¹Kareta, Theodore,²Fuentes-Muñoz, Oscar,¹Moskovitz, Nicholas²Farnocchia, Davide,³Sharkey, Benjamin N. L.
Astrophysical Journal Letters 979, L8 Open Access Link to Article [DOI 10.3847/2041-8213/ad9ea8]
¹Lowell Observatory, Flagstaff, AZ, United States
²Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, 91109, CA, United States
³Department of Astronomy, University of Maryland, 4296 Stadium Dr., PSC (Bldg. 415) Rm. 1113, College Park, 20742-2421, MD, United States

The near-Earth asteroid (NEA) 2024 PT5 is on an Earth-like orbit that remained in Earth’s immediate vicinity for several months at the end of 2024. PT5’s orbit is challenging to populate with asteroids originating from the main belt and is more commonly associated with rocket bodies mistakenly identified as natural objects or with debris ejected from impacts on the Moon. We obtained visible and near-infrared reflectance spectra of PT5 with the Lowell Discovery Telescope and NASA Infrared Telescope Facility on 2024 August 16. The combined reflectance spectrum matches lunar samples but does not match any known asteroid types—it is pyroxene-rich, while asteroids of comparable spectral redness are olivine-rich. Moreover, the amount of solar radiation pressure observed on the PT5 trajectory is orders of magnitude lower than what would be expected for an artificial object. We therefore conclude that 2024 PT5 is ejecta from an impact on the Moon, thus making PT5 the second NEA suggested to be sourced from the surface of the Moon. While one object might be an outlier, two suggest that there is an underlying population to be characterized. Long-term predictions of the position of 2024 PT5 are challenging due to the slow Earth encounters characteristic of objects in these orbits. A population of near-Earth objects that are sourced by the Moon would be important to characterize for understanding how impacts work on our nearest neighbor and for identifying the source regions of asteroids and meteorites from this understudied population of objects on very Earth-like orbits.

^1,2Dorian Leger,¹Fardin Ghaffari-Tabrizi,³ Matthew Shaw,⁴Joshua Rasera,⁵David Dickson,^6,7Baptiste Valentin,⁸Anton Morlock,¹Freja Thoresen,¹Aidan Cowley Proceedings of the National Academy od Science of the USA (PNAS) 122, e2306146122 Link to Article [https://doi.org/10.1073/pnas.2306146122] ¹Spaceship, European Astronaut Center, Exploration Preparation, Research and Technology Team (ExPeRT), Directorate of Human and Robotic Exploration, European Space Agency, Cologne 51147, Germany ²Cx Bio, Luxembourg 2521, Luxembourg ³Future Mining Team, Commonwealth Scientific and Industrial Research Organisation, Mineral Resources, Clayton VIC 3168, Australia ⁴Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, United Kingdom ⁵Center for Space Resources, Colorado School of Mines, Golden, CO 80401, Colorado ⁶Spaceship FR, Centre National d’Etudes Spatial, Toulouse 31400, France ⁷Belgian Air and Space Component, Control & Reporting Centre, Belgian Armed Forces, Brussels 1140, Belgium ⁸Karlsruhe Institute of Technology, Karlsruhe 76131, Germany Spacecraft using combustion engines require substantial amounts of oxygen for their propellant. The Moon could be a source of oxygen for rocket propellant, since the material composing the lunar surface can be processed to extract oxygen. However, little is known about overall energy requirements of the processes described in the literature for oxygen extraction from lunar regolith. This knowledge gap constrains the planning of lunar missions, since the scale of energy infrastructure required for oxygen production facilities is not well characterized. This study presents an energy consumption model for oxygen production via hydrogen reduction of the mineral ilmenite (FeTiO₃). We consider an end-to-end production chain starting from dry regolith as the feedstock. The production includes the following process steps: excavation, transportation, beneficiation, hydrogen reduction, water electrolysis, liquefaction, and zero boil-off storage. The model predicts the energy demand per kilogram oxygen produced based on adjustable parameters for each process step. As expected, the model indicates a strong dependence on feedstock composition. For regolith composed of 10 wt% ilmenite, the model predicts that a total of 24.3 (± 5.8) kWh is needed per kg of liquid oxygen produced. This study confirms that the hydrogen reduction and electrolysis steps have the highest energy requirements in the production chain. Sensitivity analysis reveals that the enrichment factor of the beneficiation process is the most critical parameter for optimizing energy utilization. Overall, this study provides a parameterized end-to-end model of energy consumption that can serve as a foundation for various production systems on the Moon.

^1,2Marine Paquet , ¹Frederic Moynier, ³Paolo A. Sossi, ¹Wei Dai, James M.D. Day
Earth and Planetary Science Letters 656, 119250 Open Access Link to Article [https://doi.org/10.1016/j.epsl.2025.119250]
¹Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, F-75005, France
²Université de Lorraine, CNRS, CRPG, F-54000, Nancy, France
³Institute of Geochemistry and Petrology, ETH Zürich, Clausiusstrasse 25, Zürich CH-8092, Switzerland
⁴Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0244, USA
Copyright Elsevier

The abundances and isotopic signatures of volatile elements provide critical information for understanding the delivery of water and other essential life-giving compounds to planets. It has been demonstrated that the Moon is depleted in moderately volatile elements (MVE), such as Zn, Cl, S, K and Rb, relative to the Earth. The isotopic compositions of these MVE in lunar rocks suggest loss of volatile elements during the formation of the Moon, as well as their modification during later differentiation and impact processes. Due to its moderately volatile and strongly chalcophile behaviour, copper (Cu) provides a distinct record of planetary accretion and differentiation processes relative to Cl, Rb, Zn or K. Here we present Cu isotopic compositions of Apollo 11, 12, 14 and 15 mare basalts and lunar basaltic meteorites, which range from δ65Cu of +0.55±0.01 ‰ to +3.94±0.04 ‰ (per mil deviation of the 65Cu/63Cu from the NIST SRM 976 standard), independent of mare basalt Ti content. The δ65Cu values of the basalts are negatively correlated with their Cu contents, which is interpreted as evidence for volatile loss upon mare basalt emplacement, plausibly related to the presence Cl- and S-bearing ligands in the vapour phase. This relationship can be used to determine the Cu isotopic composition of the lunar mantle to a δ65Cu of +0.57 ± 0.15 ‰. The bulk silicate Moon (BSM) is 0.5‰ heavier than the bulk silicate Earth (+0.07 ± 0.10 ‰) or chondritic materials (from -1.45 ± 0.08 ‰ to 0.07 ± 0.06 ‰). Owing to the ineffectiveness of sulfide segregation and lunar core formation in inducing Cu isotopic fractionation, the isotopic difference between the Moon and the Earth is attributed to volatile loss during the Moon-forming event, which must have occurred at- or near-equilibrium.

^1,2Matthew J. Genge, ³Matthias Van Ginneken, ⁴Chi Ma, ⁵Martin D. Suttle, ^1,2Natasha Almeida, ⁶Noriko T. Kita, ⁶Mingming Zhang, ⁷Luca Bindi
Earth and Planetary Science Letters 656, 119276 Open Access Link to Articel [https://doi.org/10.1016/j.epsl.2025.119276]
¹Department of Earth Science and Engineering, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
²Planetary Materials Group, Natural History Museum, London, SW7 5BD, UK
³Department of Physics and Astronomy, Centre for Astrophysics and Planetary Science, University of Kent, Canterbury, Kent, CT2 7NH, UK
⁴Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
⁵School of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
⁶Department of Geoscience, University of Wisconsin-Madison, 1215W. Dayton St., Madison, WI, 53706, USA
⁷Dipartimento di Scienze della Terra, Università di Firenze, Via La Pira 4, I, 50121, Florence, Italy
Copyright Elsevier

We report the discovery of Al-Cu-alloys within a coarse-grained micrometeorite from the Congo. Oxygen isotope ratios of the sample are consistent with a CV3 source, similar to the Khatyrka meteorite. The petrology of the micrometeorite is also similar to Khatyrka and testifies to the disequilibrium impact mixing between the CV3 parent body and a differentiated body, which was the source of the Al-Cu-alloys. The oxygen isotope composition, however, suggests either limited mixing with projectile silicates or a differentiated projectile with oxygen isotopes close to the CCAM. The most plausible origin of the Al-Cu-alloys is the desilication of an aluminous igneous protolith by hydrothermal activity under highly reduced conditions. We argue that the ureilite parent body is the most likely source for the projectile owing to its silicic magmatism, late-stage reduction and similar oxygen isotope ratios. Al-Cu-alloys can, thus, be found on the disrupted remnants of such protoplanets.

¹Dian Ji, ¹Rajdeep Dasgupta
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2025.02.019]
¹Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX 77005, United States of America
Copyright Elsevier

Assessing whether the lunar mantle retains sulfide, through episodes of magmatism, is important in tracking the origin and evolution of sulfur and other volatile and chalcophile elements on the Moon. To determine sulfur concentrations at sulfide saturation (SCSS) in the mantle conditions of young Chang’e-5 (CE-5) mare basalts, we conducted experiments with three possible CE-5 parental melt compositions and Fe ± Ni-S sulfide at 1.0–3.0 GPa and 1250–1550 °C. We doped excess Fe metal in a subset of experiments in order to generate sulfide of various metal/sulfur molar ratio (M/S; 1.0–2.1), and thus investigate the effect of sulfide composition on SCSS under different oxygen fugacities (fO2s). Our experimental results indicate that SCSS is sensitive to temperature, pressure, silicate melt, sulfide compositions, and fO2. Using our new and literature data, we developed a new thermodynamic SCSS model and utilized the model to calculate the SCSS for scenarios that the CE-5 parental melt is in equilibrium with pure FeS, high Fe/S ratio sulfide, as well as high M/S Ni-bearing sulfide. All results suggest predictive SCSS values are higher than the S concentration in CE-5 parental magma, indicating the CE-5 mantle residue was likely sulfide-absent, unless an extremely S-poor and Ni-rich, Fe-alloy was the chief S-bearing accessory phase. We further reconstruct the S abundance in the CE-5 mantle source. Compared with the mantle of Apollo mare basalts, the ∼ 2 Gyrs lunar mantle has much lower S abundances, suggesting sulfur extraction by mantle melting over the magmatic history of the Moon, or S distribution heterogeneity in the lunar interior.

¹Svetlana Demidova et al. (>10)
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2025.02.022]
¹Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, 119991 Kosygin Street, Moscow, Russia
Copyright Elsevier

Two types of mare basalt have been previously reported in the Luna-16 returned soil samples: dominant Intermediate-Ti basalts and minor Very-Low-Ti (VLT) basalts. The crystallization age of the main group of Intermediate-Ti basalts determined for 14 fragments by the Pb-Pb isochron approach is 3590.3 ± 9.4 Ma. Intermediate-Ti basalts are likely to represent the late episode of volcanism that occupies the largest part of the Mare Fecunditatis surface. The VLT group Pb-Pb isochron obtained from 3 fragments corresponds to an age 3919 ± 27 Ma. The VLT basalts may represent an initial underlying basaltic filling of Mare Fecunditatis, at least in some parts of the basin.

¹Bourdelle De Micas J. et al. (>10)
Astronomy and Astrophysics 693, L19 Open Access Link to Article [DOI 10.1051/0004-6361/202452498]
¹INAF, Osservatorio Astronomico di Roma, Via Frascati 33, Monte Porzio Catone, I-00078, Italy

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

¹Tatsumi, Eri,²Vilas, Faith,^3,4De León, Julia,⁵Popescu, Marcel,¹Hasegawa, Sunao,⁶De Prá, Mario,^3,4Tinaut-Ruano, Fernando,^3,4Licandro, Javier
Astronomy and Astrophysics 693, A140 Open Access Link to Article [DOI 10.1051/0004-6361/202450662]
¹Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Kanagawa, Sagamihara, Japan
²Planetary Science Institute (PSI), Tucson, AZ, United States
³Instituto de Astrofísica de Canarias (IAC), University of La Laguna, Tenerife, La Laguna, Spain
⁴Department of Astrophysics, University of La Laguna, Tenerife, La Laguna, Spain
⁵Astronomical Institute of the Romanian Academy, 5 Cuţitul de Argint, Bucharest, 040557, Romania
⁶Florida Space Institute, University of Central Florida, Orland, CA, United States

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¹Matthew J. O. Svensson,¹Gordon R. Osinski,¹Fred J. Longstaffe,²Timothy A. Goudge,³Haley M. Sapers
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.14330]
¹Department of Earth Sciences, The University of Western Ontario, London, Ontario, Canada
²Department of Earth and Planetary Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas, USA
³Department Astronomy & Planetary Science, Northern Arizona University, Flagstaff, Arizona, USA
Published by arrangement with John Wiley & Sons

Impact-generated hydrothermal systems and postimpact crater lake systems are well-documented geological phenomena; however, evidence of hydrothermal venting into impact crater lake systems has rarely been reported. We investigated the well-preserved contact between hydrothermally altered impact melt-bearing breccia (outer/surficial suevite) and postimpact crater lake deposits sampled by the Wörnitzostheim drill core at the Ries impact structure, Germany. We logged the upper 32 m of core, describing sedimentary structures and general lithological and mineralogical variations. Mineralogy was studied in detail using X-ray diffraction, optical microscopy, backscattered electron imagery, secondary electron imagery, and wavelength-dispersive spectroscopy analyses. Twelve different units were identified in the logged section of drill core, which we broadly separated into four distinct groups: (1) marlstones and limestones, (2) sand/siltstones, (3) conglomerates, and (4) impact melt-bearing breccias. The sedimentary deposits (groups 1–3) likely represent a transition from a back-stepping alluvial fan to a transgressing, shallow lake shoreline. Secondary dolomite, smectitic clay minerals and clinoptilolite occur as void-filling phases in the conglomerates—the earliest sedimentary deposits of the Wörnitzostheim drill core. A potential temperature range of 50–130°C was estimated for these void-filling minerals based on previous mineral synthesis experiments, and the typical mineral assemblages reported for the principal sequence of hydrothermal mineralization in impact craters and argillic alteration. Early postimpact sedimentary deposits likely host limited hydrothermal mineralization, potentially indicating ideal conditions for some microbial life forms during initial crater lake formation.

¹Oliver Christ,²Anna Barbaro,^3,4Ludovic Ferrière,³Lidia Pittarello,¹M. Chiara Domeneghetti,²Frank E. Brenker,^1,5Fabrizio Nestola,¹Matteo Alvaro
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.14326]
¹Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy
²Schwiete Cosmochemistry Laboratory, Department of Geoscience, Goethe-University Frankfurt, Frankfurt, Germany
³Natural History Museum Vienna, Vienna, Austria
⁴Natural History Museum Abu Dabi, Abu Dhabi, United Arab Emirates
⁵Section Alessandro Guastoni, Museum of Nature and Humankind, University of Padova, Padova, Italy
Published by arrangement with John Wiley & Sons

Iron meteorites, originating from the deepest parts of their parent bodies and separated during major break-up events, surprisingly rarely contain diamonds despite experiencing similar pressure–temperature conditions as diamond-bearing ureilites. In this study, graphite from three non-magmatic IAB iron meteorites Canyon Diablo, Campo del Cielo, and Yardymly was analyzed using micro-Raman spectroscopy, revealing the presence of the graphite G-band, the disorder-induced D-band, and occasionally the D′-band. Temperature estimates based on the G-band full width at half maximum (ranging from 1155 to 1339°C) are consistent with those found in ureilites. However, unlike in ureilites, no diamond bands were detected, as confirmed by μ-X-ray diffraction. The absence of diamonds is interpreted to be related to the thermal and mechanical properties of the iron meteorite matrix. Its high thermal diffusivity results in similar temperatures to ureilites, but its ductility dissipates shock-wave energy through plastic deformation, unlike the brittle ureilite matrix, which more effectively transmits the energy. Consequently, graphite in iron meteorites was heated but did not experience the high-pressure conditions required for diamond formation. Thus, we propose that impacts must either involve substantial energy or that graphite must be located close to the impact site, where it can experience high energies before these dissipate.