The Russian Phobos-Grunt spacecraft originally planned to return a 200 g sample of surface material from Phobos to Earth. Although it was anticipated that this material would mainly be from the body of Phobos, there is a possibility that such a sample may also contain material ejected from the surface of Mars by large impacts. An analysis of this possibility is completed by using current knowledge of aspects of impact cratering on the surface of Mars and the production of high-speed ejecta that might reach Phobos or Deimos.
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http://dx.doi.org/10.1089/ast.2012.0942 | DOI Listing |
Sci Rep
January 2025
Institut de Recherche en Astrophysique et Planétologie, UPS/CNRS/CNES, F-31400, Toulouse, France.
The radioactive gas radon-222, a fluid and aerosol tracer in Earth's lithosphere and atmosphere, can also reveal subtle rock physics processes in extraterrestrial environments, such as those involving water, but remains poorly constrained in planetary bodies due to the limited number of samples available. Here we measure the effective radium-226 concentration (EC) of six Martian and nine lunar meteorites to derive radon source terms for Martian and lunar rocks. EC values are 0.
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January 2025
Laboratory of Materials, Nanotechnologies and Environment, Center of Sciences of Materials, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP:1014, 10000, Rabat, Morocco.
In this study, novel polyaniline-coated perovskite nanocomposites (PANI@CoTiO and PANI@NiTiO) were synthesized using an in situ oxidative polymerization method and evaluated for the photocatalytic degradation of Rhodamine B (RhB) a persistent organic pollutant. The nanocomposites displayed significantly enhanced photocatalytic efficiency compared to pure perovskites. The 1%wt PANI@NiTiO achieved an impressive 94% degradation of RhB under visible light after 180 min, while 1wt.
View Article and Find Full Text PDFAstrobiology
January 2025
NASA Goddard Space Flight Center, Greenbelt, Maryland, USA.
Meteoritic impacts on planetary surfaces deliver a significant amount of energy that can produce prebiotic organic compounds such as cyanides, which may be a key step to the formation of biomolecules. To study the chemical processes of impact-induced organic synthesis, we simulated the physicochemical processes of hypervelocity impacts (HVI) in experiments with both high-speed C projectiles and laser ablation. In the first approach, a C beam was accelerated to collide with ammonium nitrate (NHNO) to reproduce the shock process and plume generation of meteoritic impacts on nitrogen-rich planetary surfaces.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Institute of Nanomaterials, Faculty of Materials Science, Kim Il Sung University, Ryongnam-Dong, Taesong District, Pyongyang, Democratic People's Republic of Korea.
Significant research efforts have been devoted to improving the efficiency of catalytic carbon monoxide (CO) oxidation over α-FeO-based catalysts, but details of the underlying mechanism are still under debate. Here we apply the thermodynamic method (AITM) within the density functional theory framework to investigate the phase diagram of α-FeO(0001) surfaces with various terminations and the catalytic mechanism of CO oxidation on these surfaces. By extending the conventional AITM to consider the charge state of surface defects, we build the phase diagram of α-FeO(0001) surfaces in relation to the Fermi energy as well as the oxygen chemical potential, which makes it possible to explain the influence of point defects on the surface morphology and to predict the existence of the experimentally observed functional sites such as the ferryl group (FeO) and oxygen vacancies.
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January 2025
Department of Plant Pathology, Space Life Sciences Lab, University of Florida, 505 Odyssey Way, Exploration Park,, Merritt Island, FL, 32953, USA.
Mars, with its ancient history of long-lived habitable environments, continues to captivate researchers exploring the potential for extant life. This study investigates the biosignature potential of Martian methane by assessing the viability of hydrogenotrophic methanogenesis in Methanosarcina barkeri MS under simulated Martian surface conditions. We expose M.
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