the 3D dynamic presentation of an exploration scenery will get a standard and low-effort means for immersively sharing observations and findings. Manifold application cases, not restricted to the Martian environment, contain the 3D explanation of dynamic processes such as landing [8], atmospheric processes (e.g. dust devils’ motion), the accumulation of measurements as the rover drives, or 3D change documentation [9]. Acknowledgements JR, VRVis and ÖAW receive funding from ESA PRODEX Contract PEA4000117520 and FFG ASAP Projects 882828 and 885326. VRVis is funded by BMK, BMDW, Styria, SFG, Tyrol and Vienna Business Agency in the scope of COMET - Competence Centers for Excellent Technologies (879730) managed by FFG. We thank Rebecca Nowak for implementing the Sequenced Bookmarks suite. References [1] Bell et al., Space Science Reviews, 2021; [2] Traxler et al., 2022 https://doi.org/10.1002/9781119313922.ch3; [3] Ortner et al., Real Corp, 2010; [4] Barnes et al., ESS, 2018; [5] McEwen et al., JGR-Planets, 2007; [6] Beaty et al., MPS, 2019; [7] Hausrath, in submission, 2022; [8] Perseverance Descent Reconstruction in PRo3D, https://www.youtube.com/watch?v=-z1KySwtnuU; [9] QZCAM 0268 0255 ZCAM03258 8278 L0R0 110 034 HiRISE PRo3D Brac SampleHole1 E01, https://www.youtube.com/watch?v=5Sn4MpZdgpg

International audience; Orbital and rover observations of relictgeomorphic features and stratigraphic architectures indicate Mars once had a warmer, wetter climate. Constraining the character, relative timing and persistence of ancient aqueous activity on Mars is possible through detailed interrogation of the stratal geometry of aqueously deposited sedimentary bodies. Such analyses inform interpretations of Martian climate evolution, potential habitability, and search strategies for rocks that might contain potential biosignatures. A prominent sedimentary fan deposit at the westernmargin of Jezero crater has been inferred to be a river delta that built into an ancient lake basin during the Late Noachian-Early Hesperian epochs on Mars (~3.6-3.8 Ga) [1, 2, 3]. The Perseverance rover landed on 18 February 2021 ~2.2 km from the western fan. During the early phase of mission investigations, highresolution images obtained from the Mastcam-Z camera and from the Remote Micro-Imager of the SuperCaminstrument provided the first ground-based observations of the western fan and an associated remnant outcrop, named Kodiak. Here, we report its sedimentology, which provide new constraints on the nature of the fan deposits, and their paleoenvironmental implications (4).

In this contribution we report measurements and interpretations of aeolian abrasion features observed along the Mars Science Laboratory rover traverse at Gale Crater on Mars. Aeolian abrasion of surface rocks has been documented by most missions that have landed on Mars, but attention has largely focused on relatively resistant rocks that display ventifact morphologies well‐known from Earth. The current study instead emphasizes abrasion features developed on mudstone surfaces, because aeolian abrasion textures are very common in the mudstone‐dominated Murray Formation at Gale Crater. These abrasion textures have been observed over a wide area, and they allow deductions about dominant past wind regimes that differ from those observed at present. On Earth, aeolian abrasion features in mudstone outcrops have minimal preservation potential because of the susceptibility of mudstones to moisture and aqueous erosion, even in dominantly arid surface environments. Because of this there is no literature on potential terrestrial analogs. In order to better understand aeolian abrasion morphologies in mudstones on Mars, laboratory experiments were conducted that exposed a range of mudstone samples and rock simulant samples to wind‐driven sand for periods of up to four months. These experiments produced a range of aeolian abrasion textures (‘wind tails’, fluting, differential ‘etching’ of laminae, stalks and pedestals) that can serve as analogs for features in the Murray Formation, increasing our confidence regarding aeolian origins for these and the deductions of formative, sand‐driving wind azimuths. Orientations of aeolian abrasion textures along the Mars Science Laboratory traverse were compared with active ripple orientations in rover images, and with previous analyses of orbital images of the study area, in order to evaluate whether the current, complex wind environment can explain the abrasion orientations observed in rover images, or if the abrasion record might also contain signatures of past wind regimes that differed from those of the present. Results show relatively coherent patterns of airflow and sand movement that vary in accordance with factors like local topography and upwind availability of sand for abrasion. Wind events blowing southwest that are primarily responsible for southwest migration of the Bagnold Dunes have also caused bedrock abrasion of similar orientation between these dunes. Less effective wind events (from an abrasion standpoint) blowing south‐southeast have broadly affected bedrock exposures elsewhere across the Mars Science Laboratory landing site away from the Bagnold Dunes. A notable exception are northeast abrasion textures on the more erosion‐resistant sandstones of the Naukluft Plateau. The latter are consistent with one of two abrasion directions measured in previous studies, prior to the rover's arrival at the Murray Formation mudstones, and probably reflect the preservation of an ancient sand‐driving wind regime that differs from that of the present.

The Mars Science Laboratory Curiosity rover has explored over 400 m of vertical stratigraphy within Gale crater to date. These fluvio-deltaic, lacustrine, and aeolian strata have been well-documented by Curiosity's in situ and remote science instruments, including the Mast Camera (Mastcam) pair of multispectral imagers. Mastcam visible to near-infrared spectra can broadly distinguish between iron phases and oxidation states, and in combination with chemical data from other instruments, Mastcam spectra can help constrain mineralogy, depositional origin, and diagenesis. However, no traverse-scale analysis of Mastcam multispectral data has yet been performed. We compiled a database of Mastcam spectra from >600 multispectral observations and quantified spectral variations across Curiosity's traverse through Vera Rubin ridge (sols 0-2302). From principal component analysis and an examination of spectral parameters, we identified nine rock spectral classes and five soil spectral classes. Rock classes are dominated by spectral differences attributed to hematite and other oxides (due to variations in grain size, composition, and abundance) and are mostly confined to specific stratigraphic members. Soil classes fall along a mixing line between soil spectra dominated by fine-grained Fe-oxides and those dominated by olivine-bearing sands. By comparing trends in soil versus rock spectra, we find that locally derived sediments are not significantly contributing to the spectra of soils. Rather, varying contributions of dark, mafic sands from the active Bagnold Dune field is the primary spectral characteristic of soils. These spectral classes and their trends with stratigraphy provide a basis for comparison in Curiosity's ongoing exploration of Gale crater.

Perseverance landed at the Octavia E. Butler landing site next to the Seitah dune region in Jezero crater on 18 February 2021, in close proximity...

Perseverance images of a delta on Mars The Perseverance rover landed in Jezero crater, Mars, in February 2021. Earlier orbital images showed that the crater contains an ancient river delta that was deposited by water flowing into a lake billions of years ago. Mangold et al . analyzed rover images taken shortly after landing that show distant cliff faces at the edge of the delta. The exposed stratigraphy and sizes of boulders allowed them to determine the past lake level and water discharge rates. An initially steady flow transitioned into intermittent floods as the planet dried out. This history of the delta’s geology provides context for the rest of the mission and improves our understanding of Mars’ ancient climate. —KTS

International audience; On February 18, 2021 NASA's Perseverance rover landed in Jezero crater, located at the northwestern edge of the Isidis basin on Mars. The uppermost surface of the present-day crater floor is dominated by a distinct geologic assemblage previously referred to as the dark-toned floor. It consists of a smooth, dark-toned unit overlying and variably covering light-toned, roughly eroded deposits showing evidence of discrete layers. In this study, we investigated the stratigraphic relations between materials that comprise this assemblage, the main western delta deposit, as well as isolated mesas located east of the main delta body that potentially represent delta remnants. A more detailed classification and differentiation of crater floor units in Jezero and determination of their relative ages is vital for the understanding of the geologic evolution of the crater system, and determination of the potential timeline and environments of habitability. We have investigated unit contacts using topographic profiles and DEMs as well as the distribution of small craters and fractures on the youngest portions of the crater floor. Our results indicate that at least some of the deltaic deposition in Jezero postdates emplacement of the uppermost surface of the crater floor assemblage. The inferred age of the floor assemblage can therefore help to constrain the timing of the Jezero fluviolacustrine system, wherein at least some lake activity postdates the age of the uppermost crater floor. We present hypotheses that can be tested by Perseverance and can be used to advance our knowledge of the geologic evolution of the area.

The Mars Science Laboratory Curiosity rover conducted a reconnaissance traverse across the Pahrump Hills outcrop within Gale crater from Sols 780–797. During the traverse, the Mars Descent Imager (MARDI) acquired a continuous imaging record of primary and secondary sedimentary features throughout the outcrop. The characteristics of the features (laminae, resistant features, fractures, gray clasts) and their spatial distribution provide insight into the processes that contributed to the formation of Pahrump Hills. Thin, regular laminae (mm-scale) are ubiquitous in the bedrock, implying that depositional processes at that scale did not change appreciably during deposition of the mudstone succession at Pahrump Hills. Higher bedrock slopes correlate with undulatory bedrock surfaces, bedrock with elevated Mg contents, and fractures exhibiting wide, raised edges. These collective features are consistent with increased erosional resistance caused by greater quantities of erosionally-resistant, Mg-bearing cement within the bedrock permitted by coarser grain sizes. Resistant features exhibit a range of morphologies, elevated Mg contents, and do not deflect laminae within the bedrock. Their characteristics implicate the involvement of Mg-enriched fluids in a late diagenetic overprint affecting the bedrock. The variations of fracture fill and edge morphologies and chemistries further suggest repeated fracturing and fluid interaction events within the strata exposed at Pahrump Hills. Gray clasts strongly resemble fragments eroded from sandstone horizons interspersed throughout the Pahrump Hills outcrop.

Stack, K. et al., The Mars 2020 Perseverance rover landing site is located within Jezero crater, a ∼50km diameter impact crater interpreted to be a Noachian-aged lake basin inside the western edge of the Isidis impact structure. Jezero hosts remnants of a fluvial delta, inlet and outlet valleys, and infill deposits containing diverse carbonate, mafic, and hydrated minerals. Prior to the launch of the Mars 2020 mission, members of the Science Team collaborated to produce a photogeologic map of the Perseverance landing site in Jezero crater. Mapping was performed at a 1:5000 digital map scale using a 25 cm/pixel High Resolution Imaging Science Experiment (HiRISE) orthoimage mosaic base map and a 1 m/pixel HiRISE stereo digital terrain model. Mapped bedrock and surficial units were distinguished by differences in relative brightness, tone, topography, surface texture, and apparent roughness. Mapped bedrock units are generally consistent with those identified in previously published mapping efforts, but this study’s map includes the distribution of surficial deposits and sub-units of the Jezero delta at a higher level of detail than previous studies. This study considers four possible unit correlations to explain the relative age relationships of major units within the map area. Unit correlations include previously published interpretations as well as those that consider more complex interfingering relationships and alternative relative age relationships. The photogeologic map presented here is the foundation for scientific hypothesis development and strategic planning for Perseverance’s exploration of Jezero crater., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)

Geochemical results are presented from Curiosity's exploration of Vera Rubin ridge (VRR), in addition to the full chemostratigraphy of the predominantly lacustrine mudstone Murray formation up to and including VRR. VRR is a prominent ridge flanking Aeolis Mons (informally Mt. Sharp), the central mound in Gale crater, Mars, and was a key area of interest for the Mars Science Laboratory mission. ChemCam data show that VRR is overall geochemically similar to lower-lying members of the Murray formation, even though the top of VRR shows a strong hematite spectral signature as observed from orbit. Although overall geochemically similar, VRR is characterized by a prominent decrease in Li abundance and Chemical Index of Alteration across the ridge. This decrease follows the morphology of the ridge rather than elevation and is inferred to reflect a nondepositionally controlled decrease in clay mineral abundance in VRR rocks. Additionally, a notable enrichment in Mn above baseline levels is observed on VRR. While not supporting a single model, the results suggest that VRR rocks were likely affected by multiple episodes of postdepositional groundwater interactions that made them more erosionally resistant than surrounding Murray rocks, thus resulting in the modern-day ridge after subsequent erosion.

The Dynamic Albedo of Neutrons instrument aboard the Mars Science Laboratory rover, Curiosity, has been used to map a stratigraphically conformable layer of high-SiO (Formula presented.) material in Gale crater. Previous work has shown that this material contains tridymite, a high-temperature/low-pressure felsic mineral, interpreted to have a volcanic source rock. We describe several characteristics including orientation, extent, hydration, and geochemistry, consistent with a volcaniclastic material conformably deposited within a lacustrine mudstone succession. Relationships with widely dispersed alteration features and orbital detections of hydrated SiO (Formula presented.) suggest that this high-SiO (Formula presented.) layer extends at least 17 km laterally. Mineralogical abundances previously reported for this high-SiO (Formula presented.) material indicated that hydrous species were restricted to the amorphous (non-crystalline) fraction, which is dominated by SiO (Formula presented.). The low mean bulk hydration of this high-SiO (Formula presented.) layer (1.85 (Formula presented.) 0.13 wt.% water-equivalent hydrogen) is consistent with silicic glass in addition to opal-A and opal-CT. Persistent volcanic glass and tridymite in addition to opal in an ancient sedimentary unit indicates that the conversion to more ordered forms of crystalline SiO (Formula presented.) has not proceeded to completion and that this material has had only limited exposure to water since it originally erupted, despite having been transported in a fluviolacustrine system. Our results, including the conformable nature, large areal extent, and presence of volcanic glass, indicate that this high-SiO (Formula presented.) material is derived from the product of evolved magma on Mars. This is the first identification of a silicic volcaniclastic layer on another planet and has important implications for magma evolution mechanisms on single-plate planets.

The Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) spacecraft landed successfully on Mars and imaged the surface to characterize the surficial geology. Here we report on the geology and subsurface structure of the landing site to aid in situ geophysical investigations. InSight landed in a degraded impact crater in Elysium Planitia on a smooth sandy, granule- and pebble-rich surface with few rocks. Superposed impact craters are common and eolian bedforms are sparse. During landing, pulsed retrorockets modified the surface to reveal a near surface stratigraphy of surficial dust, over thin unconsolidated sand, underlain by a variable thickness duricrust, with poorly sorted, unconsolidated sand with rocks beneath. Impact, eolian, and mass wasting processes have dominantly modified the surface. Surface observations are consistent with expectations made from remote sensing data prior to landing indicating a surface composed of an impact-fragmented regolith overlying basaltic lava flows., The InSight spacecraft landed on Mars on November 2018. Here, the authors characterize the surficial geology of the landing site and compare with observations and models derived from remote sensing data prior to landing and from ongoing in situ geophysical investigations of the subsurface.

This study reports in-situ sedimentologic evidence of giant floods in Gale crater, Mars, during the Noachian Period. Features indicative of floods are a series of symmetrical, 10 m-high gravel ridges that occur in the Hummocky Plains Unit (HPU). Their regular spacing, internal sedimentary structures, and bedload transport of fragments as large as 20 cm suggest that these ridges are antidunes: a type of sedimentary structure that forms under very strong flows. Their 150 m wavelength indicates that the north-flowing water that deposited them was at least 24 m deep and had a minimum velocity of 10 m/s. Floods waned rapidly, eroding antidune crests, and re-deposited removed sediments as patches on the up-flow limbs and trough areas between these ridges forming the Striated Unit (SU). Each patch of the SU is 50–200 m wide and long and consists of 5–10 m of south-dipping layers. The strike and dip of the SU layers mimic the attitude of the flank of the antidune on which they were deposited. The most likely mechanism that generated flood waters of this magnitude on a planet whose present-day average temperature is − 60 °C was the sudden heat produced by a large impact. The event vaporized frozen reservoirs of water and injected large amounts of CO and CH from their solid phases into the atmosphere. It temporarily interrupted a cold and dry climate and generated a warm and wet period. Torrential rainfall occurred planetwide some of which entered Gale crater and combined with water roaring down from Mt. Sharp to cause gigantic flash floods that deposited the SU and the HPU on Aeolis Palus. The warm and wet climate persisted even after the flooding ended, but its duration cannot be determined by our study., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)

Knowing precisely where a spacecraft lands on Mars is important for understanding the regional and local context, setting, and the offset between the inertial and cartographic frames. For the InSight spacecraft, the payload of geophysical and environmental sensors also particularly benefits from knowing exactly where the instruments are located. A ~30 cm/pixel image acquired from orbit after landing clearly resolves the lander and the large circular solar panels. This image was carefully georeferenced to a hierarchically generated and coregistered set of decreasing resolution orthoimages and digital elevation models to the established positive east, planetocentric coordinate system. The lander is located at 4.502384°N, 135.623447°E at an elevation of −2,613.426 m with respect to the geoid in Elysium Planitia. Instrument locations (and the magnetometer orientation) are derived by transforming from Instrument Deployment Arm, spacecraft mechanical, and site frames into the cartographic frame. A viewshed created from 1.5 m above the lander and the high‐resolution orbital digital elevation model shows the lander is on a shallow regional slope down to the east that reveals crater rims on the east horizon ~400 m and 2.4 km away. A slope up to the north limits the horizon to about 50 m away where three rocks and an eolian bedform are visible on the rim of a degraded crater rim. Azimuths to rocks and craters identified in both surface panoramas and high‐resolution orbital images reveal that north in the site frame and the cartographic frame are the same (within 1°)., Key Points A carefully georeferenced high‐resolution image of the InSight lander shows it is located at 4.5024N, 135.6234E in Elysium Planitia, MarsInstrument locations are derived by transforming from spacecraft and site frames into the cartographic frameA viewshed shows the lander is on a shallow regional slope down to the east and a local slope up to the north

The Sample Analysis at Mars instrument evolved gas analyzer (SAM-EGA) has detected evolved water, H2, SO2, H2S, NO, CO2, CO, O2 and HCl from two eolian sediments and nine sedimentary rocks from Gale Crater, Mars. These evolved gas detections indicate nitrates, organics, oxychlorine phase, and sulfates are widespread with phyllosilicates and carbonates occurring in select Gale Crater materials. Coevolved CO2 (160 ± 248 - 2373 ± 820 μgC(CO2)/g), and CO (11 ± 3 - 320 ± 130 μgC(CO)/g) suggest organic-C is present in Gale Crater materials. Five samples evolved CO2 at temperatures consistent with carbonate (0.32± 0.05 - 0.70± 0.1 wt.% CO3). Evolved NO amounts to 0.002 ± 0.007 - 0.06 ± 0.03 wt.% NO3. Evolution of O2 suggests oxychlorine phases (chlorate/perchlorate) (0.05 ± 0.025 - 1.05 ± 0.44wt. % ClO4) are present while SO2 evolution indicates the presence of crystalline and/or poorly crystalline Fe- and Mg-sulfate and possibly sulfide. Evolved H2O (0.9 ± 0.3 - 2.5 ± 1.6 wt.% H2O) is consistent with the presence of adsorbed water, hydrated salts, interlayer/structural water from phyllosilicates, and possible inclusion water in mineral/amorphous phases. Evolved H2 and H2S suggest reduced phases occur despite the presence of oxidized phases (nitrate, oxychlorine, sulfate, carbonate). SAM results coupled with CheMin mineralogical and APXS elemental analyses indicate that Gale Crater sedimentary rocks have experienced a complex authigenetic/diagenetic history involving fluids with varying pH, redox, and salt composition. The inferred geochemical conditions were favorable for microbial habitability and if life ever existed, there was likely sufficient organic-C to support a small microbial population.

Diagenetic silica enrichment in fracture-associated halos that crosscut lacustrine and unconformably overlying aeolian sedimentary bedrock is observed on the lower north slope of Aeolis Mons in Gale crater, Mars. The diagenetic silica enrichment is colocated with detrital silica enrichment observed in the lacustrine bedrock yet extends into a considerably younger, unconformably draping aeolian sandstone, implying that diagenetic silica enrichment postdates the detrital silica enrichment. A causal connection between the detrital and diagenetic silica enrichment implies that water was present in the subsurface of Gale crater long after deposition of the lacustrine sediments and that it mobilized detrital amorphous silica and precipitated it along fractures in the overlying bedrock. Although absolute timing is uncertain, the observed diagenesis likely represents some of the most recent groundwater activity in Gale crater and suggests that the timescale of potential habitability extended considerably beyond the time that the lacustrine sediments of Aeolis Mons were deposited.

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 Mt. 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 K_2O 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 Mt. Sharp, a process that has continued to the present day.

This study provides the first systematic comparison of orbital facies maps with detailed ground-based geology observations from the Mars Science Laboratory (MSL) Curiosity rover to examine the validity of geologic interpretations derived from orbital image data. Orbital facies maps were constructed for the Darwin, Cooperstown, and Kimberley waypoints visited by the Curiosity rover using High Resolution Imaging Science Experiment (HiRISE) images. These maps, which represent the most detailed orbital analysis of these areas to date, were compared with rover image-based geologic maps and stratigraphic columns derived from Curiosity's Mast Camera (Mastcam) and Mars Hand Lens Imager (MAHLI). Results show that bedrock outcrops can generally be distinguished from unconsolidated surficial deposits in high-resolution orbital images and that orbital facies mapping can be used to recognize geologic contacts between well-exposed bedrock units. However, process-based interpretations derived from orbital image mapping are difficult to infer without known regional context or observable paleogeomorphic indicators, and layer-cake models of stratigraphy derived from orbital maps oversimplify depositional relationships as revealed from a rover perspective. This study also shows that fine-scale orbital image-based mapping of current and future Mars landing sites is essential for optimizing the efficiency and science return of rover surface operations.

The Instrument Site Selection and deployment for the upcoming Mars InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) Lander is highly dependent on image products, particularly mosaics, created from the Instrument Deployment Camera (IDC) and Instrument Context Camera (ICC). When data are downlinked, the Multimission Image Processing Lab (MIPL) at JPL will process image and instrument data to aid in the deployment and monitoring of these instruments. MIPL’s functions include raw telemetry processing, stereo correlation, mosaic generation, terrain mesh generation, radiometric correction, pointing correction (bundle adjustment), and the creation of products such as instrument deployment maps, surface normal products, slope products, XYZ point clouds, and roughness map layers. A software pipeline performs systematic, automated execution of the programs that create these products on every image and stereo pair received, while the pointing correction and most mosaics are hand-generated by the MIPL team members for testing and surface operations. Several mission operations software packages are used to view, query, and analyze the processed images and mosaics for placing the main science instruments for the mission.

By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars’ surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking’s Mars seismic monitoring by a factor of ∼2500 at 1 Hz and ∼200000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars’ surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of Mw∼3 at 40∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution., Space Science Reviews, 215 (1), ISSN:1572-9672, ISSN:0038-6308

The Curiosity rover observed high Mn abundances (>25 wt % MnO) in fracture-filling materials that crosscut sandstones in the Kimberley region of Gale crater, Mars. The correlation between Mn and trace metal abundances plus the lack of correlation between Mn and elements such as S, Cl, and C, reveals that these deposits are Mn oxides rather than evaporites or other salts. On Earth, environments that concentrate Mn and deposit Mn minerals require water and highly oxidizing conditions; hence, these findings suggest that similar processes occurred on Mars. Based on the strong association between Mn-oxide deposition and evolving atmospheric dioxygen levels on Earth, the presence of these Mn phases on Mars suggests that there was more abundant molecular oxygen within the atmosphere and some groundwaters of ancient Mars than in the present day.

Recurring Slope Lineae, RSL, are visible steaks on the sides of Martian craters and other steep landforms with three distinct characteristics: i) they occur seasonally, ii) they lengthen with time, and iii) they fade. Recently, 474 RSL-like (>= 1 characteristic) and 69 RSL (all 3 characteristics) sites have been identified and are located in four primary regions of Mars: Chryse and Acidalia Planitiae, Valles Marineras, the Equatorial highlands, and the Southern Mid-Latitudes. There are several hypotheses that explain the origin of RSL, ranging from the motion of dry, granular material downhill, to the presence of underground aquifers. These hypotheses can be partially resolved by proximal ( = 1km) observations. However, complete disambiguation can only be achieved through surface contact science. The Jet Propulsion Laboratory recently conducted a study into the methods by which a landed asset could access RSL sites to assist in the separation of RSL hypotheses. During this study, 8 of the 69 RSL sites were considered to be landable based on their latitude, elevation, topography, and ability to support an 8 km landing ellipse. In this paper, the accessibility of these sites is detailed through a discussion of their geometry, terrain types, slope and surface roughness. Particular attention is paid to three craters: Selevac, Andapa, and Garni, which were assessed to be strong candidates for scientific investigation. The challenges of accessibility provide the basis for which an assessment of the concepts of operation of 22 architectures is given. Though individually assessed, these concepts can be broadly compiled into balloon, helicopter, missile, and ground ascent/descent groups. First order sizing, power, and mass calculations for each group are detailed along with their advantages and concept specific challenges. The merits of each concept is assessed as a function of the science they enable, technology readiness and feasibility, cost, and risk. A ranking matrix is presented along with selected weightings. Based on the results of the trade study, the highest rated concepts are identified and their next stages of analysis and development are proposed.

We report on the first 360 sols (LS 150° to 5°), representing just over half a Martian year, of atmospheric monitoring movies acquired using the NavCam imager from the Mars Science Laboratory (MSL) Rover Curiosity. Such movies reveal faint clouds that are difficult to discern in single images. The data set acquired was divided into two different classifications depending upon the orientation and intent of the observation. Up to sol 360, 73 Zenith movies and 79 Supra-Horizon movies have been acquired and time-variable features could be discerned in 25 of each. The data set from MSL is compared to similar observations made by the Surface Stereo Imager (SSI) onboard the Phoenix Lander and suggests a much drier environment at Gale Crater (4.6°S) during this season than was observed in Green Valley (68.2°N) as would be expected based on latitude and the global water cycle. The optical depth of the variable component of clouds seen in images with features are up to 0.047 ± 0.009 with a granularity to the features observed which averages 3.8°. MCS also observes clouds during the same period of comparable optical depth at 30 and 50 km that would suggest a cloud spacing of 2.0 to 3.3 km. Multiple motions visible in atmospheric movies support the presence of two distinct layers of clouds. At Gale Crater, these clouds are likely caused by atmospheric waves given the regular spacing of features observed in many Zenith movies and decreased spacing towards the horizon in sunset movies consistent with clouds forming at a constant elevation. Reanalysis of Phoenix data in the light of the NavCam equatorial dataset suggests that clouds may have been more frequent in the earlier portion of the Phoenix mission than was previously thought.

The Navigation Cameras (Navcam) of the Mars Science Laboratory rover, Curiosity, have been used to examine two aspects of the planetary boundary layer: vertical dust distribution and dust devil frequency. The vertical distribution of dust may be obtained by using observations of the distant crater rim to derive a line-of-sight optical depth within Gale Crater and comparing this optical depth to column optical depths obtained using Mastcam observations of the solar disc. The line of sight method consistently produces lower extinctions within the crater compared to the bulk atmosphere. This suggests a relatively stable atmosphere in which dust may settle out leaving the air within the crater clearer than air above and explains the correlation in observed column opacity between the floor of Gale Crater and the higher elevation Meridiani Planum. In the case of dust devils, despite an extensive campaign only one optically thick vortex (τ = 1.5 ± 0.5 × 10−3) was observed compared to 149 pressure events >0.5 Pa observed in REMS pressure data. Correcting for temporal coverage by REMS and geographic coverage by Navcam still suggests 104 vortices should have been viewable, suggesting that most vortices are dustless. Additionally, the most intense pressure excursions observed on other landing sites (pressure drop >2.5 Pa) are lacking from the observations by the REMS instrument. Taken together, these observations are consistent with pre-landing circulation modeling of the crater showing a suppressed, shallow boundary layer. They are further consistent with geological observations of dust that suggests the northern portion of the crater is a sink for dust in the current era.

International audience; The Yellowknife Bay formation represents a similar to 5m thick stratigraphic section of lithified fluvial and lacustrine sediments analyzed by the Curiosity rover in Gale crater, Mars. Previous works have mainly focused on the mudstones that were drilled by the rover at two locations. The present study focuses on the sedimentary rocks stratigraphically above the mudstones by studying their chemical variations in parallel with rock textures. Results show that differences in composition correlate with textures and both manifest subtle but significant variations through the stratigraphic column. Though the chemistry of the sediments does not vary much in the lower part of the stratigraphy, the variations in alkali elements indicate variations in the source material and/or physical sorting, as shown by the identification of alkali feldspars. The sandstones contain similar relative proportions of hydrogen to the mudstones below, suggesting the presence of hydrous minerals that may have contributed to their cementation. Slight variations in magnesium correlate with changes in textures suggesting that diagenesis through cementation and dissolution modified the initial rock composition and texture simultaneously. The upper part of the stratigraphy (similar to 1m thick) displays rocks with different compositions suggesting a strong change in the depositional system. The presence of float rocks with similar compositions found along the rover traverse suggests that some of these outcrops extend further away in the nearby hummocky plains.

The selection of the Discovery Program InSight landing site took over four years from initial identification of possible areas that met engineering constraints, to downselection via targeted data from orbiters (especially Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) and High-Resolution Imaging Science Experiment (HiRISE) images), to selection and certification via sophisticated entry, descent and landing (EDL) simulations. Constraints on elevation ( ${\leq}{-}2.5\ \mbox{km}$ for sufficient atmosphere to slow the lander), latitude (initially 15°S–5°N and later 3°N–5°N for solar power and thermal management of the spacecraft), ellipse size (130 km by 27 km from ballistic entry and descent), and a load bearing surface without thick deposits of dust, severely limited acceptable areas to western Elysium Planitia. Within this area, 16 prospective ellipses were identified, which lie ∼600 km north of the Mars Science Laboratory (MSL) rover. Mapping of terrains in rapidly acquired CTX images identified especially benign smooth terrain and led to the downselection to four northern ellipses. Acquisition of nearly continuous HiRISE, additional Thermal Emission Imaging System (THEMIS), and High Resolution Stereo Camera (HRSC) images, along with radar data confirmed that ellipse E9 met all landing site constraints: with slopes

We present the results of a systematic mapping of seasonally sculpted terrains on the South Polar region of Mars with the Planet Four: Terrains (P4T) online citizen science project. P4T enlists members of the general public to visually identify features in the publicly released Mars Reconnaissance Orbiter CTX images. In particular, P4T volunteers are asked to identify: 1) araneiforms (including features with a central pit and radiating channels known as 'spiders'); 2) erosional depressions, troughs, mesas, ridges, and quasi-circular pits characteristic of the South Polar Residual Cap (SPRC) which we collectively refer to as 'Swiss cheese terrain', and 3) craters. In this work we present the distributions of our high confidence classic spider araneiforms and Swiss cheese terrain identifications. We find no locations within our high confidence spider sample that also have confident Swiss cheese terrain identifications. Previously spiders were reported as being confined to the South Polar Layered Deposits (SPLD). Our work has provided the first identification of spiders at locations outside of the SPLD, confirmed with high resolution HiRISE imaging. We find araneiforms on the Amazonian and Hesperian polar units and the Early Noachian highland units, with 75% of the identified araneiform locations in our high confidence sample residing on the SPLD. With our current coverage, we cannot confirm whether these are the only geologic units conducive to araneiform formation on the Martian South Polar region. Our results are consistent with the current CO2 jet formation scenario with the process exploiting weaknesses in the surface below the seasonal CO2 ice sheet to carve araneiform channels into the regolith over many seasons. These new regions serve as additional probes of the conditions required for channel creation in the CO2 jet process. (Abridged), Comment: accepted to Icarus - Supplemental data files are available at https://www.zooniverse.org/projects/mschwamb/planet-four-terrains/about/results - Icarus print version available at http://www.sciencedirect.com/science/article/pii/S0019103517300556