Sazuna/UAT_keywords huggingface dataset:
Implications of Differentiated Late Accretion for the Volatile Inventory of the Bulk Silicate Earth. Earth is believed to have acquired its highly siderophile element (HSE) inventory through the late accretion of ∼0.3%–0.5% of its mass in chondrite-like materials, following the main stage of its growth. Late accretion, particularly if it originated from the outer solar system, could have significantly contributed to the bulk silicate Earth's (BSE = mantle + crust + hydrosphere + atmosphere) carbon–nitrogen–hydrogen (C–N–H) inventory. However, recent studies, noting differences between the HSE inventory of the Earth and Moon's mantle, suggest that relatively large lunar-sized differentiated impactors, rather than small chondritic projectiles, delivered HSEs to Earth's mantle during late accretion. The implications of a differentiated late accretion event for the BSE's C–N–H inventory remain unclear. In this study, we modeled the equilibrium partitioning of highly volatile C–N–H and moderately volatile sulfur–selenium–tellurium (S–Se–Te) between the atmosphere, magma ocean (MO), and core of lunar-sized or slightly larger impactors. The impactor's MO-degassed atmosphere contained most of its C–N–H inventory, whereas almost all of the S–Se–Te was present in its core or mantle. Given the low escape velocity of lunar-sized impactors, the MO-degassed atmosphere was likely dissipated quickly after core formation. As a result, in contrast to S–Se–Te, the contribution of differentiated late accretion to BSE's C–N–H inventory was limited, irrespective of its inner or outer solar system origin. The C–N–H-depleted nature of differentiated objects suggests that most of BSE's highly volatile inventory was delivered by primitive chondritic materials toward the final stages of Earth's accretion, before the Moon-forming event.

Keywords: Planetary system formation, Planetary science, Solar system formation, Earth (planet)
The Peregrine Ion Trap Mass Spectrometer (PITMS): Results from a CLPS-delivered Mass Spectrometer. The Peregrine Ion Trap Mass Spectrometer (PITMS) was a mass spectrometer designed to measure lunar gases. PITMS flew on the first flight of Astrobotic's Peregrine lander via the Commercial Lunar Payload Services (CLPS) program in 2024 January. After launch, the lander suffered a propulsion system anomaly that prevented the mission from reaching the Moon, but PITMS collected 80 high-quality spectra while in cislunar space. PITMS observed abundant outgassing products from the Peregrine lander, including water, MON-25 oxidizer from the propulsion system leak, and traces of combustion products. PITMS data help constrain the nature of the propulsion system failure: oxidizer molecular ratios show that the leak released molecules rapidly enough for them to fully dissociate, and the high observed abundances imply that the oxidizer traveled within the lander surfaces rather than jetting into space. The amount of water offgassed by the spacecraft is substantially more than other planetary spacecraft, so the PITMS results suggest that instruments flying in the CLPS paradigm need to consider lander cleanliness. Though not successful in measuring the native lunar exosphere, the PITMS results showcase the capabilities of a mass spectrometer on board a lunar lander, along with lessons in pragmatism and flexibility that would enable such an instrument to ultimately be successful in the CLPS initiative.

Keywords: Ion trapping, Mass spectrometry, Earth-moon system, Experimental techniques
Improved Constraints on the Vertical Profile of CH<SUB>4</SUB> at Jupiter's Mid- to High Latitudes, Using IRTF-TEXES and SOFIA-EXES Spectroscopy. We present radiative transfer analyses of IRTF-TEXES and SOFIA-EXES mid-infrared spectra of Jupiter's mid- to high latitudes recorded between 2019 April 16 and 2023 July 20. The spectra were inverted across a photochemical model grid of varying eddy diffusion coefficient profiles, and the quality of fit of the synthetic spectra to the observed was used to constrain the CH4 homopause level. For a subset of latitudes/dates, we find that the CH4 homopause level is elevated in the region enclosed inside of, or magnetospherically poleward of, the northern ultraviolet main auroral emissions (MAEs) in comparison to the region outside or equatorward of the MAE. For example, using SOFIA-EXES results on 2021 June 10, we derived a CH4 homopause level of log(pH(nbar)) = 1.54  or zH = 453  km above 1 bar poleward of the northern MAE at 68∘N compared to a lower limit of log(pH) &gt; 2.43 and upper limit of zH &lt; 322 km derived equatorward of the northern MAE. We therefore conclude that the region poleward of the northern MAE is, at times, subject to enhanced vertical transport resulting from auroral energy deposition. The exact mechanisms responsible for the enhanced vertical transport in Jupiter's auroral regions are uncertain: time-dependent circulation modeling of Jupiter's polar atmosphere is required to better understand this phenomenon. Poleward of the southern MAE, derived homopause levels agreed within uncertainty with those at equatorward locations. However, we consider this result a spatial sampling artifact rather than concluding that the southern auroral region is not subject to enhanced vertical transport.

Keywords: Space weather, Planetary atmospheres, Jupiter, Aurorae, Atmospheric composition, Atmospheric dynamics
Recent Tectonic Deformation of the Lunar Farside Mare and South Pole–Aitken Basin. The timing and scale of lunar tectonism provide a crucial insight into the geologic evolution of Earth's Moon. Within the nearside lunar maria, wrinkle ridges formed during and after the emplacement of the mare basalts as a result of subsidence-induced contraction. Past analyses of lunar wrinkle ridges and associated fault structures have helped to constrain lunar tectonic and thermal history. However, contractional tectonics in the lunar maria may not be limited to the formation of large-scale structures in the distant geologic past. In contrast to larger, subsidence-induced lunar wrinkle ridges, recent investigations have identified contractional structures within the nearside lunar maria that are dimensionally small and recently formed via a combination of global stresses. The identification of those small mare ridges (SMRs) demonstrated that the lunar nearside maria are subject to compressional stresses that are recently and potentially currently active, but the presence of such features in the lunar farside maria was never investigated. Furthermore, the exact timing of SMR formation and the geometry of the associated fault structures remain poorly constrained. Here, we present the first observations of widespread SMRs in the lunar farside maria and South Pole–Aitken Basin. We also derive absolute model age estimates for SMR formation, and we constrain SMR-forming fault geometries via elastic dislocation modeling. Our analysis provides the first globally complete perspective of recent lunar tectonics, and we show that lunar fault structures may be recently and potentially currently active within regions of interest for upcoming lunar missions.

Keywords: The Moon, Tectonics
A Survey of Cassini Images of Spokes in Saturn's Rings: Unusual Spoke Types and Seasonal Trends. Spokes are localized clouds of fine particles that appear over the outer part of Saturn's B ring. Over the course of the Cassini mission, the Imaging Science Subsystem obtained over 20,000 images of the outer B ring, providing the most comprehensive data set for quantifying spoke properties currently available. Consistent with prior work, we find that spokes typically appear as dark features when the lit side of the rings is viewed at low phase angles and as bright features when the rings are viewed at high phase angles or the dark side of the rings is observed. However, we also find examples of spokes on the dark side of the rings that transition between being brighter and darker than the background ring as they move around the planet. Most interestingly, we also identify spokes that appear to be darker than the background ring near their center and brighter than the background ring near their edges. These "mixed spokes" indicate that the particle size distribution can vary spatially within a spoke. In addition, we document seasonal variations in the overall spoke activity over the course of the Cassini mission using statistics derived from lit-side imaging sequences. These statistics demonstrate that while spokes can be detected over a wide range of solar elevation angles, spoke activity increases dramatically when the Sun is within 10° of the ring plane.

Keywords: Spokes, Saturn, Planetary rings
FindPOTATOs: Minor Planet Observation Linking Software. For minor planet observations to be archived and used by the scientific community, observations of individual objects must be linked together into groups called tracklets. This linking is nontrivial, as linking software must find real tracklets in noisy data within a reasonable amount of time. We describe FindPOTATOs, a linking software written in Python that can assemble minor planet tracklets. With the appropriate parameters, FindPOTATOs assembles tracklets for a variety of objects, including close-approaching near-Earth objects and trans-Neptunian objects. FindPOTATOs is ideal for processing data sets taken at small observatories, processing archival data, or finding tracklets of minor planets on unusual orbits. This paper describes the code structure, usage, and validation.

Keywords: Publicly available software, Near-Earth objects, Observational astronomy, Astronomy software, Main belt asteroids, Trans-Neptunian objects
An Automated Occultation Network for Gravitational Mapping of the Trans-Neptunian Solar System. We explore the potential of an array of   small fixed telescopes, aligned along a meridian and automated to measure millions of occultations of Gaia stars by minor planets, to constrain gravitational signatures from a "Planet X" mass in the outer solar system. The accuracy of center-of-mass tracking of occulters is limited by photon noise, uncertainties in asteroid shapes, and Gaia's astrometry of the occulted stars. Using both parametric calculations and survey simulations, we assess the total information obtainable from occultation measurements of main-belt asteroids (MBAs), Jovian Trojans, and trans-Neptunian objects (TNOs). We find that MBAs are the optimal target population due to their higher occultation rates and abundance of objects above Legacy Survey of Space and Time detection thresholds. A 10 yr survey of occultations by MBAs and Trojans using an array of 200 40 cm telescopes at 5 km separation would achieve 5σ sensitivity to the gravitational tidal field of a 5M⊕ Planet X at 800 au for &gt;90% of potential sky locations. This configuration corresponds to an initial cost of ≈$15 million. While the survey's sensitivity to tidal forces improves rapidly with increasing number of telescopes, sensitivity to a Planet X becomes limited by degeneracy with the uncertain masses of large moonless TNOs. The 200-telescope survey would additionally detect ≈1800 TNO occultations, providing detailed shape, size, and albedo information. It would also measure the Yarkovsky effect on many individual MBAs, measure masses of many asteroids involved in mutual gravitational deflections, and enable better searches for primordial black holes and departures from general relativity.

Keywords: Asteroids, Gravitation, Stellar occultation, Astrometry, Trans-Neptunian objects, Planetary dynamics
Investigating the Compositional Heterogeneity of Pure, Crystalline Plagioclase Exposures within the Moon's Anorthositic Crust Using Moon Mineralogy Mapper and Diviner Data. Questions about the formation of the primary anorthositic crust of the Moon remain unanswered. Spectroscopic surveys of the lunar crust have evidenced the presence of pure, crystalline plagioclase exposures (PCPEs) across the surface, which are assumed to be remnants of the Moon's ancient anorthositic crust. Results from our work show that the plagioclase composition within PCPEs in all geochemical terranes is relatively uniform and consistent with highly calcic anorthite found in immature and mature Apollo highlands regolith samples. Observed variations in our spectroscopic data sets are likely related to maturity, not plagioclase composition, supporting a single crust-forming event rather than serial magmatism. To constrain the plagioclase composition within the primary anorthositic crust, we use remote sensing data from two instruments on board different lunar orbiters, Moon Mineralogy Mapper (M3) and Diviner Lunar Radiometer (Diviner). When working with data sets acquired by different instruments, coregistration is key if one wants to extract values from those instruments at the same point on the lunar surface. Due to the suboptimal selenolocation of the M3 observations, misalignments exist between the M3 data and Diviner data sets. Here we present a methodology for extracting both data sets from a single locality while mitigating offsets, and provide results about the composition of the primary anorthositic crust. M3 was used to identify regions of interest within previously reported PCPEs at a selection of craters, and Diviner Christiansen feature data was utilized to constrain these locations' plagioclase composition by comparing them against laboratory measurements of Apollo 16 highland soil samples.

Keywords: Spectroscopy
Profiling Near-surface Winds on Mars Using Attitude Data from Mars 2020 Ingenuity. We used attitude data from the Mars Ingenuity helicopter with a simple steady-state model to estimate wind speeds and directions at altitudes between 3 and 24 m, the first time winds at such altitudes have been probed on Mars. We compared our estimates to wind data from the meteorology package MEDA on board the Mars 2020 Perseverance rover and to predictions from meteorological models. Wind directions inferred from Ingenuity data agreed with the directions measured by MEDA, when the latter were available, but deviated from model-predicted directions by as much as 180° in some cases. The inferred wind speeds are often much higher than expected. For example, meteorological predictions suggest that Ingenuity should not have seen wind speeds above about 15 m s‑1 during its 59th flight, but we inferred speeds reaching nearly 25 m s‑1. For flights during which we have MEDA data to compare to, inferred wind speeds imply friction velocities &gt;1 m s‑1 and roughness lengths &gt;10 cm, which seem implausibly large. These results suggest that Ingenuity was probing winds sensitive to aerodynamic conditions hundreds of meters upwind instead of the conditions very near Mars 2020, but they may also reflect a need for updated boundary layer wind models. An improved model for Ingenuity's aerodynamic response that includes the effects of transient winds may also modify our results. In any case, the work here provides a foundation for exploration of planetary boundary layers using drones and suggests important future avenues for research and development.

Keywords: Mars, Planetary atmospheres
JWST Near-infrared Spectroscopy of High-albedo Jupiter Trojans: A New Surface Type in the Trojan Belt. We present 0.8–5 μm JWST spectra of four ~20 km diameter Jupiter Trojans known to have albedos elevated above the values typical in the remaining Trojan population. The spectra of these four high-albedo Jupiter Trojans are all similar, with red slopes in the optical–IR transition region, a break to lower slopes at 1.3 μm, and a broad absorptions from 2.8 to 4 μm. The 0.8–2.5 μm spectra of these objects match the spectra of neither the well-known "red" and "less-red" Jupiter Trojans nor of any known asteroid taxonomic class. The reflectivity of these objects does not rise redward of 4 μm, a property that is seen in the previous JWST observations of Jupiter Trojans only in Polymele. Indeed, the high-albedo Jupiter Trojan spectra are a good match to that of Polymele, and Polymele is both the smallest Jupiter Trojan in the previous JWST sample and has the highest albedo of the objects in that sample. We conclude that Polymele and the other high-albedo Jupiter Trojans represent a third class of Jupiter Trojans not represented in the more heavily studied larger objects and are perhaps the products of recent disruptions. The Lucy flyby of Polymele in 2027 September will give a direct view of one of this new class of Jupiter Trojans.

Keywords: James Webb Space Telescope, Jupiter trojans, Infrared spectroscopy
Impact of Jupiter's Heating and Self-shadowing on the Jovian Circumplanetary Disk Structure. Deciphering the structure of the circumplanetary disk (CPD) that surrounded Jupiter at the end of its formation is key to understanding how the Galilean moons formed. Three-dimensional hydrodynamic simulations have shown that this disk was optically thick and significantly heated to very high temperatures owing to the intense radiation emitted by the hot, young planet. Analyzing the impact of Jupiter's radiative heating and shadowing on the structure of the CPD can provide valuable insights into the conditions that shaped the formation of the Galilean moons. To assess the impact of Jupiter's radiative heating and shadowing, we have developed a two-dimensional quasi-stationary CPD model and used a gray atmosphere radiative transfer method to determine the thermal structure of the disk. We find that the CPD self-shadowing has a significant effect, with a temperature drop of approximately 100 K in the shadowed zone compared to the surrounding areas. This shadowed zone, located around 10 Jupiter radii, can act as a cold trap for volatile species such as NH3, CO2, and H2S. The existence of these shadows in Jupiter's CPD may have influenced the composition of the building blocks of the Galilean moons, potentially shaping their formation and characteristics. Our study suggests that the thermal structure of Jupiter's CPD, particularly the presence of cold traps due to self-shadowing, may have played a crucial role in the formation and composition of the Galilean moons.

Keywords: Planetary system formation, Galilean satellites, Natural satellites (Solar system), Natural satellite formation
The Interplay of Surface Composition, Mineralogy, and Physical Conditions That Affect the Surface Release Processes and Particle Environment of Mercury. Mercury has a very tenuous atmosphere starting at the surface, which is referred to as a surface-bound exosphere, where there are no collisions between exospheric particles. Having a surface-bound exosphere means that the particles in the exosphere have their origin on Mercury's surface; thus, the composition of the exosphere is connected to the composition of the surface. In situ composition measurements of the exosphere can contribute to the study of the composition of the surface, together with a range of remote sensing techniques (ultraviolet, visible, infrared, X-ray, gamma-ray, and neutron spectroscopy). The external drivers for the particle release from the surface are solar photons, solar wind plasma, and micrometeoroid impacts. These drivers also cause space weathering of the surface, resulting in significant physical and chemical alterations in the regolith, ranging from the very surface to depths up to one meter. Modifications of the surface by space weathering must be considered when interpreting the composition measurements of the exosphere as well as the composition measurements of the surface by the established remote sensing techniques, because their information comes from the space-weathered volume of the surface. Therefore, the particle populations in the exosphere, space weathering, and the composition of the surface are intimately connected and must be studied together. In the following, we will review the connections between the surface and the exosphere of Mercury.

Keywords: Planetary atmospheres, Planetary science
History and Habitability of the LP 890-9 Planetary System. We present numerous aspects of the evolution of the LP 890-9 (SPECULOOS-2/TOI-4306) planetary system, focusing on the likelihood that planet c can support life. We find that the host star reaches the main sequence in 1 Gyr and that planet c lies close to the inner boundary of the habitable zone. We find the magma ocean stage can last up to 50 Myr, remove eight Earth oceans of water, and leave up to 2000 bars of oxygen in the atmosphere. However, if the planet forms with a hydrogen envelope as small as 0.1 Earth masses, no water will be lost during the star's pre-main-sequence phase from thermal escape processes. We find that the planets are unlikely to be in a 3:1 mean motion resonance and that both planets tidally circularize within 0.5 Gyr when tidal dissipation is held constant. However, if tidal dissipation is a function of mantle temperature and rheology, then we find that planet c's orbit may require more than 7 Gyr to circularize, during which time tidal heating may reach hundreds of terawatts. We thus conclude that the habitability of planet c depends most strongly on the initial volatile content and internal properties, but no data yet preclude the viability of an active biosphere on the planet.

Keywords: Exoplanets
Cross Validation of Albedo Determination for 1627 Ivar from Three Different Techniques. Near-Earth asteroids are of great interest to the scientific community due to their proximity to Earth, making them both potential hazards and possible targets for future missions, as they are relatively easy to reach by spacecraft. A number of techniques and models can be used to constrain their physical parameters and build a comprehensive assessment of these objects. In this work, we compare physical property results obtained from improved HV absolute magnitude values, thermophysical modeling, and polarimetry data for the well-known Amor-class NEO 1627 Ivar. We show that our fits for albedo are consistent with each other, thus demonstrating the validity of this cross-referencing approach, and propose a value for Ivar's albedo of  . Future observations will extend this work to a larger sample size, increasing the reliability of polarimetry for rapid asteroid property characterization as a technique independent of previously established methods and requiring significantly fewer observations.

Keywords: Albedo, Polarimetry, Asteroids
Interior and Gravity Field Models for Uranus Suggest a Mixed-composition Interior: Implications for the Uranus Orbiter and Probe. The interior composition and structure of Uranus are ambiguous. It is unclear whether Uranus is composed of fully differentiated layers dominated by an icy mantle or has smooth compositional gradients. The Uranus Orbiter and Probe (UOP), the next NASA flagship mission prioritized by the Planetary Science and Astrobiology Survey 2023–2032, will constrain the planet's interior by measuring its gravity and magnetic fields. To characterize the Uranian interior, here we present CORGI, a newly developed planetary interior and gravity model. We confirm that high degrees of mixing are required for Uranus interior models to be consistent with the J2 and J4 gravity harmonics measured by Voyager 2. Empirical models, which have smooth density profiles that require extensive mixing, can reproduce the Voyager 2 measurements. Distinct-layer models with mantles composed of H2O–H/He or H2O–CH4–NH3 mixtures are consistent with the Voyager 2 measurements if the heavy element mass fraction, Z, in the mantle ≲85%, or if atmospheric Z ≳ 25%. Our gravity harmonics model shows that UOP J2 and J4 measurements can distinguish between high (Z ≥ 25%) and low (Z = 12.5%) atmospheric metallicity scenarios. The UOP can robustly constrain J6 and potentially J8 given polar orbits within rings. An ice-rich composition can naturally explain the source of Uranus's magnetic field. However, because the physical properties of rock–ice mixtures are poorly known, magnetic field generation by a rock-rich composition cannot be ruled out. Future experiments and simulations on realistic planetary building materials will be essential for refining Uranus interior models.

Keywords: Uranus, Planetary interior, Solar system planets