Journal of Geophysical Research: Planets最新文献

{"title":"Meridional Distribution of CO, H2O, and H2SO4 in the Venus' Atmosphere: A Two-Dimensional Model Incorporating Transport and Chemical Reaction","authors":"Shinya Kuwayama, George L. Hashimoto","doi":"10.1029/2024JE008596","DOIUrl":"https://doi.org/10.1029/2024JE008596","url":null,"abstract":"<p>We developed a 2-dimensional model of Venus' atmosphere which calculates meridional distributions of chemical species such as CO, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>H</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{H}}_{2}$</annotation>\u0000 </semantics></math>O, and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>H</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <msub>\u0000 <mtext>SO</mtext>\u0000 <mn>4</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{H}}_{2}{text{SO}}_{4}$</annotation>\u0000 </semantics></math>. To calculate the meridional distribution of chemically active species, we combined chemical model, cloud model, and transport model. Partitioning between gas and liquid phase is calculated assuming vapor-liquid equilibrium, and the number density of cloud droplet is calculated by taking coagulation into account. Our model demonstrated that the meridional distributions of CO and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>H</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{H}}_{2}$</annotation>\u0000 </semantics></math>O are sensitive to the circulation of the Venus' atmosphere. Observed meridional distribution of CO indicates that there is a large scale meridional circulation from the lower (below 20 km altitude) to the upper (around 80 km altitude) atmosphere. Also observed concentration of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>H</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{H}}_{2}$</annotation>\u0000 </semantics></math>O vapor above the cloud top suggests that meridional circulation ventilates the air above the cloud top on a time scale of 600 days. In our model, thick clouds at low latitudes are maintained by meridional circulation, while thick clouds at high latitudes are caused by latitudinal temperature gradient and horizontal transport of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>H</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <msub>\u0000 <mtext>SO</mtext>\u0000 <mn>4</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{H}}_{2}{text{SO}}_{4}$</annotation>\u0000","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008596","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Slopes of Lunar Crater Size-Frequency Distributions on Exterior Impact Melt Deposits of Young Craters","authors":"A. Oetting,&nbsp;W. Iqbal,&nbsp;N. Schmedemann,&nbsp;G. Michael,&nbsp;H. Hiesinger,&nbsp;C. H. van der Bogert,&nbsp;T. Heyer","doi":"10.1029/2024JE008589","DOIUrl":"https://doi.org/10.1029/2024JE008589","url":null,"abstract":"<p>Lunar impact craters can be used as a tool to derive information about the timing and sequence of the emplacement of geologic units and surface processes on the Moon. The production function (PF) derived from crater size-frequency distribution (CSFD) measurements is an essential component in determining the model age of a geologic surface. The PFs of Neukum (1983) and Neukum et al. (2001), https://doi.org/10.1007/978-94-017-1035-0_3 are defined only over a crater diameter range between 10 m and 300 km and are among the most frequently used PFs. However, a potential extension of the valid crater diameter range to smaller craters may be possible due to the availability of high-resolution image data, and a larger number of small craters could reduce the statistical errors in age determinations. To evaluate whether CSFD measurements with craters ≤10 m are suitable for inclusion in a PF, we complement the investigation of ejecta blankets (Oetting et al., 2023, https://doi.org/10.1029/2023je007816) by analyzing the CSFD slopes of small craters formed on impact melt deposits of young Copernican-aged craters Tharp, Korolev Z, Thales, and Glushko. The resulting CSFD slopes are slightly steeper for craters between 10 and 20 m than the proposed cumulative −3 slopes by Neukum (1983) and Neukum et al. (2001), https://doi.org/10.1007/978-94-017-1035-0_3. The CSFD slope for craters ≤10 m is shallower than −3. In this study, the CSFD slopes are derived from unbinned data, but we present our CSFD measurements in both unbinned and binned form. Our results indicate that small crater diameters (≤10 m) can be included for extending a PF.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008589","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detectability of Coastal Landforms on Titan With the Cassini RADAR","authors":"S. P. D. Birch,&nbsp;R. V. Palermo,&nbsp;U. G. Schneck,&nbsp;A. Ashton,&nbsp;A. G. Hayes,&nbsp;J. M. Soderblom,&nbsp;W. H. Mitchell,&nbsp;J. T. Perron","doi":"10.1029/2024JE008737","DOIUrl":"https://doi.org/10.1029/2024JE008737","url":null,"abstract":"<p>Earth's coastlines serve as the intersection for numerous physical and chemical processes between terrestrial and marine systems. Liquids of different compositions meet, materials eroded from the continents are concentrated in sedimentary deposits, and the diverse planform morphologies of coastal landforms are shaped by erosional and sediment transport processes. Accordingly, coastal landscapes preserve valuable records of processes that govern Earth's climate, materials, and tectonic history. Applying our understanding from Earth to the coastlines around Titan's liquid hydrocarbon seas allows us to investigate the climate history of the only other known active hydrological system. The study of Titan's coastlines, particularly its deltas, however, remains challenging due to the limitations of Cassini Synthetic Aperture Radar (SAR) data and the transparency of Titan's fluids to microwave radiation. To understand these limitations, we developed a numerical model to simulate Earth's coastlines as they would appear in Cassini SAR images. We show that multi-kilometer-scale landforms are detectable on Titan, provided there is sufficient contrast between the land surface and seafloor. We revisit Titan and show that many of its large coastal rivers do not terminate in deltas, in contrast to Earth. Additionally, we uncover submerged features on Titan's seafloors, suggesting sea-level cycling and/or active sub-aqueous flow. We propose preliminary hypotheses to explain the presence or absence of various coastal landforms on Titan, offering directions for future investigations into Titan's climate and materials. Moreover, we emphasize the opportunities and benefits a superior imaging system at Titan could provide to both Titan science and studies of Earth's changing coasts.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Martian Highlands Differentiation Concomitant to Dichotomy Formation","authors":"Valentin Bonnet Gibet,&nbsp;Chloé Michaut,&nbsp;Thomas Bodin,&nbsp;Mark Wieczorek,&nbsp;Fabien Dubuffet","doi":"10.1029/2024JE008486","DOIUrl":"https://doi.org/10.1029/2024JE008486","url":null,"abstract":"<p>The Martian surface composition appears mainly mafic but recent observations have revealed the presence of differentiated rocks, only in the highlands. Here, we demonstrate that differentiated melts can form during the construction of thick crustal regions on Mars by fractional crystallisation of a mafic magma, without plate tectonics. On a stagnant-lid planet, regions of thicker crusts contain more heat-producing elements and are associated to thinner lithospheres and to higher mantle melt fractions. This induces larger crustal extraction rates where the crust is thicker. This positive feedback mechanism is favored at large wavelengths and can explain the formation of the Martian dichotomy. We further develop an asymmetric parameterized thermal evolution model accounting for crustal extraction, where the well-mixed convective mantle is topped by two lithospheres (north/south) characterized by specific thermal and crustal structures. We use this model in a Bayesian inversion to investigate the conditions that allow crustal temperatures to be maintained above the basalt solidus during crustal growth, resulting in the formation of evolved melts. Among the thermal evolution models matching constraints on the structure of the Martian crust and mantle provided by the InSight NASA mission, a non-negligible fraction allows partial melting and differentiation of the crust in the south, which can occur very early (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>&lt;</mo>\u0000 </mrow>\u0000 <annotation> ${&lt; } $</annotation>\u0000 </semantics></math>100 Myr) as well as during the Hesperian; partial melting in the north appears unlikely. Although crustal differentiation may occur on a hemispheric scale on Mars, its vertical extent would be limited to less than a third of the crustal thickness.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008486","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metal Limiting Habitability in Enceladus? Availability of Trace Metals for Methanogenic Life in Hydrothermal Fluids","authors":"Shuya Tan,&nbsp;Yasuhito Sekine,&nbsp;Takazo Shibuya","doi":"10.1029/2024JE008591","DOIUrl":"https://doi.org/10.1029/2024JE008591","url":null,"abstract":"<p>Enceladus' ocean could support methanogenic life in terms of the availability of chemical energy (H₂ and CO₂) and nutrients (N and P). However, excess energy and nutrients in the ocean raise the question of why they remain abundant if Enceladus is inhabited. Terrestrial methanogens require trace metals, such as Co, Ni, Cu, Zn, and Mo, for their enzyme activation; nevertheless, the availability of these trace metals is largely unknown in Enceladus' ocean. Here, we investigate concentrations of dissolved trace metals in Enceladus based on hydrothermal experiments and thermodynamic equilibrium calculations in order to understand the minerals that control their concentrations in water-rock interactions. Our results show that Ni and Co concentrations in hydrothermal fluids can be controlled by dissolution of a sulfide mineral, pentlandite, in chondritic rocks. In a pH range for Enceladus' ocean, our calculations show that hydrothermal environments would be the source of dissolved Ni and Co. Given a suggested range of water chemistry (pH and dissolved species) of Enceladus' ocean, Ni, Zn, and Mo concentrations in hydrothermal fluids would be comparable to the levels required for terrestrial methanogens. However, both Co and Cu concentrations would be depleted compared with the levels required for terrestrial methanogens. We suggest that if methanogenic life in Enceladus requires trace metals at the same levels as for terrestrial methanogens, the availability of Co and Cu could control the activity of methanogenesis, possibly leaving excess chemical energy and nutrients in the ocean.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008591","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oceanus Procellarum and Mare Imbrium Lava Flows: A New Comparative Look Using Microwave Radiometer Data","authors":"R. Bugiolacchi,&nbsp;Z. Meng,&nbsp;G.-P. Hu,&nbsp;U. Mall","doi":"10.1029/2024JE008827","DOIUrl":"https://doi.org/10.1029/2024JE008827","url":null,"abstract":"<p>Chang'E-2 passive microwave radiometer (MRM) data from two frequency channels (3 and 37 GHz) were converted into brightness temperature (<i>T</i>_b) maps to study large lunar mare provinces in Oceanus Procellarum and the Imbrium basin. Twenty-four locations were identified with the largest differences between midday and midnight <i>T</i>_b values. These areas were then analyzed and compared against 16 geochemical data sets. A numerical relationship was derived between iron, titanium and rock abundance using three sample points from large, young craters. Additionally, a 1,760 km cross-section of the region of interest was investigated to assess potential common trends among the data sets and microwave radiance, finding the strongest correlation with elemental abundance estimations derived from gamma-ray data. Longer-wavelength data have the potential to probe deeper into the regolith layer and assess composition while minimizing the effects of surface contamination by allochthonous materials.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insight Into Venusian Ridge Belts With Maps, Models, and Earth Analogs","authors":"K. T. Crane,&nbsp;P. K. Byrne","doi":"10.1029/2024JE008625","DOIUrl":"https://doi.org/10.1029/2024JE008625","url":null,"abstract":"<p>Ridge belts are globally distributed mountain belts on Venus comprised of closely spaced shortening structures superimposed on longer wavelengths (1 km spacing over 30–400 km-wide belt), positive topography often surrounded by topographically smooth, intact crustal blocks. Although interpreted as large-scale shortening systems, we understand little about the causes of that shortening. On Earth, analogous mountain belts represent a range of crustal or tectonic block boundary collisions, and so the concentration of ridge belt structures could likewise be linked to crustal block collision at a reactivated suture or pre-existing crustal weakness. We can examine this hypothesis using structural maps, cross sections, and three-dimensional models of faults associated with ridge belts. We produced three detailed structural maps and 11 cross sections, which show that the ridge belts we selected represent two shortening styles-one with a single dominant fault, and one with two oppositely verging faults. These results may indicate that fresh or reactivated block collisions lead to ridge belt development.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global Transport of Chlorine Species in the Martian Atmosphere and the Resulting Surface Distribution of Perchlorates","authors":"K. Rajendran,&nbsp;P. M. Streeter,&nbsp;S. R. Lewis,&nbsp;M. K. D. Duffy,&nbsp;J. A. Holmes,&nbsp;K. S. Olsen,&nbsp;O. Korablev,&nbsp;M. R. Patel","doi":"10.1029/2024JE008537","DOIUrl":"https://doi.org/10.1029/2024JE008537","url":null,"abstract":"&lt;p&gt;Recent observations by instruments aboard the ExoMars Trace Gas Orbiter (TGO) have revealed the seasonal presence of hydrogen chloride (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;HCl&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $text{HCl}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) in the Martian atmosphere. This discovery may have important implications for Martian photochemistry as chlorine species are chemically active, and it may provide a link between the atmosphere and known surface reservoirs of chlorine. However, the global distribution of atmospheric &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;HCl&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $text{HCl}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is unknown beyond the very sparse TGO observations, and the source and sink processes driving the observed variability of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;HCl&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $text{HCl}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; are not currently understood. We used a Martian global climate model to investigate, for the first time, the spatial distribution of chlorine species in the Martian atmosphere, and the resulting distribution of surface perchlorates formed via adsorption of atmospheric chlorine species. We adapted an existing Martian photochemical scheme to include gas-phase chlorine chemistry with HCl as the source species, and the resulting atmospheric perchloric acid was allowed to deposit onto the Martian surface via a heterogeneous adsorption scheme. We found that odd-oxygen (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $mathrm{O},{mathrm{O}}_{3}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) and odd-hydrogen (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mtext&gt;OH&lt;/mtext&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;HO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $mathrm{H},text{OH},{text{HO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) species play a major role in controlling the distribution of atmospheric chorine species. Surface perchlorate deposition was found to occur preferentially at high latitudes; in the tropics, the perchlorate distribution was anti-correlated with surface thermal inertia and agreed qualitatively with ob","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008537","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143639004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late-Stage Aqueous Activity at Gale Crater, Mars, Recorded by Sediment Fans Eroded From Aeolis Mons","authors":"Joel M. Davis,&nbsp;Sanjeev Gupta,&nbsp;Peter M. Grindrod,&nbsp;Steven G. Banham,&nbsp;Amanda Rudolph,&nbsp;Sharon A. Wilson,&nbsp;John A. Grant,&nbsp;Rebecca M. E. Williams,&nbsp;Edwin S. Kite,&nbsp;Amelie L. Roberts,&nbsp;Emma Harris,&nbsp;Gerhard Paar","doi":"10.1029/2024JE008808","DOIUrl":"https://doi.org/10.1029/2024JE008808","url":null,"abstract":"<p>Gale crater, the landing site of NASA's <i>Curiosity</i> rover, and the mountain at its center, Aeolis Mons, hosts an extensive record of sedimentary rocks, which provide a window into the climate history of Mars. <i>Curiosity</i> has demonstrated that Gale hosted long-lived lakes early in its history, indicating warm, quiescent surface conditions, before transitioning into a period of heightened aridity. Recent investigations using orbital data have suggested that the surface of Mars was intermittently wet late in its history. However, an ongoing challenge is linking these orbital observations to on-ground investigations by rovers. Here we use combined orbital image and topographic data sets to investigate a series of sediment fans and related catchment regions within the wider Gale crater, and regional to <i>Curiosity</i>'s exploration zone. These systems can be stratigraphically linked to the sedimentary rocks that <i>Curiosity</i> has investigated. We find that most of the sediment fans are likely alluvial fans, recording intermittent flow conditions, with deposition concentrated near the base of Aeolis Mons. The sediment fans are intermixed with landslide deposits and source canyons have been significantly backfilled. We find that these systems formed after regional geological units which <i>Curiosity</i> has shown to record periods of prolonged aridity. Our study demonstrates that intermittent surface water was likely to be present regionally with Gale crater during or after the exhumation of Aeolis Mons. <i>Curiosity</i> may be able to constrain the source and duration of these late-stage flow events as it ascends Aeolis Mons.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008808","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydroxylation and Hydrogen Diffusion in Lunar Samples: Spectral Measurements During Proton Irradiation","authors":"Li Hsia Yeo,&nbsp;Anastasis Georgiou,&nbsp;Liam Morrissey,&nbsp;William Farrell,&nbsp;Jason McLain","doi":"10.1029/2024JE008334","DOIUrl":"https://doi.org/10.1029/2024JE008334","url":null,"abstract":"<p>Widespread OH/<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>H</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{H}}_{2}$</annotation>\u0000 </semantics></math>O has been detected across the lunar surface, but its origin remains a matter of active investigation. We present laboratory measurements of Apollo-17 samples LS 78421 and LS 73131 that demonstrate, in situ, the formation of OH/<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>H</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{H}}_{2}$</annotation>\u0000 </semantics></math>O during irradiation by energetic hydrogen ions similar to the solar wind. Results unambiguously show the growth of the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math>3 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>μ</mi>\u0000 </mrow>\u0000 <annotation> ${upmu }$</annotation>\u0000 </semantics></math>m spectral band due to hydrogen irradiation alone with no contribution from terrestrially adsorbed water. Significant variations in the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math>3 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>μ</mi>\u0000 </mrow>\u0000 <annotation> ${upmu }$</annotation>\u0000 </semantics></math>m band characteristics and position are measured between LS 78421, LS 73131, and a control of crushed silica, reflecting the unique crystal structures and chemical environments within each sample. By cycling sample temperatures to 400 K (lunar dayside maximum), we highlight the role of hydrogen diffusion in the dynamics of OH/<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>H</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{H}}_{2}$</annotation>\u0000 </semantics></math>O within the lunar soil. Diffusion activation energies of 0.66–0.75 eV and 0.72–0.81 eV are obtained for LS 78421 and LS 73131, respectively.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 3","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008334","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}