Icarus最新文献

{"title":"A global colour mosaic of Mars from Mars Express HRSC high altitude observations","authors":"","doi":"10.1016/j.icarus.2024.116350","DOIUrl":"10.1016/j.icarus.2024.116350","url":null,"abstract":"<div><div>The ever-changing transparency of the Martian atmosphere hinders the determination of absolute surface colour from spacecraft images. While individual high-resolution images from low orbit reveal numerous colour details of the geology, the colour variation between images caused by scattering off atmospheric dust can easily be of greater magnitude. The construction of contiguous large-scale mosaics has thus required a strategy to suppress the influence of scattering, often a form of high-pass filtering, which limits their ability to convey colour variation information over distances greater than the dimensions of single images. Here we use a dedicated high altitude observation campaign with the Mars Express High Resolution Stereo Camera (HRSC) (Neukum and Jaumann, 2004; Jaumann et al., 2007), applying a novel iterative method to construct a globally self-consistent colour model. We apply the model to colour-reference a high-altitude mosaic incorporating long-range colour variation information. Using only the relative colour information internal to individual images, the influence of absolute image to image colour changes caused by scattering is minimised, while the model enables colour variations across image boundaries to be self-consistently reconstructed. The resulting mosaic shows a level of colour detail comparable to single images, while maintaining continuity of colour features over much greater distances, thereby increasing the utility of HRSC colour images in the tracing and analysis of martian surface structures.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539238","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":"Principal-plane BRDF of CO2 ice morphologies in controlled Mars polar conditions","authors":"","doi":"10.1016/j.icarus.2024.116347","DOIUrl":"10.1016/j.icarus.2024.116347","url":null,"abstract":"<div><div>Mars South Polar Residual Cap (SPRC) persists throughout the Southern hemisphere's warmest months. During the colder seasons, carbon dioxide (CO₂) accumulates as ice on the surface of the planet, forming a seasonal cap during fall and winter and sublimating throughout spring. The seasonal cap and SPRC both exhibit unexpected reflectance properties that have not been explained. To better understand the Martian surface CO₂ ice and how it affects Mars' geomorphology, atmosphere, and climate, it is imperative to corroborate laboratory experiments with orbital observations. This study uses a custom-designed goniometer for making reflectance measurements within the MARs Volatile and Ice evolutioN (MARVIN) environmental chamber, in which we can measure the Bidirectional Reflectance Distribution Function (BRDF) of different phases of CO₂ under Mars polar conditions for the first time. This has the potential to explain present-day observations from orbit and enhance our understanding of the evolution of ice on Mars.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560983","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":"New insights into the geological evolution history of Mare Fecunditatis","authors":"","doi":"10.1016/j.icarus.2024.116348","DOIUrl":"10.1016/j.icarus.2024.116348","url":null,"abstract":"<div><div>The Luna 16 probe returned 101 g of lunar regolith from the northeast of the Mare Fecunditatis in 1970. Studies on these samples were primarily conducted in the 1970s and 1980s, and limited scientific achievements were obtained due to available technology at that time. China received 1.5 g Luna 16 samples in 2023 and it is expected to conduct in-depth research in the near future. We conducted a thorough investigation on several fundamental issues in this region to provide a refined geological background in the paper. Firstly, a detailed division of the basaltic units within the Mare Fecunditatis was conducted based on the TiO₂ content, and impact craters in each geological unit were mapped with the high-resolution Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) images. With the method of lunar surface dating from the crater size-frequency distribution, we found that the model ages of these basalt units range from 3.71 Ga to 3.31 Ga. Next, the thickness of the basalt within the Mare Fecunditatis is estimated with different types of craters, and local basalt thickness ranges from 3 m to 304 m from seven rim-completely-exposed craters in the mare. The rim-completely-exposed craters on the mare-highland boundary, the rim-partially-exposed craters in the mare, and rim-completely-buried craters in the maria also provide information on the thickness of local basalt. Finally, numerical simulations of the formation process of the largest young impact crater in this region, Langrenus crater, was conducted. The simulations show that the Langrenus crater could be formed by a 11.2-km-diameter asteroid hitting the lunar surface with a speed of ∼10 km/s. The average thickness of the ejecta from the Langrenus crater is ∼4.9 m near Luna 16 landing site, indicating that a significant fraction of Luna 16 samples might be the ejecta from the Langrenus crater. The simulations also reveal that the maximum shock pressure on the materials ejected to Luna 16 landing site can reach 92 GPa, and their maximum source depth is approximately 7.1 km. These interpretations can provide valuable information for further study of the Luna 16 samples and inferring the geological history of the Mare Fecunditatis.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539237","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":"Short-wave fadeout on mars: Radio absorption in the dayside martian ionosphere enhanced by solar flares","authors":"","doi":"10.1016/j.icarus.2024.116342","DOIUrl":"10.1016/j.icarus.2024.116342","url":null,"abstract":"<div><div>Solar flares can cause radio absorption in the D region of the Earth’s ionosphere and consequently interrupt high-frequency radio communication systems, also known as short-wave fadeout or the Dellinger effect. We present an analogous radio absorption event observed at Mars during a solar flare. In this event, the Mars Express Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument fortuitously operated at low altitudes on the dayside around the terminator in a favorable configuration for surface echo measurements at the flare peak. The surface echo power during the flare is abnormally weak compared to nominal echo powers at corresponding solar zenith angles, suggesting flare-induced radio absorption in the dayside lower ionosphere of Mars. Additionally, long-term MARSIS data statistically demonstrate the radio absorption dependence on solar soft X-ray fluxes. Our results point to the need for Martian space weather prediction including ionospheric effects on radio waves.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539455","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":"Resonant amplitude distribution of the Hilda asteroids and the free-floating planet flyby scenario","authors":"","doi":"10.1016/j.icarus.2024.116340","DOIUrl":"10.1016/j.icarus.2024.116340","url":null,"abstract":"<div><div>In some recent work, we provided a quantitative explanation for the number asymmetry of Jupiter Trojans by hypothesizing a free-floating planet (FFP) flyby into the Solar System. In support of that explanation, this paper examines the influence of the same FFP flyby on the Hilda asteroids, which orbit stably in the 3:2 mean motion resonance with Jupiter. The observed Hilda population exhibits two distinct resonant patterns: (1) a lack of Hildas with resonant amplitudes <span><math><mrow><mo>&lt;</mo><mn>40</mn><mo>°</mo></mrow></math></span> at eccentricities <span><math><mrow><mo>&lt;</mo><mn>0</mn><mo>.</mo><mn>1</mn></mrow></math></span>; (2) a nearly complete absence of Hildas with amplitudes <span><math><mrow><mo>&lt;</mo><mn>20</mn><mo>°</mo></mrow></math></span>, regardless of eccentricity. Previous models of Jupiter migration and resonance capture could account for the eccentricity distribution of Hildas but have failed to replicate the unusual absence of those with the smallest resonant amplitudes, which theoretically should be the most stable. Here we report that the FFP flyby can trigger an extremely rapid outward migration of Jupiter, causing a sudden shift in the 3:2 Jovian resonance. Consequently, Hildas with varying eccentricities would have their resonant amplitudes changed by different degrees, leading to the observed resonant patterns. We additionally show that, in our FFP flyby scenario, these patterns are consistently present across different resonant amplitude distributions of primordial Hildas arising from various formation models. We also place constraints on the potential parameters of the FFP, suggesting it should have an eccentricity of 1–1.3 or larger, an inclination up to <span><math><mrow><mn>30</mn><mo>°</mo></mrow></math></span> or higher, and a minimum mass of about 50 Earth masses.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539184","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":"Probabilities of collisions of bodies ejected from forming Earth with the terrestrial planets","authors":"","doi":"10.1016/j.icarus.2024.116341","DOIUrl":"10.1016/j.icarus.2024.116341","url":null,"abstract":"<div><div>During formation of the Earth and at the stage of the Late Heavy Bombardment, some bodies collided with the Earth. Such collisions caused ejection of material from the Earth. The motion of bodies ejected from the Earth was studied, and the probabilities of collisions of such bodies with the present terrestrial planets were calculated. The dependences of these probabilities on velocities, angles and points of ejection of bodies were studied. These dependences can be used in the models with different distributions of ejected material. On average, about a half and less than 10 % of initial ejected bodies remained moving in elliptical orbits in the Solar System after 10 and 100 Myr, respectively. A few ejected bodies collided with planets after 250 Myr. As dynamical lifetimes of bodies ejected from the Earth can reach hundreds of million years, a few percent of bodies ejected at the Chicxulub and Popigai events about 36–65 Myr ago can still move in the zone of the terrestrial planets and have small chances to collide with planets, including the Earth. The fraction of ejected bodies that collided with the Earth was greater for smaller ejection velocity. The fractions of bodies delivered to the Earth and Venus probably did not differ much for these planets and were about 0.2–0.3 each. Such obtained results testify in favour of that the upper layers of the Earth and Venus can contain similar material. The fractions of bodies ejected from the Earth that collided with Mercury and Mars did not exceed 0.08 and 0.025, respectively. The fractions of bodies collided with Jupiter were of the order of 0.001. In most calculations the fraction of bodies collided with the Sun was between 0.2 and 0.5. Depending on parameters of ejection, the fraction of bodies ejected into hyperbolic orbits could vary from 0 to 1. Small fractions of material ejected from the Earth can be found on other terrestrial planets and Jupiter, as the ejected bodies could collide with these planets. Bodies ejected from the Earth could deliver organic material to other celestial objects, e.g. to Mars.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427334","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 correction to: Tessier et al. 2024 “Heng-o Corona, Venus: Dyke swarms record evolution of its underlying mantle plume” Icarus 417 (2024) 116090, https://doi.org/10.1016/j.icarus.2024.116090","authors":"","doi":"10.1016/j.icarus.2024.116332","DOIUrl":"10.1016/j.icarus.2024.116332","url":null,"abstract":"","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426850","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":"Research on lunar regolith of the Chang'E-4 landing site: An automated analysis method based on deep learning framework","authors":"","doi":"10.1016/j.icarus.2024.116338","DOIUrl":"10.1016/j.icarus.2024.116338","url":null,"abstract":"<div><div>On January 3, 2019, the Chang'E-4 lander successfully landed within the Von Kármán crater, located in the South P ole-Aitken Basin (SPA) on the farside of the Moon (45.5°S, 177.6°E), marking the first soft landing on the lunar farside. The lander, equipped with the Lunar Penetrating Radar (LPR) system, aimed to provide insights into the structure and evolution of the Moon. Previous research often relied on manually identifying hyperbolic features to analyze the lunar shallow subsurface properties. This inefficient approach may lead to subjective biases, resulting in unstable outcomes. This research constructed an automatic analysis framework by integrating the Swin Transformer with a 3D velocity spectrum, which is then applied to analyze the properties of the Chang'E-4 LPR data. The experimental results indicate that the framework achieved a precision of 98.9 % and a recall of 96.7 % in hyperbolic feature identification, with an <span><math><msub><mi>F</mi><mn>1</mn></msub></math></span> of 0.9782 and AP of 94.8 %. Additionally, it has been experimentally validated that the framework can accurately invert hyperbolic features' two-way travel time and velocity. Finally, the framework is applied to analyze the lunar shallow subsurface structure and properties within the landing area of the Chang'E-4 mission.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426849","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 effect of ionizing radiation on hydrated fungal cells: Implications for planetary protection and mars habitability","authors":"","doi":"10.1016/j.icarus.2024.116339","DOIUrl":"10.1016/j.icarus.2024.116339","url":null,"abstract":"<div><div>Liquid water is one of the essential conditions for life as we know it. Its presence has been currently reported beyond Earth. Geological and mineralogical evidence indicates that water once flowed on Mars. The recent discovery of present ice-water on the planet's surface is one of the driving factors for life-detection missions. The highly radiative Martian surface, combined with aqueous thin layers, is prohibitive for the presence of hypothetical forms of terrestrial-like life on the planet. In this context, we examined the survival of hydrated colonies of the Antarctic black fungus <em>Cryomyces antarcticus,</em> which thrives in the extreme environment of McMurdo Dry Valleys in Antarctica, after the exposure to increasing doses of space relevant γ-rays. Results suggest that water significantly reduces the number of survivors at the lowest doses, while at the higher dose (117 kGy) the cumulative damage caused by radiation could no longer be counteracted by dehydration.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426851","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":"Origin of Mars’s moons by disruptive partial capture of an asteroid","authors":"","doi":"10.1016/j.icarus.2024.116337","DOIUrl":"10.1016/j.icarus.2024.116337","url":null,"abstract":"<div><div>The origin of Mars’s small moons, Phobos and Deimos, remains unknown. They are typically thought either to be captured asteroids or to have accreted from a debris disk produced by a giant impact. Here, we present an alternative scenario wherein fragments of a tidally disrupted asteroid are captured and evolve into a collisional proto-satellite disk. We simulate the initial disruption and the fragments’ subsequent orbital evolution. We find that tens of percent of an unbound asteroid’s mass can be captured and survive beyond collisional timescales, across a broad range of periapsis distances, speeds, masses, spins, and orientations in the Sun–Mars frame. Furthermore, more than one percent of the asteroid’s mass could evolve to circularise in the moons’ accretion region. This implies a lower mass requirement for the parent body than that for a giant impact, which could increase the likelihood of this route to forming a proto-satellite disk that, unlike direct capture, could also naturally explain the moons’ orbits. These three formation scenarios each imply different properties of Mars’s moons to be tested by upcoming spacecraft missions.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445688","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}