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Rodriguez JAP, Wilhelm MB, Travis B, Kargel JS, Zarroca M, Berman DC, Cohen J, Baker V, Lopez A, Buckner D. Exploring the evidence of Middle Amazonian aquifer sedimentary outburst residues in a Martian chaotic terrain. Sci Rep 2023; 13:17524. [PMID: 37853014 PMCID: PMC10584912 DOI: 10.1038/s41598-023-39060-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 07/19/2023] [Indexed: 10/20/2023] Open
Abstract
The quest for past Martian life hinges on locating surface formations linked to ancient habitability. While Mars' surface is considered to have become cryogenic ~3.7 Ga, stable subsurface aquifers persisted long after this transition. Their extensive collapse triggered megafloods ~3.4 Ga, and the resulting outflow channel excavation generated voluminous sediment eroded from the highlands. These materials are considered to have extensively covered the northern lowlands. Here, we show evidence that a lacustrine sedimentary residue within Hydraotes Chaos formed due to regional aquifer upwelling and ponding into an interior basin. Unlike the northern lowland counterparts, its sedimentary makeup likely consists of aquifer-expelled materials, offering a potential window into the nature of Mars' subsurface habitability. Furthermore, the lake's residue's estimated age is ~1.1 Ga (~3.2 Ga post-peak aquifer drainage during the Late Hesperian), enhancing the prospects for organic matter preservation. This deposit's inferred fine-grained composition, coupled with the presence of coexisting mud volcanoes and diapirs, suggest that its source aquifer existed within abundant subsurface mudstones, water ice, and evaporites, forming part of the region's extremely ancient (~ 4 Ga) highland stratigraphy. Our numerical models suggest that magmatically induced phase segregation within these materials generated enormous water-filled chambers. The meltwater, originating from varying thermally affected mudstone depths, could have potentially harbored diverse biosignatures, which could have become concentrated within the lake's sedimentary residue. Thus, we propose that Hydraotes Chaos merits priority consideration in future missions aiming to detect Martian biosignatures.
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Affiliation(s)
- J Alexis P Rodriguez
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA.
- External Geodynamics and Hydrogeology Group, Department of Geology, Autonomous University of Barcelona, Bellaterra, 08193, Barcelona, Spain.
| | | | - Bryan Travis
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA
| | - Jeffrey S Kargel
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA
| | - Mario Zarroca
- External Geodynamics and Hydrogeology Group, Department of Geology, Autonomous University of Barcelona, Bellaterra, 08193, Barcelona, Spain
| | - Daniel C Berman
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA
| | - Jacob Cohen
- NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Victor Baker
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Anthony Lopez
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA
| | - Denise Buckner
- Blue Marble Space Institute of Science, Seattle, WA, 98104, USA
- University of Florida, Gainesville, FL, 32611, USA
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2
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Posiolova LV, Lognonné P, Banerdt WB, Clinton J, Collins GS, Kawamura T, Ceylan S, Daubar IJ, Fernando B, Froment M, Giardini D, Malin MC, Miljković K, Stähler SC, Xu Z, Banks ME, Beucler É, Cantor BA, Charalambous C, Dahmen N, Davis P, Drilleau M, Dundas CM, Durán C, Euchner F, Garcia RF, Golombek M, Horleston A, Keegan C, Khan A, Kim D, Larmat C, Lorenz R, Margerin L, Menina S, Panning M, Pardo C, Perrin C, Pike WT, Plasman M, Rajšić A, Rolland L, Rougier E, Speth G, Spiga A, Stott A, Susko D, Teanby NA, Valeh A, Werynski A, Wójcicka N, Zenhäusern G. Largest recent impact craters on Mars: Orbital imaging and surface seismic co-investigation. Science 2022; 378:412-417. [DOI: 10.1126/science.abq7704] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Two >130-meter-diameter impact craters formed on Mars during the later half of 2021. These are the two largest fresh impact craters discovered by the Mars Reconnaissance Orbiter since operations started 16 years ago. The impacts created two of the largest seismic events (magnitudes greater than 4) recorded by InSight during its 3-year mission. The combination of orbital imagery and seismic ground motion enables the investigation of subsurface and atmospheric energy partitioning of the impact process on a planet with a thin atmosphere and the first direct test of martian deep-interior seismic models with known event distances. The impact at 35°N excavated blocks of water ice, which is the lowest latitude at which ice has been directly observed on Mars.
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Affiliation(s)
| | - P. Lognonné
- Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - W. B. Banerdt
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - J. Clinton
- Swiss Seismological Service, ETH Zurich, Zurich, Switzerland
| | - G. S. Collins
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | - T. Kawamura
- Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - S. Ceylan
- Institute of Geophysics, ETH Zurich, Zurich, Switzerland
| | - I. J. Daubar
- Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, RI, USA
| | - B. Fernando
- Department of Earth Sciences, University of Oxford, Oxford, UK
| | - M. Froment
- Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, France
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - D. Giardini
- Institute of Geophysics, ETH Zurich, Zurich, Switzerland
| | - M. C. Malin
- Malin Space Science Systems, San Diego, CA, USA
| | - K. Miljković
- Space Science and Technology Centre, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
| | - S. C. Stähler
- Institute of Geophysics, ETH Zurich, Zurich, Switzerland
| | - Z. Xu
- Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - M. E. Banks
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - É. Beucler
- Nantes Université, Université Angers, Le Mans Université, CNRS, UMR 6112, Laboratoire de Planétologie et Géosciences, Nantes, France
| | | | - C. Charalambous
- Department of Electrical and Electronic Engineering, Imperial College London, London, UK
| | - N. Dahmen
- Institute of Geophysics, ETH Zurich, Zurich, Switzerland
| | - P. Davis
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA, USA
| | - M. Drilleau
- Institut Supérieur de l’Aéronautique et de l’Espace ISAE-SUPAERO, Toulouse, France
| | - C. M. Dundas
- U.S. Geological Survey, Astrogeology Science Center, Flagstaff, AZ, USA
| | - C. Durán
- Institute of Geophysics, ETH Zurich, Zurich, Switzerland
| | - F. Euchner
- Institute of Geophysics, ETH Zurich, Zurich, Switzerland
| | - R. F. Garcia
- Institut Supérieur de l’Aéronautique et de l’Espace ISAE-SUPAERO, Toulouse, France
| | - M. Golombek
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - A. Horleston
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - C. Keegan
- Malin Space Science Systems, San Diego, CA, USA
| | - A. Khan
- Institute of Geophysics, ETH Zurich, Zurich, Switzerland
- Physik-Institut, University of Zurich, Zurich, Switzerland
| | - D. Kim
- Institute of Geophysics, ETH Zurich, Zurich, Switzerland
- Department of Geology, University of Maryland, College Park, MD, USA
| | - C. Larmat
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - R. Lorenz
- Johns Hopkins Applied Physics Laboratory, Laurel, MD, USA
| | - L. Margerin
- Institut de Recherche en Astrophysique et Planétologie, Université Toulouse III Paul Sabatier, CNRS, CNES, Toulouse, France
| | - S. Menina
- Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - M. Panning
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - C. Pardo
- Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - C. Perrin
- Nantes Université, Université Angers, Le Mans Université, CNRS, UMR 6112, Laboratoire de Planétologie et Géosciences, Nantes, France
| | - W. T. Pike
- Department of Electrical and Electronic Engineering, Imperial College London, London, UK
| | - M. Plasman
- Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, France
| | - A. Rajšić
- Space Science and Technology Centre, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia
| | - L. Rolland
- Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, IRD, Géoazur, Valbonne, France
| | - E. Rougier
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - G. Speth
- Malin Space Science Systems, San Diego, CA, USA
| | - A. Spiga
- Laboratoire de Météorologie Dynamique/IPSL, Sorbonne Université, CNRS, Ecole Normale Supérieure, PSL Research University, Ecole Polytechnique, Paris, France
| | - A. Stott
- Institut Supérieur de l’Aéronautique et de l’Espace ISAE-SUPAERO, Toulouse, France
| | - D. Susko
- Malin Space Science Systems, San Diego, CA, USA
| | - N. A. Teanby
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - A. Valeh
- Malin Space Science Systems, San Diego, CA, USA
| | - A. Werynski
- Malin Space Science Systems, San Diego, CA, USA
| | - N. Wójcicka
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | - G. Zenhäusern
- Institute of Geophysics, ETH Zurich, Zurich, Switzerland
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3
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Chojnacki M, Vaz DA, Silvestro S, Silva DCA. Widespread Megaripple Activity Across the North Polar Ergs of Mars. JOURNAL OF GEOPHYSICAL RESEARCH. PLANETS 2021; 126:e2021JE006970. [PMID: 35096495 PMCID: PMC8793034 DOI: 10.1029/2021je006970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
The most expansive dune fields on Mars surround the northern polar cap where various aeolian bedform classes are modified by wind and ice. The morphology and dynamics of these ripples, intermediate-scale bedforms (termed megaripples and Transverse Aeolian Ridges [TARs]), and sand dunes reflect information regarding regional boundary conditions. We found that populations of polar megaripples and larger TARs are distinct in terms of their morphology, spatial distribution, and mobility. Whereas regionally restricted TARs appeared degraded and static in long-baseline observations, polar megaripples were not only widespread but migrating at relatively high rates (0.13 ± 0.03 m/Earth year) and possibly more active than other regions on Mars. This high level of activity is somewhat surprising since there is limited seasonality for aeolian transport due to surficial frost and ice during the latter half of the martian year. A comprehensive analysis of an Olympia Cavi dune field estimated that the advancement of megaripples, ripples, and dunes avalanches accounted for ~1%, ~10%, and ~100%, respectively, of the total aeolian system's sand fluxes. This included dark-toned ripples that migrated the average equivalent of 9.6 ± 6 m/yr over just 22 days in northern summer-unprecedented rates for Mars. While bedform transport rates are some of the highest yet reported on Mars, the sand flux contribution between the different bedforms does not substantially vary from equatorial sites with lower rates. Seasonal off-cap sublimation winds and summer-time polar storms are attributed as the cause for the elevated activity, rather than cryospheric processes.
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Affiliation(s)
| | - David A Vaz
- Centre for Earth and Space Research of the University of Coimbra, Observatório Geofísico e Astronómico da Universidade de Coimbra, Coimbra, Portugal
| | - Simone Silvestro
- SETI Institute, Carl Sagan Center, Mountain View, CA, USA
- INAF Osservatorio Astronomico di Capodimonte, Napoli, Italia
| | - David C A Silva
- Centre for Earth and Space Research of the University of Coimbra, Observatório Geofísico e Astronómico da Universidade de Coimbra, Coimbra, Portugal
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4
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Recognition of Sedimentary Rock Occurrences in Satellite and Aerial Images of Other Worlds—Insights from Mars. REMOTE SENSING 2021. [DOI: 10.3390/rs13214296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Sedimentary rocks provide records of past surface and subsurface processes and environments. The first step in the study of the sedimentary rock record of another world is to learn to recognize their occurrences in images from instruments aboard orbiting, flyby, or aerial platforms. For two decades, Mars has been known to have sedimentary rocks; however, planet-wide identification is incomplete. Global coverage at 0.25–6 m/pixel, and observations from the Curiosity rover in Gale crater, expand the ability to recognize Martian sedimentary rocks. No longer limited to cases that are light-toned, lightly cratered, and stratified—or mimic original depositional setting (e.g., lithified deltas)—Martian sedimentary rocks include dark-toned examples, as well as rocks that are erosion-resistant enough to retain small craters as well as do lava flows. Breakdown of conglomerates, breccias, and even some mudstones, can produce a pebbly regolith that imparts a “smooth” appearance in satellite and aerial images. Context is important; sedimentary rocks remain challenging to distinguish from primary igneous rocks in some cases. Detection of ultramafic, mafic, or andesitic compositions do not dictate that a rock is igneous, and clast genesis should be considered separately from the depositional record. Mars likely has much more sedimentary rock than previously recognized.
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5
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Dundas CM, Becerra P, Byrne S, Chojnacki M, Daubar IJ, Diniega S, Hansen CJ, Herkenhoff KE, Landis ME, McEwen AS, Portyankina G, Valantinas A. Active Mars: A Dynamic World. JOURNAL OF GEOPHYSICAL RESEARCH. PLANETS 2021; 126:e2021JE006876. [PMID: 35845553 PMCID: PMC9285055 DOI: 10.1029/2021je006876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 06/17/2021] [Accepted: 06/21/2021] [Indexed: 06/15/2023]
Abstract
Mars exhibits diverse surface changes at all latitudes and all seasons. Active processes include impact cratering, aeolian sand and dust transport, a variety of slope processes, changes in polar ices, and diverse effects of seasonal CO2 frost. The extent of surface change has been surprising and indicates that the present climate is capable of reshaping the surface. Activity has important implications for the Amazonian history of Mars: understanding processes is a necessary step before we can understand their implications and variations over time.
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Affiliation(s)
- Colin M. Dundas
- U.S. Geological SurveyAstrogeology Science CenterFlagstaffAZUSA
| | | | - Shane Byrne
- Lunar and Planetary LaboratoryUniversity of ArizonaTucsonAZUSA
| | | | - Ingrid J. Daubar
- Department of Earth, Environmental, and Planetary SciencesBrown UniversityProvidenceRIUSA
| | - Serina Diniega
- Jet Propulsion Laboratory/California Institute of TechnologyPasadenaCAUSA
| | | | | | - Margaret E. Landis
- Laboratory for Atmospheric and Space PhysicsUniversity of ColoradoBoulderCOUSA
| | | | - Ganna Portyankina
- Laboratory for Atmospheric and Space PhysicsUniversity of ColoradoBoulderCOUSA
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6
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The Preliminary Study of Dust Devil Tracks in Southern Utopia Planitia, Landing Area of Tianwen-1 Mission. REMOTE SENSING 2021. [DOI: 10.3390/rs13132601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
China’s first Mars exploration mission (Tianwen-1) landed on the southern part of Mars’ Utopia Planitia on 15 May 2021. The Zhurong rover will focus on high-resolution and in situ observations of key areas on the surface of Mars. Dust devils (DDs) are heat-driven vortices that lift material from the surface and inject it into the atmosphere. The dark or bright surface lineaments left by DDs are called dust devil tracks (DDTs). Dust devils can clear dust from solar panels deposited by gusts and dust storms. Therefore, it is of importance to study the encounter rates of dust devils at the Tianwen-1 landing site for achieving the rover’s long-term scientific goals. Based on High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) images, 248 newly formed DDTs in 12 image pairs were firstly identified, and their lengths, widths, and direction in the study area were measured. The distribution of their width frequency follows a −2 differential power law. Secondly, DDT formation rates were computed and analyzed with the range of 0.00006 to 0.1275 ddt km−2 sol−1, mainly affected by factors such as seasons and dust storm occurrence. Thirdly, the solar panel clearing recurrence interval derived from the orbital data in our study area was calculated from ~980 to 166,700 sols. The dust storm occurrence probability at the Tianwen-1 landing area is less than 3%, and there is a special anti-dust coating on board the Zhurong rover. Thus, the Zhurong rover can be considered competent for scientific exploration.
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7
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Clancy RT, Wolff MJ, Heavens NG, James PB, Lee SW, Sandor BJ, Cantor BA, Malin MC, Tyler D, Spiga A. Mars Perihelion Cloud Trails as revealed by MARCI: Mesoscale Topographically Focussed Updrafts and Gravity Wave Forcing of High Altitude Clouds. ICARUS 2021; 362:114411. [PMID: 33867569 PMCID: PMC8051166 DOI: 10.1016/j.icarus.2021.114411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Daily, global wide angle imaging of Mars clouds in MARCI (MARs Color Imager, (Malin et al., 2008)) ultraviolet and visible bands reveals the spatial/seasonal distributions and physical characteristics of perihelion cloud trails (PCT); a class of high altitude (40-50 km), horizontally extended (200-1000 km, trending W to WSW) water ice clouds formed over specific southern low-to-mid latitude (5S-40S), mesoscale (~50 km) locations during the Mars perihelion, southern summer season. PCT were first reported in association with rim regions of Valles Marineris (Clancy et al., 2009). The current study employs MARCI 2007-2011 imaging to sample the broader distributions and properties of PCT; and indicates several distinct locations of peak occurrences, including SW Arsia Mons, elevated regions of Syria, Solis, and Thaumasia Planitia, along Valles Marineris margins, and the NE rim of Hellas Basin. PCT are present over Mars solar longitudes (L S ) of 210-310°, in late morning to mid afternoon hours (10am-3pm), and are among the brightest and most distinctive clouds exhibited during the perihelion portion of the Mars orbit. Their locations (i.e., eastern margin origins) correspond to strong local elevation gradients, and their timing to peak solar heating conditions (perihelion, subsolar latitudes and midday local times). They occur approximately on a daily basis among all locations identified (i.e., not daily at a single location). Based on cloud surface shadow analyses, PCT form at 40-50 km aeroid altitudes, where water vapor is generally at near-saturation conditions in this perihelion period (e.g. Millour et al., 2014). They exhibited notable absences during periods of planet encircling and regional dust storm activity in 2007 and 2009, respectively, presumably due to reduced water saturation conditions above 35-40 km altitudes associated with increased dust heating over the vertically extended atmosphere (e.g., Neary et al., 2019). PCT exhibit smaller particle sizes (R eff =0.2-0.5μm) than typically exhibited in the lower atmosphere, and incorporate significant fractions of available water vapor at these altitudes. PCT ice particles are inferred to form continuously (over ~4 hours) at their PCT eastern origins, associated with localized updrafts, and are entrained in upper level zonal/meridional winds (towards W or WSW with ~50 m/sec speeds at 40-50 km altitudes) to create long, linear cloud trails. PCT cloud formation is apparently forced in the lower atmosphere (≤10-15 km) by strong updrafts associated with distinctive topographic gradients, such as simulated in mesoscale studies (e.g., Tyler and Barnes, 2015) and indicated by the surface-specific PCT locations. These lower scale height updrafts are proposed to generate vertically propagating gravity waves (GW), leading to PCT formation above ~40 km altitudes where water vapor saturation conditions promote vigorous cloud ice formation. Recent mapping of GW amplitudes at ~25 km altitudes, from Mars Climate Sounder 15 μm radiance variations (Heavens et al., 2020), in fact demonstrates close correspondences to the detailed spatial distributions of observed PCT, relative to other potential factors such as surface albedo and surface elevation (or related boundary layer depths).
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Affiliation(s)
- R Todd Clancy
- Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA
| | - Michael J Wolff
- Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA
| | - Nicholas G Heavens
- Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA
| | - Philip B James
- Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA
| | - Steven W Lee
- Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA
| | - Brad J Sandor
- Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA
| | - Bruce A Cantor
- Malin Space Science Systems, 5880 Pacific Center Blvd, San Diego, CA 92121, USA
| | - Michael C Malin
- Malin Space Science Systems, 5880 Pacific Center Blvd, San Diego, CA 92121, USA
| | - Daniel Tyler
- College of Earth Oceanic and Atmospheric Science, Oregon State University, Corvallis, OR 97331, USA
| | - Aymeric Spiga
- Laboratoire de Météorologie Dynamique/Institut Pierre-Simon Laplace (LMD/IPSL), Sorbonne Universités, UPMC Univ Paris 06, PSL Research University, France
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8
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Mc Keown L, McElwaine JN, Bourke MC, Sylvest ME, Patel MR. The formation of araneiforms by carbon dioxide venting and vigorous sublimation dynamics under martian atmospheric pressure. Sci Rep 2021; 11:6445. [PMID: 33742009 PMCID: PMC7979800 DOI: 10.1038/s41598-021-82763-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 01/18/2021] [Indexed: 11/22/2022] Open
Abstract
The local redistribution of granular material by sublimation of the southern seasonal \documentclass[12pt]{minimal}
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\begin{document}$${\hbox {CO}}_2$$\end{document}CO2 ice deposit is one of the most active surface shaping processes on Mars today. This unique geomorphic mechanism is hypothesised to be the cause of the dendritic, branching, spider-like araneiform terrain and associated fans and spots—features which are native to Mars and have no Earth analogues. However, there is a paucity of empirical data to test the validity of this hypothesis. Additionally, it is unclear whether some araneiform patterns began as radial and then grew outward, or whether troughs connected at mutual centres over time. Here we present the results of a suite of laboratory experiments undertaken to investigate if the interaction between a sublimating \documentclass[12pt]{minimal}
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\begin{document}$${\hbox {CO}}_2$$\end{document}CO2 ice overburden containing central vents and a porous, mobile regolith will mobilise grains from beneath the ice in the form of a plume to generate araneiform patterns. We quantify the branching and area of the dendritic features that form. We provide the first observations of plume activity via \documentclass[12pt]{minimal}
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\begin{document}$${\hbox {CO}}_2$$\end{document}CO2 sublimation and consequent erosion to form araneiform features. We show that \documentclass[12pt]{minimal}
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\begin{document}$${\hbox {CO}}_2$$\end{document}CO2 sublimation can be a highly efficient agent of sediment transport under present day Martian atmospheric pressure and that morphometry is governed by the Shields parameter.
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Affiliation(s)
- Lauren Mc Keown
- Trinity College Dublin, College Green, Dublin 2, Ireland. .,The Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom.
| | - J N McElwaine
- Durham University, Durham, DH1, UK.,Planetary Science Institute, 1700 E Fort Lowell Rd, Tucson, AZ, 85719, USA
| | - M C Bourke
- Trinity College Dublin, College Green, Dublin 2, Ireland
| | - M E Sylvest
- The Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom
| | - M R Patel
- The Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom
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9
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Bell JF, Maki JN, Mehall GL, Ravine MA, Caplinger MA, Bailey ZJ, Brylow S, Schaffner JA, Kinch KM, Madsen MB, Winhold A, Hayes AG, Corlies P, Tate C, Barrington M, Cisneros E, Jensen E, Paris K, Crawford K, Rojas C, Mehall L, Joseph J, Proton JB, Cluff N, Deen RG, Betts B, Cloutis E, Coates AJ, Colaprete A, Edgett KS, Ehlmann BL, Fagents S, Grotzinger JP, Hardgrove C, Herkenhoff KE, Horgan B, Jaumann R, Johnson JR, Lemmon M, Paar G, Caballo-Perucha M, Gupta S, Traxler C, Preusker F, Rice MS, Robinson MS, Schmitz N, Sullivan R, Wolff MJ. The Mars 2020 Perseverance Rover Mast Camera Zoom (Mastcam-Z) Multispectral, Stereoscopic Imaging Investigation. SPACE SCIENCE REVIEWS 2021; 217:24. [PMID: 33612866 PMCID: PMC7883548 DOI: 10.1007/s11214-020-00755-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 09/25/2020] [Indexed: 05/16/2023]
Abstract
Mastcam-Z is a multispectral, stereoscopic imaging investigation on the Mars 2020 mission's Perseverance rover. Mastcam-Z consists of a pair of focusable, 4:1 zoomable cameras that provide broadband red/green/blue and narrowband 400-1000 nm color imaging with fields of view from 25.6° × 19.2° (26 mm focal length at 283 μrad/pixel) to 6.2° × 4.6° (110 mm focal length at 67.4 μrad/pixel). The cameras can resolve (≥ 5 pixels) ∼0.7 mm features at 2 m and ∼3.3 cm features at 100 m distance. Mastcam-Z shares significant heritage with the Mastcam instruments on the Mars Science Laboratory Curiosity rover. Each Mastcam-Z camera consists of zoom, focus, and filter wheel mechanisms and a 1648 × 1214 pixel charge-coupled device detector and electronics. The two Mastcam-Z cameras are mounted with a 24.4 cm stereo baseline and 2.3° total toe-in on a camera plate ∼2 m above the surface on the rover's Remote Sensing Mast, which provides azimuth and elevation actuation. A separate digital electronics assembly inside the rover provides power, data processing and storage, and the interface to the rover computer. Primary and secondary Mastcam-Z calibration targets mounted on the rover top deck enable tactical reflectance calibration. Mastcam-Z multispectral, stereo, and panoramic images will be used to provide detailed morphology, topography, and geologic context along the rover's traverse; constrain mineralogic, photometric, and physical properties of surface materials; monitor and characterize atmospheric and astronomical phenomena; and document the rover's sample extraction and caching locations. Mastcam-Z images will also provide key engineering information to support sample selection and other rover driving and tool/instrument operations decisions.
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Affiliation(s)
| | | | | | - M. A. Ravine
- Malin Space Science Systems, Inc., San Diego, CA USA
| | | | | | - S. Brylow
- Malin Space Science Systems, Inc., San Diego, CA USA
| | | | | | | | | | | | | | - C. Tate
- Cornell Univ., Ithaca, NY USA
| | | | | | - E. Jensen
- Malin Space Science Systems, Inc., San Diego, CA USA
| | - K. Paris
- Arizona State Univ., Tempe, AZ USA
| | | | - C. Rojas
- Arizona State Univ., Tempe, AZ USA
| | | | | | | | - N. Cluff
- Arizona State Univ., Tempe, AZ USA
| | | | - B. Betts
- The Planetary Society, Pasadena, CA USA
| | | | - A. J. Coates
- Mullard Space Science Laboratory, Univ. College, London, UK
| | - A. Colaprete
- NASA/Ames Research Center, Moffett Field, CA USA
| | - K. S. Edgett
- Malin Space Science Systems, Inc., San Diego, CA USA
| | - B. L. Ehlmann
- JPL/Caltech, Pasadena, CA USA
- Caltech, Pasadena, CA USA
| | | | | | | | | | | | - R. Jaumann
- Inst. of Geological Sciences, Free University Berlin, Berlin, Germany
| | | | - M. Lemmon
- Space Science Inst., Boulder, CO USA
| | - G. Paar
- Joanneum Research, Graz, Austria
| | | | | | | | - F. Preusker
- DLR/German Aerospace Center, Berlin, Germany
| | - M. S. Rice
- Western Washington Univ., Bellingham, WA USA
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10
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DoMars16k: A Diverse Dataset for Weakly Supervised Geomorphologic Analysis on Mars. REMOTE SENSING 2020. [DOI: 10.3390/rs12233981] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mapping planetary surfaces is an intricate task that forms the basis for many geologic, geomorphologic, and geographic studies of planetary bodies. In this work, we present a method to automate a specific type of planetary mapping, geomorphic mapping, taking machine learning as a basis. Additionally, we introduce a novel dataset, termed DoMars16k, which contains 16,150 samples of fifteen different landforms commonly found on the Martian surface. We use a convolutional neural network to establish a relation between Mars Reconnaissance Orbiter Context Camera images and the landforms of the dataset. Afterwards, we employ a sliding-window approach in conjunction with a Markov Random field smoothing to create maps in a weakly supervised fashion. Finally, we provide encouraging results and carry out automated geomorphological analyses of Jezero crater, the Mars2020 landing site, and Oxia Planum, the prospective ExoMars landing site.
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11
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Edgett KS, Banham SG, Bennett KA, Edgar LA, Edwards CS, Fairén AG, Fedo CM, Fey DM, Garvin JB, Grotzinger JP, Gupta S, Henderson MJ, House CH, Mangold N, McLennan SM, Newsom HE, Rowland SK, Siebach KL, Thompson L, VanBommel SJ, Wiens RC, Williams RME, Yingst RA. Extraformational sediment recycling on Mars. GEOSPHERE (BOULDER, COLO.) 2020; 16:1508-1537. [PMID: 33304202 PMCID: PMC7116455 DOI: 10.1130/ges02244.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Extraformational sediment recycling (old sedimentary rock to new sedimentary rock) is a fundamental aspect of Earth's geological record; tectonism exposes sedimentary rock, whereupon it is weathered and eroded to form new sediment that later becomes lithified. On Mars, tectonism has been minor, but two decades of orbiter instrument-based studies show that some sedimentary rocks previously buried to depths of kilometers have been exposed, by erosion, at the surface. Four locations in Gale crater, explored using the National Aeronautics and Space Administration's Curiosity rover, exhibit sedimentary lithoclasts in sedimentary rock: At Marias Pass, they are mudstone fragments in sandstone derived from strata below an erosional unconformity; at Bimbe, they are pebble-sized sandstone and, possibly, laminated, intraclast-bearing, chemical (calcium sulfate) sediment fragments in conglomerates; at Cooperstown, they are pebble-sized fragments of sandstone within coarse sandstone; at Dingo Gap, they are cobble-sized, stratified sandstone fragments in conglomerate derived from an immediately underlying sandstone. Mars orbiter images show lithified sediment fans at the termini of canyons that incise sedimentary rock in Gale crater; these, too, consist of recycled, extraformational sediment. The recycled sediments in Gale crater are compositionally immature, indicating the dominance of physical weathering processes during the second known cycle. The observations at Marias Pass indicate that sediment eroded and removed from craters such as Gale crater during the Martian Hesperian Period could have been recycled to form new rock elsewhere. Our results permit prediction that lithified deltaic sediments at the Perseverance (landing in 2021) and Rosalind Franklin (landing in 2023) rover field sites could contain extraformational recycled sediment.
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Affiliation(s)
- Kenneth S Edgett
- Malin Space Science Systems, P.O. Box 910148, San Diego, California 92191-0148, USA
| | - Steven G Banham
- Department of Earth Science and Engineering, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Kristen A Bennett
- U.S. Geological Survey, Astrogeology Science Center, 2255 N. Gemini Drive, Flagstaff, Arizona 86001, USA
| | - Lauren A Edgar
- U.S. Geological Survey, Astrogeology Science Center, 2255 N. Gemini Drive, Flagstaff, Arizona 86001, USA
| | - Christopher S Edwards
- Department of Astronomy and Planetary Science, Northern Arizona University, P.O. Box 6010, Flagstaff, Arizona 86011, USA
| | - Alberto G Fairén
- Department of Planetology and Habitability, Centro de Astrobiología (CSIC-INTA), M-108, km 4, 28850 Madrid, Spain
- Department of Astronomy, Cornell University, Ithaca, New York 14853, USA
| | - Christopher M Fedo
- Department of Earth and Planetary Sciences, The University of Tennessee, 1621 Cumberland Avenue, 602 Strong Hall, Knoxville, Tennessee 37996-1410, USA
| | - Deirdra M Fey
- Malin Space Science Systems, P.O. Box 910148, San Diego, California 92191-0148, USA
| | - James B Garvin
- National Aeronautics and Space Administration (NASA) Goddard Space Flight Center, Mail Code 600, Greenbelt, Maryland 20771, USA
| | - John P Grotzinger
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
| | - Sanjeev Gupta
- Department of Earth Science and Engineering, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Marie J Henderson
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, USA
| | - Christopher H House
- Department of Geosciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Nicolas Mangold
- Laboratoire de Planétologie et Géodynamique de Nantes, CNRS UMR 6112, Université de Nantes, Université Angers, 44300 Nantes, France
| | - Scott M McLennan
- Department of Geosciences, Stony Brook University, Stony Brook, New York 11794-2100, USA
| | - Horton E Newsom
- Institute of Meteoritics and Department of Earth and Planetary Sciences, 1 University of New Mexico, MSC03-2050, Albuquerque, New Mexico 87131, USA
| | - Scott K Rowland
- Department of Earth Sciences, University of Hawai'i at Mānoa, Honolulu, Hawai'i 96822, USA
| | - Kirsten L Siebach
- Department of Earth, Environmental and Planetary Sciences, Rice University, MS-126, 6100 Main Street, Houston, Texas 77005, USA
| | - Lucy Thompson
- Department of Earth Sciences, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick E3B 5A3, Canada
| | - Scott J VanBommel
- Department of Earth and Planetary Sciences, Washington University in St. Louis, 1 Brookings Drive, St. Louis, Missouri 63130, USA
| | - Roger C Wiens
- MS C331, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Rebecca M E Williams
- Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, Arizona 85719-2395, USA
| | - R Aileen Yingst
- Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, Arizona 85719-2395, USA
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12
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PlaNet: A Neural Network for Detecting Transverse Aeolian Ridges on Mars. REMOTE SENSING 2020. [DOI: 10.3390/rs12213607] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transverse aeolian ridges (TARs) are unusual bedforms on the surface of Mars. TARs are common but sparse on Mars; TAR fields are small, rarely continuous, and scattered, making manual mapping impractical. There have been many efforts to automatically classify the Martian surface, but they have never explicitly located TARs successfully. Here, we present a simple adaptation of the off-the-shelf neural network RetinaNet that is designed to identify the presence of TARs at a 50-m scale. Once trained, the network was able to identify TARs with high precision (92.9%). Our model also shows promising results for applications to other surficial features like ripples and polygonal terrain. In the future, we hope to apply this model more broadly and generate a large database of TAR distributions on Mars.
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13
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Horgan BHN, Johnson JR, Fraeman AA, Rice MS, Seeger C, Bell JF, Bennett KA, Cloutis EA, Edgar LA, Frydenvang J, Grotzinger JP, L'Haridon J, Jacob SR, Mangold N, Rampe EB, Rivera‐Hernandez F, Sun VZ, Thompson LM, Wellington D. Diagenesis of Vera Rubin Ridge, Gale Crater, Mars, From Mastcam Multispectral Images. JOURNAL OF GEOPHYSICAL RESEARCH. PLANETS 2020; 125:e2019JE006322. [PMID: 33282614 PMCID: PMC7685111 DOI: 10.1029/2019je006322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 09/03/2020] [Accepted: 09/19/2020] [Indexed: 05/13/2023]
Abstract
Images from the Mars Science Laboratory (MSL) mission of lacustrine sedimentary rocks of Vera Rubin ridge on "Mt. Sharp" in Gale crater, Mars, have shown stark color variations from red to purple to gray. These color differences crosscut stratigraphy and are likely due to diagenetic alteration of the sediments after deposition. However, the chemistry and timing of these fluid interactions is unclear. Determining how diagenetic processes may have modified chemical and mineralogical signatures of ancient Martian environments is critical for understanding the past habitability of Mars and achieving the goals of the MSL mission. Here we use visible/near-infrared spectra from Mastcam and ChemCam to determine the mineralogical origins of color variations in the ridge. Color variations are consistent with changes in spectral properties related to the crystallinity, grain size, and texture of hematite. Coarse-grained gray hematite spectrally dominates in the gray patches and is present in the purple areas, while nanophase and fine-grained red crystalline hematite are present and spectrally dominate in the red and purple areas. We hypothesize that these differences were caused by grain-size coarsening of hematite by diagenetic fluids, as observed in terrestrial analogs. In this model, early primary reddening by oxidizing fluids near the surface was followed during or after burial by bleaching to form the gray patches, possibly with limited secondary reddening after exhumation. Diagenetic alteration may have diminished the preservation of biosignatures and changed the composition of the sediments, making it more difficult to interpret how conditions evolved in the paleolake over time.
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Affiliation(s)
- Briony H. N. Horgan
- Department of Earth, Atmospheric, and Planetary SciencesPurdue UniversityWest LafayetteINUSA
| | | | - Abigail A. Fraeman
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Melissa S. Rice
- Geology Department, Physics and Astronomy DepartmentWestern Washington UniversityBellinghamWAUSA
| | - Christina Seeger
- Geology Department, Physics and Astronomy DepartmentWestern Washington UniversityBellinghamWAUSA
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
| | - James F. Bell
- School of Earth and Space ExplorationArizona State UniversityTempeAZUSA
| | | | | | - Lauren A. Edgar
- U.S. Geological SurveyAstrogeology Science CenterFlagstaffAZ
| | | | - John P. Grotzinger
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
| | - Jonas L'Haridon
- Laboratoire de Planétologie et GéodynamiqueCNRS, Univ Nantes, Univ AngersNantesFrance
| | - Samantha R. Jacob
- School of Earth and Space ExplorationArizona State UniversityTempeAZUSA
| | - Nicolas Mangold
- Laboratoire de Planétologie et GéodynamiqueCNRS, Univ Nantes, Univ AngersNantesFrance
| | | | | | - Vivian Z. Sun
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Lucy M. Thompson
- Planetary and Space Science CentreUniversity of New BrunswickFrederictonNew BrunswickCanada
| | - Danika Wellington
- School of Earth and Space ExplorationArizona State UniversityTempeAZUSA
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14
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Salese F, Kleinhans MG, Mangold N, Ansan V, McMahon W, de Haas T, Dromart G. Estimated Minimum Life Span of the Jezero Fluvial Delta (Mars). ASTROBIOLOGY 2020; 20:977-993. [PMID: 32434374 DOI: 10.1089/ast.2020.2228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The paleo-lake floor at the edge of the Jezero delta has been selected as the NASA 2020 rover landing site. In this article, we demonstrate the sequences of lake filling and delta formation and constrain the minimum life span of the Jezero paleo-lake from sedimentological and hydrological analyses. Two main phases of delta evolution can be recognized by utilizing imagery provided by the High Resolution Imaging Science Experiment (NASA Mars Reconnaissance Orbiter) and High Resolution Stereo Camera (ESA Mars Express): (1) basin infilling before the breaching of the Jezero rim and (2) the delta formation itself. Our results suggest that delta formation occurred over a minimum period of 90-550 years of hydrological activity. Breaching of the Jezero rim occurred in at least three distinct episodes, which spanned a far longer time-period than overall delta formation. This evolutionary history implies that the Jezero-lake floor would have been a haven for fine-grained sediment accumulation and hosted an active environment of significant astrobiological importance.
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Affiliation(s)
- Francesco Salese
- Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
- International Research School of Planetary Sciences, Università Gabriele D'Annunzio, Pescara, Italy
| | | | - Nicolas Mangold
- Laboratoire de Planétologie et de Géodynamique de Nantes, UMR6112, CNRS/Nantes University, Nantes, France
| | - Veronique Ansan
- Laboratoire de Planétologie et de Géodynamique de Nantes, UMR6112, CNRS/Nantes University, Nantes, France
| | - William McMahon
- Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Tjalling de Haas
- Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Gilles Dromart
- University of Lyon, ENSL, University of Lyon 1, CNRS, LGL-TPE, Lyon, France
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15
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Silvestro S, Chojnacki M, Vaz DA, Cardinale M, Yizhaq H, Esposito F. Megaripple Migration on Mars. JOURNAL OF GEOPHYSICAL RESEARCH. PLANETS 2020; 125:e2020JE006446. [PMID: 33133993 PMCID: PMC7583471 DOI: 10.1029/2020je006446] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 06/09/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
Aeolian megaripples, with 5- to 50-m spacing, are abundant on the surface of Mars. These features were repeatedly targeted by high-resolution orbital images, but they have never been observed to move. Thus, aeolian megaripples (especially the bright-toned ones often referred as Transverse Aeolian Ridges-TARs) have been interpreted as relict features of a past climate. In this report, we show evidence for the migration of bright-toned megaripples spaced 1 to 35 m (5 m on average) in two equatorial areas on Mars indicating that megaripples and small TARs can be active today. The moving megaripples display sand fluxes that are 2 orders of magnitudes lower than the surrounding dunes on average and, unlike similar bedforms on Earth, can migrate obliquely and longitudinally. In addition, the active megaripples in the two study areas of Syrtis Major and Mawrth Vallis show very similar flux distributions, echoing the similarities between dune crest fluxes in the two study areas and suggesting the existence of a relationship between dune and megaripple fluxes that can be explored elsewhere. Active megaripples, together with high-sand flux dunes, represent a key indicator of strong winds at the surface of Mars. A past climate with a denser atmosphere is not necessary to explain their accumulation and migration.
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Affiliation(s)
- S. Silvestro
- INAF Osservatorio Astronomico di CapodimonteNapoliItaly
- SETI InstituteMountain ViewCAUSA
| | - M. Chojnacki
- Lunar and Planetary LaboratoryUniversity of ArizonaTucsonAZUSA
- Planetary Science InstituteTucsonAZUSA
| | - D. A. Vaz
- Centre for Earth and Space Research of the University of CoimbraObservatório Geofísico e Astronómico da Universidade de CoimbraCoimbraPortugal
| | | | - H. Yizhaq
- Department of Solar Energy and Environmental Physics, BIDRBen‐Gurion University of the NegevBeershebaIsrael
| | - F. Esposito
- INAF Osservatorio Astronomico di CapodimonteNapoliItaly
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16
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Dundas CM. Geomorphological evidence for a dry dust avalanche origin of slope streaks on Mars. NATURE GEOSCIENCE 2020; 13:473-476. [PMID: 34221112 PMCID: PMC8243413 DOI: 10.1038/s41561-020-0598-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 05/21/2020] [Indexed: 06/13/2023]
Abstract
Mars has several different types of slope feature that resemble aqueous flows. However, current cold, dry conditions are inimical to liquid water, resulting in uncertainty about its role in modern surface processes. Dark slope streaks were among the first distinctive young slope features to be identified on Mars and the first with activity seen in orbital images. They form markings on steep slopes that can persist for decades, and the role of water in their formation remains under debate. Here I analyze the geomorphic features of new slope streaks using high-resolution orbital images. Comparison of before-and-after images reveals how the streak formation process affects the surface and provides information about the cause. These observations demonstrate that slope streaks erode and deposit material in some instances. They also reveal that streaks can jump slopes and may be erosive very near their termini. These observations support a formation model where dark slope streaks form as ground-hugging, low-density avalanches of dry surface dust. Such streaks need not be treated as Special Regions for planetary protection.
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Affiliation(s)
- Colin M Dundas
- U.S. Geological Survey, Astrogeology Science Center, 2255 N. Gemini Dr., Flagstaff, AZ 86001, USA
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17
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Rodriguez JAP, Dobrea EN, Kargel JS, Baker VR, Crown DA, Webster KD, Berman DC, Wilhelm MB, Buckner D. The Oldest Highlands of Mars May Be Massive Dust Fallout Deposits. Sci Rep 2020; 10:10347. [PMID: 32587301 PMCID: PMC7316829 DOI: 10.1038/s41598-020-64676-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 04/14/2020] [Indexed: 11/17/2022] Open
Abstract
The oldest terrains of Mars are cratered landscapes, in which extensive valleys and basins are covered by ubiquitous fluvial plains. One current paradigm maintains that an impact-generated megaregolith underlies these sediments. This megaregolith was likely largely generated during the Early Noachian (~4.1 to ~3.94 Ga) when most Martian impact basins formed. We examined the geologic records of NW Hellas and NW Isidis, which include this epoch’s most extensive circum-basin outcrops. Here, we show that these regions include widespread, wind-eroded landscapes, crater rims eroded down by several hundred meters, pitted plains, and inverted fluvial and crater landforms. These surfaces exhibit few fresh craters, indicating geologically recent wind erosion. The deep erosion, topographic inversions, and an absence of dunes on or near talus across these regions suggest that sediments finer than sand compose most of these highland materials. We propose that basin-impact-generated hurricane-force winds created sediment-laden atmospheric conditions, and that muddy rains rapidly settled suspended sediments to construct extensive Early Noachian highlands. The implied high abundance of fine-grained sediments before these impacts suggests large-scale glacial silt production and supports the previously proposed Noachian “icy highlands” hypothesis. We suggest that subglacial meltwater interactions with the sedimentary highlands could have promoted habitability, particularly in clay strata.
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Affiliation(s)
- J Alexis P Rodriguez
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA.
| | - Eldar Noe Dobrea
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA
| | - Jeffrey S Kargel
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA
| | - V R Baker
- Department of Hydrology & Atmospheric Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - David A Crown
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA
| | - Kevin D Webster
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA
| | - Daniel C Berman
- Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ, 85719-2395, USA
| | | | - Denise Buckner
- University of North Dakota, Department of Space Studies, Grand Forks, ND, 58202, USA.,Blue Marble Space Institute of Science, 1001 4th Ave, Suite 3201, Seattle, WA, 98154, USA
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18
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Abstract
Recurring Slope Lineae (RSL) on Mars have been enigmatic since their discovery; their behavior resembles a seeping liquid but sources of water remain puzzling. This work demonstrates that the properties of RSL are consistent with observed behaviors of Martian and terrestrial aeolian processes. Specifically, RSL are well-explained as flows of sand that remove a thin coating of dust. Observed RSL properties are supportive of or consistent with this model, which requires no liquid water or other exotic processes, but rather indicates seasonal aeolian behavior. These settings and behaviors resemble features observed by rovers and also explain the occurrence of many slope lineae on Mars that do not meet the strict definition of RSL. This indicates that RSL can be explained simply as aeolian features. Other processes may add complexities just as they could modify the behavior of any sand dune.
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Affiliation(s)
- Colin M. Dundas
- U.S. Geological Survey, Astrogeology Science Center, 2255 N. Gemini Dr., Flagstaff, AZ 86001, USA
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19
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Abstract
To assess Mars’ potential for both harboring life and providing useable resources for future human exploration, it is of paramount importance to comprehend the water situation on the planet. Therefore, studies have been conducted to determine any evidence of past or present water existence on Mars. While the presence of abundant water on Mars very early in its history is widely accepted, on its modern form, only a fraction of this water can be found, as either ice or locked into the structure of Mars’ plentiful water-rich materials. Water on the planet is evaluated through various evidence such as rocks and minerals, Martian achondrites, low volume transient briny outflows (e.g., dune flows, reactivated gullies, slope streaks, etc.), diurnal shallow soil moisture (e.g., measurements by Curiosity and Phoenix Lander), geomorphic representation (possibly from lakes and river valleys), and groundwater, along with further evidence obtained by probe and rover discoveries. One of the most significant lines of evidence is for an ancient streambed in Gale Crater, implying ancient amounts of “vigorous” water on Mars. Long ago, hospitable conditions for microbial life existed on the surface of Mars, as it was likely periodically wet. However, its current dry surface makes it almost impossible as an appropriate environment for living organisms; therefore, scientists have recognized the planet’s subsurface environments as the best potential locations for exploring life on Mars. As a result, modern research has aimed towards discovering underground water, leading to the discovery of a large amount of underground ice in 2016 by NASA, and a subglacial lake in 2018 by Italian scientists. Nevertheless, the presence of life in Mars’ history is still an open question. In this unifying context, the current review summarizes results from a wide variety of studies and reports related to the history of water on Mars, as well as any related discussions on the possibility of living organism existence on the planet.
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20
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Heavens NG. An Observational Overview of Dusty Deep Convection in Martian Dust Storms. JOURNAL OF THE ATMOSPHERIC SCIENCES 2019; 76:3299-3326. [PMID: 32848258 PMCID: PMC7446947 DOI: 10.1175/jas-d-19-0042.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Deep convection, as used in meteorology, refers to the rapid ascent of air parcels in the Earth's troposphere driven by the buoyancy generated by phase change in water. Deep convection undergirds some of the Earth's most important and violent weather phenomena and is responsible for many aspects of the observed distribution of energy, momentum, and constituents (particularly water) in the Earth's atmosphere. Deep convection driven by buoyancy generated by the radiative heating of atmospheric dust may be similarly important in the atmosphere of Mars but lacks a systematic description. Here we propose a comprehensive framework for this phenomenon of dusty deep convection (DDC) that is supported by energetic calculations and observations of the vertical dust distribution and exemplary dusty deep convective structures within local, regional, and global dust storm activity. In this framework, DDC is distinct from a spectrum of weaker dusty convective activity because DDC originates from pre-existing or concurrently forming mesoscale circulations that generate high surface dust fluxes, oppose large-scale horizontal advective-diffusive processes, and are thus able to maintain higher dust concentrations than typically simulated. DDC takes two distinctive forms. Mesoscale circulations that form near Mars's highest volcanoes in dust storms of all scales can transport dust to the base of the upper atmosphere in as little as two hours. In the second distinctive form, mesoscale circulations at low elevations within regional and global dust storm activity generate freely convecting streamers of dust that are sheared into the middle atmosphere over the diurnal cycle.
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Affiliation(s)
- Nicholas G. Heavens
- Department of Atmospheric and Planetary Sciences, Hampton University, Hampton, Virginia; Space Science Institute, Boulder, Colorado
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21
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Martínez-Pabello PU, Navarro-González R, Walls X, Pi-Puig T, González-Chávez JL, de la Rosa JG, Molina P, Zamora O. Production of nitrates and perchlorates by laser ablation of sodium chloride in simulated Martian atmospheres. Implications for their formation by electric discharges in dust devils. LIFE SCIENCES IN SPACE RESEARCH 2019; 22:125-136. [PMID: 31421844 DOI: 10.1016/j.lssr.2019.02.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 02/25/2019] [Accepted: 02/25/2019] [Indexed: 06/10/2023]
Abstract
Nitrates and perchlorates are present both on Earth and Mars. In the Martian environment perchlorates dominate over nitrates whereas on Earth is contrariwise. This implies that the mechanisms responsible for their formation are different for both planets. The chemical elements required for their formation are nitrogen and chlorine, which are present in the atmosphere and surface, respectively. Dust in the Martian atmosphere causes atmospheric perturbations that lead to the development of dust-devils and sandstorms. Dust devils contain both chemical elements simultaneously, and normally generate high electric fields that can trigger the formation of electric discharges. Here we present laboratory experiments of this phenomenon using laser ablation of a sodium chloride (NaCl) plate in two different simulated atmospheres: (1) 96% CO2, 2% N2 and 2% Ar; and (2) 66% CO2, 33% N2 and 1% Ar. The dust that condensed and accumulated on the walls of the reactor was analyzed by different analytical techniques that included Fourier transform infrared spectroscopy, visible spectroscopy using azo dyes, thermogravimetry/simultaneous thermal analyses coupled to mass spectrometry, powder X-ray diffraction, and ion chromatography. The main components of the ablated dust corresponded to NaCl ≥ 91.5%, sodium nitrate (NaNO3 = 1.6-6.0%), and sodium perchlorate (NaClO4 ∼ 0.2-0.3%). It is interesting to note that these salts formed in a dry process that is relevant to Mars today. A thermochemical model was used to understand the chemical steps that led to the formation of these salts in the gas phase. The NaNO3NaClO4 (wt/wt) ratio of this process was estimated to vary from 5.0 to 30.0; this ratio is too high compared to that found on Mars (NO3-ClO4- (wt/wt)) from 0.004 to 0.13). This implies that gaseous NaCl was not efficiently oxidized to perchlorate by the electric discharge process. We propose instead that gaseous metal chlorides (e.g., MgCl2, NaCl, CaCl2, KCl) were supplied to the atmosphere by the volatilization of chloride minerals present in the dust by electric discharges generated in dust devils and were subsequently oxidized to perchlorate by photochemical processes. Further work is required to assess the relative contribution of this possible source.
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Affiliation(s)
- Pável U Martínez-Pabello
- Laboratorio de Química de Plasmas y Estudios Planetarios, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Apartado Postal 70-543, Coyoacán, Ciudad de México 04510, Mexico
| | - Rafael Navarro-González
- Laboratorio de Química de Plasmas y Estudios Planetarios, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Apartado Postal 70-543, Coyoacán, Ciudad de México 04510, Mexico.
| | - Xavier Walls
- Laboratorio de Química de Plasmas y Estudios Planetarios, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Apartado Postal 70-543, Coyoacán, Ciudad de México 04510, Mexico
| | - Teresa Pi-Puig
- Departamento de Geoquímica, Instituto de Geología y LANGEM (Laboratorio Nacional de Geoquímica y Mineralogía), Universidad Nacional Autónoma de México, Ciudad Universitaria 04510, Coyoacán, Ciudad de México 04510, Mexico
| | - José L González-Chávez
- Departamento de Química Analítica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, Ciudad de México 04510, Mexico
| | - José G de la Rosa
- Laboratorio de Química de Plasmas y Estudios Planetarios, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Apartado Postal 70-543, Coyoacán, Ciudad de México 04510, Mexico
| | - Paola Molina
- Laboratorio de Química de Plasmas y Estudios Planetarios, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Apartado Postal 70-543, Coyoacán, Ciudad de México 04510, Mexico
| | - Olivia Zamora
- Departamento de Ciencias Ambientales y del Suelo, Instituto de Geología y LANGEM, Universidad Nacional Autónoma de México, Ciudad Universitaria 04510, Coyoacán, Ciudad de México 04510, Mexico
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22
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Dundas CM, Mellon MT, Conway SJ, Gastineau R. Active Boulder Movement at High Martian Latitudes. GEOPHYSICAL RESEARCH LETTERS 2019; 46:5075-5082. [PMID: 31423033 PMCID: PMC6686660 DOI: 10.1029/2019gl082293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/04/2019] [Accepted: 04/22/2019] [Indexed: 06/10/2023]
Abstract
Lobate stony landforms occur on steep slopes at high latitudes on Mars. We demonstrate active boulder movement at seven such sites. Submeter-scale boulders frequently move distances of a few meters. The movement is concentrated in the vicinity of the lobate landforms but also occurs on other slopes. This provides evidence for a newly discovered, common style of activity on Mars, which may play an important role in slope degradation. It also opens the possibility that the lobate features are currently forming in the absence of significant volumes of liquid water.
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Affiliation(s)
- Colin M. Dundas
- U.S. Geological SurveyAstrogeology Science CenterFlagstaffAZUSA
| | - Michael T. Mellon
- Center for Astrophysics and Planetary ScienceCornell UniversityIthacaNYUSA
| | - Susan J. Conway
- CNRS UMR6112 Laboratoire de Planétologie et Géodynamique, Université de NantesNantesFrance
| | - Renaldo Gastineau
- CNRS UMR6112 Laboratoire de Planétologie et Géodynamique, Université de NantesNantesFrance
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerreGrenobleFrance
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23
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Trace Evidence from Mars’ Past: Fingerprinting Transverse Aeolian Ridges. REMOTE SENSING 2019. [DOI: 10.3390/rs11091060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Linear dunes and human fingerprints share many characteristics. Both have ridges, valleys, and defects (minutiae) in the form of bifurcations and termination of ridgeline features. For dunes, determining how defects vary across linear and transverse dunefields is critical to understanding the physics of their formative processes and the physical forcing mechanisms that produce dunefields. Unfortunately, manual extraction of defect locations and higher order characteristics (type, orientation, and quality) from remotely sensed imagery is both time-consuming and inconsistent. This problem is further exacerbated when, in the case of imagery from sensors in orbit around Mars, we are unable to field check interpretations. In this research, we apply a novel technique for extracting defects from multiple imagery sources utilizing a robust and well-documented fingerprint minutiae detection and extraction software (MINDTCT: MINutiae DecTeCTion) developed by the National Institute of Standards and Technology (NIST). We apply our ‘fingerprinting’ approach to Transverse Aeolian Ridges (TARs), relict aeolian features commonly seen on the surface of Mars, whose depositional and formative processes are poorly understood. Our algorithmic approach demonstrates that automating the rapid extraction of defects from orbitally-derived high-resolution imagery of Mars is feasible and produces maps that allow the quantification and analysis of these features.
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Distribution and Morphologies of Transverse Aeolian Ridges in ExoMars 2020 Rover Landing Site. REMOTE SENSING 2019. [DOI: 10.3390/rs11080912] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Aeolian processes are believed to play a major role in the landscape evolution of Mars. Investigations on Martian aeolian landforms such as ripples, transverse aeolian ridges (TARs), and dunes, and aeolian sediment flux measurements are important to enhance our understanding of past and present wind regimes, the ongoing dust cycle, landscape evolution, and geochemistry. These aeolian bedforms are often comprised of loose sand and sharply undulating topography and thus pose a threat to mobility and maneuvers of Mars rovers. Here we present a first-hand account of the distribution, morphologies, and morphometrics of TARs in Oxia Planum, the recently selected ExoMars 2020 Rover landing site. The gridded mapping was performed for contiguous stretches of TARs within all the landing ellipses using 57 sub-meter high resolution imaging science experiment (HiRISE) scenes. We also provide the morphological descriptions for all types of TARs present within the landing ellipses. We use HiRISE digital terrain models (DTMs) along with the images to derive morphometric information for TARs in Oxia Planum. In general, the average areal TAR coverage was found to be 5.4% (±4.9% standard deviation), increasing from west to east within the landing ellipses. We report the average TAR morphometrics in the form of crest–ridge width (131.1 ± 106.2 m), down-wind TAR length (17.6 ± 10.1 m), wavelength (37.3 ± 11.6 m), plan view aspect ratio (7.1 ± 2.3), inter-bedform spacing (2.1 ± 1.1), slope (10.6° ± 6.1°), predominant orientations (NE-SW and E-W), and height (1.2 ± 0.8 m). While simple TARs are predominant, we report other TAR morphologies such as forked TAR, wavy TAR with associated smaller secondary ripples, barchan-like TAR, networked TAR, and mini-TARs from the region. Our results can help in planning the rover traverses in terms of both safe passage and scientific returns favoring aeolian research, particularly improving our understanding of TARs.
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25
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Chuang FC, Williams RME. Valley network morphology in the greater Meridiani Planum region, Mars. JOURNAL OF MAPS 2018; 14:652-660. [PMID: 34712355 PMCID: PMC8549781 DOI: 10.1080/17445647.2018.1530154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/21/2018] [Accepted: 09/24/2018] [Indexed: 06/10/2023]
Abstract
The Greater Meridiani Planum region on Mars is a key locale for a diverse range of fluvial landforms. Valley networks in this region have a range of geomorphologic styles that include negative relief, positive relief, or some combination of both along their lengths. Using high-resolution ~5-6 m/pixel orbital images in ArcGIS Desktop software, we mapped previously under-recognized fine-scale valley networks within the Greater Meridiani Planum region and recorded their geomorphic characteristics as feature attributes. The objectives in using the mapped features are to 1) document the full range of valley network morphologic types in the region, 2) document changes in morphologic types both on a regional scale and along the valley network segments, and 3) to use the mapped features along with other geologic information from previous studies to better understand landscape evolution in the Greater Meridiani Planum region.
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26
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Raack J, Reiss D, Balme MR, Taj-Eddine K, Ori GG. In Situ Sampling of Relative Dust Devil Particle Loads and Their Vertical Grain Size Distributions. ASTROBIOLOGY 2018; 18:1305-1317. [PMID: 28422534 PMCID: PMC6205092 DOI: 10.1089/ast.2016.1544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 12/29/2016] [Indexed: 06/07/2023]
Abstract
During a field campaign in the Sahara Desert in southern Morocco, spring 2012, we sampled the vertical grain size distribution of two active dust devils that exhibited different dimensions and intensities. With these in situ samples of grains in the vortices, it was possible to derive detailed vertical grain size distributions and measurements of the lifted relative particle load. Measurements of the two dust devils show that the majority of all lifted particles were only lifted within the first meter (∼46.5% and ∼61% of all particles; ∼76.5 wt % and ∼89 wt % of the relative particle load). Furthermore, ∼69% and ∼82% of all lifted sand grains occurred in the first meter of the dust devils, indicating the occurrence of "sand skirts." Both sampled dust devils were relatively small (∼15 m and ∼4-5 m in diameter) compared to dust devils in surrounding regions; nevertheless, measurements show that ∼58.5% to 73.5% of all lifted particles were small enough to go into suspension (<31 μm, depending on the used grain size classification). This relatively high amount represents only ∼0.05 to 0.15 wt % of the lifted particle load. Larger dust devils probably entrain larger amounts of fine-grained material into the atmosphere, which can have an influence on the climate. Furthermore, our results indicate that the composition of the surface, on which the dust devils evolved, also had an influence on the particle load composition of the dust devil vortices. The internal particle load structure of both sampled dust devils was comparable related to their vertical grain size distribution and relative particle load, although both dust devils differed in their dimensions and intensities. A general trend of decreasing grain sizes with height was also detected.
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Affiliation(s)
- Jan Raack
- School of Physical Science, Faculty of Science, Technology, Engineering & Mathematics (STEM), The Open University, Milton Keynes, UK
| | - Dennis Reiss
- Institut für Planetologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Matthew R. Balme
- School of Physical Science, Faculty of Science, Technology, Engineering & Mathematics (STEM), The Open University, Milton Keynes, UK
| | - Kamal Taj-Eddine
- Géologie et Géoinformatique, Faculté des Sciences Semlalia, Université Cadi Ayyad, Marrakech, Morocco
- Ibn Battuta Centre, Faculté des Sciences Semlalia, Université Cadi Ayyad, Marrakech, Morocco
| | - Gian Gabriele Ori
- Ibn Battuta Centre, Faculté des Sciences Semlalia, Université Cadi Ayyad, Marrakech, Morocco
- International Research School of Planetary Sciences, Università “G. D'Annunzio”, Pescara, Italy
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27
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Experiments On Sublimating Carbon Dioxide Ice And Implications For Contemporary Surface Processes On Mars. Sci Rep 2017; 7:14181. [PMID: 29079829 PMCID: PMC5660181 DOI: 10.1038/s41598-017-14132-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 10/09/2017] [Indexed: 11/26/2022] Open
Abstract
Carbon dioxide is Mars’ primary atmospheric constituent and is an active driver of Martian surface evolution. CO2 ice sublimation mechanisms have been proposed for a host of features that form in the contemporary Martian climate. However, there has been very little experimental work or quantitative modelling to test the validity of these hypotheses. Here we present the results of the first laboratory experiments undertaken to investigate if the interaction between sublimating CO2 ice blocks and a warm, porous, mobile regolith can generate features similar in morphology to those forming on Martian dunes today. We find that CO2 sublimation can mobilise grains to form (i) pits and (ii) furrows. We have documented new detached pits at the termini of linear gullies on Martian dunes. Based on their geomorphic similarity to the features observed in our laboratory experiments, and on scaling arguments, we propose a new hypothesis that detached pits are formed by the impact of granular jets generated by sublimating CO2. We also study the erosion patterns formed underneath a sublimating block of CO2 ice and demonstrate that these resemble furrow patterns on Mars, suggesting similar formation mechanisms.
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Sizemore HG, Platz T, Schorghofer N, Prettyman TH, De Sanctis MC, Crown DA, Schmedemann N, Neesemann A, Kneissl T, Marchi S, Schenk PM, Bland MT, Schmidt BE, Hughson KHG, Tosi F, Zambon F, Mest SC, Yingst RA, Williams DA, Russell CT, Raymond CA. Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution. GEOPHYSICAL RESEARCH LETTERS 2017; 44:6570-6578. [PMID: 28989206 PMCID: PMC5606497 DOI: 10.1002/2017gl073970] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/19/2017] [Accepted: 06/22/2017] [Indexed: 06/07/2023]
Abstract
Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.
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Affiliation(s)
| | - T. Platz
- Max Planck Institute for Solar System ResearchGöttingenGermany
| | | | | | | | | | - N. Schmedemann
- Department of Earth SciencesFreie Universität BerlinBerlinGermany
| | - A. Neesemann
- Department of Earth SciencesFreie Universität BerlinBerlinGermany
| | - T. Kneissl
- Department of Earth SciencesFreie Universität BerlinBerlinGermany
| | - S. Marchi
- Southwest Research InstituteBoulderColoradoUSA
| | | | - M. T. Bland
- USGS Astrogeology Science CenterFlagstaffArizonaUSA
| | - B. E. Schmidt
- Department of Planetary and Space PhysicsGeorgia Institute of TechnologyAtlantaGeorgiaUSA
| | - K. H. G. Hughson
- Department of Earth, Planetary, and Space SciencesUniversity of California Los AngelesLos AngelesCaliforniaUSA
| | - F. Tosi
- Istituto di Astrofisica e Planetologia Spaziali, INAFRomeItaly
| | - F. Zambon
- Istituto di Astrofisica e Planetologia Spaziali, INAFRomeItaly
| | - S. C. Mest
- Planetary Science InstituteTucsonArizonaUSA
| | | | - D. A. Williams
- School of Earth and Space SciencesArizona State UniversityTempeArizonaUSA
| | - C. T. Russell
- Department of Earth, Planetary, and Space SciencesUniversity of California Los AngelesLos AngelesCaliforniaUSA
| | - C. A. Raymond
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCaliforniaUSA
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Chojnacki M, Urso A, Fenton LK, Michaels TI. Aeolian dune sediment flux heterogeneity in Meridiani Planum, Mars. AEOLIAN RESEARCH 2017; 26:73-88. [PMID: 29576818 PMCID: PMC5863747 DOI: 10.1016/j.aeolia.2016.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
It is now known unambiguously that wind-driven bedform activity is occurring on the surface of Mars today, including early detections of active sand dunes in Meridiani Planum's Endeavour crater. Many of these reports are only based on a few sets of observations of relatively isolated bedforms and lack regional context. Here, we investigate aeolian activity across central Meridiani Planum and test the hypothesis that dune sites surrounding Endeavour crater are also active and part of region-wide sediment migration driven by northwesterly winds. All 13 dune fields investigated clearly showed evidence for activity and the majority exhibited dune migration (average rates of 0.6 m/Earth-year). Observations indicate substantial geographic and temporal heterogeneity of dune crest fluxes across the area and per site. Locations with multiple time steps indicate dune sand fluxes can vary by a factor of five, providing evidence for short periods of rapid migration followed by near-stagnation. In contrast, measurements at other sites are nearly identical, indicating that some dunes are in a steady-state as they migrate. The observed sediment transport direction was consistent with a regional northeasterly-to-northwesterly wind regime, revealing more variations than were appreciated from earlier, more localized studies. Craters containing shallow, degraded, flat-floored interiors tended to have dunes with high sediment fluxes/activity, whereas local kilometer-scale topographic obstructions (e.g., central peaks, yardangs) were found to be inversely correlated with dune mobility. Finally, the previous, more limited detections of dune activity in Endeavour crater have been shown to be representative of a broader, region-wide pattern of dune motion.
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Affiliation(s)
- Matthew Chojnacki
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
- Corresponding author at: Lunar and Planetary Lab, University of Arizona, 1541 E. University Blvd, Tucson, AZ 85721-0063, USA. (M. Chojnacki)
| | - Anna Urso
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
| | - Lori K. Fenton
- Carl Sagan Center at the SETI Institute, 189 Bernardo Ave, Mountain View, CA 94043, USA
| | - Timothy I. Michaels
- Carl Sagan Center at the SETI Institute, 189 Bernardo Ave, Mountain View, CA 94043, USA
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Heavens N. Textured Dust Storm Activity in NE Amazonis-SW Arcadia, Mars: Phenomenology and Dynamical Interpretation. JOURNAL OF THE ATMOSPHERIC SCIENCES 2017; 74:1011-1037. [PMID: 32855571 PMCID: PMC7449148 DOI: 10.1175/jas-d-16-0211.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dust storms are Mars's most notable meteorological phenomenon, but many aspects of their structure and dynamics remain mysterious. The cloud-top appearance of dust storms in visible imagery varies on a continuum between diffuse/hazy and textured. Textured storms contain cellular structure and/or banding, which is thought to indicate active lifting within the storm. Some textured dust storms may contain the deep convection that generates the detached dust layers observed high in Mars's atmosphere. This study focuses on textured, local dust storms in a limited area within NE Amazonis and SW Arcadia Planitiae (25°-40° N,155°-165° W) using collocated observations by instruments on board the Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) satellites. In northern fall and winter, this area frequently experiences dust storms with a previously unreported ruffled texture that resembles wide, mixed-layer rolls in the Earth's atmosphere, a resemblance that is supported by high resolution active sounding and passive radiometry in both the near and thermal infrared. These storms are mostly confined within the atmospheric boundary layer and are rarely sources of detached dust layers. The climatology and structure of these storms is thus consistent with an underlying driver of cold air advection events related to the passage of strong baroclinic waves. While the properties of the studied region may be ideal for detecting these structures and processes, the dynamics here are likely relevant to dust storm activity elsewhere on Mars.
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Affiliation(s)
- N.G. Heavens
- Department of Atmospheric and Planetary Sciences, Hampton University, Hampton, Virginia
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31
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Satellite-Based Thermophysical Analysis of Volcaniclastic Deposits: A Terrestrial Analog for Mantled Lava Flows on Mars. REMOTE SENSING 2016. [DOI: 10.3390/rs8020152] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly? Sci Rep 2015; 5:13404. [PMID: 26346067 PMCID: PMC4562069 DOI: 10.1038/srep13404] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/17/2015] [Indexed: 11/17/2022] Open
Abstract
Catastrophic floods generated ~3.2 Ga by rapid groundwater evacuation scoured the Solar System’s most voluminous channels, the southern circum-Chryse outflow channels. Based on Viking Orbiter data analysis, it was hypothesized that these outflows emanated from a global Hesperian cryosphere-confined aquifer that was infused by south polar meltwater infiltration into the planet’s upper crust. In this model, the outflow channels formed along zones of superlithostatic pressure generated by pronounced elevation differences around the Highland-Lowland Dichotomy Boundary. However, the restricted geographic location of the channels indicates that these conditions were not uniform Boundary. Furthermore, some outflow channel sources are too high to have been fed by south polar basal melting. Using more recent mission data, we argue that during the Late Noachian fluvial and glacial sediments were deposited into a clastic wedge within a paleo-basin located in the southern circum-Chryse region, which was then completely submerged under a primordial northern plains ocean. Subsequent Late Hesperian outflow channels were sourced from within these geologic materials and formed by gigantic groundwater outbursts driven by an elevated hydraulic head from the Valles Marineris region. Thus, our findings link the formation of the southern circum-Chryse outflow channels to ancient marine, glacial, and fluvial erosion and sedimentation.
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Keske AL, Hamilton CW, McEwen AS, Daubar IJ. Episodes of fluvial and volcanic activity in Mangala Valles, Mars. ICARUS 2015; 245:333-347. [PMID: 29176911 PMCID: PMC5701667 DOI: 10.1016/j.icarus.2014.09.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A new mapping-based study of the 900-km-long Mangala Valles outflow system was motivated by the availability of new high-resolution images and continued debates about the roles of water and lava in outflow channels on Mars. This study uses photogeologic analysis, geomorphic surface mapping, cratering statistics, and relative stratigraphy. Results show that Mangala Valles underwent at least two episodes of fluvial activity and at least three episodes of volcanic activity during the Late Amazonian. The occurrence of scoured bedrock at the base of the mapped stratigraphy, in addition to evidence provided by crater retention ages, suggests that fluvial activity preceded the deposition of two of the volcanic units. Crater counts performed at 30 locations throughout the area have allowed us to construct the following timeline: (1) formation of Noachian Highlands and possible initial flooding event(s) before ~1 Ga, (2) emplacement of Tharsis lava flows in the valley from ~700 to 1000 Ma, (3) a megaflooding event at ~700-800 Ma sourced from Mangala Fossa, (4) valley fill by a sequence of lava flows sourced from Mangala Fossa ~400-500 Ma, (5) another megaflooding event from ~400 Ma, (6) a final phase of volcanism sourced from Mangala Fossa ~300-350 Ma, and (7) emplacement of eolian sedimentary deposits in the northern portion of the valley ~300 Ma. These results are consistent with alternating episodes of aqueous flooding and volcanism in the valles. This pattern of geologic activity is similar to that of other outflow systems, such as Kasei Valles, suggesting that there is a recurring, and perhaps coupled, nature of these processes on Mars.
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Affiliation(s)
- Amber L. Keske
- School of Earth and Space Exploration, Arizona State University, 201 E. Orange Mall, Tempe, AZ 85287, United States
| | | | - Alfred S. McEwen
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, United States
| | - Ingrid J. Daubar
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, United States
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King AJ, Gehl RW, Grossman D, Jensen JD. Skin self-examinations and visual identification of atypical nevi: comparing individual and crowdsourcing approaches. Cancer Epidemiol 2013; 37:979-84. [PMID: 24075797 DOI: 10.1016/j.canep.2013.09.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 08/29/2013] [Accepted: 09/02/2013] [Indexed: 11/25/2022]
Abstract
PURPOSE Skin self-examination (SSE) is one method for identifying atypical nevi among members of the general public. Unfortunately, past research has shown that SSE has low sensitivity in detecting atypical nevi. The current study investigates whether crowdsourcing (collective effort) can improve SSE identification accuracy. Collective effort is potentially useful for improving people's visual identification of atypical nevi during SSE because, even when a single person has low reliability at a task, the pattern of the group can overcome the limitations of each individual. METHODS Adults (N=500) were recruited from a shopping mall in the Midwest. Participants viewed educational pamphlets about SSE and then completed a mole identification task. For the task, participants were asked to circle mole images that appeared atypical. Forty nevi images were provided; nine of the images were of nevi that were later diagnosed as melanoma. RESULTS Consistent with past research, individual effort exhibited modest sensitivity (.58) for identifying atypical nevi in the mole identification task. As predicted, collective effort overcame the limitations of individual effort. Specifically, a 19% collective effort identification threshold exhibited superior sensitivity (.90). CONCLUSIONS The results of the current study suggest that limitations of SSE can be countered by collective effort, a finding that supports the pursuit of interventions promoting early melanoma detection that contain crowdsourced visual identification components.
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Affiliation(s)
- Andy J King
- College of Media & Communication, Texas Tech University, United States.
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Autonomous real-time landing site selection for Venus and Titan using Evolutionary Fuzzy Cognitive Maps. Appl Soft Comput 2012. [DOI: 10.1016/j.asoc.2012.01.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kok JF, Parteli EJR, Michaels TI, Karam DB. The physics of wind-blown sand and dust. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2012; 75:106901. [PMID: 22982806 DOI: 10.1088/0034-4885/75/10/106901] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols. This paper presents an extensive review of the physics of wind-blown sand and dust on Earth and Mars. Specifically, we review the physics of aeolian saltation, the formation and development of sand dunes and ripples, the physics of dust aerosol emission, the weather phenomena that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices. We also discuss the physics of wind-blown sand and dune formation on Venus and Titan.
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Affiliation(s)
- Jasper F Kok
- Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, USA.
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Irwin RP, Zimbelman JR. Morphometry of Great Basin pluvial shore landforms: Implications for paleolake basins on Mars. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012je004046] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Oehler DZ, Allen CC. Giant polygons and mounds in the lowlands of Mars: signatures of an ancient ocean? ASTROBIOLOGY 2012; 12:601-615. [PMID: 22731685 DOI: 10.1089/ast.2011.0803] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This paper presents the hypothesis that the well-known giant polygons and bright mounds of the martian lowlands may be related to a common process-a process of fluid expulsion that results from burial of fine-grained sediments beneath a body of water. Specifically, we hypothesize that giant polygons and mounds in Chryse and Acidalia Planitiae are analogous to kilometer-scale polygons and mud volcanoes in terrestrial, marine basins and that the co-occurrence of masses of these features in Chryse and Acidalia may be the signature of sedimentary processes in an ancient martian ocean. We base this hypothesis on recent data from both Earth and Mars. On Earth, 3-D seismic data illustrate kilometer-scale polygons that may be analogous to the giant polygons on Mars. The terrestrial polygons form in fine-grained sediments that have been deposited and buried in passive-margin, marine settings. These polygons are thought to result from compaction/dewatering, and they are commonly associated with fluid expulsion features, such as mud volcanoes. On Mars, in Chryse and Acidalia Planitiae, orbital data demonstrate that giant polygons and mounds have overlapping spatial distributions. There, each set of features occurs within a geological setting that is seemingly analogous to that of the terrestrial, kilometer-scale polygons (broad basin of deposition, predicted fine-grained sediments, and lack of significant horizontal stress). Regionally, the martian polygons and mounds both show a correlation to elevation, as if their formation were related to past water levels. Although these observations are based on older data with incomplete coverage, a similar correlation to elevation has been established in one local area studied in detail with newer higher-resolution data. Further mapping with the latest data sets should more clearly elucidate the relationship(s) of the polygons and mounds to elevation over the entire Chryse-Acidalia region and thereby provide more insight into this hypothesis.
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Affiliation(s)
- Dorothy Z Oehler
- Astromaterials Research and Exploration Science Directorate, NASA-Johnson Space Center, Houston, Texas 77058, USA.
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Wagstaff KL, Panetta J, Ansar A, Greeley R, Pendleton Hoffer M, Bunte M, Schörghofer N. Dynamic Landmarking for Surface Feature Identification and Change Detection. ACM T INTEL SYST TEC 2012. [DOI: 10.1145/2168752.2168763] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Given the large volume of images being sent back from remote spacecraft, there is a need for automated analysis techniques that can quickly identify interesting features in those images. Feature identification in individual images and automated change detection in multiple images of the same target are valuable for scientific studies and can inform subsequent target selection. We introduce a new approach to orbital image analysis called dynamic landmarking. It focuses on the identification and comparison of visually salient features in images. We have evaluated this approach on images collected by five Mars orbiters. These evaluations were motivated by three scientific goals: to study fresh impact craters, dust devil tracks, and dark slope streaks on Mars. In the process we also detected a different kind of surface change that may indicate seasonally exposed bedforms. These experiences also point the way to how this approach could be used in an onboard setting to analyze and prioritize data as it is collected.
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Affiliation(s)
| | - Julian Panetta
- Jet Propulsion Laboratory, California Institute of Technology
| | - Adnan Ansar
- Jet Propulsion Laboratory, California Institute of Technology
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Appéré T, Schmitt B, Langevin Y, Douté S, Pommerol A, Forget F, Spiga A, Gondet B, Bibring JP. Winter and spring evolution of northern seasonal deposits on Mars from OMEGA on Mars Express. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010je003762] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chojnacki M, Burr DM, Moersch JE, Michaels TI. Orbital observations of contemporary dune activity in Endeavor crater, Meridiani Planum, Mars. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010je003675] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Tirsch D, Jaumann R, Pacifici A, Poulet F. Dark aeolian sediments in Martian craters: Composition and sources. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2009je003562] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Irwin RP, Craddock RA, Howard AD, Flemming HL. Topographic influences on development of Martian valley networks. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010je003620] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Hansen CJ, Bourke M, Bridges NT, Byrne S, Colon C, Diniega S, Dundas C, Herkenhoff K, McEwen A, Mellon M, Portyankina G, Thomas N. Seasonal Erosion and Restoration of Mars’ Northern Polar Dunes. Science 2011; 331:575-8. [DOI: 10.1126/science.1197636] [Citation(s) in RCA: 180] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- C. J. Hansen
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - M. Bourke
- Planetary Science Institute, Tucson, AZ 85719, USA
- School of Geography and the Environment, University of Oxford, Oxford OX1 3QY, UK
| | - N. T. Bridges
- Applied Physics Lab, John Hopkins University, Laurel, MD 20723, USA
| | - S. Byrne
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
| | - C. Colon
- Department of Earth and Environmental Science, Rutgers University, Newark, NJ 07102, USA
| | - S. Diniega
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - C. Dundas
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
| | | | - A. McEwen
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
| | - M. Mellon
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309, USA
| | - G. Portyankina
- Space Research and Planetology Division, University of Bern, CH-0132 Bern, Switzerland
| | - N. Thomas
- Space Research and Planetology Division, University of Bern, CH-0132 Bern, Switzerland
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Geissler PE, Sullivan R, Golombek M, Johnson JR, Herkenhoff K, Bridges N, Vaughan A, Maki J, Parker T, Bell J. Gone with the wind: Eolian erasure of the Mars Rover tracks. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010je003674] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Golombek M, Robinson K, McEwen A, Bridges N, Ivanov B, Tornabene L, Sullivan R. Constraints on ripple migration at Meridiani Planum from Opportunity and HiRISE observations of fresh craters. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010je003628] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Mangold N, Mangeney A, Migeon V, Ansan V, Lucas A, Baratoux D, Bouchut F. Sinuous gullies on Mars: Frequency, distribution, and implications for flow properties. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009je003540] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Osterloo MM, Anderson FS, Hamilton VE, Hynek BM. Geologic context of proposed chloride-bearing materials on Mars. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010je003613] [Citation(s) in RCA: 174] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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El Maarry MR, Markiewicz WJ, Mellon MT, Goetz W, Dohm JM, Pack A. Crater floor polygons: Desiccation patterns of ancient lakes on Mars? ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010je003609] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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