Article
Astronomy & Astrophysics
C. D. Neish, K. M. Cannon, L. L. Tornabene, R. L. Flemming, M. Zanetti, E. Pilles
Summary: Researchers investigated impact melt deposits from seven lunar craters and found that their unique surface texture might be caused by a mixture of pyroxene and/or glassy material.
Article
Astronomy & Astrophysics
Rupali Mohanty, P. Senthil Kumar, K. Jaya Prasanna Lakshmi, Vivek Krishnan, Abhisek Mishra, G. Sree Sai Karthik
Summary: This study presents new evidence for ejecta boulder falls around 135 fresh simple impact craters in the Orientale multi-ring basin on the Moon. These boulder falls exhibit characteristics different from moonquake-triggered boulder falls, such as radial boulder trails, shorter trail lengths, narrower trail widths, and shallower trail depths. The boulder falls are believed to be produced by ejecta boulders during the ejecta blanket formation stage of the impact craters.
Article
Astronomy & Astrophysics
A. B. Cunje, A. J. Dombard, R. R. Ghent
Summary: Larger impact craters and basins on the Moon show a discrepancy in crater size frequency distributions between their interior melt surfaces and exterior ejecta blankets. Despite elevated thermal conditions favorable to relaxation, simulations suggest that other mechanisms are likely responsible for the discrepancy in ages between the melt and ejecta surfaces.
Article
Environmental Sciences
Jiayin Deng, Weiming Cheng, Yimeng Jiao
Summary: This research studied the diversity in the geological evolution of three impact basins on the lunar surface using topography, geomorphology, chemical composition, mineralogical composition, lunar crust thickness, and subsurface structures analyses. The results showed that the basins have cavity-like shapes with variations in crustal thickness and uplift of the crust-mantle interface. Collapses occurred at the crust-mantle interface in the mare regions of two basins. The chemical and mineral compositions of both basin and mare formations exhibited bimodal distributions, and olivine-rich materials were found in specific locations.
Article
Astronomy & Astrophysics
Qinghai Sun, Wenzhe Fa, Meng-Hua Zhu, Jun Du
Summary: In this study, the morphology of impact craters on the Moon was analyzed, showing differences in slope, height, and rock abundance between craters in maria and non-maria regions. The findings also revealed differences in degradation rates and depth-dependent features among different terrains. The revised onset of transitional crater diameters was also determined.
Article
Astronomy & Astrophysics
C. Millot, C. Quantin-Nataf, C. Leyrat, V Lherm, M. Volat
Summary: Digital Elevation Models (DEMs) are widely used in planetary sciences, including for Mars. They provide necessary topography parameters for geomorphological studies. However, DEMs are not free from vertical errors, leading to uncertainties in calculating parameters such as local slopes. Slope maps computed from DEMs often display slope patterns unrelated to the original images, which may originate from DEM vertical errors. To investigate this, a numerical method is proposed to quantitatively analyze slope errors based on DEM error propagation using synthetic models. The method reveals that vertical errors in DEMs can generate slope patterns similar to those observed. Estimates of slope errors are also provided for four martian cameras, aiming to constrain local slope uncertainties in geomorphological studies.
Article
Astronomy & Astrophysics
Emerson J. Speyerer, Mark S. Robinson, Aaron Boyd, Victor H. Silva, Samuel Lawrence
Summary: The UVVIS camera on the Clementine spacecraft provided a global, multispectral view of the Moon. Cross-mission comparisons were impaired by spatial offsets between the derived products. With new data from the LRO and GRAIL missions, image-based feature-matching algorithms were used to improve the positional accuracy of the UVVIS observations with the LROC WAC basemap, resulting in a foundational geospatial data product that aligns with the current lunar reference frame.
Article
Geochemistry & Geophysics
Sierra N. Ferguson, Alyssa R. Rhoden, Michelle R. Kirchoff
Summary: Recent modeling suggests that Saturn's inner moons may be younger than previously thought, with a specific impactor source identified for Dione. A comparison with Tethys reveals differences in crater distributions, indicating varying bombardment histories among Saturn's moons.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2022)
Article
Geochemistry & Geophysics
C. Riedel, G. G. Michael, C. Orgel, C. Baum, C. H. van der Bogert, H. Hiesinger
Summary: In this study, impact crater records on planetary surfaces were analyzed for spatial randomness. The research found global clustering of craters on Mercury, largely random distribution of craters on Venus, and more pronounced global clustering of craters on the Moon. The study also highlighted the importance of considering planetary curvature in statistical analyses of impact craters.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2021)
Article
Engineering, Multidisciplinary
Alexander Zakharov, Anton Yu Poroykov, Sergei A. Bednyakov, Andrey N. Lyash, Inna A. Shashkova, Ilia A. Kuznetsov, Gennadiy G. Dolnikov
Summary: This study showcases the visualization and recovery of 3D dynamic trajectories of charged microparticles in electric field conditions, with the aim of simulating plasma-dust processes above the surfaces of the Moon and other Solar system bodies without atmospheres. The experimental setup includes a vacuum chamber for simulation and a stereo camera system for image registration, along with image processing techniques developed for estimating particle trajectories in 3D. Examples of processing results and potential applications are also discussed.
Article
Astronomy & Astrophysics
Michelle R. Kirchoff, Simone Marchi, William F. Bottke, Clark R. Chapman, Brian Enke
Summary: Lunar impact crater chronologies have been developed by combining carefully measured crater densities of lunar terrains with radiometric ages provided by returned samples. Research suggests that the impact flux of impactors larger than a few kilometers in diameter on the Moon may have varied over the past three billion years, with hints of a relative increase approximately 2 billion years ago and a decrease around 1 billion years ago.
Article
Environmental Sciences
Yiren Chang, Zhiyong Xiao, Yang Liu, Jun Cui
Summary: Self-secondaries are a background population of secondary craters formed by impacts of sub-vertically launched ejecta, posing a potential threat to the reliability of crater chronology. They are mainly located around complex impact craters on the Moon, but their first discovery around simple craters has been reported. The spatial density of self-secondaries is highly heterogeneous and they are more abundant downrange of the ejecta deposits from non-vertical impacts.
Article
Astronomy & Astrophysics
Joseph M. Boyce, Peter J. Mouginis-Mark
Summary: This study conducted a detailed morphologic and morphometric analysis of the radial grooves on Martian layered ejecta, proposing three different categories of grooves in correlation with different types of ejecta craters. The findings suggest that the formation of these grooves is closely related to geological processes and eruption mechanisms.
Article
Geosciences, Multidisciplinary
Philip D. Gingerich
Summary: Rates are widely used in geological sciences to characterize processes, with the numerator representing change or difference and the denominator corresponding to an interval of time. Temporal scaling examines the relationship between differences, rates, and their associated time intervals, often analyzed on logarithmic axes. Geological studies commonly involve rates dependent on denominators due to observed changes being constrained to a narrower range compared to the longer spans of geological time. When rates are dependent on denominators, comparisons must be made on a common scale of time.
EARTH-SCIENCE REVIEWS
(2021)
Article
Astronomy & Astrophysics
Rie Honda, Masahiko Arakawa, Yuri Shimaki, Kei Shirai, Yasuhiro Yokota, Toshihiko Kadono, Koji Wada, Kazunori Ogawa, Ko Ishibashi, Naoya Sakatani, Satoru Nakazawa, Minami Yasui, Tomokatsu Morota, Shingo Kameda, Eri Tatsumi, Manabu Yamada, Toru Kouyama, Yuichiro Cho, Moe Matsuoka, Hidehiko Suzuki, Chikatoshi Honda, Masahiko Hayakawa, Kazuo Yoshioka, Naru Hirata, Naoyuki Hirata, Hirotaka Sawada, Seiji Sugita, Takanao Saiki, Hiroshi Imamura, Yasuhiko Takagi, Hajime Yano, Chisato Okamoto, Yuichi Tsuda, Yu-ichi Iijima
Summary: The resurfacing process on Ryugu was studied by comparing pre- and post-impact images captured by an optical navigation camera, revealing the appearance of new boulders which helped resolve the discrepancy of the ejecta blanket thickness.
Article
Astronomy & Astrophysics
R. N. Clegg-Watkins, B. L. Jolliff, A. Boyd, M. S. Robinson, R. Wagner, J. D. Stopar, J. B. Plescia, E. J. Speyerer
Article
Astronomy & Astrophysics
R. V. Wagner, D. M. Nelson, J. B. Plescia, M. S. Robinson, E. J. Speyerer, E. Mazarico
Article
Astronomy & Astrophysics
Mark S. Robinson, Jekan Thangavelautham, Brian J. Anderson, Ahmet Deran, Samuel J. Lawrence, Robert Wagner, Rex Ridenoure, Bobby Williams, David Dunham, Alessandra Babuscia, Kar-Ming Cheung, Anthony L. Genova
PLANETARY AND SPACE SCIENCE
(2018)
Article
Geochemistry & Geophysics
R. Wagner, M. S. Robinson
Summary: Lunar pits, which are small collapse features with vertical walls, may provide access to lava tubes or other caves. After investigating 21 known pits, we found that some may indeed be lava tubes, although the majority remain ambiguous. We also propose that pit formation is an ongoing process.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2022)
Article
Astronomy & Astrophysics
Maria Angeles Lopez-Cayuela, Maria-Paz Zorzano, Juan Luis Guerrero-Rascado, Carmen Cordoba-Jabonero
Summary: The atmospheric dust cycle on Mars plays a dominant role in the planetary radiative balance, atmospheric photochemistry escape, and redistribution of materials on the surface. A methodology is presented to accurately describe the annual dust redistribution cycle on Mars using orbital global and seasonal measurements of atmospheric dust opacity. The analysis shows that approximately 4 trillion kilograms of dust is transported globally in the atmosphere during a typical Mars year.
Article
Astronomy & Astrophysics
Audrey Vorburger, Shahab Fatemi, Shane R. Carberry Mogan, Andre Galli, Lucas Liuzzo, Andrew R. Poppe, Lorenz Roth, Peter Wurz
Summary: The study presents new model results for the composition of Ganymede's atmosphere, finding that sublimation remains the major source process for H2O, while radiolysis induced by auroral electrons dominates the source fluxes for O2 and H2.
Article
Astronomy & Astrophysics
Qi He, Zhi Cao, Yuqi Qian, Hejiu Hui, Ioannis Baziotis, Long Xiao, Zaicong Wang, Biji Luo, Yiheng Li, Zongjun Ying, Yang Li
Summary: The Chang'e-5 mission collected lunar soil containing magnesian troctolitic granulites, which provide valuable information on the composition of the lunar crust. Through analysis and modeling, it is suggested that these granulites may have originated from the Pythagoras crater and were transported to the landing site.
Article
Astronomy & Astrophysics
Jordan M. Bretzfelder, Kathryn M. Stack, Abigail A. Fraeman, Mackenzie Day, William E. Dietrich, Alexander B. Bryk
Summary: This study investigates the development of bedrock ridges on Mars and their implications for wind history, deposition, and erosion in Gale crater.
Article
Astronomy & Astrophysics
Lot Ram, Diptiranjan Rout, Rahul Rathi, Paul Withers, Sumanta Sarkhel
Summary: This study investigates the impacts of interplanetary coronal mass ejections (ICMEs) on the Martian ionosphere, specifically the behavior of the ionospheric peak density and height during ICME passages. The study used observations from the Radio Occultation Science Experiment (ROSE) aboard the MAVEN spacecraft and selected 8 ICMEs from existing catalogs. The results show that ICMEs lead to an elevation of the ionospheric peak height and a decrease in peak density, and propose that vertical pressure gradient and electron temperature enhancement are plausible causes for ionospheric variability.
Article
Astronomy & Astrophysics
Benoit Jabaud, Riccardo Artoni, Gabriel Tobie, Erwan Le Menn, Patrick Richard
Summary: The Cassini spacecraft discovered active jets of water vapour and ice grains at the South Pole of Enceladus, resulting in the deposit of freshly erupted materials on the moon's icy surface. Similar processes may be happening on Europa as well. Determining the mechanical properties of fresh icy powder-like materials is essential for future landing and sampling missions. The flowability and surface energy of ice powders decrease with increasing temperatures, which may have implications for stable landing and the flow of ice materials on Enceladus and Europa.
Article
Astronomy & Astrophysics
Lydie Bonal, Eric Quirico, Gilles Montagnac, Mutsumi Komatsu, Yoko Kebukawa, Hikaru Yabuta, Kana Amano, Jens Barosch, Laure Bejach, George D. Cody, Emmanuel Dartois, Alexandre Dazzi, Bradley De Gregorio, Ariane Deniset-Besseau, Jean Duprat, Cecile Engrand, Minako Hashiguchi, Kanami Kamide, David Kilcoyne, Zita Martins, Jeremie Mathurin, Smail Mostefaoui, Larry Nittler, Takuji Ohigashi, Taiga Okumura, Laurent Remusat, Scott Sandford, Miho Shigenaka, Rhonda Stroud, Hiroki Suga, Yoshio Takahashi, Yasuo Takeichi, Yusuke Tamenori, Maximilien Verdier-Paoletti, Shohei Yamashita, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Hisayoshi Yurimoto, Shogo Tachibana, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Satoru Nakazawa, Masahiro Nishimura, Tatsuaki Okada, Takanao Saiki, Kanako Sakamoto, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Tomohiro Usui, Sei-ichiro Watanabe, Toru Yada, Kasumi Yogata, Makota Yoshikawa
Summary: This paper focuses on characterizing the thermal history of asteroid Ryugu by studying the structure of polyaromatic carbonaceous matter in the returned samples. The study finds that there is no structural difference in the polyaromatic component between the two sampling sites on Ryugu, indicating that the thermal metamorphism related to radioactive decay was not significant. However, some structural variability is observed within the particle set.
Article
Astronomy & Astrophysics
M. Luginin, A. Fedorova, D. Belyaev, F. Montmessin, O. Korablev, J. -l. Bertaux
Summary: Spectroscopic solar occultation measurements by the SPICAV/SOIR instrument onboard the Venus Express orbiter provided new data on the upper haze aerosol properties, its distribution, and variations. A joint analysis of data from two spectrometers revealed a bimodal distribution in about 50% of observations previously believed to be unimodal, and characterized the size distribution 10 km higher in the atmosphere compared to previous analysis.
Article
Astronomy & Astrophysics
A. Mahieux, S. Viscardy, K. L. Jessup, F. P. Mills, L. Trompet, S. Robert, S. Aoki, A. Piccialli, A. C. Vandaele
Summary: We report on the mean upper limit number densities and volume concentrations of H2CO, O-3, NH3, HCN, N2O, NO2, NO, and HO2 at the Venus terminator above the cloud layer. Attempts to detect these species using a statistical algorithm and the method presented by Trompet et al. (2021) were unsuccessful, and upper limits of detection are provided.
Article
Astronomy & Astrophysics
P. M. Streeter, S. R. Lewis, M. R. Patel, J. A. Holmes, K. Rajendran
Summary: The northern polar vortex on Mars shows a high degree of interannual repeatability in its structure and evolution, except during large dust storms. The seasonal timing of these storms seems to be the key factor determining their impacts on the polar vortex.
Article
Astronomy & Astrophysics
Michael T. Mellon, Hanna G. Sizemore, Jennifer L. Heldmann, Christopher P. McKay, Carol R. Stoker
Summary: The search for life is a major focus of Mars exploration, with temperature and water activity being key factors for habitability. The most recent habitable conditions occurred about 510 kyrs ago and lasted for about 10s of kyrs each occurrence. All latitudes offer potential for life exploration, but middle-latitude sites have access to 100-kyr-old ice that experienced past habitable conditions, while high-latitude sites offer access to ancient ice over 1 Myrs old.
Article
Astronomy & Astrophysics
Anthony Ozerov, Jeffrey C. Smith, Jessie L. Dotson, Randolph S. Longenbaugh, Robert L. Morris
Summary: The Geostationary Lightning Mapper (GLM) instruments, with their large combined field of view, are useful for studying the population of atmospheric phenomena like bolides. However, there are biases when using GLM for non-lightning purposes, which need to be studied and accounted for before precise measurements of bolide flux can be obtained. A Bayesian Poisson regression model was developed to estimate instrumental biases and the latitudinal variation of bolide flux concurrently. The estimated bias corresponds to the known sensitivity of the GLM instruments, and the latitudinal flux variation estimates are consistent with a strong bias towards high-velocity bolides, as compared to existing theoretical models.
Article
Astronomy & Astrophysics
P. Beck, P. Y. Meslin, A. Fau, O. Forni, O. Gasnault, J. Lasue, A. Cousin, S. Schroeder, S. Maurice, W. Rapin, R. C. Wiens, A. M. Ollila, E. Dehouck, N. Mangold, B. Garcia, S. Schwartz, W. Goetz, N. Lanza
Summary: Analysis of data obtained by ChemCam on Mars reveals that the carbon signal is mainly related to ionization of the atmosphere, with variability potentially linked to the physical state of the atmosphere. Up to sol 3355, no carbonate was detected in the ChemCam dataset, suggesting that it is not a major constituent (>50%) in the analyzed targets and that carbon in soils is not enriched beyond the limit of detection. The dominant salts found in Gale are sulfate and chlorides, while the absence of carbonates, seen in Jezero, may be due to differences in protolith.
Article
Astronomy & Astrophysics
Eloy Pena-Asensio, Jaakko Visuri, Josep M. Trigo-Rodriguez, Hector Socas-Navarro, Maria Gritsevich, Markku Siljama, Albert Rimola
Summary: The observation of interstellar objects 1I/'Oumuamua and 2I/Borisov suggests the existence of a larger population of smaller projectiles that impact our planet with unbound orbits. A statistical evaluation of uncertainties in the CNEOS database and study of its hyperbolic fireballs reveals an anisotropic geocentric radiant distribution and low orbital inclinations, challenging the assumption of a randomly incoming interstellar population. These findings suggest that apparent interstellar meteors may, in fact, be the result of accelerated meteoroid impacts caused by close encounters with massive objects within or passing through our solar system.
Article
Astronomy & Astrophysics
Cecilia W. S. Leung, Leslie K. Tamppari, David M. Kass, German Martinez, Erik Fischer, Michael D. Smith
Summary: Using a combination of orbital and surface observations, this study investigates the vertical distribution of water vapor in the lower atmospheres of Mars. The findings suggest that the assumption of uniformly mixed water vapor in the boundary layer is not always consistent with observational constraints. The results provide important insights into the seasonal transport of water and the role of regolith-atmospheric exchange.