cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.15no4v
title: Alteration history of aluminum-rich rocks at Jezero crater, Mars: Insights from deeply weathered terrestrial materials

description: Sedimentary sequences containing aluminum-rich clay minerals have been detected across the surface of Mars and likely indicate periods of intense aqueous alteration by liquid water billions of years ago. On Earth, these clay minerals can form as a result of rainfall-driven chemical weathering in tectonically stable landscapes over thousands to millions of years, but exactly how they once formed on Mars remains a mystery. During its traverse in Jezero crater, the Mars 2020 Perseverance rover discovered distinct light-toned, cobble-sized, aluminum-rich (30-40 wt. %) “float” rocks (rock fragments), with some bearing the spectral signature of kaolinite and/or halloysite. These rocks now fortuitously enable an investigation into the 3-to-4-billion-year-old kaolinite-bearing terrains of early Mars. To contextualize these materials with analogs from Earth, we compare their elemental compositions and reflectance spectra to deeply weathered terrestrial paleosols (ancient, lithified soils) and hydrothermal kaolin deposits from Earth’s geological record. Aluminum and titanium enrichments along with depletion of iron and magnesium observed in several Jezero crater float rocks are unlike hydrothermal kaolin deposits and instead comparable to the bleached "pallid zone" of deeply weathered Eocene (55 Ma) and Paleoproterozoic (2.2 Ga) kaolinitic paleosols that formed from intense rainfall (pedogenic weathering) during past greenhouse climates on Earth. However, either pedogenic or hydrothermal processes can form kaolinite, and until the source outcrop of this material is discovered, either remains a possibility. These rocks may have been associated with the wettest, and possibly most habitable periods of Mars’ early history.
DOI: 10.48577/jpl.en5gwk
title: Sensitivity to soil moisture of Capella X-band high-resolution SAR data over forests

description: Sensitivity to soil moisture of X-band high-resolution Synthetic Aperture Radar (SAR) data over the 10 openings between the trees in forests is evaluated. The VV backscattering coefficient is extracted 11 from a time-series of Capella images collected over two different regions across the United States. 12 In-situ soil moisture measurements recorded at fixed locations from the National Ecological 13 Observatory Network (NEON) are used as reference for the analysis. The geolocation uncertainty of 14 the original ground range detected Capella images at 0.8 m resolution was evaluated at 5 to 15 m. 15 Ground control points were used to improve geolocation accuracy to 1 to 5 m. Radar backscattering 16 and soil moisture exhibit linear correlation values up to 0.95, confirming the strong response of X17 band Capella to soil moisture changes when trees are not interfering with the scattering from the 18 thinly-vegetated soil over the openings. These findings reveal the potential for forest soil moisture 19 monitoring by micro-satellites offering meter-level high-resolution and agile tasking. Accordingly, 20 applications such as wildfire precursors, landslide prediction, and forest management may benefit as 21 long as the moisture conditions at the openings represent the soil moisture over larger areas.
DOI: 10.48577/jpl.akg2mf
title: Probing the Outskirts of M Dwarf Planetary Systems with a Cycle 1 JWST NIRCam Coronagraphy Survey

description: The population of giant planets on wide orbits around low-mass M dwarf stars is poorly understood, 22 but the unprecedented sensitivity of JWST NIRCam coronagraphic imaging now provides direct access 23 to planets significantly less massive than Jupiter beyond 10 AU around the closest, youngest M dwarfs. 24 We present the design, observations, and results of JWST GTO Program 1184, a Cycle 1 NIRCam 25 coronagraphic imaging survey of 9 very nearby and young low-mass stars at 3 − 5μm wavelengths. In 26 the F356W and F444W filters, we achieve survey median 5σ contrasts deeper than 10−5 at a separation 27 of 1′′, corresponding to 0.20 MJup in F444W and 1.30 MJup in F356W at planet-star separations of 28 10 AU. Our results include 3 − 5μm debris disk detections and the identification of many extended 29 and point-like sources in the final post-processed images. In particular, we have identified a marginal 30 point source candidate having a flux and color limit consistent with model predictions for a young 31 sub-Jupiter mass exoplanet. Under the assumption that the candidate is not confirmed, we place 32 the first direct-imaging occurrence constraints on M dwarf wide-orbit (semimajor axes 10 − 100 AU), 33 sub-Jupiter mass exoplanets (0.3 − 1 MJup). We find frequency limits of &lt; 0.10 and &lt; 0.16 objects 34 per star with 1 and 3σ confidence, respectively. This survey brings to the forefront the unprecedented 35 capabilities of JWST NIRCam coronagraphic imaging when targeting young, low-mass stars and acts 36 as a precursor to broader surveys to place deep statistical constraints on wide-orbit, sub-Jupiter mass 37 planets around M dwarfs.
DOI: 10.48577/jpl.mxcnms
title: Achieving Mission Success: A Comprehensive Look at the Verification and Validation Approach for the Psyche Mission – the First Demonstration of Hall Thrusters in Interplanetary Space

description: On October 13, 2023, the Psyche spacecraft launched from Kennedy Space Center aboard a Falcon Heavy Rocket, marking the first use of SPT-140 Hall thrusters for interplanetary propulsion, supported by a cold gas system for launch separation, faulted conditions, and counterbalancing the momentum of the electric propulsion thrusters. This paper explores the system-level verification and validation campaign, covering spacecraft integration, environmental testing, launch and cruise validation, and flight operations transition. The test program had to balance the use of flight, engineering, and simulation models, particularly in closed-loop guidance, navigation, and control testing. The paper details the mission operations validation approach, addressing challenges in hardware-software compatibility and the unique demands of a low-thrust, electric propulsion deep-space mission.
DOI: 10.48577/jpl.ns9pzl
title: Habitable Worlds Observatory Wavefront Sensing and Control: Methods for Ultrastability

description: Coronagraphic observations on the Habitable Worlds Observatory will only be possible if the telescope and coronagraph optics can be made ultrastable, with the goal of limiting changes in raw contrast during observations to the order of $10^{-12}$. Current modeling of the HWO Exploratory Analysis Configuration 1 design concept shows that there will be significant thermal and vibrational disturbances coupling through to the Optical Telescope Assembly and coronagraph optics. This paper presents Wavefront Sensing and Control (WFSC) methods for EAC-1 that, with further technology development, can compensate these disturbances, to limit total wavefront error to the single-digit picometers to meet this stringent delta-contrast goal.
DOI: 10.48577/jpl.rkys25
title: Toward Better Greenhouse Gas Monitoring and Climate Intervention

description: The world's nations have made progress in slowing the rate of carbon dioxide (CO2) emissions and mitigating methane (CH4) leaks from oil and gas facilities. However, there is more need than ever for early, targeted, and sustained climate intervention. For such interventions to succeed, they must rely on accurate, timely information that integrates data from surface, airborne, and satellite sensors, covering local, regional, and international scales. This effort requires cross-disciplinary collaboration among many organizations from many nations. Last September, members of the carbon cycle monitoring community met to determine how best to establish a system to more effectively monitor progress in reducing emissions and to help accelerate climate intervention through better data and decision support. Here, we highlight some of the issues and challenges facing efforts to monitor and document greenhouse gas emissions, and we discuss the ideas and proposals put forth as a result of the September meeting.
DOI: 10.48577/jpl.z5v7y4
title: Relativistic framework for high-precision GNSS-based navigation in cislunar space

description: We present a relativistic modeling framework for GNSS-based navigation in geocentric and barycentric coordinate reference systems, i.e., GCRS and BCRS, respectively. Using the IAU-adopted GCRS and BCRS conventions, we derive closed-form transformations for position, velocity, and acceleration that are required to achieve fractional-frequency transfer precision of 10 16 and sub-centimeter positional accuracy. We introduce the Lunicentric Coordinate Reference System (LCRS) and its associated time scale to extend GNSS-based navigation into cislunar space. Numerical simulations with GipsyX validate centimeter-level orbit determination and timing stability within tens of picoseconds across GCRS, BCRS, and LCRS. These results underscore the necessity of relativistic corrections for high-precision GNSS throughout the Earth–Moon system and demonstrate that GNSS signals can support a decimeter-level orbit accuracy and sub-nanosecond-scale timing synchronization in cislunar space, establishing a robust framework for future operations. We present a minimal cislunar case study (NRHO-like geometry) that applies the improved position/velocity/acceleration transformations, the LCRS transformations, and the light-time model. We also define and verify a frame-closure metric between BCRS and LCRS, providing an implementation-ready approach for cislunar navigation.
DOI: 10.48577/jpl.tx1uia
title: Euclid Quick Data Release (Q1) The first catalogue of strong-lensing galaxy clusters

description: We present the first catalogue of strong lensing galaxy clusters identified in the Euclid quick release 1 observations (∼ 53 deg2 ). This catalogue is the result of the visual inspection of 1260 cluster fields, primarily identified by Wen & Han (2024). Specifically, we identified 84 gravitational lenses with a probability larger than 0.5, of which 14 with a probability of 1, and clearly exhibiting secure strong lensing features, such as giant tangential and radial arcs, and multiple images. We forecast that Euclid will discover ∼6000 secure cluster-scale lenses over the course of its full survey. The identified strong lensing features will be crucial for training sophisticated deep learning models for identifying gravitational arcs and multiple images automatically in Euclid observations. This study confirms the huge potential of Euclid for finding new strong lensing clusters, enabling exciting new discoveries on the nature of dark matter and dark energy and the study of the high-redshift Universe. Key words. Galaxies: clusters: general – Gravitational lensing: strong – cosmology: observations – dark matter
DOI: 10.48577/jpl.3wquxv
title: Simultaneous modeling of water leaving reflectance and sun and sky glint contributions from imaging spectroscopy measurements

description: Remote imaging spectroscopy, with its ability to quantify phytoplankton pigments and benthic reflectance, is a powerful tool for monitoring aquatic ecosystems, giving valuable insights into environmental processes. However, the accuracy of these retrievals is impacted by specular glint at the air-water interface. Current imaging spectrometer missions either ignore glint-contaminated pixels, or apply post-hoc corrections, which can introduce substantial uncertainties in reflectance estimates. To address this challenge, we present a new approach that simultaneously models water-leaving reflectance and sun and sky glint contributions from imaging spectroscopy measurements. We reveal accurate performance of our model by utilizing measurements and derived chlorophyll-a products from the PRISM airborne imaging spectrometer during the SubMesoscale Ocean Dynamics Experiment (S-MODE) campaign.
DOI: 10.48577/jpl.mh05pq
title: Detection of an NH3 absorption band at 2.2 μm on Europa

description: The presence of NH3-bearing components on icy planetary bodies has important implications for their geology and potential habitability. Here, I report the detection of a characteristic NH3 absorption feature at 2.20 ± 0.02 µm on Europa, identified in an observation from the Galileo Near Infrared Mapping Spectrometer. Spectral modeling and band position indicate that NH3-hydrate and NH4-chloride are the most plausible candidates. Spatial correlation between detected ammonia signatures and Europa’s microchaos, linear, and band geologic units suggests emplacement from the underground or shallow subsurface. I posit that NH3-bearing materials were transported to the surface via effusive cryovolcanism or similar mechanisms during Europa's recent geological past. The presence of ammoniated compounds implies a thinner ice shell (Spohn & Schubert, 2003) and a thicker, chemically reduced, high-pH subsurface ocean on Europa (Hand et al. 2009). With the detection of NH3-bearing components, this study presents the first evidence of a nitrogen-bearing species on Europa— an observation of astrobiological significance given nitrogen’s essential role in the chemistry of life.
DOI: 10.48577/jpl.fze5cc
title: The End of the Road for Far-infrared Reddening Maps? Evidence for Reddening Errors Driven by Changes in PAH Abundance

description: Accurate correction for extinction by Galactic dust is essential for studying the extragalactic sky. In7 the low-extinction regions of the Ursa Major molecular cloud complex, we demonstrate that Galactic8 dust reddening maps constructed from observations of far-infrared emission are insensitive to variations9 in the abundance of polycyclic aromatic hydrocarbons (PAHs), and, as a result, to PAH-induced10 variations in reddening. Using galaxy counts to validate various reddening maps, we find evidence that11 maps based on far-infrared emission erroneously under-predict reddening compared to stellar reddening12 maps. This underestimation by far-infrared emission based reddening maps—representing the largest13 discrepancy between maps of up to E(B − V ) = 0.08 mag—is correlated with the relative brightness14 of PAH emission. Furthermore, we demonstrate theoretically that changes in PAH abundance via15 accretion is capable of altering extinction significantly with only minor changes to far-infrared emission.16 We show that modeling the extinction of Ursa Major using both far-infrared and mid-infrared emission17 is capable of more accurately tracing dust extinction variations due to changes in PAH abundance.18 Finally, we explore the ability of SPHEREx observations of the 3.3 µm PAH feature to overcome this19 limitation of far-infrared emission.
DOI: 10.48577/jpl.umlcvd
title: Factors contributing to the unusually low Antarctic springtime ozone in 2020– 2023

description: The 2020–2023 Antarctic spring seasons saw large ozone holes, significant ozone mass deficit, 38 and low polar cap total ozone compared to the second decade of the 21st Century, prompting 39 questions about the pace of ozone recovery over Antarctica. Here we use a stratospheric 40 composition reanalysis developed at the NASA Global Modeling and Assimilation Office, and 41 chemical ozone loss estimates derived from NASA’s Aura Microwave Limb Sounder 42 observations to identify the key factors contributing to these unusually large ozone holes. We 43 find that the below-average Antarctic ozone in each of the years of interest resulted from a 44 different combination of the following: anomalous initial polar vortex ozone content, chemical 45 ozone depletion, dynamical ozone resupply, and the size and geometry of the stratospheric 46 polar vortex, with dynamically-driven factors playing a key role. We also interpret our findings 47 in the broader context of ozone recovery, with a particular focus on September, the month 48 when signs of recovery are most evident. We find no evidence challenging the current 49 consensus that springtime Antarctic ozone is recovering in response to the implementation of 50 the Montreal Protocol and its amendments.
DOI: 10.48577/jpl.vejq45
title: Atmospheric Drivers of Interannual Variability from the Northern Hemisphere Seasonal Cap on Mars

description: The seasonal exchange of volatiles (CO2 and H2O) between the atmosphere and surface on Mars drives seasonal changes in the extent of ice at the poles. Interannual variability, or year to year changes, in the extent of seasonal ice have been observed, suggesting fluctuations in the processes that drive volatile exchange. In the northern hemisphere, previous studies have mapped seasonal frosts during the winter and spring months. However, a critical knowledge gap persists, namely multi-year records of seasonal frost extent that distinguish composition. In this work, we fill this gap, quantifying the interannual variability of seasonal frost extent for CO2 and H2O across 6 Mars years. To identify potential drivers of the observed variations, we further compare our results with atmospheric measurements of dust, the position of the polar vortex, and water vapor availability. We identify the edges of seasonal CO2 and H2O frost caps with binary ice mask products, derived from CRISM mapping-style observations taken during Mars Year 28-33. We find that the extent of CO2 seasonal frost is fairly consistent between years, changing by ~1.5° of global equivalent latitude, but the extent of H2O seasonal frost can change by ~3.9° of global equivalent latitude.
DOI: 10.48577/jpl.wwyjdi
title: A Mid-Infrared Spectroscopic Study of Young Stellar Objects in the SMC Region NGC 346: JWST Detects Dust, Accretion, Ices and Outflows

description: We present mid-infrared spectroscopic observations of intermediate- to high-mass young stellar objects (YSOs) in the low-metallicity star-forming region NGC 346 located within the Small Magellanic Cloud (SMC). We conduct these integral-field-unit observations with the Mid-Infrared Instrument / Medium Resolution Spectroscopy instrument on board JWST. The brightest and most active star forming region in the SMC, NGC 346 has a metallicity of ∼1/5 Z⊙, analogous to the era when star formation in the early Universe (z ≃ 2) peaked. We discuss the emission and absorption features present in the spectral energy distributions (SEDs) of five YSOs with coverage from 4.9 - 27.9 µm and three other sources with partial spectral coverage. Via SED model-fitting, we estimate their parameters, finding masses ranging from 2.9-18.0 M⊙. These targets show dusty silicates, polycyclic aromatic hydrocarbons and ices of CO2, CO, H2O and CH3OH in their protostellar envelopes. We measure emission from H2 and atomic fine-structure lines, suggesting the presence of protostellar jets and outflows. We detect H I lines indicating ongoing accretion and estimate accretion rates for each source which range from 2.50×10−6 -2.23×10−4 M⊙ yr−1 based on H I (7-6) line emission. We present evidence for a ∼ 30,000AU protostellar jet traced by fine-structure, H I and H2 emission about the YSO Y535, the first detection of a resolved protostellar outflow in the SMC, and the most distant yet detected.
DOI: 10.48577/jpl.2amqa3
title: Euclid Quick Data Release (Q1) From spectrograms to spectra: the SIR spectroscopic processing function⋆

description: Context. Spectrographic mode of NISP on board Euclid Aims. PF SIR Methods. Slitless spectroscopy Results. Spectroscopic Q1 release Conclusions. Optional: Yeah! Key words. Cosmology: observations – Instrumentation: spectrographs – Techniques: imaging spectroscopy – Methods: data analysis
DOI: 10.48577/jpl.ibbacq
title: Euclid Quick Data Release (Q1) First Euclid statistical study of the active galactic nuclei contribution fraction

description: Active galactic nuclei (AGN) are an important phase in galaxy evolution. However, they can be difficult to identify due to their varied observational signatures. Furthermore, to understand the impact of an AGN on its host galaxy, it is important to quantify the strength of the AGN with respect to the host galaxy. We developed a deep learning (DL) model for identifying AGN in imaging data by deriving the contribution of the central point source. The model was trained with Euclidised mock galaxy images in which we artificially injected different levels of AGN, in the form of varying contributions of the point-spread function (PSF). Our DL-based method can precisely and accurately recover the injected AGN contribution fraction fPSF, with a mean difference between the predicted and true fPSF of −0.0078 and an overall root mean square error (RMSE) of 0.051. With this new method, we move beyond the simplistic AGN versus non-AGN classification, allowing us to precisely quantify the AGN contribution and study galaxy evolution across a continuous spectrum of AGN activity. We apply our method to a stellar-mass-limited sample (with M∗ ≥ 109.8M⊙ and 0.5 ≤ z ≤ 2.0 ) selected from the first Euclid quick data release (Q1) and, using a threshold of fPSF &gt; 0.2, we identify 48 840 ± 78 AGN over 63.1 deg2 (7.8 ± 0.1% of our sample). We compare these DL-selected AGN with AGN selected in the X-ray, mid-infrared (MIR), and via optical spectroscopy and investigate their overlapping fractions depending on different thresholds on the PSF contribution. We find that the overlap increases with increasing X-ray or bolometric AGN luminosity. We observe a positive correlation between the luminosity in the IE filter of the AGN and the host galaxy stellar mass, suggesting that supermassive black holes (SMBHs) generally grow faster (in absolute terms, i.e., the luminosity of the PSF component is larger) in more massive galaxies. Moreover, the mean relative contribution of the AGN is higher in the quiescent galaxy population than in the star-forming population. In terms of absolute power, starburst galaxies, as well as the most massive galaxies (across the star-formation main sequence), tend to host the most luminous AGN, indicating concomitant assembly of the SMBH and the host galaxy. Key words. Galaxies: active – Galaxies: statistics