The composition and layering of the Martian crust provide important constraints on planetary crustal evolution as well as on present-day conditions, e.g., with regard to the presence of liquid water or ice. The seismic data of the InSight mission yielded new and critical information on crustal structure at several locations on Mars. Here, we use rock physical models to investigate the range of lithologies, porosities and alteration scenarios compatible with seismic P- and S-wave velocities as well as vP/vS ratios from InSight. We find that present-day crustal porosity extends to 20-25 km depth at all sampled locations, with large Noachian impacts as main drivers for the creation of porosity, and viscous pore closure as likely agent of removal of porosity at depth, resulting in a discontinuous increase in seismic velocities. Spatially heterogeneous seismic velocities can be related to differences in porosity that could be caused by subsequent localized magmatic activity. At the InSight landing site, where seismic data indicate a four-layered crust, hydrated minerals as traces of aqueous alteration are present throughout the crust, though the water within these minerals could be fairly limited at 0.3 wt% or less. The most likely types of hydrated minerals are also consistent with a post-depositional environment that was limited in water. The velocity increase at about 10 km depth beneath InSight can either be attributed to a change in composition from felsic to basaltic, or to a change in porosity by the deposition of Utopia ejecta. A felsic component to the crust, e.g. due to impact-generated buoyant partial melts, can accordingly not be excluded, but would not be present globally. Seismic and geological constraints for the layer at approximately 200 m to 2000 m depth beneath the lander strongly favor basaltic Noachian sediments saturated with a mixture of up to 10 % ice and brine. However, the lateral extent of this present day aquifer is not constrained by the available data.

The InSight mission is a geophysical mission aimed at better understanding the structure of Mars and of the other rocky planets of the solar system. To do so, a lander accommodating two cameras, a very sensitive seismometer, and a dynamic self-penetrating heat probe nicknamed the mole were placed on the Mars surface by the Instrument Deployment Arm (IDA). Besides geophysical data (which definitely enriched the existing knowledge on the structure of Mars), the InSight instruments significantly increased the knowledge of the geological and geotechnical characteristics of the surface material at the InSight site. Small strain (elastic) parameters were derived from wave velocity measurements during the hammering sessions between the self-penetrating probe and the seismometer. A detailed observation of the soil profile along a depth of 37 cm was made possible thanks to the photos taken by the cameras, and to a detailed analysis of the mole penetration process. Further information was provided by an intense campaign of scraping and piling conducted by the IDA on the surface sand/dust layer. It was shown that the soil profile was composed of a surface 1 cm thick sand/dust layer, overlaying an around 20 cm thick loose duricrust made up of a cohesive matrix containing some pebbles, located above a 12 cm layer of sand overlaying a gravel/sand deposit. It is believed that the geology and soil mechanics data provided by the InSight mission will help for further robotic exploration of Mars.

The InSight lander carried an Instrument Deployment System (IDS) that included an Instrument Deployment Arm (IDA), scoop, five finger “claw” grapple, forearm-mounted Instrument Deployment Camera (IDC) requiring arm motion to image a target, and lander-mounted Instrument Context Camera (ICC), designed to image the workspace, and to place the instruments onto the surface. As originally proposed, the IDS included a previously built arm and flight spare black and white cameras and had no science objectives or requirements, or expectation to be used after instrument deployment (90 sols). During project development the detectors were upgraded to color, and it was recognized that the arm could be used to carry out a wide variety of activities that would enable both geology and physical properties investigations. During surface operations for two martian years, the IDA was used during major campaigns to image the surface around the lander, to deploy the instruments, to assist the mole in penetrating beneath the surface, to bury a portion of the seismometer tether, to clean dust from the solar arrays to increase power, and to conduct a surface geology investigation including soil mechanics and physical properties experiments. No other surface mission has engaged in such a sustained and varied campaign of arm and scoop activities directed at such a diverse suite of objectives. Images close to the surface and continuous meteorology measurements provided important constraints on the threshold friction wind speed needed to initiate aeolian saltation and surface creep. The IDA was used extensively for almost 22 months to assist the mole in penetrating into the subsurface. Soil was scraped into piles and dumped onto the seismometer tether six times in an attempt to bury the tether and ∼30% was entrained in the wind and dispersed downwind 1-2 m, darkening the surface. Seven solar array cleaning experiments were conducted by dumping scoops of soil from 35 cm above the lander deck during periods of high wind that dispersed the sand onto the panels that kicked dust off of the panels into suspension in the atmosphere, thereby increasing the power by ∼15

Abstract Water ice in the Martian mid‐latitudes has advanced and retreated in response to variations in the planet's orbit, obliquity, and climate. A 150 m‐diameter new impact crater near 35°N provides the lowest‐latitude impact exposure of subsurface ice on Mars. This is the largest known ice‐exposing crater and provides key constraints on Martian climate history. This crater indicates a regional, relatively pure ice deposit that is unstable and has nearly vanished. In the past, this deposit may have been tens of meters thick and extended equatorward of 35°N. We infer that it is overlain by pore ice emplaced during temporary stable intervals, due to recent climate variability. The marginal survival of ice here suggests that it is near the edge of shallow ice that regularly exchanges with the atmosphere.

This upload contains four distinct zipped files with several different datasets contained within used for the analysis in publication "Investigating the role of Amazonian mesoscale wind patterns and strength on the spatial distribution of Martian bedrock exposures" by Gary-Bicas et al., 2022 Description for each dataset is below. - External data (Contains data used for thermophysical and morphological analysis). binary files NBmap2007.bin (Putzig and Mellon, 2007) and nmap2003.bin( Putzig et al., 2005) . These contain global Mars thermal inertia maps using the Thermal Emission Spectrometer (TES) onboard Mars Global Surveyor (MGS) Comma separated files with terminations "...USGS.csv" these are files extracting data for the studies' regions from the Mars global USGS geologic map #3292 (Tanaka et al., 2014) Shape file for bedrock designations (bedrock.[shp,shx,prj,dbf]) created by Cowart et al., 2019 where they mapped locations with bedrock exposures on Mars. We also include comma separated value files of the same maps for locations studied in this analysis (files with termination "...bedrock.csv") Shape file included has the locations of craters identified in all study regions for analysis (craters.point.[shp,shx,prj,dbf] and craters.polygon.[shp,shx,prj,dbf]) paired with the comma separated value intracrat.csv Shape file with study locations for analysis (windo_modeling_locations_revised3.[shp,shx,prj,dbf]) - MRAMS data files.zip Contains 11 simulated climate states for each of the ten study location in analysis as well as Jezero crater using the Mars Regional Atmospheric Modeling System (MRAMS, Rafkin and Michaels, 2019). For each simulated case there are 4 seasonal time steps equating to 44 simulated cases for each study region in total (484 files) see associated python software publication indicating ingestion and processing of MRAMS datasets - MRAMS output files.zip After ingesting the datasets in MARS data files.zip into a python algorithm (see associated software publication) values for Wind Erosion Potential were extracted from the datasets and weighted sums were conducted to get annual values (see manuscript publication and associated python software publication,"MRAMS Data Output.ipynb") data was output into comma separated values for ease of use -MRAMS elevation and slope files.zip MRAMS data from output files.zip was further ingested into other algorithms to extract elevation and terrain slope values (see associated python software publication, "MRAMS Data Output.ipynb") that were output into comma separated values for ease of use

We present a geomorphic map of the Hypanis Valles watershed and a geomorphic map of the Hypanis deposit region at its terminus. We mapped these two regions at different scales: 1:2,000,000 for the catchment map (−5° to 10°N and 300°–315°E) and 1:500,000 for the Hypanis deposit map (10°–13.0°N and 313°–316.5°E). Our mapping provides new morphologic insights beyond previous efforts which used lower spatial resolution data. We defined units based on morphology, albedo, thermal inertia, elevation, and spectral parameters. We propose that episodic volcanism and aqueous activity filled the Chryse basin from the early Noachian. Hypanis Valles was active during the Noachian, forming the Hypanis terminal deposits in the southern Chryse region. Hundreds of kilometer‐sized mounds and cones stratigraphically post‐date Hypanis fluvial deposition as these features appear to have erupted or effused through all other major map units. We propose sedimentary diapirism or mud volcanism may be responsible for these features, a hypothesis consistent with the compressional wrinkle ridge tectonism in a sedimentary basin. Future work could further investigate the formation of these cones and mounds and better assess their astrobiologic importance.

The InSight lander rests on a regolith‐covered, Hesperian to Early Amazonian lava plain in Elysium Planitia within a ∼27‐m‐diameter, degraded impact crater called Homestead hollow. The km to cm‐scale stratigraphy beneath the lander is relevant to the mission's geophysical investigations. Geologic mapping and crater statistics indicate that ∼170 m of mostly Hesperian to Early Amazonian basaltic lavas are underlain by Noachian to Early Hesperian (∼3.6 Ga) materials of possible sedimentary origin. Up to ∼140 m of this volcanic resurfacing occurred in the Early Amazonian at 1.7 Ga, accounting for removal of craters ≤700 m in diameter. Seismic data however, suggest a clastic horizon that interrupts the volcanic sequence between depths of ∼30 and ∼75 m. Meter‐scale stratigraphy beneath the lander is constrained by local and regional regolith thickness estimates that indicate up to 10–30 m of coarse‐grained, brecciated regolith that fines upwards to a ∼3 m thick loosely‐consolidated, sand‐dominated unit. The maximum depth of Homestead hollow, at ∼3 m, indicates that the crater is entirely embedded in regolith. The hollow is filled by sand‐size eolian sediments, with contributions from sand to cobble‐size slope debris, and sand to cobble‐size ejecta. Lander‐based observations indicate that the fill at Homestead hollow contains a cohesive layer down to ∼10–20 cm depth that is visible in lander rocket‐excavated pits and the HP3 mole hole. The surface of the landing site is capped by a ∼1 to 2 cm‐thick loosely granular, sand‐sized layer with a microns‐thick surficial dust horizon.

Rock shapes and heights around the InSight lander are examined to refine the degradation history of the 27 m‐diameter Homestead hollow . Results document decreasing average exposed rock height and increasing percentage of rocks where height comprises the short axis from outside to within the hollow and support prior models of ejecta deflation accompanied by hollow infilling. We estimate 0.3 m of deflation at the current rim that is realistic compared to rock relief, original ejecta thickness, and predicted aeolian contributions to infilling. We also find that shapes of embayed basalt rocks outside the hollow appear platy, bladed, and elongate in a triangular form factor plot, and more discoidal and bladed in an axes ratio plot. By contrast, expected shapes based on terrestrial studies of basalt rocks are mostly compact, compact platy, compact bladed, compact elongated, platy, bladed, and elongate in triangular form factor plots, and equant with lesser, but significant disc‐ and blade‐shaped rocks in axes ratio plots. We find addition of 10 cm to the heights of rocks near the hollow rim, to account for continued partial embedding in ejecta, yields the best match between observed and expected rock shapes. Exposure of small ejecta rocks in the hollow supports degradation rates of 10 −4 m/Myr during most of hollow history. Results indicate that deflation from ejecta accompanied by downwind deposition in the hollow can account for the current degraded form of the crater. Our approach is a new tool for characterizing small crater degradation on regolith‐covered lava plains on Mars.

We report the aeolian changes observed in situ by NASA's InSight lander during the first 400 sols of operations: Granule creep, saltation, dust removal, and the formation of dark surface tracks. Aeolian changes are infrequent and sporadic. However, on sols, when they do occur, they consistently appear between noon to 3 p.m., and are associated with the passage of convective vortices during periods of high vortex activity. Aeolian changes are more frequent at elevated locations, such as the top surfaces of rocks and lander footpads. InSight observed these changes using, for the first time, simultaneous in‐situ and orbital imaging and high‐frequency meteorological, seismological, and magnetic measurements. Seismometer measurements of ground acceleration constrain the timing and trajectory of convective vortex encounters, linking surface changes to source vortices. Magnetometer measurements show perturbations in magnetic field strength during the passage of convective vortices consistent with charged‐particle motion. Detachment of sand‐scale particles occurs when high background winds and vortex‐induced turbulence provide a peak surface friction wind speed above the classic saltation fluid threshold. However, detachment of dust‐ and granule‐scale particles also occurred when the surface friction wind speed remained below this threshold. This may be explained by local enhancement of the surface roughness and other effects described here and further studied in Part 2 (Baker et al., 2021). The lack of saltation and bright dust‐coated surfaces at the InSight landing site implies surface stability and the onset of particle motion may be suppressed by dust “cushioning.” This differentiates the InSight landing site from other areas on Mars that exhibit more aeolian activity.

The InSight mission landed on Mars in November 2018 and has since observed multiple convective vortices with both the high performance barometer and the low‐noise seismometer SEIS that has unprecedented sensitivity. Here, we present a new method that uses the simultaneous pressure and seismic measurements of convective vortices to place constraints on the elastic properties of the Martian subsurface and the Martian vortex properties, while also allowing a reconstruction of the convective vortex trajectories. From data filtered in the (0.02–0.3 Hz) frequency band, we estimate that the mean value of η ( η = E /[1 − ν 2 ], where E is the Young's modulus and ν is the Poisson's ratio) of the Martian ground in the region around SEIS is 239 ± 140 MPa. In addition, we suggest that the previously reported paucity of vortex seismic observations to the west of InSight may be due to the fact that the ground is harder to the west than to the east, consistent with geomorphological surface interpretations.

On Mars, basins formed by tectonic processes are rare and mostly have unconstrained subsidence histories. One method for understanding this record of subsidence is through associated alluvial fans, which are sourced from uplifted areas and accumulate in downthrown basins. The source, morphology, and superposition of fan deposits can be used to reconstruct fault kinematics, the relative timing of accommodation space formation, and, in turn, the influence tectonic processes had on Martian fan formation. Here we use high-resolution orbital data sets to characterize sediment fan deposits associated with syn-tectonic sedimentation in two regions of the Valles Marineris canyons: Coprates Chasma and Juventae Chasma. These deposits comprise sediment fans on the current canyon floor and low-gradient surfaces perched several kilometers above the canyon floor. We interpret the low-gradient surfaces as remnant sediment fan deposits, which originally formed at the former canyon floor and have since been offset due to normal faulting. The preservation of vertically offset generations of sediment fan deposits supports a progressive, basinward migration of fault activity into the original hanging wall or repeat activity along a fault zone. Each episode of faulting was followed by a basinward shift in drainages, which led to fault-scarp degradation and formation of a new generation of fans. Multiple episodes of syn-tectonic sedimentation occurred during the evolution of the basins, with fluvial activity sporadically active. Our results demonstrate, for the first time on Mars, that depositional cyclicity was linked to tectonic deformation, possibly representative of regional processes throughout Valles Marineris.

Geologic and climatic processes on modern‐day Mars are heavily influenced by aeolian surface activity, yet the relationship between atmospheric conditions and sediment mobilization is not well understood. The Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) spacecraft is uniquely able to address this issue, due to its joint imaging and continuous high‐frequency meteorological capabilities, which allow for direct comparison between surface activity and atmospheric conditions. Since landing in the volcanic plains of Elysium Planitia, InSight's camera's have recorded intermittent, small‐scale surface changes, including removal of fine material on the lander footpad, linear tracks and localized surface darkening caused by minor dust removal, and surface creep of granules, as presented in Part 1 (Charalambous et al., 2021, this issue). Surface activity is found to correlate well with the timing of abrupt pressure drops (Δ P ∼ 1–9 Pa) and transient wind gusts ( v ∼ 14–31 m/s) associated with convective vortex passage. Here we identify the major erosive forces acting on surface particles during these events, including the vertical pressure gradient force at the vortex core and the drag force generated by quickly‐rotating tangential winds. Orbital and ground‐truth data suggest that aeolian activity at InSight's landing site is sporadic under modern climatic conditions. Ongoing aeolian surface modifcation is driven primarily by turbulent vortices that sporadically lift dust and redistribute coarser sediment (i.e., sand and granules) but do not aid in the development of organized aeolian bedforms. Surface erosion is localized within the path these vortices take across the surface which is controlled by seasonally‐reversing background circulation patterns.

Measurements from the InSight lander radiometer acquired after landing are used to characterize the thermophysical properties of the Martian soil in Homestead hollow. This data set is unique as it stems from a high measurement cadence fixed platform studying a simple well-characterized surface, and it benefits from the environmental characterization provided by other instruments. We focus on observations acquired before the arrival of a regional dust storm (near Sol 50), on the furthest observed patch of soil (i.e., ∼3.5 m away from the edge of the lander deck) where temperatures are least impacted by the presence of the lander and where the soil has been least disrupted during landing. Diurnal temperature cycles are fit using a homogenous soil configuration with a thermal inertia of 183 ± 25 J m-2 K-1 s-1/2 and an albedo of 0.16, corresponding to very fine to fine sand with the vast majority of particles smaller than 140 μm. A pre-landing assessment leveraging orbital thermal infrared data is consistent with these results, but our analysis of the full diurnal temperature cycle acquired from the ground further indicates that near surface layers with different thermophysical properties must be thin (i.e., typically within the top few mm) and deep layering with different thermophysical properties must be at least below ∼4 cm. The low thermal inertia value indicates limited soil cementation within the upper one or two skin depths (i.e., ∼4-8 cm and more), with cement volumes <<1%, which is challenging to reconcile with visible images of overhangs in pits.

Rocks around the InSight lander were measured in lander orthoimages of the near field (<10 m), in panoramas of the far field (<40 m), and in a high‐resolution orbital image around the lander (1 km2). The cumulative fractional area versus diameter size‐frequency distributions for four areas in the near field fall on exponential model curves used for estimating hazards for landing spacecraft. The rock abundance varies in the near field from 0.6% for the sand and pebble‐rich area to the east within Homestead hollow to ∼3–5% for the progressively rockier areas to the south, north, and west. The rock abundance of the entire near field is just over 3%, which falls between that at the Phoenix (2%) and Spirit (5%) landing sites. Rocks in the far field (<40 m) that could be identified in both the surface panorama and a high‐resolution orbital image fall on the same exponential model curve as the average near‐field rocks. Rocks measured in a high‐resolution orbital image (27.5 cm/pixel) within ∼500 m of the lander that includes several rocky ejecta craters fall on 4–5% exponential model curves, similar to the northern and western near‐field areas. As a result, the rock abundances observed from orbit fall on the same exponential model rock abundance curves as those viewed from the surface. These rock abundance measurements around the lander are consistent with thermal imaging estimates over larger pixel areas as well as expectations from fragmentation theory of an impacted Amazonian/Hesperian lava flow.

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.