Icarus最新文献

{"title":"Identification and analysis of interior and exterior resonant orbits in the Sun–Venus system","authors":"Tyler J. Kapolka,&nbsp;Robert A. Bettinger","doi":"10.1016/j.icarus.2024.116328","DOIUrl":"10.1016/j.icarus.2024.116328","url":null,"abstract":"<div><div>With Venus being Earth’s nearest neighbor and it being similar in size to Earth, it is the ideal candidate for certain mission types. These missions range from scientific, such as helio-physics and space weather monitoring, to defense focused, such as monitoring Earth’s orbital path for meteoroid threats. Limited research has been done on the periodic orbits in the Sun–Venus system. The first step to understanding which orbits could be useful for such a mission is to identify families of resonant periodic orbits in the Sun–Venus system and conduct a stability analysis on these orbits. This research work identifies 90 periodic, resonant orbits in the Sun–Venus system and their associated families of orbits. The orbits are found within the Circular Restricted 3 Body Problem (CR3BP) dynamical model with solar radiation pressure included as a perturbation. The periodic orbits are found using Poincaré maps, and the families are generated using a continuation method that steps through different Jacobi constants. The stability for each orbit in the family is calculated and the structure of the eigenvalues for each is assessed to determine when the family has crossed a bifurcation point. This research work seeks to generate a catalog of resonant orbits within the Sun–Venus system while providing stability and bifurcation information for each resonant orbit family.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116328"},"PeriodicalIF":2.5,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427335","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":"Alkali metal depletion in the deep Jovian atmosphere: The role of anions","authors":"Yury S. Aglyamov ,&nbsp;Sushil K. Atreya ,&nbsp;Ananyo Bhattacharya ,&nbsp;Cheng Li ,&nbsp;Steven Levin ,&nbsp;Scott J. Bolton ,&nbsp;Michael H. Wong","doi":"10.1016/j.icarus.2024.116334","DOIUrl":"10.1016/j.icarus.2024.116334","url":null,"abstract":"<div><div>The Juno Microwave Radiometer has allowed observation of Jupiter's atmosphere down to previously inaccessible depths, although the complexity of the atmospheric dynamics has complicated analysis. The longest-wavelength channel (600 MHz) is sensitive to pressure levels of hundreds of bars, and has observed opacity sources other than the known gaseous and cloud components, likely caused by thermally ionized free electrons from alkali metal vapor. We extend previous analysis of limb darkening at these wavelengths, using radiative transfer and thermal equilibrium modeling, by considering the effect of anions in the deep Jovian atmosphere, which act as a sink for free electrons and will thus decrease opacity for a given alkali metal abundance. We show that MWR observations are consistent with a sodium and potassium abundance on the order of 0.1× solar around the 1-kilobar level, higher than previously estimated but still substantially depleted compared to other heavy elements, a value that would be within the range of observed alkali metal abundances on giant exoplanets; alternatively, MWR observations may be consistent with 3× solar sodium abundance, but only if potassium is even more strongly depleted. Such depletion may be the result of either chemical processes yet deeper in the atmosphere, such as in the silicate clouds, or of a long-lived stable layer shallower than the alkali salt clouds.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116334"},"PeriodicalIF":2.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323119","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":"Radiative signatures of circumplanetary disks and envelopes during the late stages of giant planet formation","authors":"Aster G. Taylor ,&nbsp;Fred C. Adams","doi":"10.1016/j.icarus.2024.116327","DOIUrl":"10.1016/j.icarus.2024.116327","url":null,"abstract":"<div><div>During the late stages of giant planet formation, protoplanets are surrounded by a circumplanetary disk and an infalling envelope of gas and dust. For systems with sufficient cooling, material entering the sphere of influence of the planet falls inward and approaches ballistic conditions. Due to conservation of angular momentum, most of the incoming material falls onto the disk rather than directly onto the planet. This paper determines the spectral energy distributions of forming planets in this stage of evolution. Generalizing previous work, we consider a range of possible geometries for the boundary conditions of the infall and determine the two-dimensional structure of the envelope, as well as the surface density of the disk. After specifying the luminosity sources for the planet and disk, we calculate the corresponding radiative signatures for the system, including the emergent spectral energy distributions and emission maps. These results show how the observational appearance of forming planets depend on the input parameters, including the instantaneous mass, mass accretion rate, semimajor axis of the orbit, and the planetary magnetic field strength (which sets the inner boundary condition for the disk). We also consider different choices for the form of the opacity law and attenuation due to the background circumstellar disk. Although observing forming planets will be challenging, these results show how the observational signatures depend on the underlying properties of the planet/disk/envelope system.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116327"},"PeriodicalIF":2.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326800","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":"Updated ultraviolet fluorescence efficiencies of CS: Evidence for model discrepancies in the enhancement of NUV-derived CS abundances in comets","authors":"S.J. Bromley ,&nbsp;J. Wm. Noonan ,&nbsp;B. Stachová ,&nbsp;J. Országh ,&nbsp;D. Bodewits","doi":"10.1016/j.icarus.2024.116326","DOIUrl":"10.1016/j.icarus.2024.116326","url":null,"abstract":"<div><div>Observations of carbon monosulfide (CS) have a long history serving as a remote proxy for atomic sulfur, and more broadly, one of the sulfur reservoirs in cometary bodies. Recently, systematic discrepancies between NUV- and radio-derived CS abundances have been found to exceed a factor of 2–5, with NUV-derived abundances appearing enhanced for a wide array of comets. Interpretation of cometary CS emission in the ultraviolet has relied on a murky and ill-documented lineage of calculations whose accuracy can be difficult to assess. We report new fluorescence efficiencies of the CS radical, utilizing a rovibrational structure with vibrational states up to <span><math><mrow><mi>v</mi><mo>=</mo><mn>8</mn></mrow></math></span> and rotational states up to <span><math><mrow><mi>N</mi><mo>=</mo><mn>100</mn></mrow></math></span>. The models utilize a new set of band transition rates derived from laboratory electron impact experiments. Benchmark comparisons to IUE observations of C/1979 Y1 (Bradfield) show favorable agreement with the fluorescence models. The present results affirm the accuracy of the historical record of CS abundances derived via ultraviolet CS emission in comets with IUE and HST, but do not explain the consistent enhancement of NUV-derived CS abundances relative to the radio measurements during the same apparitions. Alternative explanations of the factor of 2–5 discrepancy between NUV- and radio-derived CS abundances are discussed, as well as possible connections to sulfur reservoirs in protoplanetary disks. The model code and computed fluorescence efficiencies are made publicly available on the Zenodo service.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116326"},"PeriodicalIF":2.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326801","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":"Unlocking planetesimal magnetic field histories: A refined, versatile model for thermal evolution and dynamo generation","authors":"Hannah R. Sanderson ,&nbsp;James F.J. Bryson ,&nbsp;Claire I.O. Nichols ,&nbsp;Christopher J. Davies","doi":"10.1016/j.icarus.2024.116323","DOIUrl":"10.1016/j.icarus.2024.116323","url":null,"abstract":"<div><div>The thermal and magnetic histories of planetesimals provide unique insights into the formation and evolution of Earth’s building blocks. These histories can be gleaned from meteorites by using numerical models to translate measured properties into planetesimal behaviour. In this paper, we present a new 1D planetesimal thermal evolution and dynamo generation model. This magnetic field generation model is the first of a differentiated, mantled planetesimal that includes both mantle convection and sub-eutectic core solidification. We have improved fundamental aspects of mantle heat transport by including a more detailed viscosity model and stagnant lid convection parametrisations consistent with internal heating. We have also added radiogenic heating from ⁶⁰Fe in the metallic Fe-FeS core. Additionally, we implement a combined thermal and compositional buoyancy flux, as well as the latest magnetic field scaling laws to predict magnetic field strengths during the planetesimal’s thermal evolution until core solidification is complete. We illustrate the consequences of our model changes with an example run for a 500<!--> <!-->km radius planetesimal. These effects include more rapid erosion of core thermal stratification and longer duration of mantle convection compared to previous studies. The additional buoyancy from core solidification has a marginal effect on dynamo strength, but for some initial core sulfur contents it can prevent cessation of the dynamo when mantle convection ends. Our model can be used to investigate the effects of individual parameters on dynamo generation and constrain properties of specific meteorite parent bodies. Combined, these updates mean this model can predict the most reliable and complete magnetic field history for a planetesimal to date, so is a valuable tool for deciphering planetesimal behaviour from meteorite properties.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116323"},"PeriodicalIF":2.5,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356766","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":"Low temperature phase transitions in the visible and near-infrared (VNIR) reflectance spectra of (NH4)2HPO4 and (NH4)HSO4 salts","authors":"M. Fastelli ,&nbsp;B. Schmitt ,&nbsp;P. Beck ,&nbsp;O. Poch ,&nbsp;A. Zucchini ,&nbsp;P. Comodi","doi":"10.1016/j.icarus.2024.116321","DOIUrl":"10.1016/j.icarus.2024.116321","url":null,"abstract":"<div><div>The detection of ammonium bearing crystalline solids in salt-water systems on icy bodies and solar system bodies could provide information about the ascent of these salts from a deep reservoir within the hydrosphere. Due to their chemical-physical properties, NH₄⁺ compounds play a key role both in the internal dynamics of celestial bodies and in the potential habitability of ocean worlds. In this work we analysed the reflectance spectra of two synthetic NH₄⁺ salts: ammonium hydrogen phosphate (NH₄)₂HPO₄ and ammonium hydrogen sulphate (NH₄)HSO₄ in the 1–4.2 μm spectral range at low temperature, between 110 and 290 K. For (NH₄)₂HPO₄ we also examined the effect of three different grain sizes (150–125 μm; 125–80 μm; 80–32 μm). The collected reflectance spectra show absorption features related to NH₄⁺ group overtone and combination modes in the 1–2.5 μm range. In particular, the bands located at ∼1.09 μm (3ν₃), ∼1.30 μm (2ν₃ + ν₄), ∼1.58 μm (2ν₃), ∼2.02 μm (ν₂ + v₃) and ∼ 2.2 μm (<em>v</em>₃ + v₄) could be useful to discriminate these salts. The low temperature spectra, compared to those at ambient temperature, reveal finer structures, displaying sharper and narrower absorption bands. The selected NH₄⁺-bearing salts are subjected to reversible low temperature phase transitions, which are revealed in the spectra by a progressive growth and shift of the bands toward shorter wavelengths with a drastic change of their depth. We performed laboratory measurements of ammonium (NH₄⁺) compounds to address the limited data available expanding the existing database. The collected cryogenic spectra can be directly compared with remote sensing data from planetary missions of the upcoming decade such as NASA's Europa Clipper, and ESA's JUICE and the newly launched James Webb Space Telescope expanding the existing database of ammonium compounds at cryogenic temperature.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116321"},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326803","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":"Refined 70-cm earth-based lunar radar maps and a new interpretation of the Cruger-Sirsalis cryptomare","authors":"Bruce A. Campbell ,&nbsp;Erica R. Jawin ,&nbsp;Gareth A. Morgan","doi":"10.1016/j.icarus.2024.116324","DOIUrl":"10.1016/j.icarus.2024.116324","url":null,"abstract":"<div><div>We present a new processing approach for Earth-based, 70-cm wavelength, dual-polarization radar data collected using the Arecibo and Green Bank Telescopes. Earth-based data represent the only view of the Moon at this wavelength. This methodology greatly improves the synthetic aperture focusing of the images to their best possible spatial resolution, with a concurrent improvement in signal-to-noise ratio and multi-look summing. Image coverage is also expanded to the full illuminated beam area. Registration to a visible image basemap reduces RMS geographic placement errors to less than ∼2 km. Images collected after the first Planetary Data System archive delivery are also included. Analysis of the circular polarization ratio (CPR) suggests an uncertainty of ∼20 %, based on the likely ∼1 dB error in estimating the background noise in a radar look. We use the new 70-cm maps with topography and 12.6-cm radar images to revisit an initial study of cryptomare units in the Cruger-Sirsalis region, and find that mare contamination of the Orientale ejecta must be well-mixed with highland material, as opposed to the earlier hypothesis of a highland-dominated blanket over mare-rich regolith. This result shows that the two radar wavelengths provide a more complete view of the cryptomare regolith cross section, and that radar signatures can delineate ilmenite contamination of highlands areas where multi-spectral methods are limited by other factors.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116324"},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356762","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":"Morphometry and kinematics correlation of wrinkle ridges on Mars: Insights from Trishear modelling","authors":"F. Carboni,&nbsp;O. Karagoz,&nbsp;T. Kenkmann","doi":"10.1016/j.icarus.2024.116330","DOIUrl":"10.1016/j.icarus.2024.116330","url":null,"abstract":"<div><div>Wrinkle ridges are among the most common and controversial compressional tectonic structures on terrestrial planets. While their origins are well inferred to be related to crustal shortening driven by compressional stress, their subsurface characterization is still a matter of debate. Open questions remain about the geometry, number, structural style and kinematics of faults promoting wrinkle ridges. We use the Trishear and Fault-Parallel-Flow integrated forward kinematic modelling to model wrinkle ridges related faults. This is achieved through a series of balanced cross sections and a consequent set of narrow 3D models. We perform a detail kinematic analysis on nine wrinkle ridges: six are located in the circum-Tharsis regions of Lunae Planum and Solis Planum, while three are located in the Hellas Planitia, Hesperia Planum and Syrtis Major Planum, respectively. The applied methodology allows us to quantitatively assess wrinkle ridges geometry and kinematics, and to correlate them with morphometric parameters (i.e., width and relief). Our results indicate how wrinkle ridges tectonics can be characterized by a more complex array of faults than previously modelled. This leads to a total amount of horizontal shortening accommodated differently depending on the number and type of faults (i.e., main fault, backthrust, synthetic faults). The location and geometry of the modelled faults suggest the presence of multiple detachments at different depths and with different mechanical behaviors such as weaker and more frictional décollements, which are likely found within sedimentary interlayers. The amount of shortening, the fault geometry and spacing, as well as the upper faults tips depth are positively correlated with major morphometric parameters of wrinkle ridges topography.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116330"},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323118","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":"Chandrayaan-3 landing site evolution by South Pole-Aitken basin and other impact craters","authors":"S. Vijayan ,&nbsp;K.B. Kimi ,&nbsp;Anil Chavan ,&nbsp;R. Aditi ,&nbsp;U. Thahira ,&nbsp;V. Rama Subramanian ,&nbsp;Rishitosh K. Sinha ,&nbsp;Amitabh ,&nbsp;Santosh Vadawale ,&nbsp;M. Shanmugam ,&nbsp;N.P.S. Mithun ,&nbsp;Arpit R. Patel ,&nbsp;Amit Basu Sarbadhikari ,&nbsp;K.V. Iyer ,&nbsp;K. Suresh ,&nbsp;Ajay Prashar ,&nbsp;G. Rima ,&nbsp;Anil Bhardwaj","doi":"10.1016/j.icarus.2024.116329","DOIUrl":"10.1016/j.icarus.2024.116329","url":null,"abstract":"<div><div>The Chandrayaan-3 mission with the Vikram-lander and the Pragyan rover landed in the high latitude highland region near the south pole of the Moon. The landing site is located ∼350 km from the South Pole-Aitken basin rim, an ancient and highly cratered terrain. This site has undergone the complex emplacement sequence of SPA basin ejecta followed by the nearby and distant impact basins and crater ejecta materials. To evaluate the source of individual basin and crater ejecta emplacement over this landing site, we carefully demarcated the nearby and distal basins and craters that could have contributed to the source regolith material. We found that the SPA basin is the major contributor, which deposited nearly ∼1400 m of ejecta materials, and 11 other basins deposited ∼580 m of ejecta. The other complex craters contributed up to ∼90 m of ejecta. Meanwhile, secondary craters of a few km in diameter located adjacent to the landing site contributed to ∼0.5 m ejecta, which are crucial target materials for the Pragyan rover insitu analysis. Pragyan rover images revealed the landing site is devoid of &gt;1 m boulders along the traverse revealing typical highland terrain. The Pragyan rover Navcam and Orbital High Resolution Camera regional images revealed linear distal ejecta rays possibly from the distant impacts as insitu evidence of foreign material at the CH-3 landing site. We found a semi-circular, heavily degraded structure encompassed around the landing site, which is interpreted as a buried impact crater ∼160 km in diameter probably formed before the SPA basin. The erasure of pre-SPA basin craters is caused by both the direct burial by SPA basin ejecta, high seismic shaking during SPA formation, and then followed by various post-SPA craters and its associated some of the degradation processes. Overall, Chandrayaan-3 landed within an ancient region that hosts some of the most deeply excavated materials on the Moon.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116329"},"PeriodicalIF":2.5,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323117","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":"Survey of remnant seasonal ice patches at southern polar Mars","authors":"M. Gergacz ,&nbsp;A. Kereszturi","doi":"10.1016/j.icarus.2024.116331","DOIUrl":"10.1016/j.icarus.2024.116331","url":null,"abstract":"<div><div>On Mars after the recession of the seasonal polar ice cap, small icy patches in shady and/or low thermal conductivity places are left behind. These regions are then illuminated by direct sunlight during the summer, warm up and in an ideal case a liquid phase could emerge. This work is surveying HiRISE images for such ice patches and found 148 images with ice patches on them out of the 730 images that fit the selection criteria of location and season. Their separation of ice from other bright patches, like clouds or lighter shades of surface layers and rocks was possible by their bluish color and strong connection to local topography Images with ice patches ranged between 140° and 200° solar longitude in the latitude band between −40° and − 60°. The diameter of the ice patches ranges between 1.5 and 300 m, and they remain on the surface even after the seasonal polar cap has passed over the area for at least the duration range of 1.5–139 Martian days. This range of duration indicates not ephemerally formed ice in the night but longer presence at the surface.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116331"},"PeriodicalIF":2.5,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315756","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}