Planetary and Space Science最新文献

{"title":"Sensitivity of leakage neutrons to the abundance and depth distribution of lunar subsurface water","authors":"Hiroki Kusano ,&nbsp;Hiroshi Nagaoka ,&nbsp;Teruaki Enoto ,&nbsp;Naoyuki Yamashita ,&nbsp;Yuzuru Karouji ,&nbsp;Takeshi Hoshino ,&nbsp;Munetaka Ueno ,&nbsp;Makoto Hareyama","doi":"10.1016/j.pss.2024.105968","DOIUrl":"10.1016/j.pss.2024.105968","url":null,"abstract":"<div><p>Water on the Moon has received increasing attention due to its importance in planetary science and the utilization of space resources. Future lunar rover missions are poised to conduct explorations, specifically focusing on locating water. Neutron spectroscopy is a powerful technique for estimating subsurface water content. In this study, lunar surface neutrons induced by galactic cosmic rays were investigated through Monte Carlo simulation. This effort aims to yield insights pertinent to in-situ water search explorations utilizing neutron spectrometers. The sensitivity of the leakage neutron intensity to the depth profile of subsurface water within the top 1.5 m soil was obtained via calculations based on a lunar surface model, featuring a localized concentration of water-rich soil. Computational outcomes underscore the potential of neutron observations to provide data on the depth profile of subsurface water under specific circumstances. Notably, in scenarios where a thin and shallow water-rich layer, approximately <span><math><mo>≲</mo></math></span>20 cm thick and located <span><math><mo>≲</mo></math></span>50 cm deep, is assumable within lunar soil of density 1.6 g/cm³, a combination of thermal, epithermal, and fast neutron measurements enables concurrent estimation of water abundance and depth. To accurately understand the subsurface water abundance and depth across exploration areas along the rover’s path, a comprehensive assessment of leakage neutrons in a wide energy range becomes indispensable.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"251 ","pages":"Article 105968"},"PeriodicalIF":1.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142173532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Martian soil-analogue VI-M1 for large-scale geotechnical experiments","authors":"E.N. Slyuta ,&nbsp;E.A. Grishakina ,&nbsp;V. Yu Makovchuk ,&nbsp;A.V. Uvarova ,&nbsp;I.A. Agapkin ,&nbsp;D.D. Mironov ,&nbsp;M.S. Nikitin ,&nbsp;E.A. Voznesensky","doi":"10.1016/j.pss.2024.105959","DOIUrl":"10.1016/j.pss.2024.105959","url":null,"abstract":"<div><p>In the actively evolving research of Mars in recent decades, a special place is occupied by landers and rovers. The diversity of landscapes and soils on Mars, characteristic of terrestrial planets with an atmosphere, makes the development of soil simulators relevant for each new type of terrain in the area of a potential landing site. In the article, based on a comprehensive analysis of the physical and mechanical properties of soils at previous landing sites and a geomorphological analysis of the Oxia Planum plain, the main requirements for the properties of Martian soil analog at the landing site of the ExoMars Rosalind Franklin Mission (RFM) were determined. Readily available technogenic and natural materials have been selected and experimentally justified as components for creating a Martian soil analogue. A methodology for creating the soil analog is presented, and its physical and mechanical properties are measured. The developed Martian soil analog VI-M1 is actively used for large-scale natural experiments, including drop tests of spacecraft in the ExoMars series.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"251 ","pages":"Article 105959"},"PeriodicalIF":1.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142173394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"About the improvement in Mars Polar Motion determination from radio tracking of two landers","authors":"Marta Goli ,&nbsp;Sébastien Le Maistre ,&nbsp;Marie Yseboodt","doi":"10.1016/j.pss.2024.105958","DOIUrl":"10.1016/j.pss.2024.105958","url":null,"abstract":"<div><p>The polar motion of Mars is defined as the movement of the rotation axis with respect to a body-fixed frame tied to the crust of the planet. It is composed of forced motion at annual and sub-annual frequencies caused by the seasonal mass redistribution, formation of the polar ice caps and angular momentum variations of the atmosphere, and of the free mode called the Chandler wobble.</p><p>Radio-tracking data from landers offers the most suitable means to measure the rotation of Mars, including its polar motion. The latter, however, has not yet been achieved using lander data alone. In this study, we assess the uncertainties associated with Mars polar motion estimation using Direct-To-Earth Doppler, range and Same-Beam Interferometry (SBI) observables between multiple landers on the surface of Mars. We evaluate the improvement enabled by combining data from multiple landers with respect to one-lander scenarios, and identify the optimal mission architectures for polar motion estimation by considering the influence of respective mission parameters on the estimation uncertainty. In particular, we consider the effects of absolute and relative locations of the landers and of mission scheduling. We re-evaluate the possibility of estimating the polar motion using data from landers in proximity to the equator, and apply our considerations to simulated data consistent in number and accuracy with that collected by past Martian missions. We notice and explain a strong longitude dependence of the formal errors when the polar motion parameters are estimated concurrently with the seasonal spin variation parameters, making it impossible to properly determine all components of polar motion with a single lander regardless of its location. However, the use of two or more landers in optimal locations with respect to each other eliminates those limitations. We evaluate the influence of latitudinal and longitudinal separation on polar motion determination in such cases. In particular, we are able to determine polar motion well even in cases where the longitudes of the two landers make determination from each single lander impossible.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"251 ","pages":"Article 105958"},"PeriodicalIF":1.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polarimetric characterization of Chandrayaan-3 landing site near lunar south pole using high resolution Chandrayaan-2 DFSAR data","authors":"Tathagata Chakraborty,&nbsp;Dharmendra Kr. Pandey,&nbsp;Raghav Mehra,&nbsp;Parikshit Parasher,&nbsp;Deepak Putrevu,&nbsp;V.M. Ramanujam,&nbsp;Nilesh M. Desai","doi":"10.1016/j.pss.2024.105956","DOIUrl":"10.1016/j.pss.2024.105956","url":null,"abstract":"<div><p>The Chandrayaan-3 (CH3) Vikram lander presents an unique opportunity to study the radar scattering behavior of the landing site as well as human-made dihedral structure on the lunar surface. This opportunity is made possible by the Dual-Frequency Synthetic Aperture Radar (DFSAR) sensor onboard the Chandrayaan-2 orbiter, which has the highest resolution and polarimetric capabilities compared to any planetary SAR sensor. To explore this, we utilized DFSAR to capture high-resolution images of the CH3 landing site during pre-landing and post-landing condition, with a pixel spacing as fine as 1 m, in a hybrid-pol mode. The landing site exhibits dominant volume and even-bounce radar scattering behavior similar to an ideal dihedral geometry. Furthermore, we observed an exceptionally high Circular Polarization Ratio value at the landing site (1.99 ± 0.30), a rarity among natural features on the lunar surface. Besides, the landing site is characterized by enhanced average dielectric constant value (5.76 ± 3.11). The post-landing DFSAR image reveals a 177 m² area, surrounding the CH3 landing location, characterized by high CPR and elevated even bounce and volume scattering. The drastic enhancement of the average CPR value (7-times), dielectric value (2-times), even bounce and volume scattering in the landing site, in comparison with the pre-landing DFSAR observation, is due to presence of lander module and disturbance in the regolith structure in the landing area. The polarimetric characteristics of the landing site distinguish it from the major natural features on the lunar surface, such as regolith, debris flow, and impact ejecta. This investigation is of utmost importance as it emphasizes the effectiveness of high-resolution DFSAR acquisitions for evaluating the polarimetric behavior of small-scale features, which can be invaluable for characterizing landing sites in upcoming missions.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"251 ","pages":"Article 105956"},"PeriodicalIF":1.8,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142158086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural analysis and evolution of large Venusian coronae: Insights from low-angle faults at coronae rims","authors":"Thomas Kenkmann,&nbsp;Oguzcan Karagoz,&nbsp;Antonia Veitengruber","doi":"10.1016/j.pss.2024.105955","DOIUrl":"10.1016/j.pss.2024.105955","url":null,"abstract":"<div><p>We analyzed topography, fracture patterns, and faults of the asymmetric Atahensik Corona (700 × 900 km diameter), formerly known as Latona Corona, and their surrounding troughs using Magellan SAR imagery, and compare the results with the smaller, ovoid Didilia (400 × 450 km diameter) and Pavlova coronae (550 × 650 km diameter) to get insights on corona formation on Venus. Atahensik contains a high density of radial, oblique, and concentric fractures, the latter are inferred to be the youngest fractures. A high density of concentric fractures particularly occurs along the outer rise and indicates elastic downward bending of this part of the lithosphere in the later stage of corona formation. Along the steep inner slopes of Atahensik's arcuate troughs, large-scale faults are exposed that dip gently towards the corona center and crosscut all fractures. We propose that these low-angle faults were initially formed as thrust planes but subsequently became reactivated as low-angle normal faults, thereby exposing parts of their fault surfaces. Such faults have been identified not only along the arcuate troughs of Atahensik but also occur in Dali Chasma, northwest of Atahensik Corona.</p><p>A phenomenological formation model of large coronae is presented: corona initiation starts with radial fracturing, which is caused by the dike emplacement and thermal uplift of the corona center due to the rise of a hot asthenospheric mantle plume. Uplift and lateral plume spreading steepen the outer rim of the uplift and cause intense radial fracturing of a central volcanic edifice and the corona's outer rim. This intermediate stage is preserved in several less-evolved coronae such as Didilia and Pavlova Coronae. The fractured ridge thrusts outward onto an intact and cooler lithosphere along strongly localized thrust planes. The overthrusted, cooler lithosphere is elastically bent downward and forms arcuate troughs and associated outer rises with numerous concentric fractures along their crest line. The fractured ridge annulus of the corona is supported by the intact and thickened lithosphere surrounding the corona. The present morphology of Atahensik Corona indicates subsequent subsidence in its central part due to declining plume activity and reduced thermal buoyancy. Reactivation of the thrusts as low-angle normal faults results from the subsidence of the corona interior, a gravitational instability of the elevated corona annulus, and a lack of shortening. The evolutionary sequence derived on the basis of structural data is in agreement with geodynamic models on corona formation involving a bending lithosphere at the plume margin.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"250 ","pages":"Article 105955"},"PeriodicalIF":1.8,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0032063324001193/pdfft?md5=a6df3ff59578d8da422206fcaaebef40&pid=1-s2.0-S0032063324001193-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142088697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact cratering at the lunar Ina irregular mare patch (IMP): Experimental evidence for the nature of impacts into porous basaltic substrate and outstanding questions","authors":"James W. Head ,&nbsp;Boris Ivanov","doi":"10.1016/j.pss.2024.105954","DOIUrl":"10.1016/j.pss.2024.105954","url":null,"abstract":"<div><p>The enigma of the apparently young crater retention age for the large lunar volcanic Irregular Mare Patch Ina (∼33.2 Myr) is critically analyzed through the review of: 1) experimental data on high velocity impacts into porous targets, 2) observed small impact crater morphology, and 3) the possible variation in small impact crater morphology with age. While we find that these different data sets and approaches could not unequivocally resolve the enigma, our analysis provides directions for new studies in several disciplines that are designed to help resolve the age conundrum and improve upcoming exploration mission goals and objectives.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"250 ","pages":"Article 105954"},"PeriodicalIF":1.8,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142011377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental analogs from yellowstone hot springs on geochemical and microbial diversity with implications for the search for life on Mars","authors":"D. Boulesteix ,&nbsp;A. Buch ,&nbsp;G. Masson ,&nbsp;L.L. Kivrak ,&nbsp;J.R. Havig ,&nbsp;T.L. Hamilton ,&nbsp;B.L. Teece ,&nbsp;Y. He ,&nbsp;C. Freissinet ,&nbsp;Y. Huang ,&nbsp;E. Santos ,&nbsp;C. Szopa ,&nbsp;A.J. Williams","doi":"10.1016/j.pss.2024.105953","DOIUrl":"10.1016/j.pss.2024.105953","url":null,"abstract":"&lt;div&gt;&lt;p&gt;From Viking landers to Perseverance rover, Mars has been explored by several &lt;em&gt;in situ&lt;/em&gt; missions capable of analyzing organic compounds. Results from the SAM and SHERLOC on Curiosity and Perseverance, respectively, support the detection of lean organic matter (at ppb-ppm levels) in the top surface samples, although the source(s) and preservation mechanisms are still ambiguous. Perseverance is currently exploring a fluvio-lacustrine system at Jezero crater and may explore an ancient volcanic terrain after exiting the crater. As Perseverance would collect samples for potential return to Earth, preparation is needed for sample return efforts through various means including i) the detection of trace organic compounds in various matrices, ii) validation of compounds identified by Martian rovers, and iii) better understanding of mechanisms of their production on Mars. On these returned samples, the community may be able to resolve the timing of organic matter formation and refine hypotheses regarding organic preservation in Martian soils despite the presence of numerous oxidants, salts, and pH-temperature intra and inter-site variations that are less conductive to long-term preservation of organic matter. For instance, acidic conditions promote clay catalyzed isomerization, but seem to benefit for the fatty acid preservation producing organic-salts or favoring salt dissolution in the matrix to protect organic compounds from radiations and water alteration. With a similar aim, we selected samples from Yellowstone National Park hot springs and silica sinters as analogs to locations visited by Curiosity and Perseverance or – in the future – Rosalind Franklin rover. The hot springs in this study developed over hundreds to thousands of years, providing optimal conditions (&lt;em&gt;i.e.,&lt;/em&gt; matrix composition, temperature, pH) of preservation for organic molecules, extremophilic and mesophilic cells. In our study, the most well preserved organic matter and biosignatures were detected in acidic silica sinters with a surface (water) temperature below 50 °C and a minor crystalline phase. The gas chromatography – mass spectrometry molecular analysis revealed a variety of organic compounds we classified as bioindicators (such as amino acids, nucleobases, and sugars), and biosignatures (such as long-chain branched and/or (poly)unsaturated lipids, secondary metabolites involved in the quorum sensing or communication between individuals). We validated with a SAM/MOMA-like benchtop extracting oven the organic matter extraction protocols performed with the SAM experiment. We identified using the different SAM and MOMA extraction protocols (pyrolysis and wet-chemistry derivatizations) eight microbial classes through a unique untargeted environmental metabolomics’ method embracing space flight technology constraints. Additionally, we identified one (and likely two) agnostic biosignature(s): i) the concomitance of some elements and organic compounds in the ana","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"250 ","pages":"Article 105953"},"PeriodicalIF":1.8,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S003206332400117X/pdfft?md5=35c49baec2f21820ac9affcac8231ed0&pid=1-s2.0-S003206332400117X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142006637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using synthetic disk-integrated reflectance spectra to constrain direct imaging sensitivity requirements for a Mars-like exoplanet","authors":"C.A. Wolfe ,&nbsp;T.D. Robinson","doi":"10.1016/j.pss.2024.105944","DOIUrl":"10.1016/j.pss.2024.105944","url":null,"abstract":"<div><p>The 2020 Decadal Survey on Astronomy and Astrophysics <span><span>¹</span></span> recommended the prioritization of a space-based telescope capable of directly characterizing Earth-like exoplanets in reflected light. The planned suite of instruments onboard such a mission are expected to provide disk-integrated spectra with moderate spectral resolution and signal-to-noise (SNR). Although the detection and characterization of Earth-like exoplanets remains the primary focus of such a mission, land planets with limited available water, such as Mars, may be much more common. Mars-like exoplanets, therefore, are an equally significant set of targets when investigating the diverse climatologies and potential habitability of other worlds, especially if our own Solar System is any indication of planetary diversity. In this study, we constrain the direct imaging sensitivity requirements for observing and characterizing Mars-like exoplanets with the goal of informing future telescope design and mission planning. Employing an instrument noise model simulating a coronagraph-equipped, space-based telescope, spatially- and spectrally-resolved synthetic observations of Mars are produced. We evaluate the direct imaging sensitivity requirements across a range of wavelengths, from the ultraviolet (UV) to near-infrared (near-IR), to enable the spectral characterization of key atmospheric and surface features from disk-integrated reflectance spectra. Detectability at a given SNR is assessed through optical wavelength integration times for a range of phase angles, host star spectral types, and levels of atmospheric dustiness. Our results indicate that a Decadal-recommended space telescope featuring an aperture of 6-m is likely only proficient in detecting Mars-like exoplanets around K-type stars located within a 10 parsec (pc) radius from Earth. Furthermore, we demonstrate that when integrating over visible and near-IR wavelengths, required exposure times to detect such a planet are reasonable, especially near full phase angles. In the context of upcoming and proposed observatories, such as the Habitable Exoplanet Observatory (HabEx) and Large UV/Optical/IR Surveyor (LUVOIR), our findings provide valuable insights into the direct imaging capabilities and optimal observational strategies needed for detecting and studying Mars-like exoplanets.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"250 ","pages":"Article 105944"},"PeriodicalIF":1.8,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation and cartographic representation of Hyperion space images photogrammetric processing results","authors":"A.I. Sokolov ,&nbsp;M.V. Nyrtsov ,&nbsp;M.E. Fleis ,&nbsp;I.E. Nadezhdina","doi":"10.1016/j.pss.2024.105945","DOIUrl":"10.1016/j.pss.2024.105945","url":null,"abstract":"<div><p>In this paper a new body-fixed coordinate system, based on the results of the processing of saturnian satellite Hyperion surface data, obtained by the Cassini spacecraft and proving the chaotic nature of this satellite rotation, was constructed. In this coordinate system, an approximating triaxial ellipsoid is defined, as well as global orthomosaic obtained from images of the Cassini spacecraft. A 3D model of Hyperion, obtained on the basis of a new shape model, is presented. This model is compared with 3D model and shape model developed by P. Thomas, J. Joseph, and T. Ansty, tied to the coordinate system in which the coordinates of Hyperion features are presented in the Gazetteer of Planetary Nomenclature. A surface map and a hypsometric map of Hyperion were compiled in an equal-area cylindrical projection of the triaxial ellipsoid with calculated parameters. To plot contour lines on the map, geodetic heights were calculated relative to the triaxial ellipsoid. A comparison was made of the compiled map with an earlier map in cylindrical and azimuthal meridian section projections. It is shown that meridian section projections give a good idea of the body surface, and the use of an equal-area projection makes it possible to calculate the areas of any contours on the surface. The distortion of one of the craters outline shape in the equal-area projection and the distortion of its area in the meridian section projections are shown.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"249 ","pages":"Article 105945"},"PeriodicalIF":1.8,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The astrobiological potential of the Makgadikgadi Basin, Botswana: Field analogue for planetary exploration","authors":"Trhas Hadush Kahsay ,&nbsp;Asfawossen Asrat ,&nbsp;Fulvio Franchi","doi":"10.1016/j.pss.2024.105943","DOIUrl":"10.1016/j.pss.2024.105943","url":null,"abstract":"<div><p>Terrestrial analogue sites have been crucial for studying Martian geology and mineralogy, integrating the direct evidence available from Mars through remote sensing and <em>in situ</em> measurements carried out by the instruments on board robotic missions. Studying readily available and accessible terrestrial analogues of Martian fossil or extant environments is considered the most efficient way to answer crucial scientific questions. These analogues offer opportunities to collect a range of geological and microbiological data. The Makgadikgadi Basin (MKB) in Botswana is one of such environments hosting a system of salt pans presenting striking similarities with Mars playa deposits. The MKB presents layered mounds, relict fan deltas with inverted channels, polygonal structures and evaporitic crusts harboring communities of extremophiles. The present-day MKB is predominantly fed by groundwater and local precipitations in an overall arid to semi-arid climate, characterized by high UV radiation and salinity, deposition of evaporitic minerals and authigenic clays. The shallow subsurface of the MKB pans is covered by diagenetic features (duricrusts) including silcretes and calcretes. These pans can serve as test beds for the physical and chemical characteristics of playa deposits on Mars and help improve our understanding of the conditions that might support life outside our planet.</p></div>","PeriodicalId":20054,"journal":{"name":"Planetary and Space Science","volume":"249 ","pages":"Article 105943"},"PeriodicalIF":1.8,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141844953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}