Article
Geochemistry & Geophysics
David Haack, Solmaz Adeli, Ernst Hauber
Summary: An integrated analysis of Gorgonum Chaos in Terra Sirenum reveals a transition from humid conditions with liquid water on Mars in the past to the current hyper-arid environment. The varying content of hydrated minerals in different geological units reflects the geological history of the region.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2021)
News Item
Multidisciplinary Sciences
Alexandra Witze
Summary: After completing its first year on Mars, Perseverance will explore an ancient delta in search of evidence of past life.
Article
Astronomy & Astrophysics
Stefano Nerozzi, Maya R. Ortiz, John W. Holt
Summary: The basal unit in the Planum Boreum of Mars is a sedimentary deposit containing water ice and lithic fines. It can be divided into two subunits, rupe over bars and cavi, based on their stratigraphy and age. Despite recent studies, key questions about its nature, age, and historical record remain unanswered.
Article
Astronomy & Astrophysics
H. Savijarvi, A-M Harri
Summary: Observations from Phoenix and Curiosity show diurnal adsorption of near-surface air moisture, which is insensitive to the mineralogy of regolith. Standard-form adsorption isotherms with different specific surface areas produce nearly identical matches with observed water vapor pressures, suggesting low-pressure water vapor adsorption to martian regolith is nonspecific and associated with low enthalpy.
Article
Geochemistry & Geophysics
H. I. Savijarvi, G. M. Martinez, A. -M. Harri
Summary: Based on the M2020 mission observations and simulations, the diurnal ground surface and air temperatures, as well as the five major surface energy budget fluxes, were well modeled using diurnally variable apparent ground thermal inertia derived from hourly observations. The measurements, diagnostic method, and model results are consistent with the nonhomogeneous terrain in the field-of-view of the thermal infrared and solar sensors. However, the simulations of observed air temperatures require less extreme values of apparent ground thermal inertia consistent with THEMIS retrievals. Therefore, the measured ground temperature for the small FOV may not always represent the larger region controlling the near-surface atmospheric temperature profile around the rover.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Astronomy & Astrophysics
Norbert Schorghofer
Summary: Caves on Mars may contain water ice deposits, with hoarfrost being the main type of cave ice. The role of cave microclimates in maintaining ice bodies is comparatively evaluated.
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
R. J. Soare, S. J. Conway, J-P Williams, A. J. Hepburn
Summary: This passage discusses the cyclical glacial and periglacial activities on Mars, focusing on specific terrain features and revealing the roles of glaciation and freeze-thaw cycles in the geological history of Mars.
Article
Multidisciplinary Sciences
Timothy A. Goudge, Alexander M. Morgan, Gaia Stucky de Quay, Caleb Fassett
Summary: Lake breach flooding on early Mars significantly eroded a quarter of incised valleys, impacting the Martian landscape. The global importance of these floods in shaping valley systems highlights their role in the broader landscape evolution of Mars.
Article
Astronomy & Astrophysics
R. J. Soare, J-P Williams, A. J. Hepburn, F. E. G. Butcher
Summary: This study examines ancient geomorphic features in the Protonilus Mensae region of Mars, including continuous coverage of circular structures and polygon structures, as well as stratigraphic features intertwined with glacial and periglacial cycles. The results suggest that the cold climate geology on Mars may be more similar to Earth's than previously thought.
Article
Astronomy & Astrophysics
R. J. Soare, S. J. Conway, J-P Williams, M. Philippe, L. E. Mc Keown, E. Godin, J. Hawkswell
Summary: Ice complexes are common landscapes in Arctic coastal plains on Earth, formed by freeze-thaw cycling of water and characterized by features like thermokarst terrain, lakes, basins, and ice-wedge polygons. The hypothesis of ice-rich terrain on Mars remains unvalidated due to lack of regolith samples. The similarities between ice and sand-wedge polygons on Mars have complicated the understanding of ice-wedge hypotheses.
Article
Geochemistry & Geophysics
G. M. Martinez, E. Sebastian, A. Vicente-Retortillo, M. D. Smith, J. R. Johnson, E. Fischer, H. Savijarvi, D. Toledo, R. Hueso, L. Mora-Sotomayor, H. Gillespie, A. Munguira, A. Sanchez-Lavega, M. T. Lemmon, F. Gomez, J. Polkko, L. Mandon, V. Apestigue, I. Arruego, M. Ramos, P. Conrad, C. E. Newman, M. de la Torre-Juarez, F. Jordan, L. K. Tamppari, T. H. McConnochie, A. -M. Harri, M. Genzer, M. Hieta, M. -P. Zorzano, M. Siegler, O. Prieto, A. Molina, J. A. Rodriguez-Manfredi
Summary: The Mars Environmental Dynamics Analyzer (MEDA) on board Perseverance includes first-of-its-kind sensors to measure various radiation fluxes on Mars surface. Using these measurements and ground temperature data, the study determines the radiative budget and broadband albedo of Mars, as well as calculates the thermal inertia of homogeneous terrains. The study also compares the results with other measurements to validate model predictions and provide ground-truth data.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Astronomy & Astrophysics
Shannon M. Hibbard, Nathan R. Williams, Matthew P. Golombek, Gordon R. Osinski, Etienne Godin
Summary: Viscous flow features, including lobate debris aprons and lineated valley fill, are common ice-related features found across the mid-latitudes of Mars. The sinuous and lobate features in Arcadia Planitia are believed to be buried debris-covered glaciers formed during higher obliquity periods in Mars' recent past. These features appear to be channelized ice that once flowed but currently reside in a flat-lying region.
Article
Astronomy & Astrophysics
L. H. Lark, C. Huber, J. W. Head
Summary: Recurring slope lineae (RSL) on Mars are dark linear features that lengthen and fade seasonally. The role of water in their formation processes is still uncertain. Observations of anomalous RSL suggest a preference for the liquid flow mechanism over dry granular flow for their growth.
Article
Multidisciplinary Sciences
Xiaoguang Qin, Xin Ren, Xu Wang, Jianjun Liu, Haibin Wu, Xingguo Zeng, Yong Sun, Zhaopeng Chen, Shihao Zhang, Yizhong Zhang, Wangli Chen, Bin Liu, Dawei Liu, Lin Guo, Kangkang Li, Xiangzhao Zeng, Hai Huang, Qing Zhang, Songzheng Yu, Chunlai Li, Zhengtang Guo
Summary: Landforms on the Martian surface provide valuable insights into past surface processes, but the modern hydroclimatic conditions on Mars are still not well understood. This study reports the discovery of various surface features on salt-rich dunes in southern Utopia Planitia, suggesting the involvement of saline water from thawed frost/snow as the most likely cause. The findings shed light on the more humid conditions of the modern Martian climate and have important implications for future exploration missions searching for signs of extant life.
Article
Geochemistry & Geophysics
Csilla Orgel, Caleb Fassett, Gregory Michael, Christian Riedel, Carolyn H. van der Bogert, Harald Hiesinger
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2020)
Article
Environmental Sciences
Joseph S. Levy, Jessica T. E. Johnson
Summary: The newly developed CRWI soil moisture index can effectively determine soil moisture content through hyperspectral imaging, regardless of soil composition and grain size. Compared to other indices, CRWI shows a stronger correlation with surface soil moisture and can be utilized for monitoring soil moisture in desert environments.
Article
Geosciences, Multidisciplinary
Gaia Stucky de Quay, Timothy A. Goudge, Edwin S. Kite, Caleb Fassett, Scott D. Guzewich
Summary: Research suggests that multiple runoff episodes likely occurred on ancient Mars, lasting between 102-105 years, with model-dependent and spatially variable durations that cannot satisfy all lake systems uniformly. These quantitative constraints on early Mars lake persistence may soon be tested through in situ observations from the Perseverance rover.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Cole A. Nypaver, Bradley J. Thomson, Caleb Fassett, Edgard G. Rivera-Valentin, Gerald W. Patterson
Summary: Fresh impact ejecta deposits on the lunar surface consist of a heterogeneous mix of boulders, cobbles, and fine-grained regolith. Observations of old lunar impact craters reveal the presence of large boulders along their rims, indicating continuous rock exposure due to downslope movement of regolith. Collecting lunar samples at crater rims can help mitigate sample contamination from distant sources and ensure accurate geologic interpretations.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2021)
Article
Geosciences, Multidisciplinary
Sashank Vanga, Caleb Fassett, Michael Zanetti, Cole Nypaver, Bradley J. Thomson, Masatoshi Hirabayashi
Summary: This study analyzed rock abundance data on the lunar surface and found that the growth of lunar regolith affects the abundance of surface rocks, indicating that older surfaces have lower rock abundance, and younger surfaces have higher rock abundance. In addition, rocks reexcavated from within the regolith contribute significantly to the observed rock population on the lunar surface.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Multidisciplinary Sciences
Timothy A. Goudge, Alexander M. Morgan, Gaia Stucky de Quay, Caleb Fassett
Summary: Lake breach flooding on early Mars significantly eroded a quarter of incised valleys, impacting the Martian landscape. The global importance of these floods in shaping valley systems highlights their role in the broader landscape evolution of Mars.
Article
Geochemistry & Geophysics
Caleb I. Fassett, Timothy A. Goudge
Summary: Open-basin lakes with outlets on Mars are likely formed by single flood events that involve suspension sediment transport. The peak discharges from these lakes are significant, ranging from 10(4) to 10(6) m(3)/s, and the outlet-forming floods can last for days to weeks. The size of the lakes, topographic setting, and sediment transport by suspension play crucial roles in controlling the erosion of outlets on the Martian landscape.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2021)
Article
Geosciences, Multidisciplinary
C. L. Talkington, M. Hirabayashi, P. E. Montalvo, A. N. Deutsch, C. Fassett, M. A. Siegler, S. L. Shepherd, D. T. King
Summary: By analyzing the complex craters on the Moon, it is found that topographic diffusion and ejecta blankets can preserve up to 1wt% of water. However, impact mixing and internal heat limit the stability of ancient water to subsurface regions younger than 3.9 billion years and at depths ranging from a few meters to tens of meters.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Don R. Hood, S. F. Sholes, S. Karunatillake, C. Fassett, R. C. Ewing, J. Levy
Summary: In this study, a tool called Martian Boulder Automatic Recognition System (MBARS) is developed to automatically locate and measure boulders on the surface of Mars. This tool enables rapid and accurate assessments of boulder populations, providing insights into the processes that have operated on the Martian surface.
EARTH AND SPACE SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Emily R. Bamber, T. A. Goudge, C. Fassett, G. R. Osinski, G. Stucky de Quay
Summary: This study examines the factors that influence the formation of inlet valleys in degraded Martian craters. The researchers found that hydrologic factors related to basin hydrology play a more significant role than topographic factors in determining whether a crater possesses an inlet or not.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Caleb Fassett, Ross A. Beyer, Ariel N. Deutsch, Masatoshi Hirabayashi, C. J. Leight, Prasun Mahanti, Cole A. Nypaver, Bradley J. Thomson, David A. Minton
Summary: Crater degradation and erosion control the lifespan of craters on the lunar surface, resulting in relatively short survival time for meter-scale craters.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2022)
Article
Geochemistry & Geophysics
Timothy A. Goudge, Caleb I. Fassett, Marianne Coholich, Emily R. Bamber
Summary: More than 250 hydrologically open paleolakes on Mars have been discovered, which were filled with water before catastrophic breaching occurred. Observational results and numerical modeling experiments indicate that steeper slopes and taller crater rims are key factors in promoting more complete draining of these open-basin lakes on Mars.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Geochemistry & Geophysics
P. E. Montalvo, H. Christopher, M. Hirabayashi, C. Fassett, D. T. King Jr
Summary: We estimated the ejecta thickness of five complex craters on Ceres' equatorial region by analyzing smaller, simple craters in their ejecta deposits. The ejecta thickness ranges from 3 to 73 m around complex craters and 96-223 m at their rim crest localities. The thinner ejecta thicknesses on Ceres compared to the Moon are likely due to the presence of meltwater, which is supported by previous studies on subsurface water ice melting.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Multidisciplinary Sciences
J. L. Dickson, A. M. Palumbo, J. W. Head, L. Kerber, C. I. Fassett, M. A. Kreslavsky
Summary: Gullies on Mars are similar to water-carved channels on Earth, but they are mostly found at elevations where liquid water is not expected under the current climate conditions. Previous studies have suggested that the sublimation of carbon dioxide ice alone could form Martian gullies. However, using a general circulation model, this study suggests that the highest-elevation Martian gullies coincide with a boundary where pressures above the triple point of water have occurred when Mars' rotational axis tilt reached 35 degrees. These conditions have happened repeatedly over the past several million years, with the most recent occurrence being about 630,000 years ago. Therefore, the researchers propose a dual gully formation scenario that involves the melting of water ice followed by the sublimation of carbon dioxide ice.
Article
Environmental Sciences
Tyler M. Meng, Roberto Aguilar, Michael S. Christoffersen, Eric I. Petersen, Christopher F. Larsen, Joseph S. Levy, John W. Holt
Summary: This study uses high-resolution remote sensing imagery and photogrammetric data to automatically measure the horizontal surface displacement and estimate the vertical surface changes of four North American rock glaciers. The study provides insights into the age of glacier formation and the current surface changes.
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.