Sazuna/UAT_keywords huggingface dataset:
The Vulcan Mission to Io: Lessons Learned during the 2022 JPL Planetary Science Summer School. A mission to Jupiter's moon Io, the most volcanically active body in the solar system, was suggested as a priority for the New Frontiers program in the 2013 Planetary Science Decadal Survey. We present a New Frontiers–class mission concept, Vulcan, that was designed as an educational exercise through the Jet Propulsion Laboratory's 2022 Planetary Science Summer School. Vulcan would leverage an instrument suite consisting of wide- and narrow-angle cameras, a thermal infrared spectrometer, two fluxgate magnetometers, and ion and electron electrostatic analyzers to conduct the most thorough investigation of Io to date. Using 78 flybys over a 2 yr primary science mission, Vulcan would characterize the effects of tidal forces on the differentiation state, crustal structure, and volcanism of Io and investigate potential interactions between Io's volcanoes, surface features, and atmosphere. Although Vulcan was developed as an academic exercise, we show that a New Frontiers–class mission to Io could achieve transformative science in both geophysics and plasma physics, unifying typically disparate subfields of planetary science. A dedicated mission to Io, in combination with the Europa Clipper and Jupiter Icy Moons Explorer missions, would address fundamental questions raised by the 2023 Planetary Science Decadal Survey and could complete our understanding of the spectrum of planetary habitability. Lessons learned from Vulcan could be applied to a New Frontiers 5 Io mission concept in the near future.

Keywords: Space probes, Planetary probes, Planetary geology, Tidal interaction, Io, Galilean satellites
The Discovery and Evolution of a Possible New Epoch of Cometary Activity by the Centaur (2060) Chiron. Centaurs are small solar system objects on chaotic orbits in the giant planet region, forming an evolutionary continuum with the Kuiper Belt objects and Jupiter-family comets. Some Centaurs are known to exhibit cometary activity, though unlike comets, this activity tends not to correlate with heliocentric distance, and the mechanism behind it is currently poorly understood. We utilize serendipitous observations from the Asteroid Terrestrial-impact Last Alert System, Zwicky Transient Facility, Panoramic Survey Telescope and Rapid Response System, Dark Energy Survey, and Gaia in addition to targeted follow-up observations from the Las Cumbres Observatory, TRAnsiting Planets and PlanetesImals Small Telescope South (TRAPPIST-South), and Gemini North telescope to analyze an unexpected brightening exhibited by the known active Centaur (2060) Chiron in 2021. This is highly indicative of a cometary outburst. As of 2023 February, Chiron had still not returned to its prebrightening magnitude. We find Chiron's rotational lightcurve, phase curve effects, and possible high-albedo surface features to be unlikely causes of this observed brightening. We consider the most likely cause to be an epoch of either new or increased cometary activity, though we cannot rule out a possible contribution from Chiron's reported ring system, such as a collision of as-yet-unseen satellites shepherding the rings. We find no evidence for a coma in our Gemini or TRAPPIST-South observations, though this does not preclude the possibility that Chiron is exhibiting a coma that is too faint for observation or constrained to the immediate vicinity of the nucleus.

Keywords: Phase angle, Centaur group, Comae, Wide-field telescopes, Small Solar System bodies, Broad band photometry, Solar system astronomy
BYORP and Dissipation in Binary Asteroids: Lessons from DART. The near-Earth binary asteroid Didymos was the target of the planetary defense demonstration mission DART in 2022 September. The smaller binary component, Dimorphos, was impacted by the spacecraft in order to measure momentum transfer in kinetic impacts into rubble piles. DART and associated Earth-based observation campaigns have provided a wealth of scientific data on the Didymos–Dimorphos binary. DART revealed the largely oblate and ellipsoidal shape of Dimorphos before the impact, while the postimpact observations suggest that Dimorphos now has a prolate shape. Here we add those data points to the known properties of small binary asteroids and propose new paradigms of the radiative binary Yarkovsky–O'Keefe–Radzievskii–Paddack (BYORP) effect as well as tidal dissipation in small binaries. We find that relatively spheroidal bodies like Dimorphos made of small debris may experience a weaker and more size-dependent BYORP effect than previously thought. This could explain the observed values of period drift in several well-characterized binaries. We also propose that energy dissipation in small binaries is dominated by relatively brief episodes of large-scale movement of (likely surface) materials, rather than long-term steady-state tidal dissipation. We propose that one such episode was triggered on Dimorphos by the DART impact. Depending on the longevity of this high-dissipation regime, it is possible that Dimorphos will be more dynamically relaxed in time for the Hera mission than it was in the weeks following the impact.

Keywords: Asteroid satellites, Asteroid dynamics, Tidal friction
Mapping "Brain Terrain" Regions on Mars Using Deep Learning. One of the main objectives of the Mars Exploration Program is to search for evidence of past or current life on the planet. To achieve this, Mars exploration has been focusing on regions that may have liquid or frozen water. A set of critical areas may have seen cycles of ice thawing in the relatively recent past in response to periodic changes in the obliquity of Mars. In this work, we use convolutional neural networks to detect surface regions containing "brain terrain," a landform on Mars whose similarity in morphology and scale to sorted stone circles on Earth suggests that it may have formed as a consequence of freeze/thaw cycles. We use large images (∼100–1000 megapixels) from the Mars Reconnaissance Orbiter to search for these landforms at resolutions close to a few tens of centimeters per pixel (∼25–50 cm). Over 58,000 images (∼28 TB) were searched (∼5% of the Martian surface), and we found detections in 201 images. To expedite the processing, we leverage a classifier network (prior to segmentation) in the Fourier domain that can take advantage of JPEG compression by leveraging blocks of coefficients from a discrete cosine transform in lieu of decoding the entire image at the full spatial resolution. The hybrid pipeline approach maintains ∼93% accuracy while cutting down on ∼95% of the total processing time compared to running the segmentation network at the full resolution on every image.

Keywords: Mars, Planetary surfaces, Remote sensing
Lethal Surface Ozone Concentrations Are Possible on Habitable Zone Exoplanets. Ozone (O3) is important for the survival of life on Earth because it shields the surface from ionizing ultraviolet radiation. However, the existence of O3 in Earth's atmosphere is not always beneficial. Resulting from anthropogenic activity, O3 exists as a biologically harmful pollutant at the surface when it forms in the presence of sunlight and other pollutants. As a strong oxidizer, O3 can be lethal to several different organisms; thus, when assessing the potential habitability of an exoplanet, a key part is determining whether toxic gases could be present at its surface. Using the Whole Atmosphere Community Climate Model version 6 (WACCM6; a three-dimensional chemistry-climate model), 12 atmospheric simulations of the terrestrial exoplanet TRAPPIST-1 e are performed with a variety of O2 concentrations and assuming two different stellar spectra proposed in the literature. Four atmospheric simulations of the exoplanet Proxima Centauri b are also included. Some scenarios for both exoplanets exhibit time-averaged surface O3 mixing ratios exceeding harmful levels of 40 ppbv, with 2120 ppbv the maximum concentration found in the cases simulated. These concentrations are toxic and can be fatal to most life on Earth. In other scenarios O3 remains under harmful limits over a significant fraction of the surface, despite there being present regions that may prove inhospitable. In the case in which O3 is detected in a terrestrial exoplanet's atmosphere, determining the surface concentration is an important step when evaluating a planet's habitability.

Keywords: Exoplanet atmospheric composition , Exoplanet atmospheres, Habitable planets, Exoplanets
Nitrogen Loss from Pluto's Birth to the Present Day via Atmospheric Escape, Photochemical Destruction, and Impact Erosion. We estimate the loss of nitrogen from Pluto over its lifetime, including the giant planet instability period, which we term the "Wild Years." We analyze the orbital migration of 53 simulated Plutinos, which are Kuiper Belt Objects (KBOs) captured into 3:2 mean-motion resonance with Neptune during the instability. This orbital migration brought the Plutinos from 20 to 30 au to their present-day orbits near 40 au along a nonlinear path that includes orbits with semimajor axes from 10 to 100 au. We model the thermal history that results from this migration and estimate the volatile loss rates due to the ever-changing thermal environment. Due to the early Sun's enhanced ultraviolet radiation, the photochemical destruction rate during the Wild Years was a factor of 100 higher than the present-day rate, but this only results in a loss of ∼10 m global equivalent layer (GEL). The enhanced Jeans escape rate varies wildly with time, and a net loss of ∼100 cm GEL is predicted. Additionally, we model the impact history during the migration and find that impacts are a net source, not loss, of N2, contributing ∼100 cm GEL. The 100 cm GEL is 0.1% of the amount of N2 in Sputnik Planitia. We therefore conclude that Pluto did not lose an excessive amount of volatiles during the Wild Years, and its primordial volatile inventory can be approximated as its present-day inventory. However, significant fractions of this small total loss of N2 occurred during the Wild Years, so estimates made using present-day rates will be underestimates.

Keywords: Atmospheric evolution, Planetary atmospheres, Pluto, Planetary migration, Plutinos
Water Generation on the Moon from Solar Wind and Meteoroid Impacts. The kinetics of water formation on the lunar surface from impact-driven melts (IM) of meteoroids and recombinative desorption (RD) of solar-wind-implanted regolith grains is assessed. The ratio of water generated from RD:IM is ultimately controlled by the diffusion constant of the implanted defects. Higher diffusion activation energies of hydroxyls (-OH) result in more trapping of the implanted defects and, consequently, higher water production from IM versus RD. At diffusion activation energies &gt;1 eV, water production from RD is negligible and IM is the dominant channel. Our results suggest that RD can be associated with the observed latitude and diurnal dependence but RD and/or micrometeorite IM are not major contributors to the water ice observed within the permanently shadowed regions (PSRs). This suggests that volcanic and/or delivery via large impactors are the more likely major sources of water on the Moon. However, our model generally agrees with the observed latitudinal dependence of the inferred OH/H2O and the overall diurnal trend from orbital observations in the infrared. In addition, our results also suggest that micrometeorites are responsible for the high content of molecular water in the glass of regolith grains.

Keywords: The Moon, Lunar science, Lunar impacts, Lunar surface, Lunar atmosphere
Comparing Rover and Helicopter Planetary Mission Architectures in a Mars Analog Setting in Iceland. The Rover–Aerial Vehicle Exploration Network project field-tested planetary mission operations within a Mars analog environment in Iceland using stand-alone rover and helicopter architectures. Mission planning, implementation, and results are reported for the rover mission and briefly summarized for the helicopter mission. The outcomes of both missions are subsequently compared. Field implementation occurred from 2022 July to August at the Holuhraun lava flow. The rover science operations team executed a 14 sol (Martian day) mission that achieved mission, science, and sampling goals, including the contextualization, acquisition, and planned caching of two eolian and two rock samples. The helicopter science operations team executed a plan of comparable length but emphasized different science goals given long-range flight capabilities and landing limitations. The resolution and targetability of the rover payload enabled more detailed analyses, whereas the helicopter was better able to map flow-scale morphologies. The rover's exploration was limited by daily mobility duration limits and hazardous terrain, whereas the helicopter's exploration was constrained by landing site hazards. Resource limitations resulted from lengthier rover drives and data-volume-intensive helicopter imaging surveys. Future missions using combined rover–helicopter architectures should account for each spacecraft's resource needs and acknowledge system strengths in different geologic settings. Both missions served to establish operations strategies and mission outcomes to be applied to future combined rover and helicopter mission architectures, while the helicopter mission also evaluated strategies and outcomes for future stand-alone airborne missions. Findings in this work are relevant to future missions seeking to optimize strategies for planetary mission operations.

Keywords: Rovers, Mars
Insights on the Formation Conditions of Uranus and Neptune from Their Deep Elemental Compositions. This study, placed in the context of the preparation for the Uranus Orbiter Probe mission, aims to predict the bulk volatile compositions of Uranus and Neptune. Using a protoplanetary disk model, it examines the evolution of trace species through vapor and solid transport as dust and pebbles. Due to the high carbon abundance found in their envelopes, the two planets are postulated to have formed at the carbon monoxide ice line within the protosolar nebula. The time evolution of the abundances of the major volatile species at the location of the CO ice line is then calculated to derive the abundance ratios of the corresponding key elements, including the heavy noble gases, in the feeding zones of Uranus and Neptune. Supersolar metallicity in their envelopes likely results from accreting solids in these zones. Two types of solids are considered: pure condensates (Case 1) and a mixture of pure condensates and clathrates (Case 2). The model, calibrated to observed carbon enrichments, predicts deep compositions. In Case 1, argon is deeply depleted, while nitrogen, oxygen, krypton, phosphorus, sulfur, and xenon are significantly enriched relative to their protosolar abundances in the two planets. Case 2 predicts significant enrichments for all species, including argon, relative to their protosolar abundances. Consequently, Case 1 predicts near-zero Ar/Kr or Ar/Xe ratios, while Case 2 suggests that these ratios are 0.1 and 0.5–1 times their protosolar ratios, respectively. Both cases predict a bulk sulfur-to-nitrogen ratio consistent with atmospheric measurements.

Keywords: Neptune, Solid matter physics, Planetary atmospheres, Protoplanetary disks, Exoplanet formation, Uranus
Multiple Overspill Flood Channels from Young Craters Require Surface Melting and Hundreds of Meters of Midlatitude Ice Late in Mars's History. Mars's tadpole craters are small, young craters whose crater rims are incised by one or more exit breaches but lack visible inlets. The tadpole-forming climate records the poorly understood drying of Mars since the Early Hesperian. A third of tadpole craters have multiple breaches; therefore, the climate must have been able to generate crater rim incision in multiple locations. We use HiRISE data for four multiple-breach tadpole craters to measure their crater fill, rims, and exit breaches. We compare these measurements and other data with our calculations of liquid water supply by rain, surface melting, groundwater discharge, and basal ice sheet melting to discriminate between four proposed formation hypotheses for tadpole breaches, favoring scenarios with ice-filled craters and supraglacial melting. We conclude that multiple-breach tadpole craters record hundreds of meters of midlatitude ice and climate conditions enabling intermittent melting in the Late Hesperian and Amazonian, suggesting that liquid water on Mars has only been available in association with water ice for billions of years.

Keywords: Surface processes, Mars, Planetary surfaces, Planetary geology
The CUISINES Framework for Conducting Exoplanet Model Intercomparison Projects, Version 1.0. As JWST begins to return observations, it is more important than ever that exoplanet climate models can consistently and correctly predict the observability of exoplanets, retrieval of their data, and interpretation of planetary environments from that data. Model intercomparisons play a crucial role in this context, especially now when few data are available to validate model predictions. The CUISINES Working Group of NASA's Nexus for Exoplanet Systems Science supports a systematic approach to evaluating the performance of exoplanet models and provides here a framework for conducting community-organized exoplanet model intercomparison projects (exoMIPs). The CUISINES framework adapts Earth climate community practices specifically for the needs of the exoplanet researchers, encompassing a range of model types, planetary targets, and parameter space studies. It is intended to help researchers to work collectively, equitably, and openly toward common goals. The CUISINES framework rests on five principles: (1) define in advance what research question(s) the exoMIP is intended to address, (2) create an experimental design that maximizes community participation and advertise it widely, (3) plan a project timeline that allows all exoMIP members to participate fully, (4) generate data products from model output for direct comparison to observations, and (5) create a data management plan that is workable in the present and scalable for the future. Within the first years of its existence, CUISINES is already providing logistical support to 10 exoMIPs and will continue to host annual workshops for further community feedback and presentation of new exoMIP ideas.

Keywords: Extrasolar rocky planets, Astronomy data modeling, Theoretical models, Hot Jupiters, Planetary atmospheres, Theoretical data, Planetary climates, Spectroscopy, Mini Neptunes, Exoplanet atmospheres
Impacts on Ocean Worlds Are Sufficiently Frequent and Energetic to Be of Astrobiological Importance. Evidence for the beneficial role of impacts in the creation of urable or habitable environments on Earth prompts the question of whether meteorite impacts could play a similar role at other potentially urable/habitable worlds like Enceladus, Europa, and Titan. In this work, we demonstrate that to first order, impact conditions on these worlds are likely to have been consistent with the survival of organic compounds and/or sufficient for promoting synthesis in impact melt. We also calculate melt production and freezing times for crater sizes found at Enceladus, Europa, and Titan and find that even the smallest craters at these worlds offer the potential to study the evolution of chemical pathways within impact melt. These first-order calculations point to a critical need to investigate these processes at higher fidelity with lab experiments, sophisticated thermodynamic and chemical modeling, and, eventually, in situ investigations by missions.

Keywords: Impact phenomena, Enceladus, Titan, Europa, Craters
Science Product Pipelines and Archive Architecture for the DART Mission. On 2022 September 26, the Double Asteroid Redirection Test (DART) mission was the first successful demonstration of a kinetic impactor for planetary defense. The DART mission utilized a novel autonomous data processing pipeline architecture to quickly produce and analyze the quality of raw and calibrated images from the camera mounted on board the spacecraft. Optimization of the data processing pipeline allowed the final 150 images prior to impact to be calibrated and delivered to the Investigation Team and the press within 15 minutes of acquisition. A data quality analysis pipeline allowed for rapid identification of detector misconfigurations, missing data, and other adverse events. DART data products, along with data from LICIACube and data from ground observatories, used common file formats to facilitate the development of analysis and archiving software. This architecture is described for future missions with large volumes of data and an emphasis on quick-turnaround applications such as planetary defense.

Keywords: Near-Earth objects, Flyby missions, Astronomy data analysis, Astronomy image processing
NWA 11562: A Unique Ureilite with Extreme Mg-rich Constituents. A comprehensive study of an ungrouped achondrite meteorite, North West Africa (NWA) 11562, was conducted, involving petrology, mineralogy, and mass-independent chromium isotopic composition. NWA 11562 comprises 34.9 vol% olivine, 56.1 vol% pyroxenes, 6.7 vol% Fe–Ni metal and oxides, 2.2 vol% carbon, and 0.2 vol% anhydrite. The oxygen isotopic composition (δ 18O = 6.24‰ ± 0.13‰ and Δ17O = ‑1.81‰ ± 0.03‰; Meteoritical Bulletin Database) and chromium isotopic compositions (ɛ 54Cr = ‑0.82 ± 0.10, 2SE) are consistent with NWA 11562 being a ureilite, and petrographic observations show features similar to those of the common ureilite group meteorites. Olivine (core: Fo99.0 ± 0.1; rim: Fo98.9 ± 0.1) and pyroxene (orthopyroxene: Mg# 99.0 ± 0.2; clinopyroxene: Mg# 99.1 ± 0.7) core compositions are more magnesian than in any previously known ureilite and lack the characteristic reduction rims of ureilites. Rounded small olivine grains within NWA 11562 indicate that the meteorite experienced impact and associated melting. Combined with the characteristic Fe/Mn ratio (3.84 ± 0.16) and Mg# (99.0 ± 0.1) of olivine cores, we suggest that NWA 11562 represents a more Mg-rich ureilite than any previously reported. NWA 11562 has a high 55Mn/52Cr ratio, and when combined with literature data, it plots on a well-defined 53Mn–53Cr isochron, providing a more accurate age, i.e., 4566.7 ± 0.8 Ma, overlapping previous work. This age may represent the result of early partial melting of the ureilite parent body.

Keywords: Meteorites, Cosmochronology, Cosmochemistry, Asteroids
An Earth Encounter as the Cause of Chaotic Dynamics in Binary Asteroid (35107) 1991VH. Among binary asteroids, (35107) 1991VH stands out as unique given the likely chaotic rotation within its secondary component. The source of this excited dynamical state is unknown. In this work, we demonstrate that a past close encounter with Earth could have provided the necessary perturbation to allow the natural internal dynamics, characterized by spin–orbit coupling, to evolve the system into its current dynamical state. In this hypothesis, the secondary of 1991VH was previously in a classical 1:1 spin–orbit resonance with an orbit period likely between 28 and 35 hr before being perturbed by an Earth encounter within ∼80,000 km. We find that if the energy dissipation within the secondary is relatively inefficient, this excited dynamical state could persist to today and produce the observed ground-based measurements. Coupled with the orbital history of 1991VH, we can then place a constraint on the tidal dissipation parameters of the secondary.

Keywords: Near-Earth objects, Asteroid dynamics, Asteroid satellites, Asteroid rotation, Close encounters