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        <title>Frontiers in Astronomy and Space Sciences | Planetary Science section | New and Recent Articles</title>
        <link>https://www.frontiersin.org/journals/astronomy-and-space-sciences/sections/planetary-science</link>
        <description>RSS Feed for Planetary Science section in the Frontiers in Astronomy and Space Sciences journal | New and Recent Articles</description>
        <language>en-us</language>
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        <pubDate>2026-05-13T14:29:40.147+00:00</pubDate>
        <ttl>60</ttl>
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        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1742823</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1742823</link>
        <title><![CDATA[A giant solution to the disk mass budget problem of planet formation]]></title>
        <pubdate>2026-05-12T00:00:00Z</pubdate>
        <category>Brief Research Report</category>
        <author>Sofia Savvidou</author>
        <description><![CDATA[Understanding how dust evolves in protoplanetary disks is crucial to constraining the initial conditions of planet formation. The apparent “mass budget problem”, which stems from the comparison of the observed disk masses to the ones inferred for exoplanets, remains debated, as it is unclear whether the discrepancy arises from limitations in interpreting disk observations, from evolutionary processes that rapidly deplete dust, or from incorrect assumptions about the initial disk mass distribution. This work is built on the previously published population synthesis models by separating here the cumulative distribution functions of dust masses at different evolutionary stages into different populations according to the initial disk masses and embryo injection times. The best match to observations comes from disks with intermediate initial disk masses around 4%–7% M⊙. The largest discrepancy between the total dust mass in the models and the estimated through an “optically thin” approximation comes from the models that have the most favorable conditions for giant planet formation and thus contain a large fraction of giants and subsequently trapped “optically thick” dust mass because of the pressure bumps they generate. However, the final dust masses remain higher compared to the estimates from the observed evolved disks. Example cases in this work including planetesimal formation show that the pressure bumps that giant planets form can be prime locations for planetesimal formation and the conversion to planetesimals significantly decreases the dust mass, as expected. However, (giant) planet formation is not influenced showing that the mass in evolved protoplanetary disks can be estimated to be quite low but it can be a natural consequence of planetesimal and planet formation along with depletion due to radial drift.]]></description>
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        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1853179</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1853179</link>
        <title><![CDATA[Correction: Numerical integration and analysis of mars orbital dynamics]]></title>
        <pubdate>2026-05-06T00:00:00Z</pubdate>
        <category>Correction</category>
        <author>Shuhao Feng</author><author>Yilong Han</author><author>Shanhong Liu</author><author>Kai Tang</author><author>Jianguo Yan</author>
        <description></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1788224</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1788224</link>
        <title><![CDATA[Evaluation of lunar soil sampling disturbance based on penetration resistance method]]></title>
        <pubdate>2026-04-28T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Lan-Lan Xie</author><author>Qian Li</author><author>Ding-Kun Hu</author><author>Jia-Hang Lv</author>
        <description><![CDATA[IntroductionTo investigate the impact of surface sampling operations on the physical and mechanical properties of lunar soil—defined as the granular, sub-centimeter-sized fraction of the lunar regolith—and to mitigate design errors in sampling missions that arise from neglecting such disturbance, we conducted sampling disturbance experiments using the CUG-1A lunar soil simulant.MethodsThe degree of lunar soil disturbance was evaluated based on the change in penetration resistance of a standard probe inserted into the soil before and after sampling.ResultsThe experimental results indicate that the bucket width, sampling depth, sampling speed, and (for shovelling) the entry angle all significantly affect the disturbance degree.DiscussionThe shovelling action, a linear penetration-and-lift operation, predominantly induces a compaction effect on the lunar soil simulant. In contrast, the digging action, an arcuate scooping operation, causes compaction during the initial phase but generates a distinct loosening effect at the motion endpoint. The parameter combination that minimizes disturbance for the shovelling experiment is a bucket width of 4 cm, sampling depth of 2 cm, speed of 50 mm/s, and entry angle of 45°. For the digging experiment, the optimal combination is a bucket width of 4 cm, sampling depth of 3.5 cm, and speed of 50 mm/s.]]></description>
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        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1774478</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1774478</link>
        <title><![CDATA[Gaia DR3 supervised classification of asteroid reflectance spectra]]></title>
        <pubdate>2026-04-08T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Marco Delbo</author><author>Thomas Dyer</author><author>Ullas Bhat</author><author>Chrysa Avdellidou</author><author>Laurent Galluccio</author><author>Amelia Milton</author>
        <description><![CDATA[We present a supervised, probabilistic taxonomic classification of asteroid reflectance spectra from Gaia Data Release 3 (DR3). Using high-quality Gaia DR3 spectra and a reference set of spectra from the literature consisting exclusively of asteroids with robust spectroscopic taxonomic types, we construct a principal-component (PC) representation of the Gaia reflectances. For each major spectral complex (C, S, X) and several end-member classes (B, D, A, L, K, V), we model the distribution of reference objects in PC space using multivariate kernel density estimation (KDE). This yields likelihoods for each spectral class and provides a quantitative measure of classification confidence. Validation against a sample of objects with known spectral classes demonstrates good performance for classes with distinctive reflectance signatures, including the S-complex, D, V, and A types. Spectrally continuous classes (B-C-complex, K-L-S-complex, and X-complex) show the expected degrees of mixing given the limited wavelength range of Gaia’s spectrophotometry. We further explore the compositional structure of six major asteroid collisional families using our Gaia-derived spectral classes, finding excellent agreement with ground-based spectroscopy and revealing enhanced detections of olivine-rich A type material in the Flora and Eunomia families, as well as new insights into the spectral diversity of the Tirela family. The resulting catalogue constitutes a fully probabilistic taxonomic classification for the full Gaia DR3 asteroid sample. It offers a resource for studying the compositional structure of the main belt, identifying family interlopers, and linking asteroid populations to meteorite groups, and establishes a methodological framework for future Gaia releases, in particular for the validation of the Gaia DR4, expected by the end of 2026.]]></description>
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        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1765279</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1765279</link>
        <title><![CDATA[Numerical integration and analysis of mars orbital dynamics]]></title>
        <pubdate>2026-04-02T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Shuhao Feng</author><author>Yilong Han</author><author>Shanhong Liu</author><author>Kai Tang</author><author>Jianguo Yan</author>
        <description><![CDATA[IntroductionThe high-precision numerical ephemeris of Mars is important for its mission planning, spacecraft navigation, and solar system dynamics studies.MethodsThis study systematically compares the dynamical models employed in the DE441, EPM2021, INPOP21a, and PETREL19 ephemerides and evaluates the contributions of the principal perturbation forces to Mars orbit.ResultsOver a 30-year integration span, the effects of solar oblateness and the Lense-Thirring relativistic precession lead to the orbital difference on the order of hundreds of meters. Modeling the main asteroid belt as discrete point masses introduces deviations of about tens of kilometers, whereas the ring approximation of the main belt and the model for the Kuiper belt both contribute perturbations on the order of tens of meters. When Mars Express (MEX) ranging, ground-based radar, and VLBI data are combined and weighted based on their average precision, the RMS of orbital differences with respect to JPL/Horizons is on the order of hundreds of meters, whereas orbital deviations introduced by different ring model strategies range from several to tens of meters.DiscussionThe accuracy of Mars orbit determination is influenced by the precision and quantity of multi-source observations, as well as the strategies for ring model construction.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1764826</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1764826</link>
        <title><![CDATA[High-resolution accessibility and energy cost assessment of 31 priority permanently shadowed regions at the lunar south pole]]></title>
        <pubdate>2026-03-30T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Yihao Chen</author><author>Mao Ye</author><author>Denggao Qiu</author><author>Fei Li</author>
        <description><![CDATA[The permanently shadowed regions (PSRs) at the lunar south pole are primary targets for future robotic exploration and in situ resource utilization (ISRU). However, previous accessibility assessments utilizing coarse-resolution orbital data often mask decameter-scale hazards that are critical for surface mobility. In this study, we present a high-resolution accessibility analysis for 31 high-priority PSRs, integrating 5–20 m/pixel Digital Elevation Models (DEMs) with a terramechanics-based rover energy cost model. Using a slope-penalized path planning algorithm, we generated an ensemble of 600 optimal traverses per target to quantify geometric path lengths, slope constraints, and mechanical energy requirements. Our results reveal substantial heterogeneity in accessibility, with median path lengths ranging from ∼12 km to ∼50 km and minimum round-trip mechanical energy costs spanning an order of magnitude (from ∼0.4 kWh to ∼4.4 kWh). We demonstrate that geometric proximity does not equate to accessibility; in rugged terrain, safe corridors often require significant detours, rendering theoretical “shortest paths” impassable. Based on accessibility risks, we propose a three-tier prioritization framework: Tier I (e.g., UN11, UN10) offers robust, low-risk access suitable for initial reconnaissance; Tier II requires complex maneuvering through topographic choke points; and Tier III (e.g., Shackleton, Cabeus 2) imposes prohibitive mobility constraints necessitating advanced locomotion capabilities. This study highlights that relying on sub-10 m topography is mandatory for validating operational viability and suggests that “recharge-and-proceed” strategies are essential for deep PSR exploration.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1727532</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1727532</link>
        <title><![CDATA[Dust traps and gas kinematic signatures in a crescent structure of a planet-forming disk]]></title>
        <pubdate>2026-03-12T00:00:00Z</pubdate>
        <category>Brief Research Report</category>
        <author>Greta Guidi</author><author>François Menard</author><author>Daniel J. Price</author><author>Marion Villenave</author><author>Jie Ma</author>
        <description><![CDATA[In the past few years, ALMA unveiled a variety of substructures (rings, spirals, crescents) in the continuum emission of most protoplanetary disks imaged at high spatial resolution. While the majority of disks presents axisymmetric ring-like structures in the dust brightness distribution, some sources display asymmetric morphologies (blobs, crescents) that have been often associated to vortices and/or mechanisms generated by the presence of one or more embedded planets. In this brief research report we present the analysis of the arc structure observed in the dust continuum emission of the disk around HD 163296, using high resolution (∼8 au) matched continuum data from ALMA at four wavelengths. We characterize in detail the arc structures and present a kinematic signature observed in the CS(3–2) emission at the same location. Our results indicate that the crescent is caused by differential dust trapping in a local pressure maxima, for which plausible mechanisms can be the presence of a vortex or trapping in a Lagrangian point of the planet-star system.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1781996</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1781996</link>
        <title><![CDATA[Application of a modified commercial laser mass spectrometer as a science analog of the Mars Organic Molecule Analyzer (MOMA)]]></title>
        <pubdate>2026-03-10T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Zachary K. Garvin</author><author>Anaïs Roussel</author><author>Luoth Chou</author><author>Marco E. Castillo</author><author>Xiang Li</author><author>William B. Brinckerhoff</author><author>Sarah Stewart Johnson</author>
        <description><![CDATA[The ESA/NASA Rosalind Franklin rover, planned for launch in 2028, will carry the first laser desorption ionization mass spectrometer (LDI-MS) to Mars as part of the Mars Organic Molecule Analyzer (MOMA) instrument. MOMA will contribute to the astrobiology goals of the mission through the analysis of potential organic biosignatures. Due to minimal availability of comparable equipment, laboratory analyses using similar techniques and instrumentation have been limited. Until now, the Thermo LTQ-XL platform has been used as the main analog instrument by the MOMA team despite significant differences between the instruments. In this study, we present a series of modifications that bring this commercial benchtop LDI-MS closer to MOMA operating parameters, enabling rapid testing of samples for MOMA validation experiments. We demonstrate that our instrument can detect organic standards in mineral matrices, with MS/MS enabling structural identification even in complex mixtures. Performance was additionally validated against an existing LDI-MS prototype through the comparison of spectra derived from natural samples from a Mars analog site in the Atacama Desert. Lastly, analysis of Mars analog synthetic mineral mixes highlights the capacity of the instrument to characterize both the mineralogical and organic signals in mission-relevant samples. This modified benchtop instrument will serve as a platform for collaborative research to prepare for MOMA operations, test LDI parameters, and generate pre-flight reference data in support of the mission science and astrobiology specific goals.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1777086</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1777086</link>
        <title><![CDATA[Reassessing late-stage impact assumptions in light of modern planet formation paradigms]]></title>
        <pubdate>2026-02-19T00:00:00Z</pubdate>
        <category>Perspective</category>
        <author>Brian Turner</author>
        <description><![CDATA[In this Perspective, we examine the implications of modern cold-accretion and disk-mediated paradigms for two widely cited impact hypotheses: the Moon-forming giant impact and the Late Heavy Bombardment, with attention to consequences for planetary thermal histories and early habitability. Rather than seeking to invalidate these hypotheses, we aim to assess the extent to which their underlying assumptions remain compatible with evolving formation paradigms. Particular attention is given to the consequences for planetary thermal histories, crustal stability, volatile retention, and early habitability. We further outline observational and theoretical constraints that may help distinguish between competing formation–impact scenarios as planetary science continues to develop.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2026.1728292</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2026.1728292</link>
        <title><![CDATA[On the accuracy of mass and size measurements of young protoplanetary disks]]></title>
        <pubdate>2026-02-11T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Eduard I. Vorobyov</author><author>Aleksandr M. Skliarevskii</author><author>Vardan G. Elbakyan</author><author>Michael Dunham</author><author>Manuel Güdel</author>
        <description><![CDATA[Knowing the masses and sizes of protoplanetary disks is of fundamental importance for the contemporary theories of planet formation. However, their measurements are associated with large uncertainties. In this proof of concept study, we focus on the very early stages of disk evolution, concurrent with the formation of the protostellar seed, because it is then that the initial conditions for subsequent planet formation are likely established. Using three-dimensional hydrodynamic simulations of a protoplanetary disk followed by radiation transfer postprocessing, we constructed synthetic disk images at millimeter wavelengths. We then calculated the synthetic disk radii and masses using an algorithm that is often applied to observations of protoplanetary disks with ALMA, and compared the resulting values with the actual disk mass and size derived directly from hydrodynamic modeling. We paid specific attention to the effects of dust growth on the discrepancy between synthetic and intrinsic disk masses and radii. We find that the dust mass is likely underestimated in Band 6 by factors of 1.4–4.2 when Ossenkopf & Henning opacities and typical dust temperatures are used, but the discrepancy reduces in Band 3, where the dust mass can be even overestimated. Dust growth affects both disk mass and size estimates via the dust-size-dependent opacity, and extremely low values of dust temperature (≈ several Kelvin) are required to recover the intrinsic dust mass when dust has grown to mm-sized grains and its opacity has increased. Dust mass estimates are weakly sensitive to the distance to the source, while disk radii may be seriously affected. We conclude that the accuracy of measuring the dust mass and disk radius during the formation of a protoplanetary disk also depends on the progress in dust growth. The same disk, but observed at different stages of dust growth and with different linear resolutions, can have apparent radii that differ from the intrinsic value by up to a factor of two. Multi-wavelength observations that can help to constrain the maximum dust size would be useful when inferring the disk masses and sizes.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1712191</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1712191</link>
        <title><![CDATA[Planetary analog sites in the Indian subcontinent and the Indian Ocean: underexplored environments suited for astrobiological and space research]]></title>
        <pubdate>2026-02-06T00:00:00Z</pubdate>
        <category>Review</category>
        <author>Yamini Jangir</author><author>Subham Dutta</author>
        <description><![CDATA[Astrobiology seeks to understand the origin, evolution, distribution, and future of life in the Universe, focusing on habitability beyond Earth. Due to the high cost and complexity of space missions, studying planetary analog sites on Earth is essential for supporting and de-risking future exploration. These analog sites are extreme terrestrial environments that mirror environmental, geological, geochemical, or biological conditions on other planetary bodies. Investigating how life persists in these settings advances knowledge of extraterrestrial habitability and enables realistic testing of life-detection instruments. This review presents the first comprehensive synthesis of more than 50 planetary analog field sites across the Indian subcontinent and Indian Ocean region. We identify 2 geological regions with active astrobiological research, 4 requiring targeted geochemical and geomicrobiological surveys, and 5 with high planetary relevance but minimal study. We assess how these sites fill gaps in global astrobiological research and evaluate their readiness for future investigations. The sites include high-altitude cryospheric settings such as Himalayan glaciers and permafrost, analogues to Martian and lunar environments; saline-alkaline lakes like Sambhar Lake, comparable to Martian paleolakes; intrabasaltic bole beds in the Deccan Traps, relevant to phyllosilicate formation on Mars; subsurface caves and mines, analogous to lunar lava tubes; and hydrothermal vent systems along the Central and Southwest Indian Ridges, relevant to icy ocean worlds. Comparing these sites to global analogues reveals that, although most are not yet fully characterized, several offer unique environmental combinations. As deep-space missions prepare to search for life beyond Earth, a geographically broader set of analog sites is critical. Highlighting the diversity and scientific value of these under-characterized regions in South Asia and their marine periphery, this review provides a foundation for characterizing previously overlooked planetary analog sites. These sites expand the global analogue parameter space and offer underutilized natural laboratories for planetary habitability and biosignature research.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1706125</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1706125</link>
        <title><![CDATA[Augmenting sparse spaceflight mass spectra datasets for machine learning applications]]></title>
        <pubdate>2025-12-18T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Victoria Da Poian</author><author>Sarah M. Hörst</author><author>Eric I. Lyness</author><author>Xiang Li</author><author>Ryan M. Danell</author><author>William B. Brinckerhoff</author><author>Bethany P. Theiling</author>
        <description><![CDATA[Mass spectrometers are powerful instruments that aim to identify unknown compounds via their mass-to-charge ratio and perform quantitative and semi-quantitative analysis. These instruments have been essential to space missions over the past several decades (e.g., Pioneer Venus, Viking, Galileo, Cassini, Mars Science Laboratory) with several more en route (e.g., JUpiter ICy moons Explorer (JUICE), Europa Clipper) or under development (e.g., Rosalind Franklin, Dragonfly). However, future missions targeting remote planetary bodies increasingly face limited data transmission rates and volumes, which limit the amount of information that can be sent back to Earth. These challenges highlight the need for onboard science autonomy to optimize science return. Machine learning (ML) and data science tools can significantly contribute to the development of science autonomy by enabling rapid interpretation and prioritization of science data. Yet, these efforts for planetary science applications are hindered by the scarcity of representative datasets for training models, especially for complex flight instruments. In this work, we build on our earlier science autonomy work using the Mars Organic Molecule Analyzer (MOMA) instrument for the Rosalind Franklin (ExoMars) mission as a proof-of-concept. We investigate the generation of artificial mass spectra through “manual” augmentation techniques and evaluate their performance on mass spectrometer (MS) data using the laser desorption/ionization mass spectrometry (LDMS) mode of the flight-like MOMA engineering test unit (ETU). We implement basic transformation-based augmentation methods such as peak intensity randomization, peak shifting (by limited and realistic m/z values), etc. We assess their scientific integrity in collaboration with instrument experts and investigate how the inclusion of generated data affects the performance of ML algorithms for mass spectral analysis. We compare the performance of supervised learning models on predicting the chemical categories of new input mass spectra, both with and without augmented data, to evaluate the impact of these techniques. Our work provides guidelines for developing realistic augmented mass spectra without compromising scientific validity, while also contributing to the development of a mature framework for ML tools in MS data analysis, advancing science autonomy for existing and future planetary missions.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1696995</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1696995</link>
        <title><![CDATA[New insight into the composition of the lunar surface from SiO2 map]]></title>
        <pubdate>2025-11-14T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Wencong Chen</author><author>Denggao Qiu</author><author>Jianguo Yan</author><author>Sihai Yi</author>
        <description><![CDATA[The distribution of FeO and TiO2 reveals mantle source characteristics and basaltic diversity, whereas SiO2 distribution is closely related to magma evolution and crustal differentiation. However, global studies on SiO2 remain limited. To address this gap, we combined the latest lunar sample data, Kaguya Multiband Imager spectra, and Christiansen Feature to develop a One-Dimensional Convolutional Neural Network (1D-CNN) for mapping lunar SiO2. The results reveal a clear spatial asymmetry in SiO2: high-latitude regions on the nearside show higher SiO2, while low-latitude regions exhibit lower values. Mare Tranquillitatis and Oceanus Procellarum have low SiO2 but distinct TiO2 variations, indicating different basaltic types and magmatic sources. The highlands are dominated by ferroan anorthosite, whereas the maria mainly consist of mafic to ultramafic rocks. Incorporating Chang’E-6 samples and Christiansen Feature data improved model accuracy. Future work on silicic volcanic rocks will further refine the global SiO2 map and deepen understanding of lunar crustal evolution.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1668185</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1668185</link>
        <title><![CDATA[Re-evaluating Io’s volcanic heat flow: critical limitations in Juno/JIRAM M-band analysis]]></title>
        <pubdate>2025-11-05T00:00:00Z</pubdate>
        <category>Review</category>
        <author>Federico Tosi</author><author>Alessandro Mura</author><author>Francesca Zambon</author>
        <description><![CDATA[Understanding Io’s volcanic heat flow distribution is critical to constraining its internal structure and tidal heating mechanisms, including the debated presence of a global magma ocean. Recent analyses based on Juno/JIRAM M-band data suggest latitudinal variations in thermal emission consistent with magma ocean models. We critically assess these conclusions by addressing three key limitations in the JIRAM M-band dataset and its interpretation. First, we note that saturation effects in the JIRAM M-band imager detector, if not discussed and treated in detail, may systematically underestimate radiance from Io’s hot spots. Cross-calibration with JIRAM spectrometer data reveals non-linearity above certain values, which argues for double checking with spectrometer data whenever possible. Second, we show that using M-band integrated radiance as a direct proxy for total thermal emission is physically inconsistent without independent temperature constraints, as the spectral-to-total radiance ratio varies strongly with temperature. Reliance on M-band data alone introduces systematic biases in estimating total power outputs and spatial heat flow distributions. Third, rigorous statistical testing finds no robust correlation between latitude and spectral radiance density across multiple binning schemes. The observed latitudinal trends are highly sensitive to model-informed thresholds and dominated by a small number of bright hot spots, indicating insufficient empirical support for claimed polar heat flux asymmetries. Taken together, these findings caution against overinterpreting JIRAM M-band data in isolation and highlight the need for multi-wavelength, multi-instrument analyses with transparent data treatment to robustly constrain Io’s volcanic heat flow and internal heating models. We recommend future studies incorporate comprehensive spectral data and explicitly account for detector saturation and temperature effects to improve the physical reliability of volcanic power estimates on Io.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1666811</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1666811</link>
        <title><![CDATA[Parallels between subaqueous ridges on Earth and Mars: a new morphological potential indicator for paleolake assessment]]></title>
        <pubdate>2025-10-24T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Rebecca M. E. Williams</author><author>Rossman P. Irwin</author><author>Daniel C. Berman</author><author>Jonathon Hill</author>
        <description><![CDATA[Water levels in large lakes fluctuate in response to climatic cycles. Surface observations from rovers have validated past lakes on Mars, following multiple studies that inventoried candidate paleolake sites across the planet in satellite observations. Attempts to identify martian paleolake highstands, a key metric for constructing lake hydrographs, are hampered by few morphological indicators of water level discernible in orbital data. Construction of paleolake hydrographs, particularly in post-Noachian sites with preserved sedimentary deposits, holds tremendous promise for elucidating climate evolution on Mars. We examined image and elevation data at three topographic basins with established or candidate paleolakes. Drawing upon a terrestrial analog, we demonstrate that some depositional paleochannel ridges on Mars may have formed subaqueously in lakes. This new insight paves the way for future studies to use this landform in detailed lake hydrograph reconstructions.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1672283</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1672283</link>
        <title><![CDATA[Vertical damping of gravity waves evaluated from ACS-TGO solar occultation measurements on Mars]]></title>
        <pubdate>2025-09-10T00:00:00Z</pubdate>
        <category>Brief Research Report</category>
        <author>Ekaterina D. Starichenko</author><author>Alexander S. Medvedev</author><author>Denis A. Belyaev</author><author>Anna A. Fedorova</author><author>Alexander Trokhimovskiy</author><author>Paul Hartogh</author><author>Franck Montmessin</author><author>Oleg I. Korablev</author>
        <description><![CDATA[Amplitudes of gravity waves generated in the lower and denser atmospheric layers grow exponentially with height as they propagate to the upper and thinner atmosphere, where they are reduced by various processes. Their vertical decay is accompanied by a transfer of wave momentum and energy to the ambient flow, which represents a significant force in the upper atmosphere. Constraining the vertical damping and elucidating the related mechanisms are crucial for understanding the dynamics. Previous observations of gravity waves in the Martian thermosphere by different instruments provided evidence that amplitudes of relative temperature disturbances are inversely proportional to the mean temperature. This suggests that wave amplitudes may be limited by convective instabilities. However, this anticorrelation was not observed at all heights or in all measurements, sparking a discussion about the dominant mechanisms of wave damping. Using vertical temperature profiles collected by the Atmospheric Chemistry Suite instrument on board Trace Gas Orbiter over more than 6 years, we examined the statistical behavior of wave amplitudes and their vertical damping rates. We found a weak anticorrelation near the mesopause (∼90–140 km), suggesting the presence of convective instability and molecular diffusion mechanisms, but no robust correlations elsewhere. Instead, we found an unexpectedly persistent anticorrelation between the vertical decay rates and ambient temperature at all heights. We demonstrated that above approximately 80 km, wave breaking and/or saturation could be consistent with the convective instability mechanism, but the reason for this behavior at lower altitudes remains unclear.]]></description>
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        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1667857</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1667857</link>
        <title><![CDATA[Correction: Ion cyclotron waves: a tool for characterizing neutral particle profiles in extended exospheres]]></title>
        <pubdate>2025-09-03T00:00:00Z</pubdate>
        <category>Correction</category>
        <author>Helmut Lammer</author><author>Daniel Schmid</author><author>Martin Volwerk</author><author>Fabian Weichbold</author><author>Cyril Simon Wedlund</author><author>Ali Varsani</author><author>Magda Delva</author>
        <description></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1585683</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1585683</link>
        <title><![CDATA[Characterizing dynamical processes in surface-bound exospheres via resolved sodium D emissions]]></title>
        <pubdate>2025-08-26T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Patrick Lierle</author><author>Emma Lovett</author><author>Carl Schmidt</author><author>Aimee Merkel</author>
        <description><![CDATA[Two techniques to quantify the energy of an atmospheric gas remotely are the emission scale height and linewidth spectroscopy at high spectral resolution. In the latter, temperature, or effective temperature in the case of a collisionless exosphere, may be retrieved analytically for a single-component transition line, or by forward-modeling for transition lines with fine structure. Temperatures derived from linewidths and from scale heights need not necessarily agree, as each probes different characteristics. In fact, discrepancy between these quantities can actually reveal additional processes and the breakdown of implicit assumptions. Here, sodium D line profiles as a function of altitude are compared for the terrestrial exospheres of Mercury, the Moon, and Europa. At Mercury, effective temperature near the surface is 1,200–1500 K, consistent with MESSENGER scale heights. Away from the sub-solar point, gas linewidths are Doppler broadened, most notably down the comet-like escaping tail where effective temperatures reach >7500 K and line profiles become distinctly non-thermal in shape. We interpret this broadening as due to gravity removing the lowest energy atoms from the observed line-of-sight velocity distribution function. Growth in Doppler broadening ceases at the apex distance of ballistic bound atomic trajectories, effectively defining a boundary beyond which all gas escapes. Transitions from bound to escaping gas are expected to be universal in line profiles of planetary exospheres, and Mercury’s emissions are exemplar. Doppler broadening with altitude at the Moon and Europa cannot be attributed to this effect, however, and both offer important comparisons. Lunar sodium line profiles exhibit broadening on scales far too small for significant differences in the partitioning of bound and escaping gas, and instead superposed populations supplied by different source mechanisms may offer an explanation. Sodium linewidths at Europa continue to increase well beyond this satellite’s Hill sphere, an influence of their Keplerian motion around Jupiter. In each of these three cases, emission line morphology offers a novel diagnostic for evaluating the processes that promote atmospheric escape.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1633524</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1633524</link>
        <title><![CDATA[Modeling of non-thermal fractions formed in the extended hydrogen corona at Mars]]></title>
        <pubdate>2025-08-21T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Valery Shematovich</author><author>Dmitry Bisikalo</author>
        <description><![CDATA[Solar forcing on the upper atmospheres of terrestrial planets occurs through both the absorption of soft X-ray and extreme ultraviolet (XUV) solar radiation and the influx of solar wind plasma resulting in the formation of an extended neutral corona populated by suprathermal (hot) H, C, N and O atoms. Observations by the Imaging UV Spectrograph (IUVS) onboard of the Mars Atmosphere and Volatile EvolutioN (MAVEN) space mission at Mars confirmed the presence of an extended corona containing both thermal and suprathermal (formally with kinetic energies below 10 eV) fractions of hydrogen, carbon, and oxygen atoms. The solar wind influx also produces super-thermal atoms—energetic neutral atoms (ENAs; kinetic energies >10 eV)—via charge exchange between high-energy solar wind protons and coronal thermal neutrals. These ENAs transfer solar wind energy into the Martian neutral atmosphere. Notably, this charge-exchange process serves as an active aeronomic mechanism for generating supra- and super-thermal hydrogen populations in Mars’ extended corona and may act as a potential driver for similar phenomena on other planets. The spatial and energy distributions of both non-thermal atomic hydrogen populations in the Martian extended corona were computed using kinetic Monte Carlo models. These non-thermal H fractions must be considered when interpreting remote observations of planetary coronae. Our calculations reveal that non-thermal escape rates can reach ∼26% of the thermal escape rate during aphelion and solar minimum conditions. This finding has significant implications for Mars’ atmospheric evolution: while current escape rates are modulated by solar activity, the more active young Sun likely drove substantially higher non-thermal escape. This mechanism may have played a key role in Mars’ long-term water loss.]]></description>
      </item><item>
        <guid isPermaLink="true">https://www.frontiersin.org/articles/10.3389/fspas.2025.1608091</guid>
        <link>https://www.frontiersin.org/articles/10.3389/fspas.2025.1608091</link>
        <title><![CDATA[Automated classification of MESSENGER plasma observations via unsupervised transfer learning]]></title>
        <pubdate>2025-07-22T00:00:00Z</pubdate>
        <category>Original Research</category>
        <author>Vicki Toy-Edens</author><author>Wenli Mo</author><author>Robert C. Allen</author><author>Sarah K. Vines</author><author>Savvas Raptis</author>
        <description><![CDATA[Our methodology demonstrates a proof of concept of the applicability of transfer learning for heliophysics, a machine learning technique where knowledge learned from one task is reused to perform a similar unsupervised learning task with additional fine tuning. We applied an unsupervised clustering algorithm, initially trained on data from the Magnetospheric Multiscale (MMS) mission at Earth, to MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) observationsat Mercury to identify three distinct plasma regions: magnetosphere, magnetosheath, and solar wind. While our method requires modifications to the model from post-cleaning rules due to instrument effects, it allows for rapid classification using just a few examples to generate post-cleaning rules. Since there is no ground truth or standardized validation set to compare with, we compare our model’s result with published magnetopause and bow shock lists and find that the clustering algorithm is agreement with 67% of bow shock crossings and 74% of magnetopause crossings. These findings highlight the potential use of clustering algorithms across multiple planetary environments.]]></description>
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