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Covering the time between Curiosity’s 3548th and 3644th Martian days (sols) of operations in northern Gale crater, Mars, this document is a compilation of the Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) Team’s notes and information about MAHLI images and activities conducted during that period. The report includes brief sol-by-sol notes—written as the mission unfolded—regarding how the MAHLI instrument was used and significant events that occurred which impacted the MAHLI instrument or investigation. The document, further, contains information regarding range and scale (camera working distance and scale of in-focus elements of an image); the parent images, range, and scale information associated with each MAHLI focus merge product created onboard the instrument; and a description of the purpose and intent behind acquisition of each MAHLI image and creation of each onboard focus merge product. The MSL science team and rover engineers routinely used the information contained in this report during the course of the mission for tactical planning, strategic planning, and scientific analysis.

Covering the time between Curiosity’s 3424th and 3547th Martian days (sols) of operations in northern Gale crater, Mars, this document is a compilation of the Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) Team’s notes and information about MAHLI images and activities conducted during that period. The report includes brief sol-by-sol notes—written as the mission unfolded—regarding how the MAHLI instrument was used and significant events that occurred which impacted the MAHLI instrument or investigation. The document, further, contains information regarding range and scale (camera working distance and scale of in-focus elements of an image); the parent images, range, and scale information associated with each MAHLI focus merge product created onboard the instrument; and a description of the purpose and intent behind acquisition of each MAHLI image and creation of each onboard focus merge product. The MSL science team and rover engineers routinely used the information contained in this report during the course of the mission for tactical planning, strategic planning, and scientific analysis.

Covering the time between Curiosity’s 3290th and 3423rd Martian days (sols) of operations in northern Gale crater, Mars, this document is a compilation of the Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) Team’s notes and information about MAHLI images and activities conducted during that period. The report includes brief sol-by-sol notes—written as the mission unfolded—regarding how the MAHLI instrument was used and significant events that occurred which impacted the MAHLI instrument or investigation. The document, further, contains information regarding range and scale (camera working distance and scale of in-focus elements of an image); the parent images, range, and scale information associated with each MAHLI focus merge product created onboard the instrument; and a description of the purpose and intent behind acquisition of each MAHLI image and creation of each onboard focus merge product. The MSL science team and rover engineers routinely used the information contained in this report during the course of the mission for tactical planning, strategic planning, and scientific analysis.

Covering the time between Curiosity’s3193rd and 3289th Martian days (sols) of operations in northern Gale crater,Mars, this document is a compilation of the Mars Science Laboratory (MSL) MarsHandLens Imager (MAHLI) Principal Investigator’s notes and information aboutMAHLI images and activities conducted during that period. The report includes briefsol-by-sol notes—written as the missionunfolded—regarding how the MAHLIinstrument was used and significant events that occurred which impacted theMAHLI instrument or investigation. The document, further, contains informationregarding range and scale (camera working distance and scale of in-focuselements of an image); the parent images, range, and scale informationassociated with each MAHLI focus merge productcreated onboard the instrument;and a description of the purpose and intent behind acquisition of each MAHLIimage and creation of each onboard focus merge product. The MSL science teamand roverengineers routinely used the information contained in this reportduring the course of the mission for tactical planning, strategic planning, andscientific analysis.

International audience

International audience

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.

Covering the time between Curiosity’s3069th and 3192nd Martian days (sols) of operations in northern Gale crater,Mars, thisdocument is a compilation of the Mars Science Laboratory (MSL) MarsHand Lens Imager (MAHLI) Principal Investigator’s notesand information aboutMAHLI images and activities conducted during that period. The report includes briefsol-by-sol notes—written as the mission unfolded—regarding how the MAHLIinstrument was used and significant events that occurred whichimpacted theMAHLI instrument or investigation. The document, further, contains informationregarding range and scale (cameraworking distance and scale of in-focuselements of an image); the parent images, range, and scale informationassociated witheach MAHLI focus merge product created onboard the instrument;and a description of the purpose and intent behind acquisitionof each MAHLIimage and creation of each onboard focus merge product. The MSL science teamand rover engineers routinelyused the information contained in this reportduring the course of the mission for tactical planning, strategic planning, andscientific analysis.

Covering the time between Curiosity’s 2935th and 3068th Martian days (sols) of operations in northern Gale crater, Mars, this document is a compilation of the Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) Principal Investigator’s notes and information about MAHLI images and activities conducted during that period. The report includes brief sol-by-sol notes—written as the mission unfolded—regarding how the MAHLI instrument was used and significant events that occurred which impacted the MAHLI instrument or investigation. The document, further, contains information regarding range and scale (camera working distance and scale of in-focus elements of an image); the parent images, range, and scale information associated with each MAHLI focus merge product created onboard the instrument; and a description of the purpose and intent behind acquisition of each MAHLI image and creation of each onboard focus merge product. The MSL science team and rover engineers routinely used the information contained in this report during the course of the mission for tactical planning, strategic planning, and scientific analysis.

International audience; On February 18, 2021 NASAs Perseverance rover landed in Jezero Crater where the floor consists of various rock lithologies and abundant regolith. Using the rovers imagery and the LIBS and VISIR spectroscopies from SuperCam, we focus on the chemistry and mineralogy of coarse-grained regolith. Such regolith has been observed all along the rover traverse since the landing: it is widespread either on flat surfaces/rocks or in aeolian ripples. This coarse regolith is composed of rounded granules rather homogeneous in size (~1-2 mm), shape (nearly isotropic) and color. Some VISIR spectra are highly consistent with the presence of olivine in the regolith. No hydration band is detected, and no H is detected by LIBS, suggesting that this olivine is rather pristine. SuperCam LIBS has a laser spot size of 300 mm and is operated by performing rasters of up to 10 sampling points, each accumulating up to 50 laser shots. Combining high-resolution RMI images with microphone recordings during the laser shots, we can assess whether the LIBS laser sampled dust/fine sand or granules during the shot series, and if the laser significantly ablates a granule. Careful analysis of the LIBS spectra and derived chemical compositions, including comparison with data from calibration targets and shot to shot variability, reveal the presence at the LIBS spot size of (i) olivine only, (ii) olivine and andesine mixtures, and (iii) other assemblages including the former and/or other minerals such as pyroxenes. Most olivine grains are Fo# 60-75, but locally some grains may be lower Fo#; they all exhibit low content of Cr and Mn, Ni is below detection limit. Interestingly, this coarse regolith displays a different chemistry and mineralogy compared to the surrounding rocks raising questions about its provenance. The rover is currently making its way toward the adjacent Seitah unit which is a possible source as it may contain olivine based on orbital data. There are also some differences in composition between these granules and the finer fractions of the regolith. All these data will be compared to orbital data and observations by Curiosity on similar coarse-grained regolith at Gale crater. They will also be discussed in light of knowledge from Martian meteorites to place constraints on the formation of olivine and magmatic processes on Mars.

Refinement of the relations between motor count, working distance (range), and pixel scale for theSHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) camera, located on the turret at the end of the Perseverance rover’s robotic arm, operating in Jezero crater, Mars. The refinements to estimate image range and scale from focus stepper motor count arebased on data acquired on Mars as well as data acquired before launch. The report also considers the post-landing state of particulates on the CCD; these did not change despite pre-launch vibration testing and the launch, cruise, and entry-descent-and-landing vibration environments.&nbsp

We have used Mars Exploration Rover Opportunity data to investigate the origin and alteration of lithic types along the western rim of Noachian-aged Endeavour crater on Meridiani Planum. Two geologic units are identified along the rim: the Shoemaker and Matijevic formations. The Shoemaker formation consists of two types of polymict impact breccia: clast rich with coarser clasts in upper units; clast-poor with smaller clasts in lower units. Comparisons terrestrial craters show that the lower units represent more distal ejecta from at least two earlier impacts, and the upper units are proximal ejecta from Endeavour crater. Both are mixtures of target rocks of basaltic composition with subtle compositional variations caused by differences in post-impact alteration. The Matijevic formation and lower Shoemaker units represent pre-Endeavour geology, which we equate with the regional Noachian subdued cratered unit. An alteration style unique to these rocks is formation of smectite and Si- and Al-rich vein-like structures crosscutting outcrops. Post-Endeavour alteration is dominated by sulfate formation. Rim-crossing fracture zones include regions of alteration that produced Mg-sulfates as a dominant phase, plausibly closely associated in time with the Endeavour impact. Calcium-sulfate vein formation occurred over extended time, including before the Endeavour impact and after the Endeavour rim had been substantially degraded, likely after deposition of the Burns formation that surrounds and embays the rim. Differences in Mg, Ca and Cl concentrations on rock surfaces and interiors indicate mobilization of salts by transient water that has occurred recently and may be ongoing.

Recent mineralogical studies suggest the presence of an iron chlorine hydroxide, namely akaganeite. This mineral is known to form under specific conditions, and it has been detected in the Robert Sharp Crater, located at Mars’ low-latitudes (133.59˚E, -4.12˚N) [1]. Its detection implies an acidic and oxidizing environment in this region. Indeed, akaganeite typically forms in highly saline and chlorinated aqueous environments on Earth. These akaganeite deposits might be the ultimate alteration phase of a drying lake within the Robert Sharp Crater. Hence, we carried out morphological and stratigraphical studies, as well as age determination by crater counting to constrain the geological and hydrological history of the region [2]. We found that the Robert Sharp Crater has known a varied geological history, including the formation of fretted terrains and an airfall filling during the Hesperian epoch. Furthermore, the presence of valleys and fan-shaped deposits, and the detection of various aqueous minerals, in the region suggest the possibility of a fluvio-lacustrine activity phase within the crater during the last period of the Martian chronology, also named Amazonian epoch. The presence of a putative paleolake should be short-time and estimated between 1.3 Ga and 500 Ma. Thus, by reconstructing the paleoenvironments in the Robert Sharp Crater, we demonstrate that Mars has known several episodes of aqueous activities well after the late Noachian/ early Hesperian period. References: [1] Carter, J. et al. (2015) Icarus, 253. [2] Brossier, J. F. et al. (in prep).

Several paradigm shifts have occurred over the past several decades as our understanding of the hydrologic and climatic history of Mars has evolved. It is generally accepted that the early climate on Mars was capable of sustaining an active hydrological cycle, and that (possibly episodic) precipitation and runoff formed the low-to-mid latitude belt of valley networks. Age analyses from crater counts suggests a sudden decline in fluvial activity around the Noachian-Hesperian boundary, presumably associated with the loss of the early denser atmosphere. The climate in the Hesperian and Amazonian was generally considered less favorable for precipitation (most likely snow) and runoff. This paradigm, however, is being challenged by a growing suite of post-Noachian fluvial landforms that support evidence for a late, widespread episode(s) of aqueous activity. Because modification by water and ice on a paleolandscape is one of the most unambiguous markers of past climate, this dissertation investigates fresh shallow valleys (FSVs), deltas, paleolakes, alluvial fans and aqueous-rich ejecta deposits in northern Arabia Terra and northwestern Noachis Terra that formed in the Hesperian and Amazonian. The objective of this dissertation is to provide insight into the environment and associated climate regime that permitted the formation of these post-Noachian fluvial landforms, which furthers our understanding of the potential late-stage habitability of Mars.

Over the last ~3 years in Gusev Crater, Mars, the Spirit rover observed coherent variations in color, mineralogy, and geochemistry across Home Plate, an ~80 m-diameter outcrop of basaltic tephra. Observations of Home Plate from orbit and from the summit of Husband Hill reveal clear differences in visible/near-infrared (VNIR) colors between its eastern and western regions that are consistent with mineralogical compositions indicated by Mössbauer spectrometer (MB) and by Miniature Thermal Emission Spectrometer (Mini-TES). Pyroxene and magnetite dominate the east side, while olivine, nanophase Fe oxide (npOx) and glass are more abundant on the western side. Alpha Particle X-Ray Spectrometer (APXS) observations reveal that eastern Home Plate has higher Si/Mg, Al, Zn, Ni, and K, while Cl and Br are higher in the west. We propose that these variations are the result of two distinct alteration regimes that may or may not be temporally related: a localized, higher temperature recrystallization and alteration of the east side of Home Plate and lower temperature alteration of the western side that produced npOx.

The Mars Science Laboratory (MSL) mission will primarily search for potentially habitable, ancient geological environments, as preliminary step to future life detection, e.g., the ESA/US 20128 Pasteur ExoMars, and sample return missions. All MSL sites candidates include hydrated clay minerals, or phyllosilicates, and have been evaluated in this work by context, diversity, habitability and preservation of potential of organics. The Ubehebe volcanic field is proposed as a high fidelity analog site.