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The goals of NASA's Mars 2020 mission include searching for evidence of ancient life on Mars, studying the geology of Jezero crater, understanding Mars' current and past climate, and preparing for human exploration of Mars. During the mission's first science campaign, the Perseverance rover's SHERLOC deep UV Raman and fluorescence instrument collected microscale, two‐dimensional Raman and fluorescence images on 10 natural (unabraded) and abraded targets on two different Jezero crater floor units: Séítah and Máaz. We report SHERLOC Raman measurements collected during the Crater Floor Campaign and discuss their implications regarding the origin and history of Séítah and Máaz. The data support the conclusion that Séítah and Máaz are mineralogically distinct igneous units with complex aqueous alteration histories and suggest that the Jezero crater floor once hosted an environment capable of supporting microbial life and preserving evidence of that life, if it existed. Plain Language Summary: The goals of NASA's Mars 2020 mission include searching for evidence of ancient life on Mars, studying the geology of Jezero crater, understanding Mars' current and past climate, and preparing for human exploration of Mars. During the mission's first science campaign, SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals), one of Perseverance rover's spectroscopic instruments, collected microscale, two‐dimensional images that displayed mineral and organic molecule detections on 10 natural (unabraded) and abraded targets on two different Jezero crater floor geological units: Séítah and Máaz. We report SHERLOC mineral detections made during the Crater Floor Campaign and discuss their implications regarding the origin and history of Séítah and Máaz. The mineral detections support the conclusion that Séítah and Máaz are igneous units with different mineral compositions and distinct histories of alteration by fluids. The detections further suggest that the Jezero crater floor was once home to an environment capable of supporting microbial life and preserving evidence of that life, if it ever existed. Key Points: The floor of the Jezero crater hosts distinct igneous units with differing aqueous alteration historiesSHERLOC Raman mineral class detections indicate that the Jezero crater floor was once a habitable environmentSome Crater Floor Campaign samples may contain salts known to preserve biosignatures in terrestrial analog environments [ABSTRACT FROM AUTHOR]

The Perseverance rover, Mars 2020 mission, landed on the surface of the Jezero crater, on 18 February 2021. This Martian crater is suspected to have hosted a paleolake as evidenced by the numerous detections of aqueously altered phases and thus is a promising candidate for the search for past Martian life. The SuperCam instrument, a collaboration by a consortium of American and European laboratories, plays a leading role in this investigation, thanks to its highly versatile payload providing rapid, synergistic, fine‐scale mineralogy, chemistry, and color imaging. After its landing, the first measurements of Martian targets with the infrared spectrometer of SuperCam (IRS) showed new instrumental behaviors that had to be characterized and calibrated to derive unbiased science data. The IRS radiometric response has thus been calibrated using periodic observations of the Aluwhite SuperCam Calibration Target (SCCT). Parasitic effects were understood and mitigated, and the instrumental dark and noise are characterized and modeled. The reflectance calibrated data products, provided periodically on the NASA Planetary Data System, are corrected for the main instrumental features. This radiometric calibration allowed us to study the 2.5 μm absorption band, which has been discovered in the Séítah unit and is associated with phyllosilicates‐carbonates mixtures. Plain Language Summary: This paper is an instrumental investigation of the infrared spectrometer (IRS) portion of the SuperCam instrument on the Mars Science Laboratory Perseverance rover. Work performed prior to and during flight operations enabled the derivation of a proper instrumental response suitable for calibration of infrared point spectra of rocks and soils observed along the rover traverse. The paper describes development of a full data reduction pipeline in which the radiometric response, sensitivity of the IRS electronic board to temperature, and electromagnetic interference artifacts were removed. A companion paper (Mandon et al., 2022, https://doi.org/10.1029/2022JE007450) investigates the IRS data set through Sol 379 in more detail. Here, we specifically explore the 2.5 μm band attributed to carbonates in Séítah unit's phyllosilicate‐carbonates mixtures. We found that such mixtures likely have a low carbonate content, which may indicate low amounts of chemical alteration or an alteration by a carbon‐poor fluid. Key Points: The infrared spectrometer of SuperCam on Perseverance has been successfully flight calibrated using the onboard calibration targetsCalibration permitted to study the most challenging long wavelengths and thus to discover an absorption band at 2.5 μmStudy of the 2.3 and 2.5 μm absorption bands showed the Séitah unit has variable clay and carbonate mixtures with low carbonate content [ABSTRACT FROM AUTHOR]

Deciphering paleoclimate on Mars has been a driving goal of Martian science for decades. Most research has addressed this issue by studying Mars' large polar layered deposits (PLDs) as a paleoclimate proxy, but the certainty to which we know the link between climate and orbit is debated. Here, we instead consider the record of other, smaller ice deposits located within craters separated from the PLDs using images from NASA's High Resolution Imaging Science Experiment camera and signal processing techniques. We show that the climate record in Burroughs Crater (72.3°S, 116.6°E) contains robust evidence of orbital forcing, with periodicities that have wavelengths of 15.6 and 6.5 m. The ratio of these dominant wavelengths is 2.4, the same as the ratio between the periods of Mars' obliquity changes and orbital precession. This result suggests orbital control of recent Mars climate, and would imply an average ice accumulation rate of 0.13 mm/yr over 4.5 Myr in this region. Plain Language Summary: Understanding the relationship between Martian climate and changes in the planet's axial tilt and orbit around the Sun is one of the most important goals in Mars science. Most past studies conducted to address this goal have involved study of the polar ice caps, huge sheets of H2O ice at the north and south pole. Here, we instead study smaller ice deposits (10s of km in diameter) near the north and south pole, but located within craters and separated from the larger polar caps. We find that the ice deposit in Burroughs Crater contains particularly good evidence that recent Martian climate is strongly controlled by changes in the planet's orbit and axial tilt. Key Points: The icy record in Burroughs crater shows Martian climate is strongly controlled by astronomical forcingThe average ice accumulation rate in this region was 0.13 mm/yrThe deposit in Burroughs crater represents a younger, more easily decipherable climate record than that in the SPLD [ABSTRACT FROM AUTHOR]

The article focuses on the success of Curiosity, a new Mars rover Perseverance is on the planet's surface and specifically looking for signs of life. Topics include the largest human object to ever land on an alien planet touched down on Mars, the car-sized robot Perseverance is equipped to probe the geology of Mars and seek signs of ancient life, and Russian-European mission to Mars called ExoMars will launch another rover towards the planet.

We use time series images to identify significant active boulder falls in an impact crater on Mars. Evidence for active boulder falls include boulder trails with impact marks from bouncing and rolling, and dark patches from boulder impacts away from the base of the crater walls. We were able to define three time periods with active boulder falls and additional slope streak formation, for which we refined the most significant activity to a time period between January 2012 and March 2013. A search of 236 images within 500 km of the study site identified two further sites with similar, but reduced, activity during the same time period. We discuss plausible mechanisms for the boulder fall activity, and conclude that the local geology and crater age is likely to be of significant importance. Our method of identifying and highlighting such activity will allow further studies of active surface processes on Mars. Plain Language Summary: Mars has active surface processes, driven by environmental effects and meteorite impacts. But can interior processes cause changes at the surface today? Answering this question will help expand the recent discoveries of marsquakes by NASA's InSight lander, by identifying possible regions of seismic activity on the planet. Here we use time series orbital images to identify significant boulder falls in a crater on Mars. The temporal resolution of different cameras allows us to refine the timing of the most significant change to a time period of within just over an Earth year. Searching all similar images within 500 km revealed two further sites with similar, but reduced, activity within the same time period. Although our results do not rule out exogenic processes, the concurrent activity in several sites at similar times offers evidence of possibly related causes of boulder fall activity. Key Points: Active boulder falls identified in a near‐equatorial impact crater on MarsTiming of most significant activity refined to a period of just over one Earth yearLocal geology and crater age likely important, but not only, causes of boulder activity [ABSTRACT FROM AUTHOR]

Jezero crater is a ~45‐km impact crater on the margin of Isidis basin on Mars. Jezero is the landing site for NASA's Mars 2020 rover mission. The crater hosts a paleolake, and fluvio‐lacustrine deposits formed in this lake remain accessible to exploration. A dark‐toned deposit on the crater floor overlies light‐toned carbonate‐bearing deposits and has been interpreted as a lava flow. We determined the average thickness of this deposit at the margins to be ~13.0 ± 0.8 m. We analyzed the statistics of impact craters superposed on this deposit and estimated its model age as 2.6 ± 0.5 Ga in the Hartmann system, placing it most likely in the Early Amazonian. The error estimate here includes an estimate of the uncertainty associated with the crater counts. Acquisition, caching, and eventual return of a sample from this unit could provide an important calibration point for Mars crater chronology. Plain Language Summary: Jezero crater is a large impact crater on Mars with a diameter of about 45 km. In the Martian deep past this crater hosted a long‐lived lake. On 19 November NASA announced that Jezero crater will be the landing site for the coming Mars 2020 mission. On top of sediments on the central crater floor is a distinctive deposit of dark rocks that possibly originated as a lava flow after the lake had dried out. We studied the statistics of small impact craters on this dark deposit. Such impact crater statistic is widely used as a tool for dating Martian terrains. We report a derived "model age" of 2.6 ± 0.2 Ga for these rocks. One central goal of the Mars 2020 mission is to select and store a cache of rock samples that will be returned to Earth by a later mission for study in terrestrial laboratories. If this dark deposit is indeed lava, a sample could be dated in terrestrial laboratories. Together with our crater statistics reported here, this could provide a crucial tie‐point for recalibration of the crater count dating system for Mars, which now relies on extrapolation from samples collected on the Moon. Key Points: Based on craters 177‐500 m we estimated the model age of the dark‐toned floor unit as 2.6 ± 0.2 Ga in the Hartmann systemWith 25% as an estimate of the uncertainty associated with identifying and measuring diameters, we find a model age range of 2.6 ± 0.5 GaThe average thickness of the unit at the margins is determined to be ~13.0 ± 0.8 m [ABSTRACT FROM AUTHOR]

Highlights • We find a wide diversity of crater morphologies in the Sintana quadrangle. • Gravity-driven mass wasting plays an important role in forming Ceres' surface and their characteristics in the Sintana quadrangle support an ice-rich subsurface. • We observe no morphological structures that can be related to endogenic activity in the Sintana quadrangle as observed for other parts of Ceres. • The young absolute age of the cratered terrain in the Sintana quadrangle suggests resurfacing by Kerwan impact melt. Abstract A geologic map at a scale of 1:1,000,000 of the Ac-11 Sintana quadrangle (21–66°S and 0–90°E) from the dwarf planet Ceres and based on data from NASA's Dawn spacecraft, was produced as part of a geologic mapping campaign in order to investigate the surface structure, stratigraphy, composition and surface modifying processes. The Sintana quadrangle is geologically dominated by cratered terrain with morphologically distinct crater types. The most prominent craters, Sintana, Hamori, Jarimba, Tupo, Annona and Darzamat, have complex structures including smooth crater material covering their floors, collapsed crater walls forming terraces, and central ridges. Multiple gravity-driven blocky mass wasting features indicate post-impact crater modification and are indicative of an ice-rich subsurface, in which there is no topographic or structural evidence of endogenic activity visible in the quadrangle. Absolute age estimates suggest that the entire surface in the quadrangle was resurfaced ∼1.1 Ga ago, possibly by Kerwan-related impact-induced melting. [ABSTRACT FROM AUTHOR]

Bakhuysen Crater is a Late Noachian to Early Hesperian age ∼150 km-diameter impact structure located in the heavily cratered southern highlands of Mars. It is one of the largest craters on Mars with well-preserved ejecta deposits. Impact ejecta deposits allow an understanding of crustal composition, volatile content, and evolution of terrestrial planets, yet the emplacement of ejecta deposits on bodies throughout the solar system is still debated. Here, we present the first detailed geomorphologic map of Bakhuysen Crater. We distinguish two distinct ejecta units: (1) a largely hummocky ejecta unit (Be1) that comprises the continuous ejecta blanket; and (2) an uppermost, discontinuous unit (Be2) with a distinct ponded morphology, pitted texture, and previously unreported lobate and flow deposits. Pitted materials are present in the crater interior deposits as well as the ejecta. Bakhuysen is the largest Martian crater thus far identified with crater-related pitted material, which has been suggested previously to represent volatile-rich primary impact melt-bearing deposits. Unit Be1 is interpreted as the continuous ejecta blanket emplaced through ballistic sedimentation and radial flow. Unit Be2 shares many attributes with impact melt-rich ejecta seen on other planetary bodies (e.g., Earth, Moon, and Mercury) and is interpreted as having been emplaced as ground-hugging flows during the later modification stage of crater formation. Channels are observed as having emanated from Bakhuysen impactites and represents a clear example of the role of volatiles in the impact cratering process on Mars. Bakhuysen ejecta deposits and its associated features suggests that, if indeed a substantial volatile source is sampled by Martian impact events, then the formation of ejecta-associated channels on Mars are likely genetically linked to the formation of pitted materials where present. The preservation and exposure of the impact deposits of Bakhuysen present a unique opportunity to study these features and their relationship to the impact process on Mars. [ABSTRACT FROM AUTHOR]

Understanding of the geologic evolution of Mars has been greatly improved by recent orbital, in situ and meteorite data, but insights into the earliest period of Martian magmatism (4.1 to 3.7 billion years ago) remain scarce. The landing site of NASA's Curiosity rover, Gale crater, which formed 3.61 billion years ago within older terrain, provides a window into this earliest igneous history. Along its traverse, Curiosity has discovered light-toned rocks that contrast with basaltic samples found in younger regions. Here we present geochemical data and images of 22 specimens analysed by Curiosity that demonstrate that these light-toned materials are feldspar-rich magmatic rocks. The rocks belong to two distinct geochemical types: alkaline compositions containing up to 67 wt% SiO2 and 14 wt% total alkalis (Na2O + K2O) with fine-grained to porphyritic textures on the one hand, and coarser-grained textures consistent with quartz diorite and granodiorite on the other hand. Our analysis reveals unexpected magmatic diversity and the widespread presence of silica- and feldspar-rich materials in the vicinity of the landing site at Gale crater. Combined with the identification of feldspar-rich rocks elsewhere and the low average density of the crust in the Martian southern hemisphere, we conclude that silica-rich magmatic rocks may constitute a significant fraction of ancient Martian crust and may be analogous to the earliest continental crust on Earth. [ABSTRACT FROM AUTHOR]

Introduction: More than ~1000 newly formed impact features have been detected in images taken by orbiting spacecraft around Mars [1]. In recent months, several of these impacts were also detected seismically by the InSight seismometer [2]. Detailed characterization of the observed impact features [3, 4] has been used to calibrate a model of atmospheric disruption of meteoroids on Mars [5]. This paves the way for relating observed impact features to the properties of the impacting meteoroids. Here we use a Markov-Chain Monte Carlo (MCMC) approach to determine the statistical distribution of impactor parameters that are most likely to have formed recent impact craters and crater clusters observed on Mars that were also detected seismically. Our results inform interpretation of seismic wave signals generated by these impacts [2]. Methods: We simulate the formation of specific craters and clusters on Mars using an implementation of the Separate Fragments Model [SFM; 6, 7], calibrated by comparison with observed craters and clusters on Mars [5]. Crater sizes are predicted from fragment properties at the ground using p-group crater scaling relationships [8]. A MCMC approach is used to generate a statistical distribution of impact scenarios consistent with the observed feature. Given an observed crater or cluster of craters, we determine its characteristics B (e.g., size and number of craters). Using the SFM, together with knowledge about the variability of cluster characteristics, we compute the likelihood p(B|A) that an impact with parameters A (mass, velocity, etc.), produces a crater or cluster with the same characteristics B as the observed one. p(A) expresses our prior knowledge of impactor parameter probability. Then, with Bayes' theorem p(A|B) ? p(A)p(B|A), we can infer the likelihood of impact parameters A given the observations B. We employed the Metropolis-Hastings MCMC algorithm with Metropolis sampling, which assumes that there is no correlation between impactor parameters. Prior distributions of impactor mass [9], angle [10], velocity [11] and strength [5] were based on previous work. Impactor density and ablation parameter were held constant at representative values for stoney meteorites. We defined the likelihood p(B|A) to be the product of likelihoods for four cluster characteristics: effective diameter, number of craters, median separation distance between craters and the aspect ratio of the best-fit ellipse encompassing the craters. We assumed that all characteristics are log-normally distributed with the standard deviations based on observed cluster characteristics [4]. Because MCMC algorithms reach the desired distribution asymptotically, the first n samples were discarded. The distribution of remaining accepted samples defines the impactor parameters of maximum likelihood. Results: Impactor parameter likelihood distributions were determined for four impacts (two single craters and two clusters). One cluster-forming impact provides a particularly useful test of the approach as its highly elongated distribution of craters implies a shallow trajectory angle. The inferred trajectory is consistent with the interpreted ray paths of acoustic phases in the seismogram of the associated seismic event that were generated by the meteoroid's flight through the atmosphere [2]. The most likely pre-entry impactor mass informs comparison of the impact flux rate at the top of the atmosphere on Earth and Mars [5, 9]. The most likely impactor momentum at the ground provides a test of empirical relationships between seismic moment and impactor momentum [e.g., 12]. Acknowledgments: GSC and NW were funded by UK Space Agency grants ST/T002026/1 and ST/S001514/1. IJD was funded by NASA award 80NSSC20K0789. TN, KM and EKS were funded by the Australian Research Council (DE180100584, DP180100661 and DP200102073). [ABSTRACT FROM AUTHOR]

The NASA Mars Science Laboratory (MSL) rover, Curiosity, has safely landed near a 35-km-long dark dune field in Gale Crater on Mars. This dune field crosses the landing site from the northeast to the southwest and lies along Curiosity's traverse to Aeolis Mons. Here we present the first evidence of recent aeolian activity in the form of ripple and dune migration, and further estimate wind directions within the dune field through analysis of ripple and dune morphologies and the Mars Regional Atmospheric Modeling System (MRAMS). We measured a minimum ripple migration rate of 0.66 m per Earth year, and dune migration rate of 0.4 m per Earth year, in the southwest portion of the field. A strongly bidirectional ripple crestline orientation, nearly orthogonal dune slipfaces, and linear seif or oblique dunes indicate a bidirectional wind regime with winds mainly coming from the ENE and from the northwest; however, MRAMS results indicate primary winds from the ENE. Our constraints on the wind regime provide the unique opportunity to use ground measurements from MSL to test the accuracy of winds predicted from orbital data. [ABSTRACT FROM AUTHOR]

ChemCam is a remote sensing instrument suite on board the 'Curiosity' rover (NASA) that uses Laser-Induced Breakdown Spectroscopy (LIBS) to provide the elemental composition of soils and rocks at the surface of Mars from a distance of 1.3 to 7 m, and a telescopic imager to return high resolution context and micro-images at distances greater than 1.16 m. We describe five analytical capabilities: rock classification, quantitative composition, depth profiling, context imaging, and passive spectroscopy. They serve as a toolbox to address most of the science questions at Gale crater. ChemCam consists of a Mast-Unit (laser, telescope, camera, and electronics) and a Body-Unit (spectrometers, digital processing unit, and optical demultiplexer), which are connected by an optical fiber and an electrical interface. We then report on the development, integration, and testing of the Mast-Unit, and summarize some key characteristics of ChemCam. This confirmed that nominal or better than nominal performances were achieved for critical parameters, in particular power density (>1 GW/cm). The analysis spot diameter varies from 350 μm at 2 m to 550 μm at 7 m distance. For remote imaging, the camera field of view is 20 mrad for 1024×1024 pixels. Field tests demonstrated that the resolution (∼90 μrad) made it possible to identify laser shots on a wide variety of images. This is sufficient for visualizing laser shot pits and textures of rocks and soils. An auto-exposure capability optimizes the dynamical range of the images. Dedicated hardware and software focus the telescope, with precision that is appropriate for the LIBS and imaging depths-of-field. The light emitted by the plasma is collected and sent to the Body-Unit via a 6 m optical fiber. The companion to this paper (Wiens et al. ) reports on the development of the Body-Unit, on the analysis of the emitted light, and on the good match between instrument performance and science specifications. [ABSTRACT FROM AUTHOR]

The article presents the discussion on NASA's Perseverance rover drilling the first rock core in Mars's Jezero crater resembling ancient lava in the appearance, mineral signatures, and grain sizes.

The article reports announcement of the U.S. National Aeronautics and Space Administration (NASA) on September 2015 regarding existence of subsurface water on the planet Mars. Topics discussed include reappearance of Recurring Slope Lineae, water as dark streaks on the walls of craters during warm seasons, and low possibility of any life on the planet due to presence of oxidizing perchlorate salts in its water.

The article presents information on the U.S. National Aeronautics and Space Administration's (NASA) Curiosity spacecraft, which is the heaviest lander to reach Mars in August 2012. The rover has started its explorations around the landing site, and has reached the Gale crater. The craft has a weather station and robotic arm, and it is firing neutrons into the ground by the Russian-built DAN instrument, to assess the amount of water present on Mars.

The article focuses on the expected landing of Curiosity, the U.S. National Aeronautics & Space Administration's (NASA) Mars Science Laboratory in Gale crater. It states that Gale has a massive layered mound which composed of layers of clay minerals in the center. It cites astrobiologist Nathalie Cabrol who said that Gale is likely once to have supported a water-rich environment that changed from warm and wet to cold with ice-covered water.

The article focuses on an image about the U.S. National Aeronautics and Space Administration's (NASA) Phoenix lander and Mars Reconnaissance Orbiter (MRO). It depicts the Phoenix lander, which was ten kilometers above the surface of Mars on May 25, 2008, that was captured passing in front of Heimdall crater by the High Resolution Imaging Science Experiment (HiRISE) camera on the MRO. The engineers believed that the HiRISE would interfere with the radio on the MRO that was tracking Phoenix and expected that the image would not be captured. Fortunately, the image was entranced and it is presented in the article.

The article focuses on the plans of the U.S. National Aeronautics & Space Administration to launch a machine that is nearly identical to Curiosity rover to probe the Martian surface in 2020. Topics Discussed include NASA's plan for bringing back Martian samples, views of Philip Christensen, a planetary scientist at Arizona State University in Tempe, on the issue and analysis of Martian craters for the signs of life on the planet.

A photograph of an impact crater observed on Mars by the National Aeronautics and Space Administration's (NASA) Mars Reconnaissance Orbiter is presented.

The article presents information on the progress made by the U.S. National Aeronautics & Space Administration's (NASA) Mars planet rover, Opportunity. It examined the layering of the Victoria Crater in mars from which researches deduced that they were sedimentary rocks laid down by wind and modified by underground water. Its task includes studing the rocks on the martian surface to provide clues to the composition and geological history of deeper rock levels locally.

The article reports that the U.S. National Aeronautics and Space Administration's (NASA) Phoenix spacecraft was surrounded by polygons when it settled in Mar's northern latitudes on May 25, 2008. It states that the spacecraft had scooped its first handful of martian soil and was expected to unleash a battery of geochemical instruments on ice and soil samples. Meanwhile, the images from the Mars Reconnaissance Orbiter (MRO) satellite showed that the polygons in Phoenix's landing area had an average diameter of 4.6 metres.