Icarus最新文献

{"title":"The debiased Near-Earth object population from ATLAS telescopes","authors":"","doi":"10.1016/j.icarus.2024.116316","DOIUrl":"10.1016/j.icarus.2024.116316","url":null,"abstract":"<div><div>This work is dedicated to debias the Near-Earth Object (NEO) population based on observations from the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescopes. We have applied similar methods used to develop the recently released NEO model generator (NEOMOD), once debiasing the NEO population using data from Catalina Sky Survey (CSS) G96 telescope. ATLAS is composed of four different telescopes. We first analyzed observational data from each of all four telescopes separately and later combined them. Our results highlight main differences between CSS and ATLAS, e.g., sky coverage and survey power at debiasing the NEO population. ATLAS has a much larger sky coverage than CSS, allowing it to find bright NEOs that would be constantly “hiding” from CSS. Consequently, ATLAS is more powerful than CSS at debiasing the NEO population for H <span><math><mo>≲</mo></math></span> 19. With its intrinsically greater sensitivity and emphasis on observing near opposition, CSS excels in the debiasing of smaller objects. ATLAS, as an all sky survey designed to find imminent hazardous objects, necessarily spends a significant fraction of time looking at places on the sky where objects do not appear, reducing its power for debiasing the population of small objects. We estimate a NEO population completeness of <span><math><msubsup><mrow><mo>≈</mo><mn>88</mn><mtext>%</mtext></mrow><mrow><mo>−</mo><mn>2</mn><mtext>%</mtext></mrow><mrow><mo>+</mo><mn>3</mn><mtext>%</mtext></mrow></msubsup></math></span> for H <span><math><mo>&lt;</mo></math></span> 17.75 and <span><math><msubsup><mrow><mo>≈</mo><mn>36</mn><mtext>%</mtext></mrow><mrow><mo>−</mo><mn>1</mn><mtext>%</mtext></mrow><mrow><mo>+</mo><mn>1</mn><mtext>%</mtext></mrow></msubsup></math></span> for H <span><math><mo>&lt;</mo></math></span> 22.25. Those numbers are similar to previous estimates (within error bars for H <span><math><mo>&lt;</mo></math></span> 17.75) from CSS, yet, around 3% and 8% smaller at their face values, respectively. We also confirm previous finding that the <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>6</mn></mrow></msub></math></span> secular resonance is the main source of small and faint NEOs at H = 28, whereas the 3:1 mean motion resonance with Jupiter dominates for larger and brighter NEOs at H = 15.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence for landslides in Sisyphi Cavi (Noachis Terra, Mars): Slope evolution and role of endogenous preparatory factors","authors":"","doi":"10.1016/j.icarus.2024.116314","DOIUrl":"10.1016/j.icarus.2024.116314","url":null,"abstract":"<div><p>The surface of Mars is characterized by the presence of numerous gravity-induced processes and mass movements with greatly variable sizes and peculiarities. Detailed geomorphological studies have recently made it possible to identify many landslide-like landforms along the slopes bordering pits of Sisyphi Cavi in Noachis Terra, the southern hemisphere of Mars. These pieces of evidence are generally characterized by extended trenches, sometimes associated with uphill- or downhill-facing scarps. In this study, the gravity-induced processes observed in this region of Mars, and especially those present in a closed pit of the eastern sector, are described for the first time. A quantitative stress-strain analysis was performed, and it excludes a type of deformation process that could invoke creep processes (“viscosity-driven”) but rather favors instability induced by stress-perturbations in the slope more concentrated over time (“force-driven”). In particular, we performed a parametric analysis on both viscosity and stiffness parameters of the materials involved. It demonstrates that the time necessary for the rheological evolution of deformational processes associated with the observed landforms are compatible with genesis of short-term instabilities. This finding has significant implications for the origin of the depressed forms within and close to the study area, which are characterized by unstable slopes present at their edges. It is therefore not necessary to invoke the role of “viscosity-driven” creep processes to explain the origin of the shapes associated with the observed gravity-induced slope instabilities. The reported results drive towards a new interpretative scenario of morphological evolution of the widespread pits in the study area in terms of efficiency of endogenous processes (such as hypabyssal magmatism) which characterize the studied area of Mars, even if it is not possible to exclude the role of exogenous processes.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the dielectric loss of Martian regolith in the frequency domain using Zhurong radar data","authors":"","doi":"10.1016/j.icarus.2024.116315","DOIUrl":"10.1016/j.icarus.2024.116315","url":null,"abstract":"<div><p>Martian regolith is one of the primary science objectives of Mars exploration missions. The Rover Penetrating Radar carried by Zhurong rover allows for high-resolution subsurface imaging and <em>in-situ</em> measurements of Martian regolith dielectric properties, which are crucial to advance our understanding of Martian geology and hydrological evolution. While earlier studies have derived dielectric constants for the shallow subsurface, further characterization of subsurface materials requires the determination of attenuation properties. In this study, we applied the centroid-frequency shift method to explore the attenuation property of the Martian regolith in the frequency domain. Lateral attenuation variation was analyzed in detail by integrating subsurface radargram and navigation terrain images. The results show that, within a depth of ∼4 m, the attenuation of radar signal for Zhurong subsurface material is equal to a loss tangent of 0.0079, with a standard deviation of 0.001. Based on the loss tangent value, dielectric permittivity and ground characterization, we preclude the possibility that the regolith is predominantly igneous materials. The lateral variation of the attenuation property could likely be attributed to changes in the proportion of duricrusts, which are heterogeneously distributed along the rover traverse. Our findings offer valuable information for understanding the Martian regolith and its evolution, serving as a important reference for future Mars sample return missions.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetosonic waves in the Martian ionosphere driven by upstream proton cyclotron waves: Two-point observations by MAVEN and Mars Express","authors":"","doi":"10.1016/j.icarus.2024.116311","DOIUrl":"10.1016/j.icarus.2024.116311","url":null,"abstract":"<div><p>Recent observations from the Mars Atmosphere and Volatile EvolutioN (MAVEN) and Mars Express (MEX) spacecraft have suggested that pressure pulses originating from upstream proton cyclotron waves (PCWs) can “ring” the Martian magnetopause at the same frequency and drive magnetosonic waves in the upper ionosphere of Mars, thereby transporting energy from the solar wind into the ionosphere. However, the limitation of single-spacecraft measurements prevents simultaneous observations of the driver and response of this “ringing” process of the Martian magnetosphere. Here we utilize two-point measurements from MAVEN and MEX to characterize the ringing probability at which upstream PCWs drive compressional fluctuations in the ionospheric magnetic field. We develop an algorithm to identify PCW-driven magnetosonic waves in the upper ionosphere of Mars from the two-point magnetic field data. The derived ringing probability is higher on the dayside, outside strong crustal magnetic fields, and under high solar wind density conditions. We also show that the median power of dayside ionospheric magnetic field fluctuations is enhanced by a factor of <span><math><mo>∼</mo></math></span>2 at corresponding frequencies in the presence of upstream PCWs compared to the median power in the absence of upstream PCWs. These results demonstrate the prevalence of energy deposits into the dayside Martian ionosphere from the solar wind mediated by the PCW-driven ringing of the magnetosphere. Future studies, possibly with new multi-point observations, should address the detailed processes of wave propagation and energy transport through the system and the long-term impact of this chain of processes on the planetary ion heating in the ionosphere and atmospheric loss from Mars.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142172028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil diversity at Jezero crater and Comparison to Gale crater, Mars","authors":"","doi":"10.1016/j.icarus.2024.116299","DOIUrl":"10.1016/j.icarus.2024.116299","url":null,"abstract":"<div><p>The martian soil is of particular interest as it can help us understand the different processes that have occurred on Mars by studying the chemistry and mineralogy of its constituents as a function of grain size. The fine-grained martian soil is thought to be homogeneous across the planet and thus to represent a global component. In this study we report on the soil targets analysed by the SuperCam instrument aboard the Perseverance rover, which is currently exploring Jezero crater. A total of 343 targets were analysed. Their grain size distribution confirms the sparsity of 250–900 Â<span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span> particles in the martian soil, although both smaller and larger grains are present. We found that the local components, due to erosion of the local bedrock, are present not only in the very coarse grains or larger gravels of the soil, but also in the very fine ones (¡250 Â<span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span>). We detected some very coarse grains enriched in olivine, pyroxene and carbonate in both the crater floor and the delta front locations, whereas phyllosilicate-rich grains have been encountered only in the delta front. We have compared the Jezero fine-grained soil targets with those of Gale crater using ChemCam data. We found that those at Jezero show no evidence of Mg sulfates, in contrast to the observation at Gale. In addition, the fine-grained soil at Jezero is more hydrated than that at Gale, probably due to its higher specific surface area.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0019103524003592/pdfft?md5=fe395084f17bb0dbed650b8020c8a776&pid=1-s2.0-S0019103524003592-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preface: Ices in the Solar system; origin, evolution and distribution","authors":"","doi":"10.1016/j.icarus.2024.116303","DOIUrl":"10.1016/j.icarus.2024.116303","url":null,"abstract":"","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The diurnal variation of dust and water ice aerosol optical depth at Jezero crater observed by MEDA/TIRS over a full Martian year","authors":"","doi":"10.1016/j.icarus.2024.116313","DOIUrl":"10.1016/j.icarus.2024.116313","url":null,"abstract":"<div><p>The Thermal InfraRed Sensor (TIRS) on the Perseverance rover has provided nearly two full Mars years of systematic monitoring of the total aerosol optical depth above Jezero Crater. These observations span a wide range of timescales, capturing seasonal patterns, diurnal variations, and minute-to-minute fluctuations in aerosol loading. By combining TIRS retrievals with orbital observations, the relative contributions of dust and water ice aerosols can be estimated, revealing their different seasonal and diurnal behaviors. The TIRS record shows distinct periods of dust storm activity, including strong regional storms during the perihelion season as well as short-lived but intense dust events outside the typical dust storm season. Water ice clouds exhibit pronounced seasonal and diurnal variability, with peak activity occurring during the aphelion season but with a presence throughout the year. The diurnal variation of clouds differs significantly between the aphelion and perihelion seasons, with clouds persisting throughout the night during the aphelion season, while largely absent outside of specific periods after sunrise and sunset during the perihelion season. These results provide new insights into the complex behavior of aerosols at Jezero Crater and their connections to atmospheric dynamics and the Martian dust and water cycles.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global climate modelling of Saturn’s atmosphere, Part V: Large-scale vortices","authors":"","doi":"10.1016/j.icarus.2024.116302","DOIUrl":"10.1016/j.icarus.2024.116302","url":null,"abstract":"<div><p>This paper presents an analysis of large-scale vortices in the atmospheres of gas giants, focusing on a detailed study conducted using the Saturn-DYNAMICO global climate model (GCM). Large-scale vortices, a prominent feature of gas giant atmospheres, play a critical role in their atmospheric dynamics. By employing three distinct methods – manual detection, machine learning via artificial neural networks (ANN), and dynamical detection using the Automated Eddy-Detection Algorithm (AMEDA) – we characterise the spatial, temporal, and dynamical properties of these vortices within the Saturn-DYNAMICO GCM. Our findings reveal a consistent production of vortices due to well-resolved eddy-to-mean flow interactions, exhibiting size and intensity distributions broadly in agreement with observational data. However, notable differences in vortex location, size, and concentration highlight the model’s limitations and suggest areas for further refinement. The analysis underscores the importance of zonal wind conditions in influencing vortex characteristics and suggests that more accurate modelling of giant planet vortices may require improved representation of moist convection and jet structure. This study not only provides insights into the dynamics of Saturn’s atmosphere as simulated by the GCM but also offers a framework for comparing vortex characteristics across observations and models of planetary atmospheres.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0019103524003622/pdfft?md5=a06038aec5672d68278236e3e8477e07&pid=1-s2.0-S0019103524003622-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geometrical model of jets in cometary comae","authors":"","doi":"10.1016/j.icarus.2024.116300","DOIUrl":"10.1016/j.icarus.2024.116300","url":null,"abstract":"<div><p>Cometary comae frequently exhibit various formations such as jets, fans, and shells, which can provide crucial insights into the nuclear rotation parameters and the presence of active regions on cometary nuclei. To accurately interpret the visible shape of these jets, a geometric model has been developed. This model considers several factors, including the position of the comet nucleus’s axis of rotation, the location of active areas on the comet’s surface, the angular size of the emission cone, and the relative positions of the Earth, the Sun, and the comet. Utilizing this model, it is possible to track the evolution of the jets over extended periods, enhancing the precision of the model parameters estimation through its simplification. Application of the geometrical model is demonstrated in determining the rotational parameters of the nucleus of comet C/2017 K2 (PANSTARRS). The coordinates for the positive pole of the rotational axis of the comet’s nucleus are: right ascension <span><math><mrow><mi>α</mi><mo>=</mo><mn>70</mn><mo>°</mo><mo>±</mo><mn>15</mn><mo>°</mo></mrow></math></span>, declination <span><math><mrow><mi>δ</mi><mo>=</mo><mo>−</mo><mn>45</mn><mo>°</mo><mo>±</mo><mn>6</mn><mo>°</mo></mrow></math></span>, and the rotation period is 166.50 ± 0.02 h. The shape of the jet feature is consistent with an active area located at that latitude <span><math><mrow><mi>ϕ</mi><mo>=</mo><mo>+</mo><mn>45</mn><mo>°</mo><mo>±</mo><mn>6</mn><mo>°</mo></mrow></math></span>. The mean velocity of the dust particles is calculated to be 0.23 ± 0.03 km/s.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142151777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Polyphase tectonics on Mars: Insight from the Claritas Fossae” [Icarus 411 (15 March 2024) 115972]","authors":"","doi":"10.1016/j.icarus.2024.116287","DOIUrl":"10.1016/j.icarus.2024.116287","url":null,"abstract":"","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0019103524003476/pdfft?md5=f831516850800362e11215f31a31cf84&pid=1-s2.0-S0019103524003476-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142151910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}