Article
Astronomy & Astrophysics
Christopher O. Johnston, Eric C. Stern
Summary: This article proposes a method to evaluate the initial diameter of a meteoroid based on the measured absolute visual magnitude, and establishes a corresponding relationship formula. This method utilizes insights from recent computational fluid dynamics and radiation simulations, as well as calibrated lightcurves and recovered meteorites. This approach provides meteor diameter assessments that are independent of luminous efficiency.
Article
Astronomy & Astrophysics
Kierra A. Wilk, Janice L. Bishop, Catherine M. Weitz, Mario Parente, Arun M. Saranathan, Yuki Itoh, Christoph Gross, Jessica Flahaut, Frank Seelos
Summary: This study investigates the unique spectral features of materials in the Ius Chasma region on Mars, focusing on the Geryon Montes area. The presence of a distinct doublet feature at the border of phyllosilicate-bearing and sulfate-bearing regions is identified and analyzed using hyperspectral images. The findings suggest that these unique alteration phases may have formed through acid alteration of ancient smectites.
Article
Astronomy & Astrophysics
M. T. Lemmon, S. D. Guzewich, J. M. Battalio, M. C. Malin, A. Vicente-Retortillo, M. -p. Zorzano, J. Martin-Torres, R. Sullivan, J. N. Maki, M. D. Smith, J. F. Bell
Summary: The Mars Science Laboratory Curiosity rover has been monitoring the Martian environment in Gale crater since 2012. This study shows that the optical depth on Mars is mainly influenced by aerosols, primarily dust and ice. The optical depth varies seasonally, with higher values during southern spring and summer, and lower values during fall and winter. Dust load also shows a diurnal change during southern spring and summer, correlated with thermotidal pressure changes. The observations also indicate higher dust and ice content at high altitudes, especially during winter.
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
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
Iraklis Giannakis, Javier Martin-Torres, Yan Su, Jianqing Feng, Feng Zhou, Maria-Paz Zorzano, Craig Warren, Antonios Giannopoulos
Summary: Yutu-2 is the longest operational Lunar rover and the first rover to land on the far side of the Moon. It uses ground-penetrating radar to investigate the geological structure of the lunar surface, providing valuable data for research.
Article
Astronomy & Astrophysics
Paul M. Schenk, William B. Mckinnon
Summary: A new global topographic map and updated global mosaic of Enceladus show that the shape of this icy ocean world is distorted and exhibits a zonal latitudinal zoning of topography. Basins on this moon are shaped by the characteristics of the terrains they formed in, rather than by local-scale geologic deformation. These basins may be surface manifestations of hydrothermal activity originating from the rocky core of Enceladus.
Article
Astronomy & Astrophysics
Ronald W. Klusman, Yangcheng Luo, Pin Chen, Michael A. Mischna, Yuk L. Yung
Summary: Measurements from the Curiosity rover on Mars show that methane concentration in the atmosphere exhibits seasonality and diurnal variation, indicating the presence of a replenishing source and a modulation mechanism. A model is proposed, considering barometric pumping, adsorption and desorption processes, to explain the observed methane concentration variation. The model assumes a continuous, steady-state deep source of methane, with carbon dioxide acting as the carrier gas.
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
A. Broquet, J. C. Andrews-Hanna
Summary: The crust of the Moon has undergone a unique geodynamic evolution, leaving crucial records in the form of topographic features and gravity anomalies. By analyzing gravity and topography data, researchers can uncover the global structure of the Moon's crust and its pre-existing conditions before volcanic activities. The study reveals differences in the surface and crust of the Moon before and after volcanic activities, shedding light on various geological processes and their implications.
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
Lujendra Ojha, Jacob Buffo, Baptiste Journaux
Summary: Based on the study of the south polar layered deposits (SPLD) on Mars, it is found that specific conditions of temperature, heat flow, and thermal conductivity are required for basal melting, which contradicts current constraints on the composition of SPLD. In addition, magmatic intrusions may also cause basal melting, but specific dimensions and sustained conditions are necessary.
Article
Astronomy & Astrophysics
Zhen Cao, Zhizhong Kang, Teng Hu, Ze Yang, Longze Zhu, Chenming Ye
Summary: This article introduces a deep learning-based crater detection algorithm, the Cross-Attention-Induced Multilayer Domain Adaptation Network (CAMDA-Net), which transfers valuable crater knowledge from the Moon to Mars without the need for manual labeling. CAMDA-Net aligns crater features at both the image and instance levels and demonstrates excellent performance in crater detection on Mars.
Article
Astronomy & Astrophysics
Tianquan Gao, Li Xue, Jiali Feng
Summary: This article investigates the optical performance of corner-cube reflectors (CCRs) at near-infrared wavelength and measures the effective echo rates of L1 and L2 through experiments. The results demonstrate that there is an error in the initial pointing of the CCRs.
Article
Astronomy & Astrophysics
Bartosz Pieterek, Petr Broz, Ernst Hauber, Katrin Stephan
Summary: This study focuses on small-scale landforms in the Claritas Fossae region of Mars, and identifies volcanic origins for these features based on their morphological and spectral properties. The findings suggest relatively young volcanic activity in the area, which has implications for understanding the evolution of magma compositions on Mars.
Article
Astronomy & Astrophysics
David G. Russell
Summary: The study found that the sample of exoplanets with equilibrium temperature <= 600 K and low uncertainty in mass and radius measurements has a sub-Saturn mass-radius desert consistent with predictions from the core-accretion scenario. This desert is devoid of planets with mass > 20 M-circle plus and a radius in the range of 4.0-7.5 R(circle plus). However, the sample of planets with a higher equilibrium temperature (>630 K) includes a significant number of planets that fall into the sub-Saturn mass-radius desert found in the lower temperature range. The difference between the two populations may be due to differences in migration history in the core-accretion scenario.
Article
Astronomy & Astrophysics
Jimin Peng, Giovanni Munaretto, Livio Tornabene, Alice Lucchetti, Gabriele Cremonese, Maurizio Pajola, Cristina Re, Patricio Becerra, Nicolas Thomas
Summary: This study investigates the seasonal morphology, surface topography, spectral data, and thermal environment of Low Albedo Streaks (LAS) at the edges of the South Polar Layered Deposits (SPLD) on Mars. The analysis suggests that LAS originate from scarps and outcrops on the edge of layered structures, lengthen in spring forming sinuous branches, and eventually fade leaving bright deposits within the streaked area. The spectral data analysis indicates the presence of pyroxene- or basaltic-bearing materials on the surface mainly composed of dust by LAS. Thermal analysis shows that LAS are active in a temperature range of 145.5 K to 162 K.
Article
Astronomy & Astrophysics
Norbert Schorghofer, Rebecca Ghent, K. -Michael Aye
Summary: Surface temperature measurements of airless bodies can be used to estimate regolith thermal properties. This study applies an ensemble of thermal model calculations to lunar nighttime surface temperatures in order to constrain the mean particle size of near-surface regolith materials.
Correction
Astronomy & Astrophysics
V. J. Bray, P. M. Schenk, H. J. Melosh, J. V. Morgan, G. S. Collins
Article
Astronomy & Astrophysics
P. S. Chen, J. Y. Liu
Summary: In this paper, we have studied the infrared properties of nearly 900 dust obscured galaxies (DOGs) using 2MASS (and other observations in the JHK bands), WISE, IRAS and Herschel data. Our study reveals that DOGs with different types show different relations between redshift and infrared colors. Additionally, the near infrared two-color diagram shows that some DOGs exhibit thermal emission from stellar components and star formation, while others are dominated by AGN. Furthermore, comparing DOGs and ULIRGs, we find that ULIRGs have redder colors in the near and mid-infrared regions, while in the far infrared region, ULIRGs show similarities to the blackbody line indicative of star formation dominance.
