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Journal articles on the topic 'Moon-Plasma Interactions'
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1
Kivelson, Margaret G., Xianzhe Jia, and Krishan K. Khurana. "Medicean Moons Sailing Through Plasma Seas: Challenges in Establishing Magnetic Properties." Proceedings of the International Astronomical Union 6, S269 (2010): 58–70. http://dx.doi.org/10.1017/s1743921310007271.
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AbstractJupiter's moons, embedded in the magnetized, flowing plasma of Jupiter's magnetosphere, the plasma seas of the title, are fluids whose highly non-linear interactions imply complex behavior. In a plasma, magnetic fields couple widely separated regions; consequently plasma interactions are exceptionally sensitive to boundary conditions (often ill-specified). Perturbation fields arising from plasma currents greatly limit our ability to establish more than the dominant internal magnetic field of a moon. With a focus on Ganymede and a nod to Io, this paper discusses the complexity of plasma-moon interactions, explains how computer simulations have helped characterize the system and presents improved fits to Ganymede's internal field.
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Szabo, Paul S., Andrew R. Poppe, Andreas Mutzke, Lucas Liuzzo, and Shane R. Carberry Mogan. "Backscattering of Ions Impacting Ganymede’s Surface as a Source for Energetic Neutral Atoms." Astrophysical Journal Letters 963, no. 1 (2024): L32. http://dx.doi.org/10.3847/2041-8213/ad2701.
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Abstract Jupiter’s largest moon Ganymede has its own intrinsic magnetic field, which forms a magnetosphere that is embedded within Jupiter’s corotating magnetospheric plasma. This scenario has been shown to lead to complex ion precipitation patterns that have been connected to heterogeneous space weathering across Ganymede’s surface. We present the first simulations of energetic neutral atoms (ENAs) from backscattered H, O, and S ions, accounting for magnetospheric plasma precipitation and Ganymede’s heterogeneous surface composition. Our model shows that backscattering introduces significant atomic H and O populations to Ganymede’s ENA environment, which will allow remote observation of ion–surface interactions at Ganymede. There are distinct differences between H ENA emissions at Ganymede and the Moon, with orders of magnitude lower fluxes below 1 keV but a significant tail above 1 keV. Backscattered H ENAs will also dominate over sputtered H contributions above energies of around 1 keV, while O ENAs are less likely to be distinguished from sputtered ENAs. The backscattered H ENAs thus represent a promising candidate for studying the plasma–surface interaction on Ganymede with future observations of ESA’s JUICE mission.
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Popel, Sergey I., and Lev M. Zelenyi. "Dusty plasma interactions near the Moon and in the system of Mars." Proceedings of the International Astronomical Union 14, A30 (2018): 389–90. http://dx.doi.org/10.1017/s1743921319004861.
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Xia, Qing, Ming-Hui Cai, Liang-Liang Xu, Rui-Long Han, Tao Yang, and Jian-Wei Han. "Distribution of charged lunar dust in the south polar region of the moon." Chinese Physics B 31, no. 4 (2022): 045201. http://dx.doi.org/10.1088/1674-1056/ac2e61.
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Lunar dust is one of the most threatening problems confronting the return of human beings to the moon. In this work we studied the spatial distribution behavior of charged lunar dust in the solar wind plasma environment in the south polar region of the moon and considered the influence of a mini-crater using Spacecraft Plasma Interactions Software. The distribution of dust and plasma at low solar altitude angles of 20° and 0° was studied, and the spatial density of lunar dust was ∼ 1010.4 m−3 and ∼ 1011.5 m−3, respectively. This is because a higher surface potential will result in transportation of small dust particles and photoelectrons can also neutralize positively charged lunar dust. The dust density in the plasma void region created by a mini-crater with a 5 m high wall was studied. We obtained a quasi-neutral electric environment in the plasma void region of the mini-crater, and the dust density was about a magnitude lower than that in other regions. The dust risk to a spacesuit is much lower on the nightside than on the dayside, but there is severe charged lunar dust transport in the region between light and shade, which is dominated by the difference in surface and plasma potential caused by photoelectrons.
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Roussos, E., J. Müller, S. Simon, et al. "Plasma and fields in the wake of Rhea: 3-D hybrid simulation and comparison with Cassini data." Annales Geophysicae 26, no. 3 (2008): 619–37. http://dx.doi.org/10.5194/angeo-26-619-2008.
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Abstract. Rhea's magnetospheric interaction is simulated using a three-dimensional, hybrid plasma simulation code, where ions are treated as particles and electrons as a massless, charge-neutralizing fluid. In consistency with Cassini observations, Rhea is modeled as a plasma absorbing obstacle. This leads to the formation of a plasma wake (cavity) behind the moon. We find that this cavity expands with the ion sound speed along the magnetic field lines, resulting in an extended depletion region north and south of the moon, just a few Rhea radii (RRh) downstream. This is a direct consequence of the comparable thermal and bulk plasma velocities at Rhea. Perpendicular to the magnetic field lines the wake's extension is constrained by the magnetic field. A magnetic field compression in the wake and the rarefaction in the wake sides is also observed in our results. This configuration reproduces well the signature in the Cassini magnetometer data, acquired during the close flyby to Rhea on November 2005. Almost all plasma and field parameters show an asymmetric distribution along the plane where the corotational electric field is contained. A diamagnetic current system is found running parallel to the wake boundaries. The presence of this current system shows a direct corelation with the magnetic field configuration downstream of Rhea, while the resulting j×B forces on the ions are responsible for the asymmetric structures seen in the velocity and electric field vector fields in the equatorial plane. As Rhea is one of the many plasma absorbing moons of Saturn, we expect that this case study should be relevant for most lunar-type interactions at Saturn.
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Simon, Sven. "An analytical model of sub‐Alfvénic moon‐plasma interactions with application to the hemisphere coupling effect." Journal of Geophysical Research: Space Physics 120, no. 9 (2015): 7209–27. http://dx.doi.org/10.1002/2015ja021529.
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Omerbashich, M. "Global coupling mechanism of Sun resonant forcing of Mars, Moon, and Earth seismicity." Journal of Geophysics 65, no. 1 (2023): 1–46. https://doi.org/10.5281/zenodo.8327412.
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Global seismicity on all three solar system bodies with <em>in situ</em> measurements (Earth, Moon, and Mars) is mainly due to the mechanical Rieger resonance (RR) of macroscopic flapping of the solar wind, driven by the well-known P<sub>Rg</sub>=~154-day Rieger period and commonly detected in most heliophysical data types and the interplanetary magnetic field (IMF). Thus, InSight mission marsquakes rates are periodic with P<sub>Rg</sub> as characterized by a very high (≫12) fidelity Φ=2.8·10<sup>6</sup> and by being the only ≥99%-significant spectral peak in the 385.8–64.3-nHz (1–180-day) band of highest planetary energies; the longest-span (v.9) release of raw data revealed the entire RR, excluding a tectonically active Mars. To check this, I analyzed the rates of the October 2015–February 2019, M<sub>w</sub>5.6+ earthquakes, and all (1969–1977) Apollo program moonquakes. To decouple the magnetospheric and IMF effects, I analyzed the Earth and Moon seismicity during the traversals of the Earth’s magnetotail vs. IMF. The analysis showed with ≥99–67% confidence and Φ≫12 fidelity that (an unspecified majority of) moonquakes and M<sub>w</sub>5.6+ earthquakes also recur at RR periods. Approximately half of the spectral peaks split but also into clusters that average into the usual Rieger periodicities, where magnetotail reconnecting clears the signal. Moonquakes are mostly forced at times of solar-wind resonance and not just during tides, as previously and simplistically believed. There is no significant dependence of sun-driven seismicity recurrence on solar cycles. Earlier claims that solar plasma dynamics could be seismogenic due to electrical surging or magnetohydrodynamic interactions between magnetically trapped plasma and water molecules embedded within solid matter or for reasons unknown are corroborated. This first conclusive recovery of the global coupling mechanism of solar-planetary seismogenesis calls for a reinterpretation of the seismicity phenomenon and reliance on global seismic magnitude scales. The predictability of solar-wind macroscopic dynamics is now within reach, which paves the way for long-term, physics-based seismic and space weather prediction and the safety of space missions. Gauss–Vaníček Spectral Analysis revolutionizes geophysics by computing nonlinear global dynamics directly (renders approximating of dynamics obsolete).
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Carballo, David M., Jennifer Carballo, and Hector Neff. "Formative and Classic Period Obsidian Procurement in Central Mexico: A Compositional Study Using Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry." Latin American Antiquity 18, no. 1 (2007): 27–43. http://dx.doi.org/10.2307/25063084.
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This report presents the results of a compositional study using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to examine central Mexican obsidian procurement at four sites dating to the Formative and Classic periods. The study demonstrates LA-ICP-MS to be a highly accurate obsidian sourcing technique, with results that are directly comparable to instrumental neutron activation analysis. It documents a shift circa 600 B.C. in which Middle Formative villages in Tlaxcala began to obtain obsidian almost exclusively from sources located in the Mesa Central, when they had previously obtained approximately 50 percent from Mesa Central sources and 50 percent from sources located in the Sierra Madre Oriental. This shift broadly coincided with the development of large regional centers in Tlaxcala-Puebla and suggests a linkage between the local political evolution occurring at this time and increased interactions with the Mesa Central economic sphere, including the Basin of Mexico. Obsidian workshop dump deposits next to Teotihuacan’s Moon Pyramid, dating to a millennium later, demonstrate the continued reliance on predominantly Mesa Central sources but also diversified procurement that drew on several sources. The Teotihuacan deposits exhibit the preferential utilization of particular sources depending on the types of implements being produced.
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Hanley, K. G., Q. McKown, E. M. Cangi, et al. "The Vulcan Mission to Io: Lessons Learned during the 2022 JPL Planetary Science Summer School." Planetary Science Journal 5, no. 7 (2024): 164. http://dx.doi.org/10.3847/psj/ad5841.
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Abstract A mission to Jupiter's moon Io, the most volcanically active body in the solar system, was suggested as a priority for the New Frontiers program in the 2013 Planetary Science Decadal Survey. We present a New Frontiers–class mission concept, Vulcan, that was designed as an educational exercise through the Jet Propulsion Laboratory’s 2022 Planetary Science Summer School. Vulcan would leverage an instrument suite consisting of wide- and narrow-angle cameras, a thermal infrared spectrometer, two fluxgate magnetometers, and ion and electron electrostatic analyzers to conduct the most thorough investigation of Io to date. Using 78 flybys over a 2 yr primary science mission, Vulcan would characterize the effects of tidal forces on the differentiation state, crustal structure, and volcanism of Io and investigate potential interactions between Io's volcanoes, surface features, and atmosphere. Although Vulcan was developed as an academic exercise, we show that a New Frontiers–class mission to Io could achieve transformative science in both geophysics and plasma physics, unifying typically disparate subfields of planetary science. A dedicated mission to Io, in combination with the Europa Clipper and Jupiter Icy Moons Explorer missions, would address fundamental questions raised by the 2023 Planetary Science Decadal Survey and could complete our understanding of the spectrum of planetary habitability. Lessons learned from Vulcan could be applied to a New Frontiers 5 Io mission concept in the near future.
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Simon, S. "Real-time 3-D hybrid simulation of Titan's plasma interaction during a solar wind excursion." Annales Geophysicae 27, no. 9 (2009): 3349–65. http://dx.doi.org/10.5194/angeo-27-3349-2009.
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Abstract. The plasma environment of Saturn's largest satellite Titan is known to be highly variable. Since Titan's orbit is located within the outer magnetosphere of Saturn, the moon can leave the region dominated by the magnetic field of its parent body in times of high solar wind dynamic pressure and interact with the thermalized magnetosheath plasma or even with the unshocked solar wind. By applying a three-dimensional hybrid simulation code (kinetic description of ions, fluid electrons), we study in real-time the transition that Titan's plasma environment undergoes when the moon leaves Saturn's magnetosphere and enters the supermagnetosonic solar wind. In the simulation, the transition between both plasma regimes is mimicked by a reversal of the magnetic field direction as well as a change in the composition and temperature of the impinging plasma flow. When the satellite enters the solar wind, the magnetic draping pattern in its vicinity is reconfigured due to reconnection, with the characteristic time scale of this process being determined by the convection of the field lines in the undisturbed plasma flow at the flanks of the interaction region. The build-up of a bow shock ahead of Titan takes place on a typical time scale of a few minutes as well. We also analyze the erosion of the newly formed shock front upstream of Titan that commences when the moon re-enters the submagnetosonic plasma regime of Saturn's magnetosphere. Although the model presented here is far from governing the full complexity of Titan's plasma interaction during a solar wind excursion, the simulation provides important insights into general plasma-physical processes associated with such a disruptive change of the upstream flow conditions.
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Yan, Tao, Binzheng Zhang, Junjie Chen, et al. "Three-dimensional Magnetohydrodynamic Simulations of Periodic Variations of Ganymede’s Footprint." Astrophysical Journal 965, no. 1 (2024): 82. http://dx.doi.org/10.3847/1538-4357/ad2c8a.
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Abstract Alfvénic power is generated through the interaction between the mini-magnetosphere of Ganymede and the corotating flow of the Jovian plasma, contributing to the formation of the Ganymede auroral footprint at Jupiter’s ionosphere. Using a three-dimensional, high-resolution global magnetohydrodynamic model of the Ganymede magnetosphere, we investigate the temporal variations of the Alfvénic power generated in the mini-magnetosphere of the moon under steady-state upstream conditions. Results show that (1) the Alfvénic power caused by the intermittent magnetic reconnections and the Kelvin–Helmholtz instabilities is quasiperiodic, varying over time with the periods about 71–333 s, which are consistent with the 100 s timescale periodicities of the Ganymede footprint's emitted power; and (2) the magnitude of the Alfvénic power is smaller when Ganymede is inside the Jovian plasma sheet where the B y component is smaller, and larger when the moon is outside the plasma sheet where the B y component is larger.
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Ambili, K. M., and R. K. Choudhary. "Three-dimensional distribution of ions and electrons in the lunar ionosphere originated from the photochemical reactions." Monthly Notices of the Royal Astronomical Society 510, no. 3 (2021): 3291–300. http://dx.doi.org/10.1093/mnras/stab3734.
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ABSTRACT Using a fluid-based time-dependent numerical photochemical model, the three-dimensional distribution of ions and electrons in the lunar ionosphere, originated purely from photochemical reactions, is investigated. The photochemical model includes the production and recombination of 16 ions, namely CO$_2^+$, H2O+, H3O+, OH+, O$_2^+$, O+, Ar+, Ne+, He+, H+, H$_2^+$, CH$_3^+$, CH$_4^+$, and CH$_5^+$. The model also includes the interaction of solar wind with lunar plasma and calculates electron density profiles from the surface to 200 km altitude for the entire latitudes and longitudes. Model runs suggest that the surface electron density at the Moon could be as high as 1.2 × 105 cm−3 over the mid-latitudes if dynamical interaction between the solar wind and lunar plasma is not accounted for. The dominant ions, in this case, would be Ar+, Ne+, and He+. The absence of any intrinsic magnetic field however leads the ionosphere at the Moon to interact continuously with the solar wind and result in the removal of positive ions. This, in turn, leads to a negligible presence of plasma in the lunar ionosphere with a maximum electron density of ∼1600 cm−3. The electron density is maximum during the midnight and post-midnight periods at all the latitudes, and the maximum is centred around the polar region. Though solar wind acts as a strong removal agent, the electron density distribution is controlled by photochemistry, and ions are molecular in origin.
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Allegrini, F., F. Bagenal, R. W. Ebert, et al. "Plasma Observations During the 7 June 2021 Ganymede Flyby From the Jovian Auroral Distributions Experiment (JADE) on Juno." Geophysical Research Letters 49 (July 5, 2022): e2022GL098682. https://doi.org/10.1029/2022GL098682.
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On June 7, 2021 the Juno mission came as close as 1046 km from the surface of Ganymede, the largest moon in the solar system. Similar close encounters were previously made by the Galileo mission, from which we learned much of the interaction of the moon, with its own intrinsic magnetic field, and Jupiter’s magnetosphere. In this paper, we present an overview of the plasma observations, i.e. ions and electrons in the lower part of the energy spectrum, made by the Jovian Auroral Distributions Experiment (JADE). We find that the ion composition near Ganymede is very different than that from Jupiter’s magnetosphere. Near Ganymede, the plasma composition is dominated by molecules and ions that originate from water in the atmosphere or the surface. One surprising observation is the presence of the molecular ion H<sub>3</sub><sup>+</sup> inside Ganymede’s magnetosphere and in a region just outside and downstream, that we call the wake. H<sub>3</sub><sup>+</sup> was not included in various models of Ganymede’s atmosphere.
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Izvekova, Yu N., S. I. Popel, and A. P. Golub’. "Nonlinear Dust Acoustic Waves in Exosphere of Mercury." Физика плазмы 49, no. 10 (2023): 1010–15. http://dx.doi.org/10.31857/s0367292123600814.
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The exosphere of Mercury, which has much in common with the exosphere of the Moon, can also contain suspended dust particles, which, under the action of intense solar radiation, acquire positive charges and form one of the components of the dusty plasma system. In addition to dust particles, there are photoelectrons above the planet surface, formed as a result of interaction of solar radiation with the planet surface, as well as with suspended dust particles. Mercury, unlike the Moon, has its own magnetosphere, which affects the parameters of dusty plasma system. The dusty plasma parameters near the Mercury surface can vary depending on the distance from the planet to the Sun, which considerably changes when the planet moves along the elongated orbit, and also depending on the localization of the region under consideration on the planet surface. Thus, near the magnetic poles, the solar wind can reach the planet surface, which must be taken into account when determining the plasma parameters. Far from the magnetic poles, the effect of the solar wind can be neglected. In the dusty plasma near the surface of Mercury, one can expect the development of linear and nonlinear wave processes. In this paper, nonlinear waves are considered, namely, dust acoustic solitons and nonlinear periodic waves. The profiles of potentials of high-amplitude solitons and nonlinear periodic waves are obtained, as well as the soliton amplitudes as functions of the altitude above the planet surface and soliton velocity.
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Pohjola, V., and E. Kallio. "On the modeling of planetary plasma environments by a fully kinetic electromagnetic global model HYB-em." Annales Geophysicae 28, no. 3 (2010): 743–51. http://dx.doi.org/10.5194/angeo-28-743-2010.
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Abstract. We have developed a fully kinetic electromagnetic model to study instabilities and waves in planetary plasma environments. In the particle-in-a-cell (PIC) model both ions and electrons are modeled as particles. An important feature of the developed global kinetic model, called HYB-em, compared to other electromagnetic codes is that it is built up on an earlier quasi-neutral hybrid simulation platform called HYB and that it can be used in conjunction with earlier hybrid models. The HYB models have been used during the past ten years to study globally the flowing plasma interaction with various Solar System objects: Mercury, Venus, the Moon, Mars, Saturnian moon Titan and asteroids. The new stand-alone fully kinetic model enables us to (1) study the stability of various planetary plasma regions in three-dimensional space, (2) analyze the propagation of waves in a plasma environment derived from the other global HYB models. All particle processes in a multi-ion plasma which are implemented on the HYB platform (e.g. ion-neutral-collisions, chemical processes, particle loss and production processes) are also automatically included in HYB-em model. In this brief report we study the developed approach by analyzing the propagation of high frequency electromagnetic waves in non-magnetized plasma in two cases: We study (1) expansion of a spherical wave generated from a point source and (2) propagation of a plane wave in plasma. The analysis shows that the HYB-em model is capable of describing these space plasma situations successfully. The analysis also suggests the potential of the developed model to study both high density-high magnetic field plasma environments, such as Mercury, and low density-low magnetic field plasma environments, such as Venus and Mars.
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Lou, Yuequn, Xudong Gu, Xing Cao, et al. "Statistical Analysis of Lunar 1 Hz Waves Using ARTEMIS Observations." Astrophysical Journal 943, no. 1 (2023): 17. http://dx.doi.org/10.3847/1538-4357/aca767.
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Abstract Like 1 Hz waves occurring in the upstream of various celestial bodies in the solar system, 1 Hz narrowband whistler-mode waves are often observed around the Moon. However, wave properties have not been thoroughly investigated, which makes it difficult to proclaim the generation mechanism of the waves. Using 5.5 yr wave data from ARTEMIS, we perform a detailed investigation of 1 Hz waves in the near-lunar space. The amplitude of lunar 1 Hz waves is generally 0.05–0.1 nT. In the geocentric solar ecliptic coordinates, the waves show no significant regional differentiation pattern but show an absence inside the magnetosphere. Correspondingly, in the selenocentric solar ecliptic coordinates, the waves can occur extensively at ∼1.1–12 RL, while few events are observed in the lunar wake due to a lack of interaction with the solar wind. Furthermore, the wave distributions exhibit modest day–night and dawn–dusk asymmetries but less apparent north–south asymmetry. Compared with the nightside, more intense waves with lower peak wave frequency are present on the dayside. The preferential distribution of 1 Hz waves exhibits a moderate correlation with strong magnetic anomalies. The waves propagate primarily at wave normal angles <60° with an ellipticity of [−0.8, −0.3]. For stronger wave amplitudes and lower latitudes, 1 Hz waves generally have smaller wave normal angles and become more left-hand circularly polarized. Owing to the unique interaction between the Moon and solar wind, our statistical results might provide new insights into the generation mechanism(s) of 1 Hz waves in planetary plasma environments and promote the understanding of lunar plasma dynamics.
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Poppe, A. R., and S. Fatemi. "The Solar Wind Interaction with (1) Ceres: The Role of Interior Conductivity." Planetary Science Journal 4, no. 1 (2023): 14. http://dx.doi.org/10.3847/psj/acaf6a.
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Abstract As a potential “ocean world,” (1) Ceres’ interior may possess relatively high electrical conductivities on the order of 10−4–100 S m−1, suggesting that the solar wind interaction with Ceres may differ from other highly resistive objects such as the Moon. Here, we use a hybrid plasma model to quantify the solar wind interaction with Ceres over a range of scenarios for Ceres’ internal conductivity structure and the upstream solar wind and interplanetary magnetic field (IMF) conditions. Internal models for Ceres include one-, two-, and three-layer conductivity structures that variously include a crust, mantle, and/or subsurface ocean, while modeled solar wind conditions include a nominal case, a high IMF case, and an “extreme” space weather case. To first order, Ceres’ interaction with the solar wind is governed by the draping and enhancement of the IMF over its interior, whether from a moderate-conductivity mantle or a high-conductivity ocean. In turn, IMF draping induces compressional wings in the solar wind density and deceleration in the solar wind speed outside of Ceres. Together, all three effects are readily observable by a hypothetical orbital or landed mission with standard plasma and magnetic field instrumentation. Finally, we also consider the possible effects of unipolar induction within Ceres, which has been previously suggested as a mechanism for conducting bodies in the solar wind. Our model results show that the efficacy of unipolar induction is highly suppressed by the slow magnetic field-line diffusion through Ceres’ interior and, thus, is not a significant contributor to Ceres’ overall interaction with the solar wind.
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Lorenzini, E. C., D. Curreli, and D. Zanutto. "Exploration of the Galilean Moons using Electrodynamic Tethers for Propellantless Maneuvers and Self-Powering." Proceedings of the International Astronomical Union 6, S269 (2010): 229–33. http://dx.doi.org/10.1017/s1743921310007465.
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AbstractRecent studies have demonstrated the benefits of using electrodynamic tethers (EDT) for the exploration of the inner region of the Jovian system. Intense planetary magnetic field and reasonable environmental plasma density make the electrodynamic interaction of the conductive tether with the plasmasphere strong. The interaction is responsible for a Lorentz force that can be conveniently used for propellantless maneuvers and extraction of electrical power for on board use. Jupiter and the four Galilean Moons represent an exceptional gravitational environment for the study of the orbital dynamics of an EDT. The dynamics of such a system was analyzed using a 3-body model, consisting of the planet plus one of its moons (Io in this work) and the EDT itself. New and interesting features appear, like for example the possibility to place the tether in equilibrium with respect to a frame co-rotating with the moon at points that do not coincide with the classical Lagrangian points for non-null electrodynamic forces.
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Kleiman, J., S. Horodetsky, V. Issoupov, V. Verba, and D. Artymowicz. "Interaction of Lunar Dust Simulants with Materials: Importance of Charging." IOP Conference Series: Materials Science and Engineering 1328, no. 1 (2025): 012003. https://doi.org/10.1088/1757-899x/1328/1/012003.
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Abstract Materials exposed to lunar regolith dust and other environmental factors on the Moon may suffer permanent damage, risking catastrophic failures. Lunar dust poses the greatest threat. Preventive measures are crucial, with principles emerging to deter dust accumulation in vacuum conditions. Charging of dust and surfaces significantly affects adhesion. Charging sources include photoemission, solar wind, and secondary electron emission from Earth’s magnetosphere, resulting in positive charge on the dayside and negative charge on the nightside. In framework of NASA’s “Regolith Adherence Characterization (RAC) Payload” project, we initiated a program on conducting experiments in our Lunar Environment Simulator on interaction of lunar dust simulants with materials, similar to the RAC Payload experiment. As part of this program, we conducted a series of experiments to understand the effects of charges accumulating on dust simulants and the surfaces they interact with on the adhesion and mitigation of dust. We adapted a number of methods to charge the dust, - tribological, vacuum ultraviolet and plasma, and used a nanocoulomb meter set-up to evaluate the dust charge. A rotating disk sample holder enhances dust flow uniformity. In the experiments we measured the dust charge acquired under different conditions, with the aim to understand interaction models. This paper presents initial findings and discusses relevant models.
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Rovige, Lucas, Filipe D. Cruz, Robert S. Dorst, et al. "Laboratory Study of Magnetic Reconnection in Lunar-relevant Mini-magnetospheres." Astrophysical Journal 969, no. 2 (2024): 124. http://dx.doi.org/10.3847/1538-4357/ad4fff.
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Abstract Mini-magnetospheres are small ion-scale structures that are well suited to studying kinetic-scale physics of collisionless space plasmas. Such ion-scale magnetospheres can be found on local regions of the Moon, associated with the lunar crustal magnetic field. In this paper, we report on the laboratory experimental study of magnetic reconnection in laser-driven, lunar-like ion-scale magnetospheres on the Large Plasma Device at the University of California, Los Angeles. In the experiment, a high-repetition rate (1 Hz), nanosecond laser is used to drive a fast-moving, collisionless plasma that expands into the field generated by a pulsed magnetic dipole embedded into a background plasma and magnetic field. The high-repetition rate enables the acquisition of time-resolved volumetric data of the magnetic and electric fields to characterize magnetic reconnection and calculate the reconnection rate. We notably observe the formation of Hall fields associated with reconnection. Particle-in-cell simulations reproducing the experimental results were performed to study the microphysics of the interaction. By analyzing the generalized Ohm’s law terms, we find that the electron-only reconnection is driven by kinetic effects through the electron pressure anisotropy. These results are compared to recent satellite measurements that found evidence of magnetic reconnection near the lunar surface.
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Arridge, C. S., N. Achilleos, and P. Guio. "Electric field variability and classifications of Titan's magnetoplasma environment." Annales Geophysicae 29, no. 7 (2011): 1253–58. http://dx.doi.org/10.5194/angeo-29-1253-2011.
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Abstract. The atmosphere of Saturn's largest moon Titan is driven by photochemistry, charged particle precipitation from Saturn's upstream magnetosphere, and presumably by the diffusion of the magnetospheric field into the outer ionosphere, amongst other processes. Ion pickup, controlled by the upstream convection electric field, plays a role in the loss of this atmosphere. The interaction of Titan with Saturn's magnetosphere results in the formation of a flow-induced magnetosphere. The upstream magnetoplasma environment of Titan is a complex and highly variable system and significant quasi-periodic modulations of the plasma in this region of Saturn's magnetosphere have been reported. In this paper we quantitatively investigate the effect of these quasi-periodic modulations on the convection electric field at Titan. We show that the electric field can be significantly perturbed away from the nominal radial orientation inferred from Voyager 1 observations, and demonstrate that upstream categorisation schemes must be used with care when undertaking quantitative studies of Titan's magnetospheric interaction, particularly where assumptions regarding the orientation of the convection electric field are made.
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Tiwari, Sanjiv Kumar. "Are the photospheric sunspots magnetically force-free in nature?" Proceedings of the International Astronomical Union 6, S273 (2010): 333–37. http://dx.doi.org/10.1017/s1743921311015481.
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AbstractIn a force-free magnetic field, there is no interaction of field and the plasma in the surrounding atmosphere i.e., electric currents are aligned with the magnetic field, giving rise to zero Lorentz force. The computation of many magnetic parameters like magnetic energy, gradient of twist of sunspot magnetic fields (computed from the force-free parameter α), including any kind of extrapolations heavily hinge on the force-free approximation of the photospheric magnetic fields. The force-free magnetic behaviour of the photospheric sunspot fields has been examined by Metcalf et al. (1995) and Moon et al. (2002) ending with inconsistent results. Metcalf et al. (1995) concluded that the photospheric magnetic fields are far from the force-free nature whereas Moon et al. (2002) found the that the photospheric magnetic fields are not so far from the force-free nature as conventionally regarded. The accurate photospheric vector field measurements with high resolution are needed to examine the force-free nature of sunspots. We use high resolution vector magnetograms obtained from the Solar Optical Telescope/Spectro-Polarimeter (SOT/SP) aboard Hinode to inspect the force-free behaviour of the photospheric sunspot magnetic fields. Both the necessary and sufficient conditions for force-freeness are examined by checking global as well as as local nature of sunspot magnetic fields. We find that the sunspot magnetic fields are very close to the force-free approximation, although they are not completely force-free on the photosphere.
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Burne, Sofía, César Bertucci, Nick Sergis, et al. "Space Weather in the Saturn–Titan System." Astrophysical Journal 948, no. 1 (2023): 37. http://dx.doi.org/10.3847/1538-4357/acc738.
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Abstract New evidence based on Cassini magnetic field and plasma data has revealed that the discovery of Titan outside Saturn’s magnetosphere during the T96 flyby on 2013 December 1 was the result of the impact of two consecutive interplanetary coronal mass ejections (ICMEs) that left the Sun in 2013 early November and interacted with the moon and the planet. We study the dynamic evolution of Saturn's magnetopause and bow shock, which evidences a magnetospheric compression from late November 28 to December 4 (at least), under prevailing solar wind dynamic pressures of 0.16–0.3 nPa. During this interval, transient disturbances associated with the two ICMEs are observed, allowing for the identification of their magnetic structures. By analyzing the magnetic field direction, and the pressure balance in Titan’s induced magnetosphere, we show that Cassini finds Saturn’s moon embedded in the second ICME after being swept by its interplanetary shock and amid a shower of solar energetic particles that may have caused dramatic changes in the moon’s lower ionosphere. Analyzing a list of Saturn's bow shock crossings during 2004–2016, we find that the magnetospheric compression needed for Titan to be in the supersonic solar wind can be generally associated with the presence of an ICME or a corotating interaction region. This leads to the conclusion that Titan would rarely face the pristine solar wind, but would rather interact with transient solar structures under extreme space weather conditions.
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V.G, Sapogin, and Sapogin К.V. "Invisible Bubbles with Liquid Wall from Dark Plasma of the Sun§." Advances in Theoretical & Computational Physics 7, no. 4 (2024): 01–18. https://doi.org/10.33140/atcp.07.04.04.
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The article presents fragments of canonical physics of mass particles’ collective interaction. Equations of selfconsistent statics of mass particles and their solutions are given. The integral of "living forces" in plane symmetry is found. It allows to validate the field confinement of matter by a self-consistent field. A pair of forces of field origin, holding the layer in a static equilibrium state, is found - the compression force and the expansion force. The distribution of physical parameters in a flat layer is investigated. The thickness of layer is determined. It coincides with doubled spatial scale. An approximate solution to the problem of matter distribution in a hollow cold cluster with uniform temperature is found in spherical field traps of the first kind. The approximate solution is verified by numerical simulation. An exact solution is found for potential distribution in a field trap of the second kind. Estimates show that mass spectra of hollow neutron clusters with temperatures from 1011 to 1012 K can be identified with masses of objects observed in centers of galaxies. A hypothesis has been put forward about the existence of invisible gas bubbles of small radii and large masses with low temperatures. Flying out from dark plasma of the Sun, filled balls, due to expansion and cooling activity of gas, turn into thin-walled bubbles with liquid wall. The expansion process transfers them to the class of dark matter. Collisions with invisible bubbles can be responsible for depressurization of spacecraft, for inelastic impacts on station windows, and even for unsuccessful landings of space modules on the Moon. Processing the trajectory measurements of lunar modules’ unsuccessful landing will confirm or refute the hypothesis of their collisions with invisible bubbles.
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Ki, Soyoung, Jinhee Kim, Jungtae Na, et al. "Abstract 3227: Developing brain-penetrating MAT2A inhibitors for MTAP-deleted brain metastatic cancer and GBM." Cancer Research 84, no. 6_Supplement (2024): 3227. http://dx.doi.org/10.1158/1538-7445.am2024-3227.
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Abstract Background: Homozygous deletion of MTAP is one of the most frequent genetic alterations in various solid tumors including glioblastoma (GBM), mesothelioma, pancreatic cancer and lung cancer. While MTAP-deleted cancers are associated with a poor prognosis, there are no approved drugs for the treatment of patients with MTAP deficiency. MAT2A has emerged as a potential target for selective anticancer effects in MTAP-deleted cancers. However, development of brain-penetrating MAT2A inhibitors are yet to be reported in preclinical or clinical stages despite of high MTAP deletion fraction in GBM and brain metastatic cancers. Here, we present highly potent and selective MAT2A inhibitors capable of brain penetration for MTAP deleted cancer therapy. Methods: A MAT2A biochemical enzyme assay was performed with phosphonate colorimetric kit. To evaluate in vitro and in vivo activities of compounds, S-adenosylmethionine (SAM) and symmetrical dimethyl arginine (SDMA) levels were measured using LC-MS/MS and high-content screening systems. Cell growth inhibition assay was evaluated to confirm the selectivity in isogenic pairs of HCT116 WT and MTAP-deleted cells. In vivo efficacy was conducted using the MTAP-deleted HCT116 xenograft. Results: To develop novel brain penetrating scaffolds, we focused on interaction of hydrogen bond acceptor in the scaffolds with arginine residue Arg313 in MAT2A protein and the improvement of physicochemical properties, including logP and logBB. A series of MAT2A inhibitors significantly inhibited MAT2A enzymatic activity, resulting in the reduction of intracellular SAM level, the direct product of MAT2A. These compounds showed highly potent inhibition of SDMA and cell proliferation in MTAP-deleted cells, while displaying minimal effect on MTAP-WT cells, showing &gt;100-fold selectivity towards MTAP-deletion over MTAP-WT. Furthermore, anti-proliferative activity of MAT2A inhibitors were observed in MTAP-deleted cancer cells across various cancer types, including GBM, breast cancer, and non-small cell lung cancer. Remarkably, mouse pharmacokinetic study revealed high level of plasma and brain exposure with outstanding brain-to-plasma ratio (&gt; 0.75). Robust tumor growth inhibition as well as reduction in tumor SAM levels were observed as monotherapy in an MTAP-deleted HCT116 xenograft model. Conclusion: We have identified novel brain-penetrating MAT2A inhibitors displaying encouraging in vitro and in vivo pharmacological profiles, indicating the potential use of these compounds as therapeutic agents for MTAP deleted brain metastatic cancer and GBM. Citation Format: Soyoung Ki, Jinhee Kim, Jungtae Na, Ilkyoo Koh, Hyunho Cho, Ho Yeon Lee, Hoiyun Jung, Gyeonghi Cho, Mijin Moon, Yongje Shin, Sook-Kyung Park. Developing brain-penetrating MAT2A inhibitors for MTAP-deleted brain metastatic cancer and GBM [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3227.
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Choi, Jaeyul, Wongi Park, Soye Jeon, et al. "Abstract LB429: Discovery of a novel SOS1-KRASmulti inhibitor, HM101207, demonstrates a broad-spectrum antitumor activity across KRAS-MAPK mutant cancers." Cancer Research 85, no. 8_Supplement_2 (2025): LB429. https://doi.org/10.1158/1538-7445.am2025-lb429.
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Abstract The RAS subfamily is a well-known oncogene with the highest mutation rate and poor prognosis among various cancers. Among the RAS subfamily, KRAS is the most frequent mutation isoform, especially with a prevalence of approximately 35%∼90% in NSCLC, CRC, and PDAC. KRAS protein cycles between "off" (inactive) and "on" (active) states induce downstream signal transduction to promote cell proliferation and survival. Son of sevenless homolog 1 (SOS1) is one of guanine nucleotide exchange factor (GEF) responsible for a binary molecular switch to activate KRAS as well as a node in the negative feedback loop in the RTK-KRAS-MAPK signaling pathway. Targeting SOS1-KRAS interaction has the potential to modulate the GDP-bound state of pan-KRAS, enabling to suppress the various KRAS-driven cancers. Herein, we introduce HM101207, SOS1-KRASmulti inhibitor with a novel scaffold and favorable DMPK profiles for KRAS regulation and suggest its suitable druggability. We developed HM101207, an orally administered SOS1 inhibitor that blocks GTP binding to KRAS and investigated the profiles and mechanistic studies of drug efficacy through in vitro and in vivo models. HM101207 exhibited the wide spectrum inhibitory potency including p-ERK inhibition across KRAS mutants. HM101207 inhibited SOS1-mediated GTP exchange on KRAS WT, G12C/D/S/V/R, and Q61H mutations and decreased ERK phosphorylation in KRAS G12C-mutant cancer cell lines. Through a three-dimensional (3D) spheroid growth inhibition assay, HM101207 demonstrated promising GI50 against KRAS G12C-mutant as well as PTPN11 or NF1-mutant cancer cell lines. In vitro studies with human liver microsomes showed that HM101207 did not inhibit directly major CYP enzymes, also did not a time-dependent inhibitor (TDI). We expected the risk of drug-drug interaction (DDI) to be low potential of HM101207 with co-administered drugs. A low plasma protein binding rate suggests a higher unbound drug concentration. Furthermore, HM101207 showed promising antitumor efficacy in KRAS mutation xenograft model in dose dependent manner. Additionally, the combination of HM101207 with KRAS-MAPK vertical pathway such as KRAS G12C or MEK inhibitors led the powerful synergistic activity without significant body weight loss or notable clinical observations. Based on our exploratory research, HM101207 could be suggested as a promising therapeutic candidate for diverse cancers causing by the hyperactivation of oncogenic KRAS signaling. Preclinical studies have shown that HM101207 may overcome existing limitations of KRAS G12C or MEK inhibitors through combination strategy. HM101207 is currently preparing in IND enabling GLP-toxicity studies to support further clinical development. Citation Format: Jaeyul Choi, Wongi Park, Soye Jeon, Heesun Moon, Yunju Kang, Eun Young Lee, Seung Hyun Jung, Jooyun Byun, Sang Hyun Lee, Young Gil Ahn. Discovery of a novel SOS1-KRASmulti inhibitor, HM101207, demonstrates a broad-spectrum antitumor activity across KRAS-MAPK mutant cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_2):Abstract nr LB429.
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Holmstrom, Mats, Mark Lester, and Beatriz Sanchez-Cano. "Future opportunities in solar system plasma science through ESA’s exploration programme." npj Microgravity 10, no. 1 (2024). http://dx.doi.org/10.1038/s41526-024-00373-9.
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AbstractThe solar wind interacts with all solar system bodies, inducing different types of dynamics depending on their atmospheric and magnetic environments. We here outline some key open scientific questions related to this interaction, with a focus on the Moon and Mars, that may be addressed by future Mars and Moon missions by the European Space Agency’s Human and Robotic Exploration programme. We describe possible studies of plasma interactions with bodies with and without an atmosphere, using multi-point and remote measurements, and energetic particle observations, as well as recommend some actions to take.
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Tolba, R. E., W. M. Moslem, and R. Sabry. "Modulated dust-ion-acoustic waves result from Earth's magnetosphere and lunar ionosphere interactions." Physics of Fluids 36, no. 3 (2024). http://dx.doi.org/10.1063/5.0198213.
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The Earth's magnetosphere's modulational amplitude dust-ion-acoustic waves are studied. When the moon passes through the Earth's magnetotail, its dust grains may interact, causing these waves. The theoretical plasma model for this study includes positive ionospheric ion fluids, isothermal electrons, and fluid-negative dust grains on the moon. A perturbation technique derived the nonlinear Schrödinger equation, which exhibited dispersion and nonlinear effects. The nonlinear and dispersion term coefficients' polarity may predict stable and unstable pulse domains. A numerical study was performed to identify unstable pulse domains and their connections with bright and rogue unstable modes. The effects of critical plasma conditions on these pulses' basic features have been studied. This study showed that increasing the ratio of ions to electrons temperature and density reduces system nonlinearity. Consequently, shorter unstable pulses are formed. Amplification of plasma unstable waves results in an increase in their intensity and energy, potentially impacting any device traveling through the area of impact.
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Xiao, Chao, Fei He, Quanqi Shi, et al. "Evidence for lunar tide effects in Earth’s plasmasphere." Nature Physics, January 26, 2023. http://dx.doi.org/10.1038/s41567-022-01882-8.
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AbstractTides are universal and affect spatially distributed systems, ranging from planetary to galactic scales. In the Earth–Moon system, effects caused by lunar tides were reported in the Earth’s crust, oceans, neutral gas-dominated atmosphere (including the ionosphere) and near-ground geomagnetic field. However, whether a lunar tide effect exists in the plasma-dominated regions has not been explored yet. Here we show evidence of a lunar tide-induced signal in the plasmasphere, the inner region of the magnetosphere, which is filled with cold plasma. We obtain these results by analysing variations in the plasmasphere’s boundary location over the past four decades from multisatellite observations. The signal possesses distinct diurnal (and monthly) periodicities, which are different from the semidiurnal (and semimonthly) variations dominant in the previously observed lunar tide effects in other regions. These results demonstrate the importance of lunar tidal effects in plasma-dominated regions, influencing understanding of the coupling between the Moon, atmosphere and magnetosphere system through gravity and electromagnetic forces. Furthermore, these findings may have implications for tidal interactions in other two-body celestial systems.
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An, Xin, Vassilis Angelopoulos, Terry Z. Liu, Anton Artemyev, Andrew R. Poppe, and Donglai Ma. "Plasma Refilling of the Lunar Wake: Plasma‐Vacuum Interactions, Electrostatic Shocks, and Electromagnetic Instabilities." Journal of Geophysical Research: Space Physics 130, no. 7 (2025). https://doi.org/10.1029/2025ja034205.
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AbstractA plasma void forms downstream of the Moon when the solar wind impacts the lunar surface. This void gradually refills as the solar wind passes by, forming the lunar wake. We investigate this refilling process using a fully kinetic particle‐in‐cell (PIC) simulation. The early stage of refilling follows plasma‐vacuum interaction theory, characterized by exponential decay of plasma density into the wake, along with ion acceleration and cooling in the expansion direction. Our PIC simulation confirms these theoretical predictions. In the next stage of the refilling process, the counter‐streaming supersonic ion beams collide, generating Debye‐scale electrostatic shocks at the wake's center. These shocks decelerate and thermalize the ion beams while heating electrons into flat‐top velocity distributions along magnetic field lines. Additionally, fast magnetosonic waves undergo convective growth via anomalous cyclotron resonance as they co‐propagate with temperature‐anisotropic ion beams toward the wake's center. Electromagnetic ion cyclotron waves may also be excited through normal cyclotron resonance, counter‐propagating with these anisotropic ion beams. Our findings provide new insights into the kinetic aspects of lunar wake refilling and may enhance interpretation of spacecraft observations.
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Rabia, J., V. Hue, N. André, et al. "Properties of Electrons Accelerated by the Ganymede‐Magnetosphere Interaction: Survey of Juno High‐Latitude Observations." Journal of Geophysical Research: Space Physics 129, no. 5 (2024). http://dx.doi.org/10.1029/2024ja032604.
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AbstractThe encounter between the Jovian co‐rotating plasma and Ganymede gives rise to electromagnetic waves that propagate along the magnetic field lines and accelerate particles by resonant or non‐resonant wave‐particle interaction. They ultimately precipitate into Jupiter's atmosphere and trigger auroral emissions. In this study, we use Juno/JADE, Juno/UVS data, and magnetic field line tracing to characterize the properties of electrons accelerated by the Ganymede‐magnetosphere interaction in the far‐field region. We show that the precipitating energy flux exhibits an exponential decay as a function of downtail distance from the moon, with an e‐folding value of 29°, consistent with previous UV observations from the Hubble Space Telescope (HST). We characterize the electron energy distributions and show that two distributions exist. Electrons creating the Main Alfvén Wing (MAW) spot and the auroral tail always have broadband distribution and a mean characteristic energy of 2.2 keV while in the region connected to the Transhemispheric Electron Beam (TEB) spot the electrons are distributed non‐monotonically, with a higher characteristic energy above 10 keV. Based on the observation of bidirectional electron beams, we suggest that Juno was located within the acceleration region during the 11 observations reported. We thus estimate that the acceleration region is extended, at least, between an altitude of 0.5 and 1.3 Jupiter radius above the 1‐bar surface. Finally, we estimate the size of the interaction region in the Ganymede orbital plane using far‐field measurements. These observations provide important insights for the study of particle acceleration processes involved in moon‐magnetosphere interactions.
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Haynes, C. Michael, Tyler Tippens, Peter Addison, Lucas Liuzzo, Andrew R. Poppe, and Sven Simon. "Emission of Energetic Neutral Atoms From the Magnetosphere‐Atmosphere Interactions at Callisto and Europa." Journal of Geophysical Research: Space Physics 128, no. 10 (2023). http://dx.doi.org/10.1029/2023ja031931.
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AbstractWe analyze the emission of energetic neutral atom (ENA) flux from charge exchange between Jovian magnetospheric ions and the atmospheres of Callisto and Europa. For this purpose, we combine the draped electromagnetic fields from a hybrid plasma model with a particle tracing tool for the energetic ions. We determine the ENA flux through a concentric sphere located just outside of each moon's atmosphere, thereby capturing the complete physics imprinted in these emission patterns. In order to constrain the modifications to the ENA emissions that arise from the periodic change of the ambient plasma conditions, we calculate the emission morphology at multiple positions during a Jovian synodic rotation. To isolate the influence of field line draping, we compare to the emission patterns in uniform fields. Our major results are: (a) At Europa and Callisto, the majority of detectable ENA emissions are concentrated into a band normal to the Jovian magnetospheric field. (b) The fraction of observable ENA flux that contributes to this band depends on the number of complete gyrations that the parent ions can complete within the moon's atmosphere. (c) Field line draping partially deflects impinging parent ions around both moons, thereby attenuating the ENA flux and driving significant morphological changes to the emission patterns. (d) The band of elevated ENA flux is locally maximized on the opposite (antipodal) side of the moon where the flux is locally minimized. At Europa, detectable ENA emissions are maximized slightly west of the ramside apex. At Callisto, they maximize near the Jupiter‐facing apex.
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Li Meng-Yao, Xia Qing, Cai Ming-Hui, et al. "Characteristic research of dust and plasma environment in the lunar south pole." Acta Physica Sinica, 2024, 0. http://dx.doi.org/10.7498/aps.73.20240599.
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Unlike the Earth, the Moon lacks the protection of an atmosphere and a global magnetic field, and is directly exposed to complex radiation environments such as high-energy cosmic rays, solar wind, and the Earth's magnetotail plasma. The surface of the Moon is covered with a thick layer of lunar soil, of which particles with a size of 30nm-20<i>μ</i>m are called lunar dust. In complex environments such as solar wind or magnetotail plasma, lunar dust carries an electric charge and becomes charged lunar dust. Charged lunar dust is prone to migration under the action of the electric field on the lunar surface. Charged migrated lunar dust is easy to adhere to the surface of instruments and equipment, causing visual impairment, astronauts' movement disorders, equipment mechanical blockage, sealing failure, and material wear, which affects the lunar exploration mission. As an important lunar exploration landing site, the lunar South Pole receives special solar radiation and produces a special dust plasma environment due to its special location. In order to provide an environmental reference for lunar South Pole exploration, it is necessary to explore the characteristics of the dust plasma environment in the lunar South Pole and its impact. In view of the lunar South Pole environment, this paper uses the Spacecraft Plasma Interactions Software(SPIS) software developed by the European Space Agency to model and simulate. The simulation obtains the logarithmic distribution of the lunar dust space density within the range of 0-200 m at the lunar South Pole, the potential distribution near the lunar surface, and the spatial distribution characteristics of plasma electrons and ions. The obtained lunar dust space density and lunar surface potential are similar to the previous theoretical derivation and field detection data, so the simulation results have high reliability. The spatial potential distribution and the spatial density distribution of electrons and ions in the lunar environment with and without lunar dust are compared. Finally, the following conclusions can be drawn: The research results show that the space potential increases with increasing altitude. The potential at 0-10 m near the South Pole of the Moon is about -40 V, and the space potential at 100 m is about -20 V. The density of lunar dust in the altitude range below 10 m is 10<sup>7.22</sup> m<sup>-3</sup>-10<sup>4.66</sup> m<sup>-3</sup>. The electron density in the dust plasma near the lunar surface is 10<sup>5.47</sup> m<sup>-3</sup>, and the ion density is 10<sup>6.07</sup> m<sup>-3</sup>, and both increase with increasing altitude. Charged lunar dust affects the spatial distribution of lunar dust, mainly by affecting the distribution of the space electric field, which leads to differences in electron distribution, but has little effect on ions.
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Biswas, Ayan, Barnali Das, Poonam Chandra та ін. "Discovery of Magnetospheric Interactions in the Doubly-Magnetic Hot Binary ε Lupi". Monthly Notices of the Royal Astronomical Society, 13 червня 2023. http://dx.doi.org/10.1093/mnras/stad1756.
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Abstract Magnetic fields are extremely rare in close, hot binaries, with only 1.5% of such systems known to contain a magnetic star. The eccentric ε Lupi system stands out in this population as the only close binary in which both stars are known to be magnetic. We report the discovery of strong, variable radio emission from ε Lupi using the upgraded Giant Metrewave Radio Telescope (uGMRT) and the MeerKAT radio telescope. The light curve exhibits striking, unique characteristics including sharp, high-amplitude pulses that repeat with the orbital period, with the brightest enhancement occurring near periastron. The characteristics of the light curve point to variable levels of magnetic reconnection throughout the orbital cycle, making ε Lupi the first known high-mass, main sequence binary embedded in an interacting magnetosphere. We also present a previously unreported enhancement in the X-ray light curve obtained from archival XMM-Newton data. The stability of the components’ fossil magnetic fields, the firm characterization of their relatively simple configurations, and the short orbital period of the system make ε Lupi an ideal target to study the physics of magnetospheric interactions. This system may thus help us to illuminate the exotic plasma physics of other magnetically interacting systems such as moon-planet, planet-star, and star-star systems including T Tauri binaries, RS CVn systems, and neutron star binaries.
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Paranicas, C., B. H. Mauk, G. Clark, et al. "Energetic Charged Particle Measurements During Juno's Two Close Io Flybys." Geophysical Research Letters 51, no. 13 (2024). http://dx.doi.org/10.1029/2024gl109495.
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AbstractOn days 2023‐364 and 2024‐034, the Juno spacecraft made close passages of Jupiter's moon Io, at altitudes of about 1,500 km. Data obtained from the first flyby, when the spacecraft was on magnetic field lines connected to both Jupiter and Io, revealed deep flux decreases. In addition, Juno's energetic particle detectors observed tens to hundreds of keV electron and proton beams. Such beams could be generated near Jupiter on field lines associated with Io. The second encounter occurred in the plasma wake and a more modest flux decrease was observed. Furthermore, data from both encounters suggest a spatially extensive decrease in >1 MeV electrons that includes regions inward of Io's orbit. In the immediate vicinity of Io, signatures of absorption likely dominate the data whereas diffusion and wave‐particle interactions are expected to be needed to understand MeV electron data in the wider spatial region around Io.
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Nishino, Masaki N., Yoshiya Kasahara, Yuki Harada, et al. "An event study on broadband electric field noises and electron distributions in the lunar wake boundary." Earth, Planets and Space 74, no. 1 (2022). http://dx.doi.org/10.1186/s40623-021-01566-2.
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AbstractWave–particle interactions are fundamental processes in space plasma, and some plasma waves, including electrostatic solitary waves (ESWs), are recognised as broadband noises (BBNs) in the electric field spectral data. Spacecraft observations in recent decades have detected BBNs around the Moon, but the generation mechanism of the BBNs is not fully understood. Here, we study a wake boundary traversal with BBNs observed by Kaguya, which includes an ESW event previously reported by Hashimoto et al. Geophys Res Lett 37:L19204 10.1029/2010GL044529 (2010). Focusing on the relation between BBNs and electron pitch-angle distribution functions, we show that upward electron beams from the nightside lunar surface are effective for the generation of BBNs, in contrast to the original interpretation by Hashimoto et al. Geophys Res Lett 37:L19204 10.1029/2010GL044529 (2010) that high-energy electrons accelerated by strong ambipolar electric fields excite ESWs in the region far from the Moon. When the BBNs were observed by the Kaguya spacecraft in the wake boundary, the spacecraft’s location was magnetically connected to the nightside lunar surface, and bi-streaming electron distributions of downward-going solar wind strahl component and upward-going field-aligned beams (at $$\sim$$ ∼ 124 eV) were detected. The interplanetary magnetic field was dominated by a positive $$B_Z$$ B Z (i.e. the northward component), and strahl electrons travelled in the antiparallel direction to the interplanetary magnetic field (i.e. southward), which enabled the strahl electrons to precipitate onto the nightside lunar surface directly. The incident solar wind electrons cause negative charging of the nightside lunar surface, which generates downward electric fields that accelerate electrons from the nightside surface toward higher altitudes along the magnetic field. The bidirectional electron distribution is not a sufficient condition for the BBN generation, and the distribution of upward electron beams seems to be correlated with the BBNs. Ambipolar electric fields in the wake boundary should also contribute to the electron acceleration toward higher altitudes and further intrusion of the solar wind ions into the deeper wake. We suggest that solar wind ion intrusion into the wake boundary is also an important factor that controls the BBN generation by facilitating the influx of solar wind electrons there. Graphical Abstract
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Futaana, Yoshifumi, Esa Kallio, Olli Knuuttila, Leo Nyman, Manabu Shimoyama, and Stas Barabash. "The LimPa mission: a small mission proposal to characterize the enigmatic lunar dust exosphere." Earth, Planets and Space 76, no. 1 (2024). https://doi.org/10.1186/s40623-024-02106-4.
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AbstractThe lunar environment is known to be characterized by complex interactions between plasma, the exosphere, dust, and the surface. However, our understanding of the environment is limited due to the lack of experimental evidence. Here, we propose a small, low-cost mission to characterize the dust and exosphere environment of the Moon. Named the Limb Pathfinder (LimPa), this is a proof-of-concept mission aimed toward understanding the coupling between plasma, dust, and tenuous neutral atmosphere. The LimPa mission was proposed to a call for the Small Mission to the Moon issued by European Space Agency in 2023. LimPa is designed to examine the dust exosphere above the lunar polar regions by using an utterly novel remote-sensing technique to measure the solar wind hydrogen atoms—the solar wind protons that are neutralized to hydrogen atoms. Its goals are (1) to detect for the first time the neutralized solar wind hydrogen produced by exospheric gas and levitated dust; (2) to measure the height profiles of the levitated dust and exospheric gas densities; and (3) to determine the emission mechanism of the horizon glow. Our baseline design of the LimPa mission is a 12U CubeSat. Three highly matured instruments are used: an energetic neutral atom camera, a proton sensor, and a camera system. The LimPa CubeSat is proposed to be inserted into a circular lunar polar orbit, with an altitude of 100 km as a baseline. The Sun-pointing attitude will allow measurements of neutralized solar wind that are produced by the exosphere and dust grains above the polar regions. The nominal lifetime is for 3 months as a pathfinder mission. The LimPa mission will open a new window to remote characterization of the lunar dust exosphere environment above the poles, and will demonstrate that this monitoring can be achieved with a simple and low-cost instrument system and spacecraft operation. The concept to be proven by the LimPa mission will enable long-term monitoring of the fragile dust exosphere environment, which substantially impacts on lunar exploration and will be significantly altered by human activities. Graphical abstract
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C., Michael Haynes, Tippens Tyler, Addison Peter, Liuzzo Lucas, R. Poppe Andrew, and Simon Sven. "Emission of Energetic Neutral Atoms from the Magnetosphere-Atmosphere Interactions at Callisto and Europa." July 14, 2023. https://doi.org/10.5281/zenodo.8148611.
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Accompanying data products for publication entitled "Emission of Energetic Neutral Atoms from the Magnetosphere-Atmosphere Interactions at Callisto and Europa". The article was submitted shortly after the date of upload. Data includes all simulation outputs for both the AIKEF hybrid model and the ENA production model. Information regarding the organization and file structure can be found in haynes_paper1_zenodo/info.txt , and any inquiries shall be addressed through the email associated with this data publication.
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Cohen, Ian J., Evan J. Smith, George B. Clark, et al. "Plasma Environment, Radiation, Structure, and Evolution of the Uranian System (PERSEUS): A Dedicated Orbiter Mission Concept to Study Space Physics at Uranus." Space Science Reviews 219, no. 8 (2023). http://dx.doi.org/10.1007/s11214-023-01013-6.
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AbstractThe Plasma Environment, Radiation, Structure, and Evolution of the Uranian System (PERSEUS) mission concept defines the feasibility and potential scope of a dedicated, standalone Heliophysics orbiter mission to study multiple space physics science objectives at Uranus. Uranus’s complex and dynamic magnetosphere presents a unique laboratory to study magnetospheric physics as well as its coupling to the solar wind and the planet’s atmosphere, satellites, and rings. From the planet’s tilted and offset, rapidly-rotating non-dipolar magnetic field to its seasonally-extreme interactions with the solar wind to its unexpectedly intense electron radiation belts, Uranus hosts a range of outstanding and compelling mysteries relevant to the space physics community. While the exploration of planets other than Earth has largely fallen within the purview of NASA’s Planetary Science Division, many targets, like Uranus, also hold immense scientific value and interest to NASA’s Heliophysics Division. Exploring and understanding Uranus’s magnetosphere is critical to make fundamental gains in magnetospheric physics and the understanding of potential exoplanetary systems and to test the validity of our knowledge of magnetospheric dynamics, moon-magnetosphere interactions, magnetosphere-ionosphere coupling, and solar wind-planetary coupling. The PERSEUS mission concept study, currently at Concept Maturity Level (CML) 4, comprises a feasible payload that provides closure to a range of space physics science objectives in a reliable and mature spacecraft and mission design architecture. The mission is able to close using only a single Mod-1 Next-Generation Radioisotope Thermoelectric Generator (NG-RTG) by leveraging a concept of operations that relies of a significant hibernation mode for a large portion of its 22-day orbit.
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Addison, Peter, Lucas Liuzzo, Hannes Arnold, and Sven Simon. "Influence of Europa's Time-Varying Electromagnetic Environment on Magnetospheric Ion Precipitation." December 9, 2020. https://doi.org/10.5281/zenodo.4313883.
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Data for the manuscript "Influence of Europa's Time-Varying Electromagnetic Environment on Magnetospheric Ion Precipitation" by Addison et al., (2021). See README.txt for a description of the data files included here.
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Aaron, Stahl, Addison Peter, Liuzzo Lucas, and Simon Sven. "Data for "Modeling of Ganymede's Magnetic and Plasma Environment During the Juno PJ34 Flyby" by Stahl et al. (2024)." September 13, 2023. https://doi.org/10.5281/zenodo.8326069.
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Data repository for the study entitled "Modeling of Ganymede's Magnetic and Plasma Environment During the Juno PJ34 Flyby" by Stahl et al. (2024). Information on file structure and contents can be found in the file: readme.txt. Please email corresponding author for questions regarding the manuscript or data: astahl3@gatech.edu (Aaron Stahl).
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Aaron, Stahl, Addison Peter, Simon Sven, and Liuzzo Lucas. "Data for "Modeling of Ganymede's Magnetic and Plasma Environment During the Juno PJ34 Flyby" by Stahl et al. (2023)." September 22, 2023. https://doi.org/10.5281/zenodo.8370898.
Full textAbstract:
Data repository for the study entitled "Modeling of Ganymede's Magnetic and Plasma Environment During the Juno PJ34 Flyby" by Stahl et al. (2024). Information on file structure and contents can be found in the file: readme.txt. Please email corresponding author for questions regarding the manuscript or data: astahl3@gatech.edu (Aaron Stahl).
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Crucian, Brian E., Heather Quiriarte, Chiu-wing Lam, et al. "Pulmonary and systemic immune alterations in rats exposed to airborne lunar dust." Frontiers in Immunology 16 (February 6, 2025). https://doi.org/10.3389/fimmu.2025.1538421.
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BackgroundDue to cosmic radiation bombardment and over 4 billion meteorite and micrometeoroid impacts on the airless Moon, the lunar surface is covered by a layer of fine, reactive dust. Very little is known regarding the toxicity of lunar dust on human physiology. This study assessed airborne lunar dust exposure in rats on localized pulmonary and systemic immune parameters.MethodsRats were exposed to 0 (air only), 20.8 (low), and 60.6 (high) mg/m3 of respirable-size lunar dust for 4 weeks (6 h/day, 5 days/week). Rats were then euthanized either 1 day, 7 days, 4 weeks, or 13 weeks after the last exposure. Peripheral blood and lung lavage fluid samples were collected for analysis. Assays included leukocyte distribution by multicolor flow cytometry and electron/fluorescent microscopy to visualize cell–particulate interactions and lavage/plasma cytokine concentration. Mitogen-stimulated cytokine production profiles, as a measure of cellular function, were performed on whole blood samples only.ResultsUntreated lavage fluid was comprised primarily of pulmonary macrophages. High-dose lunar dust inhalation (60.6 mg/m3) resulted in an influx of both neutrophils and lymphocytes. Although the percentage of lymphocytes increased, the T-cell CD4:CD8 ratio was unchanged. Cytokine analysis of the lavage fluid showed increased levels of IL-1β and TNFα. These alterations generally persisted through the 13-week sampling. Blood analysis showed few systemic immune alterations from the lunar dust inhalation. By week 4, the peripheral granulocyte percentage was elevated in the treated rats. Plasma cytokine levels were unchanged in all treated rats compared to controls; however, altered mitogen-stimulated cytokine production profiles were observed consisting of increased IL-1β and IL-6 and decreased IL-2. There were minimal adverse immune effects, in both lung or peripheral blood, following low-dose exposure to 20.8 mg/m3 lunar dust.ConclusionExposures to high concentrations of lunar dust resulted in persistent lung inflammation and some systemic immune dysregulation that did not subside even 13 weeks after the dust exposure. This information is beneficial in deriving an exposure limit to airborne lunar dust and for spacecraft engineers considering dust mitigation systems in lunar landers or habitats.
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Sucerquia, Mario, Jaime A. Alvarado-Montes, Jorge I. Zuluaga, Nicolás Cuello, Jorge Cuadra, and Matías Montesinos. "The missing rings around Solar System moons." Astronomy & Astrophysics, October 4, 2024. http://dx.doi.org/10.1051/0004-6361/202449453.
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Rings are complex structures that surround various bodies within the Solar System, such as giant planets and certain minor bodies. While some formation mechanisms could also potentially promote their existence around (regular or irregular) satellites, none of these bodies currently bear these structures. We aim to understand the underlying mechanisms that govern the potential formation, stability, and/or decay of hypothetical circumsatellital rings (CSRs) orbiting the largest moons in the Solar System. This extends to the exploration of short-term morphological features within these rings, providing insights into the ring survival timescales and the interactions that drive their evolution. To conduct this study, we used numerical N-body simulations under the perturbing influence of the host planet and other moon companions. We found that, as suspected, moons with a lower Roche-to-Hill radius can preserve their rings over extended periods. Moreover, the gravitational environment in which these rings are immersed influences the morphological evolution of the system (e.g. ring size), inducing gaps through the excitation of eccentricity and inclination of constituent particles. Specifically, our results show that the rings of Iapetus and Rhea experience minimal variations in their orbital parameters, enhancing their long-term stability. This agrees with the hypothesis that some of the features of Iapetus and Rhea were produced by ancient ring systems, for example, the huge ridge in the Iapetus equator as a result of a decaying ring. From a dynamical perspective, we found that there are no mechanisms that preclude the existence of CSRs, and we attribute their current absence to non-gravitational phenomena. Effects such as stellar radiation, magnetic fields, and the influence of magnetospheric plasma can significantly impact the dynamics of constituent particles and trigger their decay. This highlights the importance of future studies of these effects.
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Bockelee-Morvan, Dominique, Olivier Poch, Francois Leblanc, et al. "A patchy CO_2 exosphere on Ganymede revealed by the James Webb Space Telescope." Astronomy & Astrophysics, September 30, 2024. http://dx.doi.org/10.1051/0004-6361/202451599.
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Jupiter's icy moon Ganymede has a tenuous exosphere produced by sputtering and possibly sublimation of water ice. To date, only atomic hydrogen and oxygen have been directly detected in this exosphere. Here, we present observations of Ganymede's CO$_2$ exosphere obtained with the James Webb Space Telescope. CO$_2$ gas is observed over different terrain types, mainly over those exposed to intense Jovian plasma irradiation, as well as over some bright or dark terrains. Despite warm surface temperatures, the CO$_2$ abundance over equatorial subsolar regions is low. CO$_2$ vapor has the highest abundance over the north polar cap of the leading hemisphere, reaching a surface pressure of 1 pbar. From modeling we show that the local enhancement observed near 12 h local time in this region can be explained by the presence of cold traps enabling CO$_2$ adsorption. However, whether the release mechanism in this high-latitude region is sputtering or sublimation remains unclear. The north polar cap of the leading hemisphere also has unique surface-ice properties, probably linked to the presence of the large atmospheric CO$_2$ excess over this region. These CO$_2$ molecules might have been initially released in the atmosphere after the radiolysis of CO$_2$ precursors, or from the sputtering of CO$_2$ embedded in the H$_2$O ice bedrock. Dark terrains (regiones), more widespread on the north versus south polar regions, possibly harbor CO$_2$ precursors. CO$_2$ molecules would then be redistributed via cold trapping on ice-rich terrains of the polar cap and be diurnally released and redeposited on these terrains. Ganymede's CO$_2$ exosphere highlights the complexity of surface-atmosphere interactions on Jupiter's icy Galilean moons.
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Rush, Tomás A., Ann M. Wymore, Miguel Rodríguez, Jr, et al. "Fungal elemental profiling unleashed through rapid laser-induced breakdown spectroscopy (LIBS)." mSystems, August 27, 2024. http://dx.doi.org/10.1128/msystems.00919-24.
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ABSTRACT Elemental profiling of fungal species as a phenotyping tool is an understudied topic and is typically performed to examine plant tissue or non-biological materials. Traditional analytical techniques such as inductively coupled plasma–optical emission spectroscopy (ICP-OES) and inductively coupled plasma–mass spectrometry (ICP-MS) have been used to identify elemental profiles of fungi; however, these techniques can be cumbersome due to the difficulty of preparing samples. Additionally, the instruments used for these techniques can be expensive to procure and operate. Laser-induced breakdown spectroscopy (LIBS) is an alternative elemental analytical technique—one that is sensitive across the periodic table, easy to use on various sample types, and is cost-effective in both procurement and operation. LIBS has not been used on axenic filamentous fungal isolates grown in substrate media. In this work, as a proof of concept, we used LIBS on two genetically distinct fungal species grown on a nutrient-rich and nutrient-poor substrate media to determine whether robust elemental profiles can be detected and whether differences between the fungal isolates can be identified. Our results demonstrate a distinct correlation between fungal species and their elemental profile, regardless of the substrate media, as the same strains shared a similar uptake of carbon, zinc, phosphorus, manganese, and magnesium, which could play a vital role in their survival and propagation. Independently, each fungal species exhibited a unique elemental profile. This work demonstrates a unique and valuable approach to rapidly phenotype fungi through optical spectroscopy, and this approach can be critical in understanding these fungi's behavior and interactions with the environment. IMPORTANCE Historically, ionomics, the elemental profiling of an organism or materials, has been used to understand the elemental composition in waste materials to identify and recycle heavy metals or rare earth elements, identify the soil composition in space exploration on the moon or Mars, or understand human disorders or disease. To our knowledge, ionomic profiling of microbes, particularly fungi, has not been investigated to answer applied and fundamental biological questions. The reason is that current ionomic analytical techniques can be laborious in sample preparation, fail to measure all potential elements accurately, are cost-prohibitive, or provide inconsistent results across replications. In our previous efforts, we explored whether laser-induced breakdown spectroscopy (LIBS) could be used in determining the elemental profiles of poplar tissue, which was successful. In this proof-of-concept endeavor, we undertook a transdisciplinary effort between applied and fundamental mycology and elemental analytical techniques to address the biological question of how LIBS can used for fungi grown axenically in a nutrient-rich and nutrient-poor environment.
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Kato, Masahisa, Yuki Harada, Yoshifumi Saito, et al. "Inhomogeneous Electrostatic Potentials on the Dayside Lunar Surface in the Terrestrial Magnetotail Lobes: The Role of Lunar Crustal Magnetic Fields." Journal of Geophysical Research: Space Physics 130, no. 2 (2025). https://doi.org/10.1029/2024ja033545.
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AbstractThough the Moon does not possess a global magnetic field like the Earth, there are localized crustal magnetic fields on the lunar surface. Because of the plasma interaction with the crustal magnetic fields, electrostatic and electromagnetic environments near magnetized regions can differ from those near non‐magnetized regions on the Moon. Previous studies observationally revealed the difference in the electrostatic potential on the lunar surface between magnetized and non‐magnetized regions of the Moon in the solar wind, which was attributed to upward electric fields formed by electron‐ion decoupling above the magnetic anomaly regions. However, these inhomogeneous distributions of surface potentials associated with lunar crustal magnetic fields remain uncharacterized in plasma regimes different from the solar wind. In this study, we use a large number of observations by Kaguya and a numerical model of photoelectrons emitted from the sunlit lunar surface to investigate the horizontal distributions of the lunar surface potential in the terrestrial magnetotail lobes. We estimate the relative surface potential variations from the measured energy shift of lunar surface photoelectrons. The results indicate that photoelectrons emitted from relatively strong crustal magnetic field regions tend to be more decelerated, suggesting more positive potentials on the magnetized surface. This implies that upward electric fields are formed by the interaction of terrestrial magnetotail plasma with the lunar crustal magnetic fields in a similar manner to the solar wind interaction with lunar crustal magnetic fields.
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Jia, Xianzhe, Margaret G. Kivelson, Krishan K. Khurana, and Raymond J. Walker. "Improved Models of Ganymede's Permanent and Induced Magnetic Fields Based on Galileo and Juno Data." Journal of Geophysical Research: Planets 130, no. 1 (2024). https://doi.org/10.1029/2024je008309.
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AbstractNear Ganymede, the magnetic field is a superposition of Jupiter's magnetospheric magnetic field, the field arising from sources within the moon, the field generated by plasma currents driven by the interaction of flowing magnetospheric plasma with the conducting moon, and the field arising from ionospheric currents. Previous fits to Ganymede's internal field have not identified the contributions of plasma and ionospheric currents, although their contributions can obscure the signature of sources internal to the moon. Fortunately, using magnetohydrodynamic simulations whose output agrees well with the measurements acquired on close passes by Galileo and Juno, we can estimate the moon‐scale contributions of plasma sources. By subtracting the magnetic signatures of plasma and ionospheric currents from the measured field, we approximate measurements made in a current‐free region. We fit the corrected data from different sets of flybys either as a sum of low order spherical harmonics or as a permanent dipole moment plus an induced dipole with approximately the same root‐mean‐square errors. For the induced dipole model, data from multiple flybys occurring at different phases of Jupiter's rotation are used to represent the time‐variation of the external field at Ganymede. Compared with earlier estimates, the magnitude of the permanent dipole moment did not significantly change in either analysis. However, for the permanent plus induced dipole model, the induction efficiency decreases from 0.84 to ∼0.72. The reduced efficiency places new constraints on the thickness of the ice shell above the ocean and the ocean's depth and conductivity.
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Peter, Addison, Michael Haynes C., Stahl Aaron, Liuzzo Lucas, and Simon Sven. "Data for "Magnetic Signatures of the Interaction Between Europa and Jupiter's Magnetosphere during Juno's Close Flyby"." Geophysical Research Letters, October 5, 2023. https://doi.org/10.5281/zenodo.8412018.
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Data for the manuscript entitled "Magnetic Signatures of the Interaction Between Europa and Jupiter's Magnetosphere during Juno's Close Flyby". All plots and conclusions were drawn from the data enclosed in this entry.Data acquired by the Juno Fluxgate Magnetometer is available at PDS. The relevant timeseries (used in this study) is included in the top level of the dataset directory, entitled 'juno_europa_092922_MAG'. The file is organized such that the columns represent, from left to right: time (utc), position x, y, and z (in EPhiO coordinates, normalized to Europa's radius), and Bx, By, and Bz (nT). The enclosed data is composed of compressed silo entries from each processor used to execute each simulation, as well as timeseries along the trajectory of the spacecraft. The naming convention for the sub-directories is commensurate with the convention within the manuscript. A "readme" file is included in the file structure. The entire directory is compressed for ease of transferral.For any inquiries regarding this data or its associated publication, please contact the corresponding author Sven Simon (sven.simon@eas.gatech.edu) or C. Michael Haynes (mhaynes@eas.gatech.edu). <strong>Note that all authors contributed equally to this work.</strong>
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Green, James, Scott Boardsen, and Chuanfei Dong. "Effects of the evolving early Moon and Earth magnetospheres." Frontiers in Astronomy and Space Sciences 10 (November 10, 2023). http://dx.doi.org/10.3389/fspas.2023.1112233.
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Recently it has been identified that our Moon had an extensive magnetosphere for several hundred million years soon after it was formed when the Moon was within 20 Earth Radii (RE) from the Earth. Some aspects of the interaction between the early Earth-Moon magnetospheres are investigated by mapping the interconnected field lines between the Earth and the Moon and investigating how the early lunar magnetosphere affects the magnetospheric dynamics within the coupled magnetospheres over time. So long as the magnetosphere of the Moon remains strong as it moves away from the Earth in the antialigned dipole configuration, the extent of the Earth’s open field lines decreases. As a result, at times it significantly changes the structure of the field-aligned current system, pushing the polar cusp significantly northward, and forcing magnetotail reconnection sites into the deeper tail region. In addition, the combined magnetospheres of the Earth and the Moon greatly extend the number of closed field lines enabling a much larger plasmasphere to exist and connecting the lunar polar cap with closed field lines to the Earth. That configuration supports the transfer of plasma between the Earth and the Moon potentially creating a time capsule of the evolution of volatiles with depth. This paper only touches on the evolution of the early Earth and Moon magnetospheres, which has been a largely neglected space physics problem and has great potential for complex follow-on studies using more advanced tools and due to the expected new lunar data coming in the next decade through the Artemis Program.