Icarus最新文献

{"title":"The YORP effect for meter-sized asteroids","authors":"Conor J. Benson,&nbsp;Daniel J. Scheeres","doi":"10.1016/j.icarus.2025.116794","DOIUrl":"10.1016/j.icarus.2025.116794","url":null,"abstract":"<div><div>The spin states of meter-sized asteroids should evolve rapidly due to the Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) effect. While these asteroids are very challenging to observe, artificial geosynchronous (GEO) satellites are convenient analogues given that they are driven primarily by solar torques, evolve rapidly, and are easy to observe. These artificial objects could provide insight about the evolution of their natural counterparts. Recent studies of YORP for defunct GEO satellites with full and tumbling-averaged models have uncovered rich dynamical structure with tumbling cycles, angular momentum sun-tracking, and tumbling resonances. Applying the tumbling-averaged YORP models to meter-sized pseudo asteroids, we find that the solar torque structure yields sun-tracking precession in many cases, particularly for asteroids with at least some elongation. Precession about the sun line results in the long-term obliquity averaging to roughly 90°. As a result, the sun-tracking behavior could potentially shut off Yarkovsky drift for these asteroids and thereby limit their mobility out of the main asteroid belt. For some asteroid shapes, tumbling cycles with alternating spin up and spin down are also observed. These tumbling cycles offer a possible avenue to prevent spin-driven disruption of meteoroids.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"444 ","pages":"Article 116794"},"PeriodicalIF":3.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048227","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":"Temperature dependence of CH3CNN2 line broadening predicted from extended rotational-band measurements","authors":"J. Buldyreva ,&nbsp;A.S. Dudaryonok ,&nbsp;N.N. Lavrentieva","doi":"10.1016/j.icarus.2025.116793","DOIUrl":"10.1016/j.icarus.2025.116793","url":null,"abstract":"<div><div>As methyl cyanide is one of the complex organic molecules present in planetary atmospheres, comets and interstellar medium but extremely scarce data are available for its radiative transfer modeling, we focus on providing exhaustive sets of theoretical nitrogen-broadening coefficients of CH<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>CN lines for a large set of quantum numbers and a wide temperature range of astrophysical interest. Taking advantage of recent extensive measurements of rotational transitions with Voigt- and Speed-Dependent-Voigt profiles at room temperature and the corresponding update of the temperature-independent parameters of the semi-empirical approach suitable for CH<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>X-type molecules with large dipole moments, we employ these parameters in calculations for lower and higher temperatures with a further determination of temperature-dependence exponents. CH<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>CN<img>N<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> line-broadening parameters are calculated for both line-profile models in the temperature range 100–2000 K for the rotational numbers <span><math><mrow><mi>J</mi><mo>=</mo><mn>0</mn></mrow></math></span>–80, <span><math><mrow><mi>K</mi><mo>=</mo><mn>0</mn></mrow></math></span>–20 typically requested by spectroscopic databases. The temperature-dependence exponents for the reference temperature <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>ref</mi></mrow></msub></math></span> = 296 K are extracted for the Earth’s-atmosphere related interval 200–400 K, the interval of theoretical validity 300–2000 K, and the full interval of interest 100–2000 K, showing an excellent applicability of the traditional one-power temperature law. Although the semi-classical treatment is not rigorously justified at low temperatures 100–300 K but seems to be the only feasible one, separate datasets are provided for this interval as well. As no clear experimental evidence exists neither for branch- nor for vibrational dependency of N<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>-broadening of CH<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>CN lines, the data computed for the rotational band can be used for other branches in other bands of vibrotational transitions.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116793"},"PeriodicalIF":3.0,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145003909","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":"A new method for density and temperature retrieval from Cassini/UVIS solar occultations at Saturn","authors":"P. Stephenson ,&nbsp;T.T. Koskinen ,&nbsp;J.I. Moses ,&nbsp;Z.L. Brown","doi":"10.1016/j.icarus.2025.116787","DOIUrl":"10.1016/j.icarus.2025.116787","url":null,"abstract":"<div><div>Ultraviolet solar occultations by Saturn probe the extent, temperature and density of the thermosphere. The Cassini Ultraviolet Imaging Spectrograph (UVIS) observed 24 solar occultations by Saturn between 2007 and 2013 in the extreme ultraviolet (EUV). We have developed a new methodology to retrieve temperature and density profiles from the solar occultations, providing calibration-independent <figure><img></figure> profiles. To demonstrate this methodology here, we present a case study on 17 Nov 2007 at a latitude of -47.5 °.Our motivation was to retrieve a robust H profile for comparison with Lyman <span><math><mi>α</mi></math></span> dayglow observations of this location and time, given the uncertainty in absolute brightness calibration at Lyman <span><math><mi>α</mi></math></span> wavelengths. We will apply this method to the remaining solar occultations in future work. With improved removal of background contamination compared to previous analyses, we retrieve H and H₂ densities as deep as the methane homopause level, simultaneously fitting the full available altitude and wavelength range in the EUV. This demonstrates the potential of solar occultations to constrain the density and temperature profiles in Saturn’s upper atmosphere and extend the coverage of other observations. We closely reproduce the observed transmission from 560<!--> <!-->Å to 1150<!--> <!-->Å, with substantial absorption by <figure><img></figure> including the fine structure of the H₂ band absorption cross sections above 804<!--> <!-->Å. We find a revised exospheric temperature of <span><math><mrow><mn>487</mn><mo>±</mo><mn>22</mn></mrow></math></span> <!--> <!-->K, a reduction from the <span><math><mrow><mn>526</mn><mo>±</mo><mn>11</mn></mrow></math></span> <!--> <!-->K previously retrieved, due to wider spectral coverage. The atomic H column density of <span><math><mrow><mn>2</mn><mo>.</mo><mn>82</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>2</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>16</mn></mrow></msup></mrow></math></span> <!--> <!-->cm⁻² above the methane homopause is consistent with column densities required to generate the Lyman-<span><math><mi>α</mi></math></span> emissions from Saturn’s disk, also observed with Cassini/UVIS. The atomic H column density and temperatures are also consistent with the Voyager Ultraviolet Spectrometer (UVS) solar occultations, but the column density exceeds photochemical model predictions by a factor of two. This may be driven by circulation or otherwise enhanced mixing near the homopause level.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"444 ","pages":"Article 116787"},"PeriodicalIF":3.0,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048155","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 history of Martian water during the Hesperian and Amazonian epochs","authors":"Bruce M. Jakosky ,&nbsp;Noora R. Alsaeed ,&nbsp;Eryn M. Cangi ,&nbsp;Michael S. Chaffin ,&nbsp;Justin Deighan ,&nbsp;Margaret E. Landis ,&nbsp;Michael T. Mellon ,&nbsp;Edward M.B. Thiemann","doi":"10.1016/j.icarus.2025.116782","DOIUrl":"10.1016/j.icarus.2025.116782","url":null,"abstract":"<div><div>Evidence points to there having been more surface and near-surface Martian water in the late Hesperian and early Amazonian than there is at present: (i) The measured enrichment in the D/H isotopic ratio suggests that the total amount of H₂O lost to space during the Amazonian was significant relative to the amount currently locked up in the polar and non-polar ice deposits, and that it was more than expected based on the current rate of loss to space. (ii) The Dorsa Argentea Formation (DAF), surrounding the South Polar Layered Deposits (SPLD) and having an area larger than the SPLD, is thought to be the remnant of a Hesperian-era polar cap that may have contained ∼20 m Global Equivalent Layer (GEL) or more of water that is not thought to be present in the DAF today. We explore the consequences of this greater surface water inventory, how it ties in with the exchange of water between the different non-atmospheric reservoirs and the loss of water to space from the Hesperian epoch up to the present. The combination of polar and atmospheric processes and the likelihood of the axial obliquity typically having been greater than today's 25.2° earlier in history would have resulted in more surface and near-surface water and therefore larger H₂O polar caps in the late Hesperian, enhanced atmospheric water content, and an enlargement of regions having stable ground ice so that global near-surface ice may have been the norm. In addition, the increased solar extreme ultraviolet (EUV) flux, solar flares, and coronal mass ejections (CMEs) during the earlier epochs would have enhanced loss of H and O to space above the current loss rate, so that much or all of the water from the DAF may have been lost to space. Coupling between solar processes, atmospheric and upper-atmospheric processes, and geological processes produces a self-consistent scenario for the evolution of water.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116782"},"PeriodicalIF":3.0,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996725","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":"Plumes emission from a fracture on a planetary surface using Smoothed Particle Hydrodynamics: The case of Enceladus","authors":"Matteo Teodori ,&nbsp;Luca Maggioni ,&nbsp;Gianfranco Magni ,&nbsp;Michelangelo Formisano ,&nbsp;Maria Cristina De Sanctis ,&nbsp;Francesca Altieri","doi":"10.1016/j.icarus.2025.116765","DOIUrl":"10.1016/j.icarus.2025.116765","url":null,"abstract":"<div><div>The emission of volatiles from the surface and subsurface of planetary bodies can provide fundamental knowledge concerning their formation, evolution, and structure. There are a variety of physical processes that shape the structural, kinematic and thermal behavior of the released material. We simulate Enceladus’ plumes outgassing from a surface fracture, characterizing their dynamical and thermal behavior by introducing an advanced numerical model, that adopts the Smoothed Particle Hydrodynamics (SPH) approach. We target and discuss the challenging implementation of several important microscopic phenomena that can alter the macroscopic properties of the simulated plume. Indeed, we consider the dynamical interaction with solid boundaries, the phase transitions, the solar radiation, the thermal interaction with Enceladus’ surface, the viscous drag coupling and the gravitational attraction. We run simulations with two values of the icy grains size, to explore the role of such parameter in the considered effects. The simulations results are consistent with the expected physical behavior and the observed properties of Enceladus’ plumes. We discuss the role of the processes in shaping the velocity, temperature, and density distributions for the vapor and ice components. We calculate the amount of mass loss from the surface fracture, obtaining values consistent with previous estimates. Similarly occurs for the ice deposition rate near the fracture, over the surface of Enceladus. The good agreement between our results and the current knowledge about Enceladus’ plumes supports the strength of an SPH based approach to study the emission of volatiles from the surface and subsurface of planetary objects. Such a model offers a unique tool in the investigation of the occurring phenomena, as well as for predicting and comparing with observations.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116765"},"PeriodicalIF":3.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144931643","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 perturbation theory approach to stability in the scattered disk","authors":"Matthew Belyakov,&nbsp;Konstantin Batygin","doi":"10.1016/j.icarus.2025.116773","DOIUrl":"10.1016/j.icarus.2025.116773","url":null,"abstract":"<div><div>Scattered disk objects (SDOs) are distant minor bodies that orbit the sun on highly eccentric orbits, frequently with perhelia near Neptune’s orbit. Gravitational perturbations due to Neptune frequently lead to chaotic dynamics, with the degree of chaotic diffusion set by an object’s perihelion distance. Batygin et al., (2021) developed a perturbative approach for scattered disk dynamics, finding that, to leading order in semi-major axis ratio, an infinite series of <span><math><mrow><mn>2</mn><mo>:</mo><mi>j</mi></mrow></math></span> resonances drives the dynamics of the distant scattered disk, with overlaps between resonances driving chaotic motion. In this work we extend this model by taking the spherical harmonic expansion for Neptune’s gravitational potential to octupole order and beyond. In continuing the expansion out to smaller semi-major axis limits, we find that the <span><math><mrow><mn>1</mn><mo>:</mo><mi>j</mi></mrow></math></span> and <span><math><mrow><mn>3</mn><mo>:</mo><mi>j</mi></mrow></math></span> resonances that emerge in the octupole expansion do not individually set new limits on the stability boundary. Instead, we find that for increasingly Neptune-proximate orbits, resonances of progressively higher index are dominant in explaining the emergence of chaotic behavior. In this picture, the mutual intersections between series of <span><math><mrow><mn>2</mn><mo>:</mo><mi>j</mi></mrow></math></span>, <span><math><mrow><mn>3</mn><mo>:</mo><mi>j</mi></mrow></math></span>, <span><math><mrow><mn>4</mn><mo>:</mo><mi>j</mi><mo>…</mo><mo>,</mo></mrow></math></span> resonant chains explain local chaotic evolution of SDOs and shape the dynamical distribution of the population at large.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116773"},"PeriodicalIF":3.0,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895780","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":"A deep learning-based two-stage feature matching method for small celestial body 3D shape reconstruction","authors":"Falin Wu ,&nbsp;Jingyao Yang ,&nbsp;Guoxin Qu ,&nbsp;Yushuang Liu ,&nbsp;Haoxin Li ,&nbsp;Yuting Cheng ,&nbsp;Dongjing Yang","doi":"10.1016/j.icarus.2025.116758","DOIUrl":"10.1016/j.icarus.2025.116758","url":null,"abstract":"<div><div>The exploration of small celestial bodies (SCBs) represents a critical frontier in deep space research. Given the weak gravitational fields characteristic of SCBs, the ‘touch-and-go’ approach has been widely adopted in recent missions. This method necessitates the development of high-resolution models of these celestial bodies. However, the significant photometric variations encountered in deep space pose substantial challenges for feature matching between images, thereby limiting the applicability of stereo photogrammetry (SPG) techniques for model construction. To address these challenges, this study proposes a novel stereo photogrammetry (SPG) method incorporating an efficient ‘two-stage’ feature matching algorithm designed to handle images with significant lighting variations. By leveraging deep learning networks and DBSCAN clustering for feature matching, the method achieves robust matching outcomes. Depth information is subsequently reconstructed using structure from motion (SfM) techniques, eliminating the need for external camera parameters. Furthermore, the proposed method enables the construction of a more accurate Bennu model, closely approximating Lidar-based models, while requiring fewer images.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116758"},"PeriodicalIF":3.0,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895779","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":"Preservation of organic traces of life under Martian conditions: Influence of the nature of the smectite in presence","authors":"I. Criouet ,&nbsp;S. Bernard ,&nbsp;E. Balan ,&nbsp;F. Baron ,&nbsp;A. Buch ,&nbsp;F. Skouri-Panet ,&nbsp;M. Guillaumet ,&nbsp;L. Delbes ,&nbsp;L. Remusat ,&nbsp;J.-C. Viennet","doi":"10.1016/j.icarus.2025.116789","DOIUrl":"10.1016/j.icarus.2025.116789","url":null,"abstract":"<div><div>Clay-rich Martian rocks are considered promising targets in the search for fossilized remains of ancient Martian life. However, the actual influence of the clay mineral compositions in preserving microbial biosignatures remains poorly understood. Here, we explore the biopreservation potential of three pure smectites typically found on Mars and containing Al in their tetrahedral sheets (i.e. a Mg-rich, a Fe-rich and a Al-rich smectite), relying on experiments run using <em>E. coli</em> as a biological analog to simulate hydrothermal alteration scenarios relevant to Mars. The results show that Mg-rich smectites (saponite) are more effective at preserving biomolecules from thermal degradation than Fe-rich and Al-rich smectites (nontronite and beidellite). Plus, in contrast to saponite, neither nontronite nor beidellite appears to significantly trap (and thus preserve) organic compounds within their interlayer spaces. Overall, the present study highlights that both the chemistry and the abundance of organic material in ancient Martian clay-rich rocks will depend on the compositional nature of smectites initially present.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116789"},"PeriodicalIF":3.0,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144917644","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":"Rotational Light Curve, phase, and visible colors of (52246) Donaldjohanson throughout Lucy Mission Flyby","authors":"A.C. Souza-Feliciano ,&nbsp;F.L. Rommel ,&nbsp;B.E. Morgado ,&nbsp;L.M. Catani","doi":"10.1016/j.icarus.2025.116771","DOIUrl":"10.1016/j.icarus.2025.116771","url":null,"abstract":"<div><div>The main belt asteroid (52246) Donaldjohanson was visited on April 20th of 2025 by the <em>Lucy</em> spacecraft. We took this opportunity to observe the object with the SOAR telescope, aiming to create synergy between ground- and space-based observations. Our goal includes refining the rotational period of (52246) <strong>Donaldjohanson</strong>, determining the rotational phase of the flyby observation, and obtaining the photometric colors of (52246) Donaldjohanson in the SDSS and <strong>Bessell–Johnson system</strong>. To achieve our goals, we used photometric observations of (52246) Donaldjohanson from three datasets: obtained in (i) <strong>during the week of Lucy flyby</strong> on the SOAR Telescope using <em>r-</em> and <em>i-</em> filters of the SDSS system in five different nights; (ii) <strong>August 2019, also on the</strong> SOAR Telescope using <em>R-</em> and <em>V-</em> filters of the Bessell–Johnson system <strong>on</strong> two nights; and (iii) between 2018 and 2025 on the <em>r-</em>, <em>g-</em>, and <em>i-</em> filters of the ZTF survey. Using the ZTF database and SOAR observations, the Lomb<strong>-</strong>Scargle periodogram confirms its long rotational period of 253.1 ± 2.6 h. The rotational light curve has an amplitude of 1.03 ± 0.03 mag, in agreement with an elongated asteroid. No signal of a secondary object is found in the residual fit <strong>at</strong> a limit of 0.2 mag. The colors <em>r</em> <span><math><mo>−</mo></math></span> <em>i</em> and <em>V</em> <span><math><mo>−</mo></math></span> <em>R</em> agree with a Cg-type asteroid for most of the phases analyzed. Some small variations in colors are found and they could be explained by some heterogeneity on Donaldjohanson’s surface. The angle between the spacecraft, Donaldjohanson, and the SOAR Telescope at the moment of the flyby was estimated to be 102 degrees. The results discussed here could serve as a reference and would support further analyses of the Lucy mission data. The comparison and combination of spacecraft and ground-based observations could allow the extension of the knowledge obtained here to an uncountable number of asteroids that will not have the opportunity to be visited by spacecraft.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116771"},"PeriodicalIF":3.0,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144931644","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 diagnostic power of surface heat flow measurements at Europa","authors":"Alyssa Rose Rhoden ,&nbsp;Matthew E. Walker ,&nbsp;Jianqing Feng ,&nbsp;Matthew A. Siegler ,&nbsp;Kathleen Craft","doi":"10.1016/j.icarus.2025.116785","DOIUrl":"10.1016/j.icarus.2025.116785","url":null,"abstract":"<div><div>Identifying ocean-bearing moons and characterizing the physical properties of their icy shells are critical investigations for the exploration of the outer solar system, with important implications for the geophysical evolution and potential habitability of the moons. However, the measurements needed to detect an ocean and constrain ice shell thickness can be challenging to obtain with remote sensing data collected from spacecraft, particularly through flybys. Recent work has shown that surface heat flow in an ocean-bearing moon may be sufficiently different from that of a frozen moon that measurements of surface heat flow could aid in ocean detection. Here, we move a step beyond previous work to investigate the extent to which measurements of surface heat flow can be used to constrain the ice shell thickness of a known ocean moon. We begin with a case study of Jupiter's moon, Europa, for which there is remote sensing data that can facilitate the investigation. We explore the behavior of a conductive ice shell with an Andrade rheology, compute location-dependent tidal heating rather than taking a global average, and utilize spacecraft measurements to account for spatially-variable surface temperatures. We also make the assumption that the ice shell is thermally stable over the timescales of human exploration. We find that patterns of surface heat flow can provide constraints on the thickness of an ice shell, and the relative contributions of basal heating and tidal heating, provided that the surface temperature is well-characterized. Hence, maps of surface temperature and heat flow from future missions would be valuable for detecting oceans and characterizing the physical properties of ice shells as well as preparing for sub-surface access missions for which knowledge of the ice shell environment is critical.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"443 ","pages":"Article 116785"},"PeriodicalIF":3.0,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892814","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}