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Direct N-body Simulations of Satellite Formation around Small Asteroids: Insights from DART’s Encounter with the Didymos System Planet. Sci. J. Pub Date : 2024-02-28 Harrison F. Agrusa, Yun Zhang, Derek C. Richardson, Petr Pravec, Matija Ćuk, Patrick Michel, Ronald-Louis Ballouz, Seth A. Jacobson, Daniel J. Scheeres, Kevin Walsh, Olivier Barnouin, R. Terik Daly, Eric Palmer, Maurizio Pajola, Alice Lucchetti, Filippo Tusberti, Joseph V. DeMartini, Fabio Ferrari, Alex J. Meyer, Sabina D. Raducan, Paul Sánchez
We explore binary asteroid formation by spin-up and rotational disruption considering the NASA DART mission's encounter with the Didymos–Dimorphos binary, which was the first small binary visited by a spacecraft. Using a suite of N-body simulations, we follow the gravitational accumulation of a satellite from meter-sized particles following a mass-shedding event from a rapidly rotating primary. The
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Large Carbonaceous Chondrite Parent Bodies Favored by Abundance–Volatility Modeling: A Possible Chemical Signature of Pebble Accretion Planet. Sci. J. Pub Date : 2024-02-28 Jeremy W. Boyce, Francis M. McCubbin, Nicole Lunning, Tyler Anderson
Primitive meteorite groups such as the Vigarano, Mighei, and Karoonda carbonaceous chondrites have enigmatic patterns of elemental abundances, with moderately volatile elements—those that transition from vapor to condensate between ∼400 and ∼900 K—defining plateaus of subequal abundances despite a wide range in volatility. In detail, each group defines a plateau with distinctive nonmonotonic “chemical
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A Solution for the Density Dichotomy Problem of Kuiper Belt Objects with Multispecies Streaming Instability and Pebble Accretion Planet. Sci. J. Pub Date : 2024-02-28 Manuel H. Cañas, Wladimir Lyra, Daniel Carrera, Leonardo Krapp, Debanjan Sengupta, Jacob B. Simon, Orkan M. Umurhan, Chao-Chin Yang, Andrew N. Youdin
Kuiper Belt objects (KBOs) show an unexpected trend, whereby large bodies have increasingly higher densities, up to five times greater than their smaller counterparts. Current explanations for this trend assume formation at constant composition, with the increasing density resulting from gravitational compaction. However, this scenario poses a timing problem to avoid early melting by decay of 26Al
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Mercury’s Lobate Scarps Reveal that Polygonal Impact Craters Form on Contractional Structures Planet. Sci. J. Pub Date : 2024-02-27 Chloe B. Beddingfield, Kelsey Crane, Christian Klimczak, Richard Cartwright
Analysis of polygonal impact craters (PICs) can be used to investigate the presence and orientations of subtle and/or buried faults and fractures across the solar system that may otherwise be unobservable in spacecraft images. Although this technique has been vetted for the analysis of extensional structures, no previous work has investigated if PICs also form on contractional thrust faults. This determination
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Five Mars Years of Cloud Observations at Gale Crater: Opacities, Variability, and Ice Crystal Habits Planet. Sci. J. Pub Date : 2024-02-27 Conor W. Hayes, Jacob L. Kloos, Alex C. Innanen, Charissa L. Campbell, Haley M. Sapers, John E. Moores
We update the record of cloud opacity observations conducted by the Mars Science Laboratory (MSL) Curiosity rover to cover the first five Mars Years (MYs) of the mission (L s = 160° of MY 31 to L s = 160° of MY 36). Over the three MY period that we add to the previously analyzed two MY record, we achieve good diurnal coverage between 07:00 and 17:00 with nearly 1200 new observations. We derive a new
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The DECam Ecliptic Exploration Project (DEEP). V. The Absolute Magnitude Distribution of the Cold Classical Kuiper Belt Planet. Sci. J. Pub Date : 2024-02-27 Kevin J. Napier, Hsing Wen Lin, David W. Gerdes, Fred C. Adams, Anna M. Simpson, Matthew W. Porter, Katherine G. Weber, Larissa Markwardt, Gabriel Gowman, Hayden Smotherman, Pedro H. Bernardinelli, Mario Jurić, Andrew J. Connolly, J. Bryce Kalmbach, Stephen K. N. Portillo, David E. Trilling, Ryder Strauss, William J. Oldroyd, Chadwick A. Trujillo, Colin Orion Chandler, Matthew J. Holman, Hilke E. Schlichting
The DECam Ecliptic Exploration Project (DEEP) is a deep survey of the trans-Neptunian solar system being carried out on the 4 m Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile using the Dark Energy Camera (DECam). By using a shift-and-stack technique to achieve a mean limiting magnitude of r ∼ 26.2, DEEP achieves an unprecedented combination of survey area and depth, enabling
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The Secular Dynamical Evolution of Binary Asteroid System (65803) Didymos Post-DART Planet. Sci. J. Pub Date : 2024-02-26 Rachel H. Cueva, Jay W. McMahon, Alex J. Meyer, Daniel J. Scheeres, Masatoshi Hirabayashi, Sabina D. Raducan, Seth A. Jacobson, Colby C. Merrill
The successful impact of NASA’s DART mission with Dimorphos, the secondary body of binary asteroid system (65803) Didymos, altered the attitude, shape, and orbit of Dimorphos. In addition to perturbing the immediate short-term dynamics of the system, these changes have major implications for the binary Yarkovsky–O’Keefe–Radzievskii–Paddack (BYORP) effect and resulting long-term secular evolution. In
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Achievement of the Planetary Defense Investigations of the Double Asteroid Redirection Test (DART) Mission Planet. Sci. J. Pub Date : 2024-02-26 Nancy L. Chabot, Andrew S. Rivkin, Andrew F. Cheng, Olivier S. Barnouin, Eugene G. Fahnestock, Derek C. Richardson, Angela M. Stickle, Cristina A. Thomas, Carolyn M. Ernst, R. Terik Daly, Elisabetta Dotto, Angelo Zinzi, Steven R. Chesley, Nicholas A. Moskovitz, Brent W. Barbee, Paul Abell, Harrison F. Agrusa, Michele T. Bannister, Joel Beccarelli, Dmitriy L. Bekker, Megan Bruck Syal, Bonnie J. Buratti
NASA's Double Asteroid Redirection Test (DART) mission was the first to demonstrate asteroid deflection, and the mission's Level 1 requirements guided its planetary defense investigations. Here, we summarize DART's achievement of those requirements. On 2022 September 26, the DART spacecraft impacted Dimorphos, the secondary member of the Didymos near-Earth asteroid binary system, demonstrating an autonomously
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Sensitivity Testing of Stereophotoclinometry for the OSIRIS-REx Mission. II. Effective Observation Geometry for Digital Terrain Modeling Planet. Sci. J. Pub Date : 2024-02-21 Eric E. Palmer, John R. Weirich, Robert W. Gaskell, Diane Lambert, Tanner Campbell, Kris Drozd, Olivier S. Barnouin, Michael G. Daly, Kenneth Getzandanner, John N. Kidd, Coralie D. Adam, Dante S. Lauretta
The OSIRIS-REx mission used stereophotoclinometry (SPC) to generate digital terrain models (DTMs) of its target asteroid, Bennu. Here we present a suite of preflight tests conducted to identify the observing geometry and number of images needed to create DTMs that would enable successful navigation around and to the surface of the asteroid. We demonstrate that high-quality DTMs can be generated by
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Leveraging the Gravity Field Spectrum for Icy Satellite Interior Structure Determination: The Case of Europa with the Europa Clipper Mission Planet. Sci. J. Pub Date : 2024-02-21 G. Cascioli, E. Mazarico, A. J. Dombard, F. Nimmo
Understanding the interior structures of icy moons is pivotal for addressing their origins and habitability. We introduce an approach employing the gravity field spectrum as an additional constraint for the inversion of differentiated icy bodies’ interior structures. After developing the general methodology, we apply it to Europa, utilizing the predicted measurement capability of NASA’s Europa Clipper
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Sensitivity Testing of Stereophotoclinometry for the OSIRIS-REx Mission. I. The Accuracy and Errors of Digital Terrain Modeling Planet. Sci. J. Pub Date : 2024-02-21 Eric E. Palmer, John R. Weirich, Robert W. Gaskell, Diane Lambert, Tanner Campbell, Kris Drozd, Olivier S. Barnouin, Michael G. Daly, Kenneth Getzandanner, John N. Kidd, Coralie D. Adam, Dante S. Lauretta
Stereophotoclinometry (SPC) was the prime method of shape modeling for NASA’s OSIRIS-REx mission to asteroid Bennu. Here we describe the extensive testing conducted before launch to certify SPC as NASA Class B flight software, which not only validated SPC for operational use but also quantified the accuracy of this technique. We used a computer-generated digital terrain model (DTM) of a synthetic asteroid
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Hunting for Hydrated Minerals on Trans-Neptunian Objects Planet. Sci. J. Pub Date : 2024-02-20 Tom Seccull, Wesley C. Fraser, Dominik A. Kiersz, Thomas H. Puzia
We present new optical reflectance spectra of three potentially silicate-rich trans-Neptunian objects (TNOs). These spectra were obtained with the aim of confirming past hints and detections of λ ∼ 0.7 μm absorption features associated with the presence of iron-bearing phyllosilicates. Our new spectrum of 120216 (2004 EW95) presents clearly detected absorption features that are similar in shape to
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Lucy Observations of the DART Impact Event Planet. Sci. J. Pub Date : 2024-02-20 H. A. Weaver, J. M. Sunshine, C. M. Ernst, T. L. Farnham, S. Mottola, J. R. Spencer, S. Marchi, N. Dello Russo, O. Barnouin, H. F. Levison, K. S. Noll, C. B. Olkin, T. S. Statler, A. F. Cheng, E. G. Fahnestock, A. Fitzsimmons, M. M. Knight, J.-Y. Li, N. A. Moskovitz, C. A. Thomas, N. L. Chabot, A. S. Rivkin, Lucy Science Team, and DART Investigation Team
The Lucy LOng Range Reconnaissance Imager (L’LORRI) took 1549 images of the Didymos–Dimorphos binary system, starting 12 hr before the Double Asteroid Redirection Test (DART) impact event on 2022 September 26 and ending 24 hr after it. The Lucy imaging campaign provided pre-impact monitoring of the baseline brightness of the Didymos system, as well as intensive 1 s cadence imaging starting 3 minutes
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Surface Heterogeneity, Physical, and Shape Model of Near-Earth Asteroid (52768) 1998 OR2 Planet. Sci. J. Pub Date : 2024-02-20 Maxime Devogèle, Anna McGilvray, Eric MacLennan, Courteney Monchinski, Sean E. Marshall, Dylan Hickson, Anne Virkki, Jon D. Giorgini, Lyu Abe, David Augustin, Amadeo Aznar-Macías, Philippe Baudouin, Raoul Behrend, Philippe Bendjoya, Zouhair Benkhaldoun, Josep Bosch, Alberto Cellino, Joseph Chatelain, Marc Deldem, Marin Ferrais, Rui Goncalves, Gerard Houdin, Marek Husárik, Emmanuel Jehin, Teddy Kareta
On 2020 April 29, the near-Earth object (52768) 1998 OR2 experienced a close approach to Earth at a distance of 16.4 lunar distances (LD). 1998 OR2 is a potentially hazardous asteroid of absolute magnitude H = 16.04 that can currently come as close to Earth as 3.4 LD. We report here observations of this object in polarimetry, photometry, and radar. Our observations show that the physical characteristics
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Electrostatic Dust Analyzer for Dust Transport Measurements on the Lunar Surface Planet. Sci. J. Pub Date : 2024-02-20 X. Wang, M. Horanyi, C. Fisher, L. Eberwein, J. Deca, S. Knappmiller, D. Hansen, Z. Levin, R. Wing, D. Summers, W. Cole, P. Buedel, J. Drouet, S. Tucker, I. Garrick-Bethell
Lunar dust charging and transport is a more than five-decade-old problem. A high-fidelity and flight-qualified Electrostatic Dust Analyzer (EDA) has been developed to measure the charge, velocity, mass (size), and flux of electrostatically lofted dust particles on the lunar surface. Recent laboratory findings have greatly advanced our fundamental understanding of the dust-charging and -lofting mechanisms
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Gravity Investigation to Characterize Enceladus's Ocean and Interior Planet. Sci. J. Pub Date : 2024-02-14 Antonio Genova, Marzia Parisi, Anna Maria Gargiulo, Flavio Petricca, Simone Andolfo, Tommaso Torrini, Edoardo Del Vecchio, Christopher R. Glein, Morgan L. Cable, Cynthia B. Phillips, Nicholas E. Bradley, Ricardo L. Restrepo, Declan M. Mages, Alessandra Babuscia, Jonathan I. Lunine
A key objective for the future exploration of the icy moon Enceladus is the characterization of the habitable conditions in its internal ocean. Radio science instrumentation on board a spacecraft in a low-altitude orbit about Enceladus would enable gravity measurements that are fundamental to providing constraints on its internal structure. We present here the concept of operations and expected results
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Measurability of the Heliocentric Momentum Enhancement from a Kinetic Impact: The Double Asteroid Redirection Test (DART) Mission Planet. Sci. J. Pub Date : 2024-02-14 Rahil Makadia, Steven R. Chesley, Davide Farnocchia, Shantanu P. Naidu, Damya Souami, Paolo Tanga, Kleomenis Tsiganis, Masatoshi Hirabayashi, Siegfried Eggl
The NASA Double Asteroid Redirection Test (DART) has demonstrated the capability of successfully conducting kinetic impact-based asteroid deflection missions. The changes in the Didymos–Dimorphos mutual orbit as a result of the DART impact have already been measured. To fully assess the heliocentric outcome of deflection missions, the heliocentric momentum enhancement parameter, β ⊙, needs to be determined
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Inferring the CO2 Abundance in Comet 45P/Honda-Mrkos-Pajdušáková from [O i] Observations: Implications for the Source of Icy Grains in Cometary Comae Planet. Sci. J. Pub Date : 2024-02-14 Mikayla R. Huffman, Adam J. McKay, Anita L. Cochran
The study of cometary composition is important for understanding our solar system's early evolutionary processes. Carbon dioxide (CO2) is a common hypervolatile in comets that can drive activity but is more difficult to study than other hypervolatiles owing to severe telluric absorption. CO2 can only be directly observed from space-borne assets. Therefore, a proxy is needed to measure CO2 abundances
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Understanding the Dust Environment at Mercury: From Surface to Exosphere Planet. Sci. J. Pub Date : 2024-02-12 Harald Krüger, Michelle S. Thompson, Masanori Kobayashi, Valeria Mangano, Martina Moroni, Anna Milillo, Lindsay P. Keller, Sho Sasaki, Joe Zender, Deborah Domingue, Johannes Benkhoff, André Galli, François LeBlanc, Go Murakami, Menelaos Sarantos, Daniel W. Savin
We provide an overview of our understanding of the dust environment at Mercury and the role that dust plays in shaping the planet's surface and exosphere. Our understanding of the role that dust impacts play in the generation of Mercury's atmosphere has evolved considerably with continued analysis of results from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission
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Detection of Molecular H2O on Nominally Anhydrous Asteroids Planet. Sci. J. Pub Date : 2024-02-12 Anicia Arredondo, Margaret M. McAdam, Casey I. Honniball, Tracy M. Becker, Joshua P. Emery, Andrew S. Rivkin, Driss Takir, Cristina A. Thomas
We used the FORCAST instrument on SOFIA to obtain mid-infrared spectra (4.9–13.7 μm) of four S-type asteroids: (7) Iris, (11) Parthenope, (18) Melpomene, and (20) Massalia. Three of these four silicate-rich asteroids (Iris, Melpomene, and Massalia) were observed to have 3 μm features indicative of hydration by McAdam et al. We report a detection of a 6 μm feature that is unambiguously attributed to
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Photometry of the Didymos System across the DART Impact Apparition Planet. Sci. J. Pub Date : 2024-02-07 Nicholas Moskovitz, Cristina Thomas, Petr Pravec, Tim Lister, Tom Polakis, David Osip, Theodore Kareta, Agata Rożek, Steven R. Chesley, Shantanu P. Naidu, Peter Scheirich, William Ryan, Eileen Ryan, Brian Skiff, Colin Snodgrass, Matthew M. Knight, Andrew S. Rivkin, Nancy L. Chabot, Vova Ayvazian, Irina Belskaya, Zouhair Benkhaldoun, Daniel N. Berteşteanu, Mariangela Bonavita, Terrence H. Bressi, Melissa
On 2022 September 26, the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, the satellite of binary near-Earth asteroid (65803) Didymos. This demonstrated the efficacy of a kinetic impactor for planetary defense by changing the orbital period of Dimorphos by 33 minutes. Measuring the period change relied heavily on a coordinated campaign of lightcurve photometry designed to detect
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Numerical Simulations of (10199) Chariklo’s Rings with a Resonant Perturber Planet. Sci. J. Pub Date : 2024-02-06 Amanda A. Sickafoose, Mark C. Lewis
The discovery of two thin rings around the ∼ 250 km sized Centaur Chariklo was the first of its kind, and their formation and evolutionary mechanisms are not well understood. Here, we explore a single shepherd satellite as a mechanism to confine Chariklo’s rings. We also investigate the impact of such a perturber on reaccretion, which is a likely process for material located outside the Roche limit
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Clues to the Origin of Jovian Outer Irregular Satellites from Reflectance Spectra Planet. Sci. J. Pub Date : 2024-02-06 Faith Vilas, Amanda R. Hendrix
Visible/near-infrared narrowband spectroscopy (dispersion per element ∼ 6 Å) was obtained of the Jovian irregular satellites JVI Himalia, JVII Elara, JVIII Pasiphae, JIX Sinope, JX Lysithea, JXI Carme, JXII Ananke, and JXVII Callirrhoe in 2006, 2009, and 2010 using the MMT Observatory Red Channel spectrograph. These spectra sample three prograde (i = 28°), four retrograde (i = 149° and 165°), and one
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Rotationally Resolved Mid-infrared Spectroscopy of (16) Psyche Planet. Sci. J. Pub Date : 2024-02-06 Anicia Arredondo, Margaret M. McAdam, Tracy M. Becker, Linda Elkins-Tanton, Zoe Landsman, Thomas Müller
Asteroid (16) Psyche is theorized to be an exposed iron core of a primordial asteroid and is the target of the upcoming NASA Psyche mission. Recent observations of Psyche identified the presence of rotational heterogeneity, a fine-grained regolith, pyroxene, and hydrated minerals on its surface. We obtained rotationally resolved mid-infrared (MIR) spectroscopy of Psyche with the Stratospheric Observatory
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Optical Constants of Ices Important to Planetary Science from Laboratory Reflectance Spectroscopy Planet. Sci. J. Pub Date : 2024-02-05 S. C. Tegler, W. M. Grundy, M. J. Loeffler, P. D. Tribbett, J. Hanley, A. V. Jasko, H. Dawson, A. N. Morgan, K. J. Koga, A. O. Madden-Watson, M. D. Gomez, J. K. Steckloff, G. E. Lindberg, S. P. Tan, S. M. Raposa, A. E. Engle, C. L. Thieberger, D. E. Trilling
Laboratory-derived optical constants are essential for identifying ices and measuring their relative abundances on solar system objects. Almost all optical constants of ices important to planetary science come from experiments with transmission geometries. Here we describe our new experimental setup and the modification of an iterative algorithm in the literature to measure the optical constants of
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Surface Roughness at the Moon’s South Pole: The Influence of Condensed Volatiles on Surface Roughness at the Moon’s South Pole Planet. Sci. J. Pub Date : 2024-02-05 Lizeth O. Magaña, Parvathy Prem, Ariel N. Deutsch, Anna C. Martin, Heather M. Meyer, Caleb I. Fassett, Michael K. Barker, Angela Stickle, Benjamin D. Byron, Kathleen E. Mandt, Kurt D. Retherford
Condensed volatiles within lunar permanently shadowed regions are of high scientific and resource utilization importance. Volatiles remain elusive and difficult to observe directly, due to low direct solar illumination. In this work, we investigate correlations between, as well as possible effects of, condensed volatiles and surface roughness. We analyze topographic roughness at 50 m and 30–120 m baselines
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Characterization of High-priority Landing Sites for Robotic Exploration Missions in the Apollo Basin, Moon Planet. Sci. J. Pub Date : 2024-02-02 Csilla Orgel, Ines Torres, Sebastien Besse, Carolyn H. van der Bogert, Rickbir Bahia, René Prissang, Mikhail A. Ivanov, Harald Hiesinger, Gregory Michael, Jan Hendrik Pasckert, Mayssa El Yazidi, Balazs Bradak, Sebastian H. G. Walter
The South Pole–Aitken (SPA) basin is the oldest and largest visible impact structure on the Moon, making it a high priority science site for exploration missions. The 492 km diameter Apollo peak-ring basin is one of the youngest and largest basins within the SPA basin. We selected three regions of interest (ROIs) in the Apollo basin for which the landing and operational hazards are minimized and evaluated
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Atmospheric Loss in Giant Impacts Depends on Preimpact Surface Conditions Planet. Sci. J. Pub Date : 2024-02-01 Simon J. Lock, Sarah T. Stewart
Earth likely acquired much of its inventory of volatile elements during the main stage of its formation. Some of Earth’s proto-atmosphere must therefore have survived the giant impacts, collisions between planet-sized bodies, that dominate the latter phases of accretion. Here, we use a suite of 1D hydrodynamic simulations and impedance-match calculations to quantify the effect that preimpact surface
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Depth-to-diameter Ratios of Fresh Craters on the Moon and Implications for Surface Age Estimates Planet. Sci. J. Pub Date : 2024-01-31 Rachael H. Hoover, Stuart J. Robbins, Brian M. Hynek, Paul O. Hayne
The depth-to-diameter (d/D) ratios of small lunar craters (D < 400 m) can be used to determine important properties of the upper regolith, specifically material strength or thickness. The d/D is also an important component of topographic diffusion models that describe how different erosive processes influence and change the topography of a surface over time, and these models have been applied to estimate
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Modeling Linear Polarization of the Didymos–Dimorphos System before and after the DART Impact Planet. Sci. J. Pub Date : 2024-01-31 Antti Penttilä, Karri Muinonen, Mikael Granvik, Zuri Gray, Stefano Bagnulo, Ludmilla Kolokolova, Fernando Moreno
We analyze the polarization observations of the Didymos–Dimorphos system before and after the impact by the NASA Double Asteroid Redirection Test spacecraft on Dimorphos. We fit empirical polarization phase curve models and statistically confirm the discovery by Gray et al. about the degree of linear polarization of the system decreasing on the impact and remaining altered for at least 30 days post-impact
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Dust Production Rates in Jupiter-family Comets: A Two Year Study with ATLAS Photometry Planet. Sci. J. Pub Date : 2024-01-30 A. Fraser Gillan, Alan Fitzsimmons, Larry Denneau, Robert J. Siverd, Ken W. Smith, John L. Tonry, David R. Young
Jupiter-family comets (JFCs) exhibit a wide range of activity levels and mass loss over their orbits. We analyzed high-cadence observations of 42 active JFCs with the wide-field Asteroid Terrestrial-impact Last Alert System (ATLAS) in 2020–2021. We measured the dust production rates of the JFCs using the Af ρ parameter and its variation as a function of heliocentric distance. There is a tendency for
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An Updated Shape Model of Dimorphos from DART Data Planet. Sci. J. Pub Date : 2024-01-29 R. Terik Daly, Carolyn M. Ernst, Olivier S. Barnouin, Robert W. Gaskell, Hari Nair, Harrison Agrusa, Nancy L. Chabot, Andrew F. Cheng, Elisabetta Dotto, Elena Mazzotta Epifani, Raymond C. Espiritu, Tony L. Farnham, Eric E. Palmer, Petr Pravec, Andrew S. Rivkin, Dany C. Waller, Angelo Zinzi, the DART and LICIACube teams
Dimorphos was the target of the Double Asteroid Redirection Test (DART) mission. This paper summarizes the properties of an updated shape model of Dimorphos, describes the differences between the updated shape model and an earlier version published by Daly, Ernst, Barnouin et al. (doi:10.1038/s41586-023-05810-5), summarizes the data products associated with this model, and explains where the products
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Organic Hazes as a Source of Life’s Building Blocks to Warm Little Ponds on the Hadean Earth Planet. Sci. J. Pub Date : 2024-01-29 Ben K. D. Pearce, Sarah M. Hörst, Joshua A. Sebree, Chao He
Over 4 billion years ago, Earth is thought to have been a hazy world akin to Saturn’s moon Titan. The organic hazes in the atmosphere at this time could have contained a vast inventory of life’s building blocks and thus may have seeded warm little ponds for life. In this work, we produce organic hazes in the lab in atmospheres with high (5%) and low (0.5%) CH4 abundances and analyze the solid particles
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The Relative Effects of Surface and Subsurface Morphology on the Deflection Efficiency of Kinetic Impactors: Implications for the DART Mission Planet. Sci. J. Pub Date : 2024-01-25 Mallory E. DeCoster, Robert Luther, Gareth S. Collins, Kaiyi Dai, Thomas Davison, Dawn M. Graninger, Felix Kaufmann, Emma S. G. Rainey, Angela M. Stickle
The Double Asteroid Redirection Test (DART) mission impacted Dimorphos, the moonlet of the binary asteroid 65803 Didymos, on 2022 September 26 and successfully tested a kinetic impactor as an asteroid deflection technique. The success of the deflection was partly due to the momentum of the excavated ejecta material, which provided an extra push to change Dimorphos’s orbital period. Preimpact images
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Tectonics and Seismicity of the Lunar South Polar Region Planet. Sci. J. Pub Date : 2024-01-25 T. R. Watters, N. C. Schmerr, R. C. Weber, C. L. Johnson, E. J. Speyerer, M. S. Robinson, M. E. Banks
The lunar south pole regions are subjected to global stresses that result in contractional deformation and associated seismicity. This deformation is mainly expressed by lobate thrust fault scarps; examples are globally distributed, including polar regions. One small cluster of lobate scarps falls within the de Gerlache Rim 2 Artemis III candidate landing region. The formation of the largest de Gerlache
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Cassini UVIS Observations of the Enceladus Auroral Footprint on Saturn in 2017 Planet. Sci. J. Pub Date : 2024-01-24 Wayne R. Pryor, Fabiola P. Magalhães, Laurent Lamy, Renée Prangé, Larry W. Esposito, Jacques Gustin, Abigail M. Rymer, Ali H. Sulaiman
Ultraviolet Imaging Spectrograph (UVIS) observations show the Enceladus auroral footprint on Saturn on 2017 September 14, near the end of the Cassini mission. A series of Saturn north polar auroral images were obtained by slowly slewing the Cassini spacecraft at right angles to the UVIS long slit. The images were limb-fit to improve the spacecraft geometry. Enhanced extreme-ultraviolet 88–118 nm channel
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Onboard Science Instrument Autonomy for the Detection of Microscopy Biosignatures on the Ocean Worlds Life Surveyor Planet. Sci. J. Pub Date : 2024-01-24 Mark Wronkiewicz, Jake Lee, Lukas Mandrake, Jack Lightholder, Gary Doran, Steffen Mauceri, Taewoo Kim, Nathan Oborny, Thomas Schibler, Jay Nadeau, James K. Wallace, Eshaan Moorjani, Chris Lindensmith
The quest to find extraterrestrial life is a critical scientific endeavor with civilization-level implications. Icy moons in our solar system are promising targets for exploration because their liquid oceans make them potential habitats for microscopic life. However, the lack of a precise definition of life poses a fundamental challenge to formulating detection strategies. To increase the chances of
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Dimorphos Orbit Determination from Mutual Events Photometry Planet. Sci. J. Pub Date : 2024-01-22 Peter Scheirich, Petr Pravec, Alex J. Meyer, Harrison F. Agrusa, Derek C. Richardson, Steven R. Chesley, Shantanu P. Naidu, Cristina Thomas, Nicholas A. Moskovitz
The NASA Double Asteroid Redirection Test spacecraft successfully impacted the Didymos–Dimorphos binary asteroid system on 2022 September 26 UTC. We provide an update to its preimpact mutual orbit and estimate the postimpact physical and orbital parameters, derived using ground-based photometric observations taken from 2022 July to 2023 February. We found that the total change of the orbital period
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Lunar Mare Lava Flow Dynamics and Emplacement: Predictions of Non-Newtonian Flow Dynamics, Syn- and Post-emplacement Cooling and Volatile Release Patterns, and Vertical and Lateral Flow Structure Development Planet. Sci. J. Pub Date : 2024-01-22 Lionel Wilson, James W. Head
We apply basic principles of magma ascent from deep source regions and its eruption into a low-gravity vacuum environment to develop a theoretical treatment of the fluid dynamics and thermodynamics of mare basalt lava flow emplacement and evolution on the Moon. The vacuum conditions influenced the release of volatiles in magma passing through lava fountains, thus controlling the syn- and post-emplacement
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Polarimetry of Didymos–Dimorphos: Unexpected Long-term Effects of the DART Impact Planet. Sci. J. Pub Date : 2024-01-22 Zuri Gray, Stefano Bagnulo, Mikael Granvik, Alberto Cellino, Geraint H. Jones, Ludmilla Kolokolova, Fernando Moreno, Karri Muinonen, Olga Muñoz, Cyrielle Opitom, Antti Penttilä, Colin Snodgrass
We have monitored the Didymos–Dimorphos binary system in imaging polarimetric mode before and after the impact from the Double Asteroid Redirection Test mission. A previous spectropolarimetric study showed that the impact caused a dramatic drop in polarization. Our longer-term monitoring shows that the polarization of the post-impact system remains lower than the pre-impact system even months after
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Resonant Stratification in Titan’s Global Ocean Planet. Sci. J. Pub Date : 2024-01-19 Benjamin Idini, Francis Nimmo
Titan’s ice shell floats on top of a global ocean, as revealed by the large tidal Love number k 2 = 0.616 ± 0.067 registered by Cassini. The Cassini observation exceeds the predicted k 2 by one order of magnitude in the absence of an ocean, and is 3σ away from the predicted k 2 if the ocean is pure water resting on top of a rigid ocean floor. Previous studies demonstrate that an ocean heavily enriched
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The Effect of Salinity on Ocean Circulation and Ice–Ocean Interaction on Enceladus Planet. Sci. J. Pub Date : 2024-01-19 Yaoxuan Zeng, Malte F. Jansen
Observational data suggest that the ice shell on Enceladus is thicker at the equator than at the pole, indicating an equator-to-pole ice flow. If the ice shell is in an equilibrium state, the mass transport of the ice flow must be balanced by the freezing and melting of the ice shell, which in turn is modulated by the ocean heat transport. Here we use a numerical ocean model to study the ice–ocean
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3 μm Phase Curves of Main-belt Asteroids from NEOWISE Photometry Planet. Sci. J. Pub Date : 2024-01-19 Matthew Varakian, Nancy Chanover, Joseph Masiero, Dagmara Oszkiewicz
The shapes of asteroid phase curves are influenced by the physical properties of asteroid surfaces. The variation of an asteroid’s brightness as a function of the solar phase angle can tell us about surface properties such as grain size distribution, roughness, porosity, and composition. Phase curves are traditionally derived from photometric observations at visible wavelengths, but phase curves using
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Titan’s Atmospheric Albedo Asymmetry and Seasonal Variability Observed through the Cassini Imaging Science Subsystem Planet. Sci. J. Pub Date : 2024-01-18 C. Snell, D. Banfield
Using images from Cassini, we analyzed the north–south albedo asymmetry that has been observed in the atmosphere of Saturn’s moon, Titan. Suitable images from the Cassini Imaging Science Subsystem taken at 889 nm spanned from 2004 to 2017—around half of a Titan year—and revealed seasonal changes in the characteristics and orientation of the north–south asymmetry boundary. Such circumglobal features
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ASTERIA—Asteroid Thermal Inertia Analyzer Planet. Sci. J. Pub Date : 2024-01-18 Bojan Novaković, Marco Fenucci, Dušan Marčeta, Debora Pavela
Thermal inertia estimates are available for a limited number of a few hundred objects, and the results are practically solely based on thermophysical modeling (TPM). We present a novel thermal inertia estimation method, the Asteroid Thermal Inertia Analyzer (ASTERIA). The core of the ASTERIA model is the Monte Carlo approach, based on the Yarkovsky drift detection. We validate our model on asteroid
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New Polarimetric Data for the Galilean Satellites: Io and Ganymede Observations and Modeling Planet. Sci. J. Pub Date : 2024-01-18 Nikolai Kiselev, Vera Rosenbush, Ari Leppälä, Karri Muinonen, Ludmilla Kolokolova, Aleksandr Savushkin, Nikolai Karpov
New high-precision disk-integrated measurements of the polarization of Io and Ganymede in the UBVRI bands are presented. The observations were obtained using polarimeters mounted on the Crimean Astrophysical Observatory and the Peak Terskol Observatory in 2019–2023. For Io, the negative polarization branch (NPB) reaches a minimum of P min ≈ −0.25 ± 0.02% in the V band at a phase angle of α min = 2
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Effect of Equation of State and Cutoff Density in Smoothed Particle Hydrodynamics Simulations of the Moon-forming Giant Impact Planet. Sci. J. Pub Date : 2024-01-17 Scott D. Hull, Miki Nakajima, Natsuki Hosono, Robin M. Canup, Rene Gassmöller
The amount of vapor in the impact-generated protolunar disk carries implications for the dynamics, devolatilization, and moderately volatile element isotope fractionation during lunar formation. The equation of state (EoS) used in simulations of the giant impact is required to calculate the vapor mass fraction (VMF) of the modeled protolunar disk. Recently, a new version of M-ANEOS (Stewart M-ANEOS)
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Retrievals Applied to a Decision Tree Framework Can Characterize Earthlike Exoplanet Analogs Planet. Sci. J. Pub Date : 2024-01-17 Amber V. Young, Jaime Crouse, Giada Arney, Shawn Domagal-Goldman, Tyler D. Robinson, Sandra T. Bastelberger
Exoplanet characterization missions planned for the future will soon enable searches for life beyond our solar system. Critical to the search will be the development of life detection strategies that can search for biosignatures while maintaining observational efficiency. In this work, we adopted a newly developed biosignature decision tree strategy for remote characterization of Earthlike exoplanets
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Temperature-related Variations of 1064 nm Surface Reflectance on Mercury: Implications for Space Weathering Planet. Sci. J. Pub Date : 2024-01-17 Ariel N. Deutsch, Gregory A. Neumann, Mikhail A. Kreslavsky, Petr Pokorný, Jose M. Martinez Camacho, David Trang, Noam R. Izenberg, Brett W. Denevi, Anna Galiano, Gianrico Filacchione
It has been predicted that high equatorial temperatures on Mercury could promote thermal annealing by Ostwald ripening, where nanophase metal particles (a product of space weathering) coalesce and grow into larger, microphase particles, resulting in lower albedo. Here, we test this prediction by studying the correlation between albedo and temperature in 1° spatial bins using newly recalibrated 1064
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Cratering and Tectonic History of the Largest Uranian Satellite, Titania: New Insights Enabled by Image Reprocessing Planet. Sci. J. Pub Date : 2024-01-17 Erica Nathan, James Head, Christian Huber
From heavily cratered Umbriel to extensively tectonized Miranda, Titania is an intermediary of the Uranian system: heavily cratered, yet tectonically modified. An outstanding mystery in Titania's crater population is its apparent relative lack of large (>30 km) craters. However, progress has been limited by the coverage and quality of images available. Here, we present a new map of Titania enabled
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Improved Orthorectification and Empirical Reduction of Topographic Effects in Monostatic Mini-RF S-band Observations of the Moon Planet. Sci. J. Pub Date : 2024-01-16 Caleb I. Fassett, Ali M. Bramson, Joshua T. S. Cahill, Cameron P. Harris, Gareth A. Morgan, Catherine D. Neish, Cole A. Nypaver, G. Wesley Patterson, Edgard Rivera-Valentin, Patrick A. Taylor, Bradley J. Thomson, the Mini-RF Team
The Miniature Radio Frequency instrument (Mini-RF) on the Lunar Reconnaissance Orbiter obtained widespread synthetic aperture radar observations of the Moon in the S band (12.6 cm), including nearly complete coverage at both lunar poles. The currently archived monostatic data have spatial offsets from the lunar reference frame, making them more difficult to compare to other data sets. To address this
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Categorization of Spatial and Temporal Ejecta Outcomes in Binary Systems Based on Variations of the Didymos System Planet. Sci. J. Pub Date : 2024-01-16 Jennifer N. Larson, Yanga Fernandez, Gal Sarid
With the increasing number of binary asteroid systems being discovered, ejecta studies must expand from solely investigating single-body systems to modeling more complex multiple-body systems. For example, the Double Asteroid Redirection Test provides an opportunity to study the dynamics of a debris cloud around Didymos and Dimorphos, a near-Earth binary asteroid system. Here we simulate 72 variations
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Bioverse: The Habitable Zone Inner Edge Discontinuity as an Imprint of Runaway Greenhouse Climates on Exoplanet Demographics Planet. Sci. J. Pub Date : 2024-01-15 Martin Schlecker, Dániel Apai, Tim Lichtenberg, Galen Bergsten, Arnaud Salvador, Kevin K. Hardegree-Ullman
Long-term magma ocean phases on rocky exoplanets orbiting closer to their star than the runaway greenhouse threshold—the inner edge of the classical habitable zone—may offer insights into the physical and chemical processes that distinguish potentially habitable worlds from others. The thermal stratification of runaway planets is expected to significantly inflate their atmospheres, potentially providing
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A New 2D Energy Balance Model for Simulating the Climates of Rapidly and Slowly Rotating Terrestrial Planets Planet. Sci. J. Pub Date : 2024-01-11 Ramses M. Ramirez
Energy balance models (EBMs), alongside radiative–convective climate models and global climate models (GCMs), are useful tools for simulating planetary climates. Historically, planetary and exoplanetary EBMs have solely been 1D latitudinally dependent models with no longitudinal dependence, until the study of Okuya et al., which focused on simulating synchronously rotating planets. Following the work
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Morphological and Spectral Characterization of Lunar Regolith Breakdown due to Water Ice Planet. Sci. J. Pub Date : 2024-01-10 A. Shackelford, K. L. Donaldson Hanna, M. Horton, D. Noce
Remote sensing observations of the Moon suggest that the lunar polar regolith environment is affected by several natural processes that may cause the regolith in these regions to become more porous and fine particulate. One of these processes may be the mechanical breakdown of regolith particles through the interaction of water ice and regolith by frost wedging. We present morphological and spectral
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Deep Dielectric Breakdown of Silicates: Microstructural Damage and Implications for Lunar Space Weathering Planet. Sci. J. Pub Date : 2023-12-29 Morgan L. MacLeod, Thomas G. Sharp, Mark S. Robinson, Andrew P. Jordan
Solar energetic particle events electrically charge the lunar surface and may produce electric fields sufficient to induce dielectric breakdown in regolith grains. We irradiated series of silicate minerals with electrons to determine their physical and chemical response to deep dielectric charging and subsequent breakdown. Two electrical phenomena, flashovers and subsurface dielectric breakdown, produced
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An Efficient Numerical Approach to Modeling the Effects of Particle Shape on Rubble-pile Dynamics Planet. Sci. J. Pub Date : 2023-12-29 Julian C. Marohnic, Joseph V. DeMartini, Derek C. Richardson, Yun Zhang, Kevin J. Walsh
We present an approach for the inclusion of nonspherical constituents in high-resolution N-body discrete element method (DEM) simulations. We use aggregates composed of bonded spheres to model nonspherical components. Though the method may be applied more generally, we detail our implementation in the existing N-body code pkdgrav. It has long been acknowledged that nonspherical grains confer additional
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The Variability of Lunar Mare Basalt Properties from Surface Rock Abundance Planet. Sci. J. Pub Date : 2023-12-29 Catherine M. Elder, Rebecca R. Ghent, James Haber, Paul O. Hayne, Gareth Morgan, Mark S. Robinson, Matt Siegler, Jean-Pierre Williams
We use the Lunar Reconnaissance Orbiter Diviner Lunar Radiometer Experiment surface rock abundance data set to investigate how rock content changes with surface age in the maria. We find that surface rock abundance decreases with unit age as expected for a thickening regolith, but age alone cannot explain most of the observed regional variability in rock abundance. We propose that this additional variability
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X-Ray Energy Deposition Model for Simulating Asteroid Response to a Nuclear Planetary Defense Mitigation Mission Planet. Sci. J. Pub Date : 2023-12-19 Mary T. Burkey, Robert A. Managan, Nicholas A. Gentile, Megan Bruck Syal, Kirsten M. Howley, Joseph V. Wasem
In the event of a potentially catastrophic asteroid impact, with sufficient warning time, deploying a nuclear device remains a powerful option for planetary defense if a kinetic impactor or other means of deflection proves insufficient. Predicting the effectiveness of a potential nuclear deflection or disruption mission depends on accurate multiphysics simulations of the device's X-ray energy deposition
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Dust Properties of Comets Observed by Spitzer Planet. Sci. J. Pub Date : 2023-12-15 David E. Harker, Diane H. Wooden, Michael S. P. Kelley, Charles E. Woodward
As comets journey into the inner solar system, they deliver particulates and volatile gases into their comae that reveal the most primitive materials in the solar system. Cometary dust particles provide crucial information for assessing the physicochemical conditions in the outer disk from which they formed. Compared to the volatiles and soluble organics, the refractory dust particles are more robust