IcarusPub Date : 2024-08-10DOI: 10.1016/j.icarus.2024.116256
{"title":"Analysis of a large buried impact crater and vertical mineral composition at the Chang'E-4 landing site by multi-source remote sensing data","authors":"","doi":"10.1016/j.icarus.2024.116256","DOIUrl":"10.1016/j.icarus.2024.116256","url":null,"abstract":"<div><p>Exploring the concealed subsurface structures and materials beneath the lunar surface can reveal significant insights into geological history. This study offers a comprehensive analysis of the stratigraphic interpretation and subsurface material composition at the Chang'E-4 landing site, integrating both in-situ and orbital radar with multispectral datasets. We report the identification of a subsurface structure, which resembles a buried impact crater (∼420 m in diameter) under the Yutu-2 rover's path. This crater could degrade over a period of 0.42 to 0.53 Ga, with an initial diameter of 293 to 323 m and an initial depth of 45.9 to 51.4 m. Surface material above the buried crater, evaluated by the in-situ visible and near-infrared imaging spectrometer (VNIS) detector, shows a higher abundance of clinopyroxene compared to surrounding areas, where a near-equal mix of clinopyroxene and orthopyroxene is observed. Assessment of crater diameters in proximity to the Chang'E-4 landing site, along with the mineral compositions at their epicenters, reveals a decrease in the abundance of clinopyroxene and plagioclase with depth. Conversely, the quantities of orthopyroxene and olivine increase, implying that orthopyroxene-rich Finsen ejecta significantly influenced the Chang'E-4 landing site's geological composition. Two potential stratigraphic boundary depths are identified at 13.5 and 22 m, based on pronounced variations in mineral abundance, offering fresh insights into subsurface delineation beyond radar data. Considering the VNIS and vertical mineral composition, we propose the buried crater's formation resulted from Finsen crater's ejecta. Also, we identify eight potential historical impacts by comparing subsurface relief variations with mineral composition ratios between clinopyroxene and orthopyroxene. The integration of subsurface structure, along with surface and subsurface mineral composition, enables a more robust stratigraphic interpretation, facilitates shallow material source analysis, and allows for historical impact tracing.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141979270","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}
IcarusPub Date : 2024-08-10DOI: 10.1016/j.icarus.2024.116257
{"title":"Lunar simulant behaviour variability and implications on terrestrial based lunar testing","authors":"","doi":"10.1016/j.icarus.2024.116257","DOIUrl":"10.1016/j.icarus.2024.116257","url":null,"abstract":"<div><p>The detrimental effects and challenges of Lunar dust for Lunar exploitation were first identified during the Apollo missions. During the extra vehicle activities (EVAs) undertaken by astronauts, the dust clogged mechanisms, disrupted sensors, and caused several health issues for the astronauts. Despite numerous studies, there is no definite understanding as to why different Apollo missions experienced varying levels of dust disruptions. The variations in dust behaviour could be attributed to the amount of radiation the Lunar soil is exposed to, as well as mineralogy and particle sizes. To enhance our understanding of Lunar dust behaviour this study investigated Space Recourse Technologies, formally known as Exolith, simulant at different mineral compositions, and their surface detachment characteristics were measured. Experiments measuring the individual minerals and their mixed simulant-like counterparts were conducted using electrostatic fields. Inclusive to this, non-dried and dried samples were compared by measuring adhesion to target plates when subject to electrostatic forces. The results found that Highlands simulant exhibited a higher buildup on a target plate than its Mare counterpart by an average of 33% under the same conditions, likely due to particle size differences. In addition to these findings, evidence of particle reactivity decay was observed under repeated tests with up to 60% less Mare simulant and 36% Highlands deposition being measured compared to the first set of experiments. A possible explanation may be particle reactivity. Microscope images identified that particles are transported in groups as opposed to individual grains. These results will help researchers in tailoring dust mitigation solutions based on different regions on the Lunar surface and influence mission planning from the perspective of dust mitigation and contamination.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0019103524003178/pdfft?md5=a3c15cea179e35faa63369af1262e83a&pid=1-s2.0-S0019103524003178-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142021047","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}
IcarusPub Date : 2024-08-08DOI: 10.1016/j.icarus.2024.116254
{"title":"Dynamical evolution of the Uranian satellite system II. Crossing of the 5/3 Ariel–Umbriel mean motion resonance","authors":"","doi":"10.1016/j.icarus.2024.116254","DOIUrl":"10.1016/j.icarus.2024.116254","url":null,"abstract":"<div><p>At present, the main satellites of Uranus are not involved in any low order mean motion resonance (MMR). However, owing to tides raised in the planet, Ariel and Umbriel most likely crossed the 5/3 MMR in the past. Previous studies on this resonance passage relied on limited time-consuming <span><math><mrow><mi>N</mi><mo>−</mo></mrow></math></span>body simulations or simplified models focusing solely on the effects of the eccentricity or the inclination. In this paper, we aim to provide a more comprehensive view on how the system evaded capture in the 5/3 MMR. For that purpose, we developed a secular resonant two-satellite model with low eccentricities and low inclinations, including tides using the weak friction model. By performing a large number of numerical simulations, we show that capture in the 5/3 MMR is certain if the initial eccentricities of Ariel, <span><math><msub><mrow><mi>e</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span>, and Umbriel, <span><math><msub><mrow><mi>e</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>, are related through <span><math><mrow><msup><mrow><mrow><mo>(</mo><msubsup><mrow><mi>e</mi></mrow><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mo>+</mo><msubsup><mrow><mi>e</mi></mrow><mrow><mn>2</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mo>)</mo></mrow></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup><mo><</mo><mn>0</mn><mo>.</mo><mn>007</mn></mrow></math></span>. Moreover, we observe that the eccentricity of Ariel is the key variable to evade the 5/3 MMR with a high probability. We determine that for <span><math><mrow><msub><mrow><mi>e</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>></mo><mn>0</mn><mo>.</mo><mn>015</mn></mrow></math></span> and <span><math><mrow><msub><mrow><mi>e</mi></mrow><mrow><mn>2</mn></mrow></msub><mo><</mo><mn>0</mn><mo>.</mo><mn>01</mn></mrow></math></span>, the system avoids capture in at least 60% of the cases. We also show that, to replicate the currently observed system, the initial inclinations of Ariel and Umbriel must lay within <span><math><mrow><msub><mrow><mi>I</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>≤</mo><mn>0</mn><mo>.</mo><mn>05</mn><mo>°</mo></mrow></math></span> and <span><math><mrow><mn>0</mn><mo>.</mo><mn>06</mn><mo>°</mo><mo>≤</mo><msub><mrow><mi>I</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>≤</mo><mn>0</mn><mo>.</mo><mn>11</mn><mo>°</mo></mrow></math></span>, respectively. We checked these results using a complete <span><math><mrow><mi>N</mi><mo>−</mo></mrow></math></span>body model with the five main satellites and did not observe any significant differences.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0019103524003142/pdfft?md5=ead07189642683424e1c775ea533b5cc&pid=1-s2.0-S0019103524003142-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142229250","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}
IcarusPub Date : 2024-08-08DOI: 10.1016/j.icarus.2024.116252
{"title":"Spatially dependent hydration features on nominally anhydrous near-earth asteroids","authors":"","doi":"10.1016/j.icarus.2024.116252","DOIUrl":"10.1016/j.icarus.2024.116252","url":null,"abstract":"<div><p>Near-Earth Asteroids (NEAs) are excellent laboratories for processes that affect the surfaces of airless bodies. Most NEAs were not expected to contain OH/H<sub>2</sub>O on their surfaces because they are primarily S-complex objects and sourced from the inner Main Belt, which is interior of the frost line, and their surface temperatures are high enough to remove these volatiles. However, a 3-μm feature typically indicative of OH/H<sub>2</sub>O was identified on other seemingly dry bodies in the inner Solar System, such as the Moon and Vesta, and more recently on the NEAs (433) Eros, (1036) Ganymed, and (3122) Florence. The most likely sources for OH/H<sub>2</sub>O on these bodies include carbonaceous chondrite impacts or interactions with protons implanted by solar wind. We investigated the causes of band depth and shape variations on NEAs by comparing new observations of Eros and Ganymed to those previously published and conducting a rotationally-resolved spectral study on Florence. All spectra discussed were collected by SpeX on NASA's IRTF using the LXD_short (1.67–4.2 μm) mode to characterize the 3-μm region. Some observations also used the prism (0.7–2.52 μm) mode to characterize asteroid spectral type and investigate silicate composition dependencies. All three asteroids possess exogenously sourced OH/H<sub>2</sub>O and have spectra that show potential spatially correlated variations in band depth or shape. Eros' band is slightly wider at the poles than at lower sub-observer latitudes, possibly due to its high obliquity, which ensures that each polar region is oriented toward the Sun over a significant part of its orbit. Ganymed's trends in hydration band depth with sub-solar longitude and band I center suggest a carbonaceous or cometary impactor that struck the surface around 0° relative longitude, excavating a relatively magnesium- and olivine-enriched layer. Florence's total hydrogen concentration remains stable across the surface even as the OH-to-H<sub>2</sub>O ratio changes as the asteroid rotates. These three examples suggest that non-native OH/H<sub>2</sub>O on other bodies will likely also be spatially dependent, regardless of delivery mechanism.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0019103524003129/pdfft?md5=ad21b61700b04183a0241116f5447c54&pid=1-s2.0-S0019103524003129-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141963804","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}
IcarusPub Date : 2024-08-08DOI: 10.1016/j.icarus.2024.116249
{"title":"Visual observation of meteorite ablation in plasma wind tunnel experiments","authors":"","doi":"10.1016/j.icarus.2024.116249","DOIUrl":"10.1016/j.icarus.2024.116249","url":null,"abstract":"<div><p>A set of 28 different meteorites was tested in 32 ablation experiments in the plasma wind tunnel PWK1 at the Institute of Space Systems. All meteorites were exposed to the same flow condition in consecutive experiments. This paper presents the detailed analysis of high-resolution images taken by DSLR cameras during 26 experiments on 22 different meteorites. It is seen that the ablation behavior of the meteorites differs in the way the material melts and flows downstream. While some meteorites appeared more viscous and most material remained connected to the main body, other samples suggest a much lower viscosity as the material was carried downstream and released droplets to the flow. Most droplets of molten material were seen for the two most carbon rich samples from meteorites Murchison and Dhofar 1575. The release of blue colored particles was observed for several meteorites, independent of the viscosity. In contrast to the molten droplets, the blue particles also traveled up to a few millimeters upstream. The abundance of these blue particles is linked to the iron content. Close to no particles or droplets were observed for achondritic samples.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0019103524003099/pdfft?md5=6cd719a9e16927e430d7d6efa49c8922&pid=1-s2.0-S0019103524003099-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141979271","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}
IcarusPub Date : 2024-08-06DOI: 10.1016/j.icarus.2024.116250
{"title":"A comparison of fireball luminous efficiency models using acoustic records","authors":"","doi":"10.1016/j.icarus.2024.116250","DOIUrl":"10.1016/j.icarus.2024.116250","url":null,"abstract":"<div><p>The total energy of a fireball is commonly obtained from optical measurements with an assumed value for luminous efficiency. Acoustic energy measurements offer an independent means of energy estimation. Here we combine optical and acoustic methods to validate the luminous efficiency model of Borovičkaet al. (2020). Our goal is to compare these models with acoustic measurements of meteoroid energy deposition. Employing theoretical blast scaling laws following the approach of Mcfaddenet al. (2021), we determine explosive yields for both fireball fragmentation events and cylindrical shocks for four different bright fireballs. We model fireballs using the <span>MetSim</span> software (Vidaet al., 2023) and find that the Borovičkaet al. (2020) model produces agreement better than a factor of two for our three chondritic fireball case studies. The major exception is an iron meteorite-producing fireball where the luminous efficiency is an order of magnitude higher than model predictions calibrated with stony fireballs. We suggest that large disparities between optical and acoustic energies could be a signature of iron fireballs and hence useful as a discriminant of that population.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141985549","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}
IcarusPub Date : 2024-08-06DOI: 10.1016/j.icarus.2024.116247
{"title":"Improvement of the Mean Field T-Matrix method for scattering by fractal aggregates of identical spheres in astrophysical environments","authors":"","doi":"10.1016/j.icarus.2024.116247","DOIUrl":"10.1016/j.icarus.2024.116247","url":null,"abstract":"<div><p>Aggregated particles and aerosols are common in natural or industrial environments. Analysing their scattering and absorption properties with precise methods may prove useful for gaining information about real particles, using remote sensing or in situ active optical instruments in natural environments. Many methods, with varying complexities, were developed in the past. For aggregates of spheres, the most recent version of the T-Matrix method by Mackowski and Mishchenko (2011) is able to treat the problem almost exactly and can yield all the details of the scattering properties. However, for computational reasons, the T-Matrix method cannot handle large particles. In order to deal with large particles, a mean-field version of the T-Matrix theory was developed by Botet et al. (1997) for aggregates of identical spheres and used in particular to analyse the case of Titan haze. This mean-field T-Matrix method is efficient to quickly calculate accurate approximations of many optical properties of aggregates of Mie spheres, but it is inherently limited by the mean field approximations. It uses crude approximation of the pair-correlation functions (Seignovert et al., 2017) and leads to inaccurate estimations in the geometrical optics limit (Tazaki and Tanaka, 2018). In the present work, we bring improvements that overcome these two limitations. This significantly increases the validity range of the method and its accuracy. We display comparisons with the results obtained with T-Matrix method in order to assess the performance of the new version of the mean field method (MFT-M<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span>).</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122405","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}
IcarusPub Date : 2024-08-05DOI: 10.1016/j.icarus.2024.116241
{"title":"Moisture transport and the methane cycle of Titan’s lower atmosphere","authors":"","doi":"10.1016/j.icarus.2024.116241","DOIUrl":"10.1016/j.icarus.2024.116241","url":null,"abstract":"<div><p>Titan’s surface and lower atmosphere support a hydrologic cycle that influences various aspects of the icy moon’s appearance and evolution. Here, we review the state of knowledge around this methane cycle, focusing on its relationship to the circulation of the troposphere and to the distribution of surface liquids. Titan’s meridional circulation consists mainly of Hadley cells, with an intertropical convergence zone—in which clouds and precipitation are promoted—that oscillates with latitude seasonally. There are separate regions at the poles wherein precipitation occurs in summertime. Overall, the character of precipitation depends on the amount of liquid available to evaporate on the surface, and a realistic liquid distribution (that is, with liquids limited to polar regions) leads to highly sporadic seasonal precipitation. This also produces a latitudinal profile of near-surface humidity wherein the poles are more humid than the lower latitudes. The lower latitude humidity reflects the horizontal transport by the Hadley circulation, but is cut off from the high near-surface humidity at the poles. Polar moist convection humidifies the mid-levels and from there the low latitudes, and equatorward, downgradient transport of moisture is accomplished by traveling storm systems in the high mid-latitudes. These waves in some cases interact with the convection to communicate the effects of latent heating nearly globally. Separately, surface and subsurface hydrology are important processes that lead to the observed distribution of liquids in polar basins, and furthermore indicate the influence of a subsurface methane table interacting with the climate system. Precipitation at lower latitudes largely runs off or infiltrates into the surface; runoff at higher latitudes feeds some of the low-lying polar basins; and subsurface methane flow regulates the distribution of near-surface methane such that the seas are surface exposures of, and other polar areas sustain evaporation from, a shallow methane table. Finally, we discuss the possible long-term evolution of surface liquids, including the influence of Croll-Milankovitch cycles and their effect on atmospheric moisture transport by eddies; whether or not Titan’s surface features indicate past cycling of polar liquids, slower secular trends, or something else entirely remains unresolved.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933806","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}
IcarusPub Date : 2024-08-05DOI: 10.1016/j.icarus.2024.116253
{"title":"Modeling the plasma composition of 67P/C-G at different heliocentric distances","authors":"","doi":"10.1016/j.icarus.2024.116253","DOIUrl":"10.1016/j.icarus.2024.116253","url":null,"abstract":"<div><p>The <em>Rosetta</em> spacecraft accompanied the comet 67P/C-G for nearly 2 years, collecting valuable data on the neutral and ion composition of the coma. The Rosetta Plasma Consortium (RPC) provided continuous measurements of the in situ plasma density while ROSINA-COPS monitored the neutral composition. In this work, we aim to estimate the composition of the cometary ionosphere at different heliocentric distances of the comet. Läuter et al. (2020) derived the temporal evolution of the volatile sublimation rates for 50 separated time intervals on the orbit of 67P/C-G using the COPS and DFMS data. We use these sublimation rates as inputs in a multifluid chemical-hydrodynamical model for 36 of the time intervals for heliocentric distances <span><math><mrow><mo><</mo><mn>3</mn></mrow></math></span> au. We compare the total ion densities obtained from our models with the local plasma density measured by the RPC instruments. We find that at the location of the spacecraft, our modeled ion densities match with the in situ measured plasma density within factors of <span><math><mrow><mn>1</mn><mo>−</mo><mn>3</mn></mrow></math></span> for many of the time intervals. We obtain the cometocentric distance variation of the ions H<sub>2</sub>O<sup>+</sup> and H<sub>3</sub>O<sup>+</sup> and the ion groups created respectively by the ionization and protonation of neutral species. We see that H<sub>3</sub>O<sup>+</sup> is dominant at the spacecraft location for nearly all the time intervals while ions created due to protonation are dominant at low cometocentric distances for the intervals near perihelion. We also discuss our ion densities in the context of their detection by DFMS.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933802","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}
IcarusPub Date : 2024-08-03DOI: 10.1016/j.icarus.2024.116243
{"title":"Weakening of olivine by hydrogen implantation: Results of nano-indentation tests and some applications to planetary materials","authors":"","doi":"10.1016/j.icarus.2024.116243","DOIUrl":"10.1016/j.icarus.2024.116243","url":null,"abstract":"<div><p>Sticking of the dust grains is a critical step in planet formation. To investigate the solar wind effect on the dust mechanical properties, we conducted hydrogen implantation experiments (using beam energies of 10 keV, 20 keV and 50 keV) on olivine single crystals and determined the elastic modulus and the hardness as a function of depth by nano-indentation tests. The near surface regions of the samples (to ∼600 nm) show a substantial decrease in both hardness (up to ∼85%) and modulus (up to ∼74%), indicating a large degree of mechanical weakening. The depth extent of the weakened region increases with implantation energy while the degree of weakening decreases with implantation energy. TEM (transmission electron microscopy) observations of the samples show that the depth where damaged region occurs increases with the implantation energy used. The results are interpreted based on the physics of ion-solid interaction during implantation. According to our results, we expect that olivine-like dust exposed to solar wind would display a similar mechanical weakening in the surface (∼ 74% reduction in elastic modulus, ∼ 85% reduction in hardness). Mechanical weakening by solar wind implantation would enhance the sticking of the dust in the disk if dust have been effectively exposed to the solar wind. The present results are also applied to interpret observations of some planetary materials.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933807","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}