Search Results (180)

Central configurations are fundamental equilibrium solutions of the Newtonian n-body problem and play a key role in understanding the structure and dynamics of gravitational systems. However, the classification and enumeration of such configurations remain incomplete in the four-body case, particularly for symmetric configurations. In this work, we develop a framework for determining and classifying symmetric four-body Dziobek configurations. The method allows the explicit determination of the number of admissible configurations directly from the mass parameters, without requiring prior knowledge of their geometric structure. Combined with previously established semi-analytical relations, this approach provides a systematic characterization of symmetric configurations in terms of mass ratios. As a physically relevant application, we apply the framework to the Earth–Moon system and determine the possible symmetric four-body central configurations involving Earth- and Moon-mass bodies and an additional object of arbitrary mass. We identify both isolated configurations and continuous families of equilibrium solutions, extending the concept of libration points to the four-body problem. The presented semi-analytical approach contributes to the understanding of equilibrium structures in multi-body gravitational systems and provides a foundation for further studies in celestial mechanics, planetary dynamics, and spacecraft motion in complex gravitational environments. Full article

Studies of deep-sea hydrothermal vent systems have generated a spectrum of hypotheses concerning the origin of life on Earth. The present paper integrates recent literature surrounding three separate hydrothermal vent systems (Lost City in the mid-Atlantic, Guaymas Basin in the Gulf of California, and 9°50′ N on the East Pacific Rise) to provide biological, chemical, and geophysical support for these origin-of-life hypotheses. Comparisons between deep-sea hydrothermal vents and impact-generated hydrothermal vent systems may provide further insights into the origin of life. Impact-generated hydrothermal vent systems may have cradled early life. A comprehensive review of studies conducted at Lonar Lake, the Haughton impact structure, and the Chicxulub impact crater provide evidence of long-term hydrothermal activity conducive to the formation of early life, as well as potentially unique DNA structures found in sediment samples—opening the discussion for further investigations into the possible origin (or origins) of life both on Earth and other planetary bodies. Full article

Liquid is a fundamental requirement for life as we understand it, but whether that liquid has to be water is not known. We propose the hypothesis that ionic liquids (ILs) and deep eutectic solvents (DES) constitute a class of non-aqueous planetary liquids capable of persisting on a wide range of bodies where stable liquid water cannot exist. This hypothesis is motivated by key physical properties of ILs and DES. Many exhibit vapor pressures orders of magnitude lower than that of water and remain liquid across exceptionally wide temperature ranges, from cryogenic to well above terrestrial temperatures. These properties permit stable liquids to exist where liquid water would rapidly evaporate or freeze and outside of bulk phases as persistent microscale reservoirs—such as thin films and pore-filling droplets. In other words, ILs and DES can persist in environments without requiring oceans, thick atmospheres, or narrowly regulated climate conditions. We further hypothesize that ILs and DES could act as solvents for non-Earth-like life, based on their polar nature and the demonstrated stability and functionality of proteins and other biomolecules in ionic liquids. More speculatively, our hypothesis extends to the idea that ILs and DES could enable prebiotic chemistry by providing long-lived, protective liquid environments for complex organic molecules on bodies such as comets and asteroids, where liquid water is absent. Additionally, based on the occurrence of DES-like mixtures as protective intracellular liquids in desiccation-tolerant plants, we propose that ILs and DES might be solvents that life elsewhere purposefully evolves. We review protein and other biomolecule studies in ILs and DES and outline planetary environments in which ILs and DES might occur by discussing available anions and cations. We present strategies to advance the IL/DES solvent hypothesis using laboratory studies, computational chemistry, planetary missions, analysis of existing spectroscopic datasets, and modeling of liquid microniches and chemical survival on small bodies. Full article

Quadruped robots possess strong adaptability to rugged terrain, soft ground, and multi-obstacle environments, offering broad application prospects in extraterrestrial planetary exploration. However, large diurnal temperature variations on extraterrestrial bodies exacerbate joint friction nonlinearity, degrading motion control accuracy and stability. To address this, a quadruped robot prototype with hybrid serial–parallel legs is designed for lunar exploration, and an 18-DOF dynamic model is derived using d’Alembert’s principle. Based on the PPO (Proximal Policy Optimization) reinforcement learning algorithm, joint friction parameters are identified using joint velocity and foot–ground contact force. By introducing friction compensation and contact force, an accurate dynamics-based feedback linearization control model is constructed, and a motion impedance control law is designed. Finally, joint friction parameters are identified and validated through both virtual and experimental prototypes, and the proposed control method is tested on flat and sloped terrain. Results show that the method can precisely regulate contact force and foot position, keeping RMSE (Root Mean Square Error) of position within 21.04 mm while preventing slipping and false contact. Full article

This essay poses a novel integrative environmental health promotion (EHP) framework inclusive of spiritual tenets to increase interdisciplinary science as well as public engagement for improved people, place, and planetary (3P) health outcomes. Environmental public health professionals have typically relied upon quantitative scientific evidence related to negative human health outcomes from toxic exposures. Environmental health lags behind more progressive mixed-methods research frameworks leveraging health promotion and 3P health initiatives. This essay argues for a novel integrative EHP framework to encourage more mixed-methods research based on merging an integrative health (body-mind-spirit) perspective and the public health ecological model. Using a three-dimensional Cartesian Coordinate System, the author developed a visual integrative EHP framework with the future ability to record, interpret, and report data with units of measure in three dimensions rather than the traditional x- and y-axis variable relationships. The long-term goal is to engage researchers, study participants, and the general public in exploring new 3P health research and outcomes inclusive of the spiritual axis to leverage more scientific evidence for the care and nurturing of our common home as a basic tenet of civil society. Full article

Automated recognition of celestial bodies from observational imagery is a cornerstone of autonomous space exploration. However, deploying deep learning models in space environments entails rigorous requirements not only for accuracy but also for reliability (calibration) and safety (anomaly rejection). Traditional Convolutional Neural Networks (CNNs) trained on small-scale astronomical datasets often suffer from overfitting and overconfidence on Out-of-Distribution (OOD) artifacts. In this work, we present a robust classification framework based on DINOv2, a Vision Transformer pre-trained via discriminative self-supervised learning. We curate a high-fidelity dataset of seven planetary classes sourced from NASA archives and propose a two-stage domain adaptation strategy to transfer large-scale foundation model features to this fine-grained task. Extensive experiments show that our method reaches 100% Top-1 accuracy on the canonical split, and remains highly stable under split variation, achieving 99.43% ± 0.85% Top-1 accuracy across R = 5 repeated stratified splits. More importantly, we address the critical issue of model trustworthiness. Through post hoc temperature scaling, our model achieves a state-of-the-art Expected Calibration Error (ECE) of 0.08%, representing a 36-fold improvement over ResNet50 (2.90%) and a 4.5-fold improvement over the EfficientNet-B3 baseline (0.36%). Furthermore, by integrating Energy-based OOD detection, the system effectively rejects non-planetary artifacts with an AUROC of 93.7%. Qualitative analysis using Grad-CAM reveals that self-supervised attention mechanisms naturally focus on intrinsic planetary features (e.g., surface textures and rings) while ignoring background noise, confirming the superior robustness of vision foundation models in astronomical vision tasks. Full article

Regions of partial melt of Fe-S-Si alloys at high pressures may arise during planetary formation or at the boundary of the inner and outer cores of small terrestrial planetary bodies. Melting experiments were performed on Fe-16wt%S-2wt%Si samples in a multi-anvil apparatus across the range 2–13 GPa with quench temperatures in partial and complete melt regions. A phase diagram is constructed from electron microprobe analyses, back-scattered electron imaging, and electrical resistivity measurements. Microstructures arising in post-quench samples include Turing patterns of Fe and FeS in the partial melt, dendritic Fe structures with tertiary arms in the partial and complete melt, and Fe-S-Si miscible regions in the complete melt. These melt structures may arise broadly or locally in small Fe-S planetary cores with consequences for the energetics of the core. Full article

The Planet Nine hypothesis encompasses a body of about 5–8 Earth’s masses whose orbital plane would be inclined to the ecliptic by one or two tens of degrees and whose perihelion distance would be as large as about 240–385 astronomical units. Recently, a couple of his epigones have appeared: Planet X and Planet Y. The former is similar to a minor version of Planet Nine in that all its physical and orbital parameters would be smaller. Instead, the latter would have a mass ranging from that of Mercury to Earth’s and a semimajor axis within 100–200 astronomical units. By using realistic upper bounds for the orbital precessions of Saturn, one can obtain insights on their position which, for Planet Nine, appears approximately confined around its aphelion. Planet Y can only be a Mercury-sized object at no less than about 125 astronomical units, while Planet X appears to be ruled out. Dedicated data reductions by modeling such perturber(s) are required to check the present conclusions, to be intended as hints of what might be detectable should planetary ephemerides include them. A probe on the same route of Voyager 1 would be perturbed by Planet Nine by about 20–40 km after some decades. Full article

Purpose: A growing body of evidence has emerged on the role of diet for health outcomes in cancer survivors. Patients transitioning to post-treatment care may seek guidance on dietary changes, and summaries of the evidence for dietary patterns recommended by guidelines can support providers in effectively answering questions. Increasing evidence suggests that food choices impact planetary health. Plant-based diets are one eating pattern that may improve patient outcomes and planetary health. Methods: We performed a literature review and used narrative reporting to summarize evidence for plant-based diets and offer specific guidance for breast, colorectal, and prostate cancer patients who are post-diagnosis. Specifically, we reviewed impacts on recurrence, all-cause, and cancer-specific mortality. Results: Increased fibre intake by consuming foods like fruits, vegetables, and whole grains is associated with a decreased risk of breast cancer-specific and all-cause mortality, as well as reduced colon cancer-specific mortality. Replacing refined grains with whole grains is associated with improved disease-free survival for colon cancer survivors. Higher tree nut consumption is associated with improved disease-free survival for breast, colorectal, and prostate cancer survivors. Soy is safe to consume for breast cancer survivors and is associated with a reduced risk of recurrence. Conversely, more Western dietary patterns high in processed meat intake are associated with an increased risk of colon cancer recurrence and prostate cancer mortality. There are also environmental benefits of a shift towards plant-based diets to address the adverse health outcomes associated with climate change and its potential impact on cancer care delivery as previously outlined in a 2024 ASCO policy statement. Conclusions: Based on the best existing evidence, providers can suggest that patients consider plant-based dietary patterns in the post-treatment phase of their cancer care to support health outcomes and planetary health. Full article

Background/Objectives: Adherence to the EAT-Lancet Planetary Health Diet (PHD) may promote human health and environmental sustainability, yet evidence regarding adherence and nutritional adequacy in Australia is limited. Globally, no research to date has used the recently updated 2025 PHD guidelines. We benchmarked the compatibility of Australian adults’ dietary patterns with the 2025 PHD and examined its associations with nutritional adequacy and sociodemographic factors. Methods: This was a cross-sectional analysis of dietary data from 5655 adults who participated in the National Nutrition and Physical Activity Survey. Usual intakes were estimated from two 24 h recalls using the Multiple Source Method. PHD adherence was measured using the Healthy Reference Diet Score (0–130 points). Nutrient adequacy was assessed using the full probability method for iron and the Australian/New Zealand Estimated Average Requirement Cut-Point Method for all other nutrients. Survey-weighted regression models examined associations with nutritional adequacy and sociodemographic factors. Results: The mean PHD adherence score was 50 (SE 0.3) points. Higher adherence was associated with lower odds of inadequate intakes of several micronutrients, but with higher odds of inadequacy for vitamin B12 (OR: 1.24; 95% CI: 1.06, 1.45) and calcium (OR: 1.09; 95% CI: 1.01, 1.17). PHD adherence was higher among females, older adults, those with higher educational attainment, those born in countries where English is not the main language, two-person households and non-smokers; adherence was non-linearly associated with alcohol and was lower among those with a Body Mass Index ≥ 30 kg/m². Conclusions: PHD adherence in Australia was low. Higher adherence was associated with improved adequacy for several micronutrients. Trade-offs for vitamin B12 and calcium warrant consideration. Equity-conscious strategies will be needed to support the adoption of nutritionally adequate, environmentally sustainable diets. Full article

This study is motivated by the severe tribological regime of PA6 composites in VR platforms operating under dry or boundary lubrication, where alternating shear during foot rotation, localised contact pressures, and third-body abrasion concurrently challenge wear resistance and retention of strength. This paper presents the results of research into the properties of composites based on polyamide PA6 and molybdenum disulphide, obtained by combining the components through high-intensity mechanochemical activation in a planetary mill and classical mixing in a turbulence mixer. We demonstrate that varying the energy of the premixing stage (mechanochemical activation versus low-energy premixing) serves as an effective means of interfacial engineering in PA6/MoS₂ composites, enabling simultaneous enhancement of mechanical and tribological properties at low filler contents. Analysis of experimental composite samples using Fourier-transform infrared spectroscopy (FTIR) indicates the interaction between MoS₂ and oxygen-containing groups of polyamide while maintaining its overall chemical composition. According to the TG-DSC curves, modification of polyamide leads to an increase in the melting temperature by 2 °C, while mechanical activation ensures stronger interaction between the matrix and the filler. Compared to pure PA6, the tensile strength of composites increases by 10–20% for mechanoactivated materials and by 5–10% for materials obtained by conventional methods. The mechanical activation effect is observed even at minimal amounts (0.25 and 0.5%) of MoS₂ in composites. The toughness of all composites, regardless of the mixing method, increases by 5–7% compared to pure polyamide. All composites show a 10–20% reduction in the coefficient of friction on steel. Simultaneously, the water absorption of composites becomes 5–20% higher than that of the original material, which indicates a change in structure and an increase in porosity. The obtained composite materials are planned to be used for manufacturing platforms for the movement of virtual reality (VR) operators. Full article

Planetary mapping has progressively evolved due to the increasing availability of high-quality data and advancements in analytical techniques applied to both surface and subsurface features. In particular, the enhanced spatial resolution and broader coverage provided by cameras and spectrometers aboard orbiting spacecraft around planetary bodies, now enable the production of more detailed geostratigraphic maps. Which maps go beyond the traditional planetary approach, with mineralogical data contributing significantly to the development of more comprehensive final products. Proclus crater is a fresh crater, 28 km in diameter, located on the northwest rim of the Crisium basin, where crystalline plagioclase, as well as pyroxenes and olivine, have been detected. Here, preliminarily, the geomorphological map showed the different surface textures and lineaments of the crater, and a spectral unit map highlighted the different spectral units present in the area. The spectral unit map has been produced by using supervised classification, where the spectral endmembers were extracted by the mean of an automatic tool. The mineralogical interpretation retrieved from spectral endmembers supports the definition of six main spectral units and, moreover, indicates how two of them could be divided into subunits. Those subunits show the systematic variation in plagioclase, low-Ca and high-Ca pyroxene, and their relative abundances. Finally, the geostratigraphic maps associate compositional heterogeneity with different units of the crater, suggesting that this crater was originally characterized by lithologies rich in plagioclase, but mixed with variable low amounts of mafic phases. Since Proclus is a relatively small crater and the units better exposing the mineral’s original heterogeneity are principally distributed in the walls, the spectral units seem to suggest the presence of magma traps during the plagioclase floating during the lunar primary crust formation and constitute heterogeneous terrains within the Highland. Full article

The 17 sustainable development goals advocated by the United Nations have played a big role in focusing the minds of policy makers in terms of sustainability issues and have also highlighted the issue of social inclusion and the need to make society more equitable. As well as referencing the sustainable development goals, attention is given to the planetary health concept as it is known to deepen our understanding of the ecological interdependence brought about by cultural, environmental and socio-economic factors, which have relevance in terms of mankind achieving the sustainable development goals. This paper addresses the following question: How can a framework to foster global partnerships leading to sustainable development be underpinned by a philosophical argument that strengthens the case for social inclusion? Consequently, a wide body of literature is reviewed, with key concepts such as collaboration being placed in context and reinforced through stakeholder theory. A philosophical discussion is entered into embracing Moore’s open question argument regarding the reliance on Intuitionism to explain how actions can be coined as immoral or moral. Such arguments are useful for raising moral issues that often end in moral disagreements, and which raise and help solve ethical problems. To effectively deal with the complexity involved, policy makers should support the use of frameworks that can be used to support and encourage social inclusion. In adopting this viewpoint, we put forward a sustainable partnership framework that provides guidance to policy makers and their advisors in terms of tackling the issue of social inclusion. In order to achieve social inclusion, policy makers need to understand the role that symbolic representation plays and how the influence of major influencers generates collaborative knowledge that is reappraised through philosophical argument. The outcome of the philosophical argument is a change in a nation’s cultural value system and the implementation of social inclusion policy. Full article

One key objective of astrobiology is to investigate and discover if other planetary bodies are habitable. The determination of whether an environment is habitable to known life requires measuring liquid water, CHNOPS elements, other nutrients, and energy supplies. Here we investigate the potential for a single instrument capable of sampling these key indicators: a ‘Total Habitability Instrument’. The proposed instrument would be capable of deployment in diverse environments and provide an integrated set of measurements that together allow for the assessment of the habitability of an environment of interest, such as those of the Moon or Mars. We explore existing and potential technological developments that would enable the construction of such an instrument, with a focus on soft systems, which are inspired by nature in their design, and microfluidics. This paper considers a multidisciplinary approach to the design and sensing requirements of a Total Habitability Instrument that would be capable of gathering and processing samples and be deployable by both robotic and human explorers on all planetary bodies, allowing for the mapping of habitability over large areas of our Solar System and beyond. Full article