The Link Between Subsurface Rheology and Ejecta Mobility: The Case of Small New Impacts on Mars

Journal of Geophysical Research Planets, Год журнала: 2025, Номер 130(5)

Опубликована: Май 1, 2025

Abstract The dynamics of crater ejecta are sensitive to the material properties target, much like size and morphology. We isolate quantify effect target on mobility (EM) ‐ maximum radial extent scaled by radius. compile geologically motivated subsurface structures based data gathered orbiters landers. Those arise from varying materials in single layers (strength, composition, porosity); thickness top regolith cover; sequence thicknesses 3–4 stacked layers. realize 2D simulations with iSALE shock physics code which result a 50 m diameter (an analog new craters formed period spacecraft observation). find that varied rheologies EM numbers wide range values between 7 19. Some models can similar EM, some have distinct EMs, shows potential for using this quantity as diagnostic properties. also show not only excavation zone but at greater depths than commonly assumed (at least 1–2 radii). depends both layering: impedance contrast governs nature wave propagation, while layer depth controls timing reflection. Detailed studies thus promise unveiling shallow many Solar System bodies future.

Язык: Английский

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Spatio‐Temporal Level Variations of the Martian Seasonal South Polar Cap From Co‐Registration of MOLA Profiles

Journal of Geophysical Research Planets, Год журнала: 2022, Номер 127(7)

Опубликована: Июль 1, 2022

Abstract The seasonal deposition and sublimation of CO 2 represents a major element in the Martian volatile cycle. Here, co‐registration strategies are applied to Mars Orbiter Laser Altimeter profiles obtain spatio‐temporal variations snow/ice level Seasonal South Polar Cap (SSPC), grid elements 0.5° latitude from 60° 87°S 10° longitude. maximum range 2–2.5 m is observed over Residual Cap. Peak at Year 25 (MY25) found be typically ∼0.5 higher than those MY24. total volume estimated peak approximately 9.4 × 10 12 3 . In addition, map average bulk density SSPC during its recession derived. It implies much more snowfall‐like precipitation surroundings elsewhere on Mars.

Язык: Английский

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Study on climbing strategy and analysis of Mars rover

Journal of Field Robotics, Год журнала: 2023, Номер 40(5), С. 1172 - 1186

Опубликована: Апрель 7, 2023

Abstract To ensure the safety and efficiency of Zhurong Mars rover when climbing a slope on Mars, forces under four methods, which are normal climbing, Z‐type diagonal bionic wriggle analyzed. Each method corresponds to different maximum slopes. The experiments carried out with backup dense soft terrains determine range for methods. According slope, peak current, cost transport, state terrain, strategy is given. For terrains, soil cohesive 0.99 1.4 kN/m n +1 friction modules 1528 700 +2 , respectively. Specifically, recommended low‐range slopes, while or suggested medium‐range found be optimal high‐range rover, it fails if critical values exceeded. These results provide valuable insights human operators planning rover's slope‐climbing actions Mars.

Язык: Английский

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Martian Araneiforms: A Review

Journal of Geophysical Research Planets, Год журнала: 2023, Номер 128(4)

Опубликована: Апрель 1, 2023

Abstract Araneiforms are enigmatic dendritic negative topography features native to Mars. Found across a variety of substrates and exhibiting range scales, morphologies, activity level, they hypothesized form via insolation‐induced basal sublimation seasonal CO 2 ice. With no direct Earth analog, araneiforms an example how our understanding extant surface can evolve through multipronged approach using high resolution change‐detection imaging, conceptual numerical modeling, analog laboratory work. This review offers primer on the current state knowledge Martian araneiforms. We outline development their driving hypothesis various methodologies used study formation. furthermore present open questions identify future modeling work mission objectives that may address these questions. Finally, this highlights be as proxy for local conditions perhaps even past dynamics also reflect lessons learnt from studying them opportunities comparative planetology harnessed in unusual icy worlds have analog.

Язык: Английский

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Modeling Slope Microclimates in the Mars Planetary Climate Model

Journal of Geophysical Research Planets, Год журнала: 2023, Номер 128(10)

Опубликована: Окт. 1, 2023

Abstract A large number of surface features (e.g., frost, gullies, slope streaks, recurring lineae) are observed on Martian slopes. Their activity is often associated with the specific microclimates these slopes, which have been mostly studied one‐dimensional radiative balance models to date. We develop here a parameterization simulate in 3D Global Climate Models. first demonstrate that any can be thermally represented by poleward or equatorward slope, is, daily average, minimum, and maximum temperatures depend North‐South component slope. Based this observation, we implement subgrid‐scale represent (radiative fluxes, volatile condensation, ignoring winds for now) Mars Planetary Model validate it through comparisons temperature measurements frost detections sloped terrains. With new model, show do not significant impact seasonal CO 2 H O cycles global scale. Furthermore, short‐scale slopes (i.e., less than ∼1 km length) significantly thermal state atmosphere. Ninety‐one percent active gullies found where our model predicts suggesting their related processes involving ice. However, low thicknesses (≤tens cm) predicted at mid‐latitudes rule out mechanisms amounts (∼meters) This opens way studies surface‐atmosphere interactions present past climates.

Язык: Английский

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Characterizing Seasonal and Residual Ices at the South Pole of Mars Using a Universal Set of CRISM Spectral Endmembers

Journal of Geophysical Research Planets, Год журнала: 2022, Номер 127(11)

Опубликована: Окт. 8, 2022

Abstract Current maps of compositional variation across south polar ice exposures on Mars do not resolve the meter‐scales at which erosional processes are most active, ultimately limiting our understanding how deposits form and evolve they can be used to interpret long‐term climate records. In this study, we use k ‐means clustering random forest classification identify map a set universal spectral endmembers 167 high‐resolution observations acquired during southern summer by Compact Reconnaissance Imaging Spectrometer for Mars. The 21 show distinct combinations strengths key infrared absorption features reflecting diverse mixtures CO 2 ice, H O dust. resulting framework characterize nature both seasonal frost residual ices it overlies variety terrains. Following large dust event Year 28, ‐ice (RCD) were covered an unusually thick or long‐lived deposit frost. Within RCD, low‐albedo material around display absorptions consistent with outer margins RCD. These peripheral water‐ice unexpected in content. Most notably, regions within several km edge RCD contributions from even after has been removed. results inform investigations focused dynamics deposition, development morphologies, creation records stratigraphy.

Язык: Английский

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Change detection and monitoring of active Martian surface phenomena with the Colour and Stereo Surface Imaging System (CaSSIS) onboard the ExoMars Trace Gas Orbiter (TGO)

Icarus, Год журнала: 2023, Номер 394, С. 115443 - 115443

Опубликована: Янв. 26, 2023

Язык: Английский

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Initial results of the meteorological data from the first 325 sols of the Tianwen-1 mission

Scientific Reports, Год журнала: 2023, Номер 13(1)

Опубликована: Фев. 27, 2023

As the Zhurong rover landed on surface of Mars in 2021, it began a months-long collection data. Equipped with highly sensitive sensors, is capable being meteorological station at Mars. The Climate Station, one onboard sensors high sensitivity, helps Tianwen-1 lander to collect data Martian surface, via which air temperature, atmospheric pressure, wind speed and direction are measured. In this paper, we present results temperature from Station Zhurong's landing site. collected 176 solar days out entire rover's mission time, 325 days. We use trigonometric function fit relationship between longitude (Ls) after compare those Viking I. Our analysis shows that seasonal evolution similar patterns concluded previous missions different sites. discover appears maximum early summer near site, analyze occurrence dust storms by combining temperature. provide some evidence changes pattern Tianwen-1's south Utopia Planitia. With ongoing further, more expected future.

Язык: Английский

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Polar science results from Mars Reconnaissance Orbiter: Multiwavelength, multiyear insights

Icarus, Год журнала: 2023, Номер 419, С. 115794 - 115794

Опубликована: Сен. 13, 2023

Язык: Английский

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Revelations of interannual dune evolution from the swiftest aeolian system on Mars by MRO/HiRISE long-term monitoring

Icarus, Год журнала: 2023, Номер 419, С. 115863 - 115863

Опубликована: Ноя. 11, 2023

The north polar region of Mars, with its greater atmospheric pressure and vast inventory ever-changing volatiles (e.g., CO2, H2O), hosts arguably the most active diverse aeolian bedform systems on planet. Here, we explore how these dune fields evolve spatiotemporally using up to 8 Mars years (16 Earth years) MRO HiRISE observations test impact various boundary conditions annual mobility. A high degree sand flux heterogeneity was observed for some dunes, whereas other sites displayed steady-state migration relative long-term rates. These large changes in are attributed variable length frost-free seasons, sediment availability relation timing peak katabatic winds, influence global dust storms seasonal ice thickness. Consistent our previous work, continue observe extremely transport rates at Olympia Cavi. All stages system evolution observable (sand patch > protodune dune), along additional phenomena not previously outside terrestrial settings calving collisions, remote transfer). Transitory protodunes may from modest mounds prominent barchans slipfaces several meters tall within 3–5 years, while adjacent duneforms suffer collapse as they lose supply. Martian protodunes, which appear be larger than equivalents, mature dunes found downwind among swiftest yet reported Mars. rapidly evolving cryo-aeolian provide a window into longer-term landscape non-polar fields.

Язык: Английский

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