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The 30,000+ known Near Earth Objects (NEOs) are some of the closest objects to Earth. A few dedicated missions such as NEAR, Hayabusa-1 and -2, OSIRIS-Rex, and DART have revealed a lot about their nature, with more to come from ESA's Hera mission, and others. Dedicated space missions to individual NEOs are relatively costly, however, so we seek to find a way to reduce costs so that the composition and structure of more NEOs can be fully characterized, and we can continue to explore how to change the trajectory of selected objects, as was done with DART. Here we describe a low-cost approach to NEO missions for small body science and planetary defense that makes use of existing or planned space vehicles. • Low-cost approach to fly by, rendezvous with, or impact Near Earth Objects. • Repurposes existing or planned space vehicles. • Case Study using the Artemis European Service Module. [ABSTRACT FROM AUTHOR]

We present an approach to calculate potential fields on a planet's surface from regionally confined gradient data at spacecraft altitude, such as measurements of magnetic fields or gravitational acceleration. Our method uses altitude cognizant Slepian functions with a reference radial position that varies as a function of longitude and latitude. This is an evolution from previous altitude cognizant Slepian functions which use a fixed reference radial position. We demonstrate the advantage of these variable altitude cognizant Slepian functions over the fixed altitude cognizant Slepian functions and the classical Slepian functions using numerical tests. [ABSTRACT FROM AUTHOR]

The exploration of small bodies in our solar system is of great interest for the planetary science community due to their high scientific value. However, their generally weak and irregular gravity fields increase the difficulty associated with close proximity operations. Moreover, solar radiation pressure (SRP) can significantly perturb the motion of objects in their vicinity, particularly for bodies with high area-to-mass ratios. In this work, we adopt the polyhedral gravity model and identify natural dynamical structures that can be used for mission operations. Further, we study forced periodic motion in the body fixed frame while accounting for the effect of SRP with eclipses. Overall, our work seeks to identify suitable orbits and locations in the vicinity of small bodies that can be exploited for the design of science orbits. To obtain periodic orbits in the model accounting for SRP perturbations, we use a Melnikov function to find orbits that satisfy resonances with the asteroid spin and show no net change in energy over the orbit. We then use a differential correction scheme to find numerical solutions in the time-periodic model. Our test cases are potentially hazardous asteroid 101955 Bennu and main belt asteroid 16 Psyche. [ABSTRACT FROM AUTHOR]

Despite their widespread application in planetary and earth sciences in the past two decades, thallium isotopic compositions have been determined via MC-ICP-MS with instrumental mass bias corrected by employing a combination of lead doping and standard-sample bracketing. Residual Pb, either from the sample matrix or contamination, may significantly distort the isotope ratio of Pb for mass bias correction, thereby affecting the accuracy of Tl isotope measurement. In this study, we employed 186W/184W (NIST SRM 3163 W) instead of 208Pb/206Pb (NIST SRM 981 Pb) to correct instrumental mass bias during the measurement of Tl isotopic compositions through MC-ICP-MS. The plot of ln(186W/184W) vs. ln(205Tl/203Tl) shows a strong linear correlation (R2 > 0.993) in the repeated analyses of NIST SRM 997 Tl using W. Two pure Tl standards, Fluka Tl and GSB Tl, produced 3205TlNIST 997 values of -1.9 ± 0.7 (2SD, n = 97) and 0.8 ± 0.7 (2SD, n = 31), respectively. The 3205TlNIST 997 of five geological reference materials (SCo-1, GSS-6, GSP-2, NOD-P-1, and NOD-A-1) are also reported here, and the external reproducibility of these results is better than 0.08& (2SD). 3205TlNIST997 values are in good agreement with previously published values determined using Pb doping to correct mass bias, demonstrating that W can serve as a calibrator and facilitate high-precision 3205TlNIST 997 measurement of geological materials. [ABSTRACT FROM AUTHOR]

The Mars Sample Return (MSR) campaign is one of the most ambitious and complex planetary science exploration missions ever pursued. With the participation of NASA, ESA, and many industry partners, MSR aims to bring Martian rock and atmosphere samples to Earth with the goal of answering key questions about Mars' geological, climatological and, potentially, biological evolution. To accomplish this ambitious goal, the MSR campaign relies on three distinct flight elements and a ground element. The Earth Return Orbiter mission that would host the Capture, Containment, and Return System (CCRS) is the last flight element of the trio. The mission would capture the orbiting sample in low Mars orbit (launched into orbit by another mission), contain it, and return it to Earth, landing at the Utah Test and Training Range. Since its early architecture, several changes were adopted by CCRS to improve overall payload efficiency and reduce mass. This paper will discuss the CCRS design, how the current CCRS architecture contributes to an improved mission concept, and the next critical steps of the mission toward its launch. • MSR is one of the most ambitious and complex exploration missions ever pursued. • CCRS is the last flight element of MSR bringing the Mars samples to Earth. • Detailed examination of the NASA CCRS payload is presented. • Insight into the operational plans of CCRS that enables a successful sample return. • Contributes to the broader body of knowledge in space exploration. [ABSTRACT FROM AUTHOR]

This article explores the controversy surrounding the colonization of Mars, presenting arguments from both proponents and critics. Proponents, such as Elon Musk and Robert Zubrin, argue that colonizing Mars is crucial for human survival and technological progress. However, critics like Mary-Jane Rubenstein and Deondre Smiles raise ethical concerns about the rights of microbial life, rocks, and indigenous peoples. The article also mentions the growing opposition to space colonization, calling for regulation and consideration of anti-imperialism. It emphasizes the importance of considering diverse perspectives and not underestimating the opposition to private space travel. [Extracted from the article]

NASA's Europa Clipper spacecraft is preparing for a mission to explore Jupiter's moon, Europa, with the goal of investigating its potential for supporting life. Europa is thought to have a liquid saltwater ocean beneath its icy exterior, making it a potentially habitable environment. The spacecraft will use its nine science instruments to conduct flybys of Europa, studying its ocean remotely and searching for chemistry that could support life. While the mission's primary focus is on habitability rather than directly searching for life, scientists acknowledge that the possibility of finding evidence of life is not out of the question. However, the mission faces challenges such as the intense radiation around Jupiter and uncertainty about whether the spacecraft will encounter the hidden ocean. If successful, the mission could revolutionize the search for extraterrestrial life. [Extracted from the article]

The JUpiter Icy Moon Explorer mission (JUICE) was designed to investigate Jupiter, its environment and its icy moons with at least one Europa flyby, a high inclination phase around Jupiter and a 280 days long near polar orbital phase around Ganymede, with 130 days on a low circular orbit. The goal of the JUICE mission analysis consisted in implementing these mission elements within a tight mass and radiation budget. A shift in the nominal launch date from June 2022 to September 2022 then April 2023 resulted in an arrival date at Jupiter in July 2031, close to equinox, so that the duration of eclipses by Jupiter became a major issue. A mission scheme meeting the requirements was designed using innovative approaches such as a double swing-by of the Moon and the Earth and a low energy endgame targeting a grazing Callisto flyby then grazing Ganymede encounters. Thanks to a near optimum launch date and launcher performance with full tanks, the post-launch Delta-V margins (150 m/s) made it possible to re-instate a 200 km circular orbital phase at the end of the nominal mission as planned in the mission proposal. The remaining Delta-V margin (55 m/s) and that expected from clean-up costs lower than allocated make it possible, while keeping adequate margins for contingencies, to consider significant improvements of the baseline mission scheme, in particular a higher maximum inclination during the tour and an inclination on the 200 km orbit close to Sun-synchronous, so that a long extended mission can be considered. [ABSTRACT FROM AUTHOR]

We report a molecular dynamics study of the heterogeneous crystallization of high-pressure glassy water using (plastic) ice VII as a substrate. We focus on the thermodynamic conditions P ∈ [6–8] GPa and T ∈ [100–500] K, at which (plastic) ice VII and glassy water are supposed to coexist in several (exo)planets and icy moons. We find that (plastic) ice VII undergoes a martensitic phase transition to a (plastic) fcc crystal. Depending on the molecular rotational lifetime τ, we identify three rotational regimes: for τ > 20 ps, crystallization does not occur; for τ ∼ 15 ps, we observe a very sluggish crystallization and the formation of a considerable amount of icosahedral environments trapped in a highly defective crystal or in the residual glassy matrix; and for τ < 10 ps, crystallization takes place smoothly, resulting in an almost defect-free plastic fcc solid. The presence of icosahedral environments at intermediate τ is of particular interest as it shows that such a geometry, otherwise ephemeral at lower pressures, is, indeed, present in water. We justify the presence of icosahedral structures based on geometrical arguments. Our results represent the first study of heterogeneous crystallization occurring at thermodynamic conditions of relevance for planetary science and unveil the role of molecular rotations in achieving it. Our findings (i) show that the stability of plastic ice VII, widely reported in the literature, should be reconsidered in favor of plastic fcc, (ii) provide a rationale for the role of molecular rotations in achieving heterogeneous crystallization, and (iii) represent the first evidence of long-living icosahedral structures in water. Therefore, our work pushes forward our understanding of the properties of water. [ABSTRACT FROM AUTHOR]

Triton and Pluto are believed to share a common origin, both forming initially in the Kuiper Belt but Triton being later captured by Neptune. Both objects display similar sizes, densities, and atmospheric and surface ice composition, with the presence of volatile ices N2, CH4, and CO. Yet their appearance, including their surface albedo and ice distribution strongly differ. What can explain these different appearances? A first disparity is that Triton is experiencing significant tidal heating due to its orbit around Neptune, with subsequent resurfacing and a relatively flat surface, while Pluto is not tidally activated and displays a pronounced topography. Here we present long-term volatile transport simulations of Pluto and Triton, using the same initial conditions and volatile inventory, but with the known orbit and rotation of each object. The model reproduces, to first order, the observed volatile ice surface distribution on Pluto and Triton. Our results unambiguously demonstrate that obliquity is the main driver of the differences in surface appearance and in climate properties on Pluto and Triton, and give further support to the hypothesis that both objects had a common origin followed by a different dynamical history. [ABSTRACT FROM AUTHOR]

Deployment of ultracold atom interferometers (AI) into space will capitalize on quantum advantages and the extended freefall of persistent microgravity to provide high-precision measurement capabilities for gravitational, Earth, and planetary sciences, and to enable searches for subtle forces signifying physics beyond General Relativity and the Standard Model. NASA's Cold Atom Lab (CAL) operates onboard the International Space Station as a multi-user facility for fundamental studies of ultracold atoms and to mature space-based quantum technologies. We report on pathfinding experiments utilizing ultracold 87Rb atoms in the CAL AI. A three-pulse Mach–Zehnder interferometer was studied to understand the influence of ISS vibrations. Additionally, Ramsey shear-wave interferometry was used to manifest interference patterns in a single run that were observable for over 150 ms free-expansion time. Finally, the CAL AI was used to remotely measure the Bragg laser photon recoil as a demonstration of the first quantum sensor using matter-wave interferometry in space. NASA's Cold Atom Lab has operated on the International Space Station since 2018 to study quantum gases and mature quantum technologies in Earth's orbit. Here, Williams et al., report on a series of pathfinding experiments exploring the first quantum sensor using atom interferometry in space. [ABSTRACT FROM AUTHOR]

The 2023–2032 Planetary Science and Astrobiology Decadal Survey prioritized the Uranus Orbiter and Probe (UOP) mission concept as the next priority flagship mission. The UOP concept includes scientific studies of the Uranian moon system. Although the Uranian moons differ greatly from the ocean worlds in the Jovian and Saturnian systems, the emerging hypothesis is that some of them could at least sustain thin, potentially concentrated, oceans. Herein, we make a case that these moons are important and interesting targets of astrobiological research. Studying these worlds would provide critical astrobiological data related to their habitability, including origin, evolution, and potential death, as well as the formation and evolution of ocean worlds more broadly. There is a strong need for research that connects astrobiology to modeling and experimentation to better characterize the possible conditions of these worlds, and this will be critical in formulating and maximizing the potential science that could be done by a Uranus flagship mission. [ABSTRACT FROM AUTHOR]

Recent observations of Jupiter's atmosphere showing unexpected depletion of ammonia below the ammonia cloud-forming region has brought up the question of whether a single point measurement below the cloud decks in a giant planet atmosphere can provide sufficient information to answer fundamental science questions. We outline here the science questions that can only be answered by in situ observations in the giant planet atmospheres, many of which are location invariant. These questions are identified in the recent planetary science decadal survey as high priority for answering over the next decade. We evaluate the implications of the ammonia observations at Jupiter for the specific measurements needed and demonstrate that they do not invalidate single point measurements made to answer these questions. [ABSTRACT FROM AUTHOR]

Spectral features of olivine across the intermediate infrared region (IMIR, 4–8 μm) shift systematically with iron‐magnesium content, enabling determination of olivine composition. Previous IMIR studies have used laboratory data with signal‐to‐noise ratios (SNRs) and spectral resolutions potentially greater than those of data derived from planetary missions. Here we employ a feature fitting algorithm to quantitatively assess the influence of data quality on olivine detection and compositional interpretation from IMIR data of 29 spectra of pure olivine of synthetic, terrestrial, lunar, and Martian origins, as well as 5 spectra of lunar pyroclastic beads measured as bulk samples. First, we demonstrate the effectiveness of the feature fitting algorithm in the interpretation of IMIR olivine spectra, predicting olivine composition with an average error of 6.4 mol% forsterite across all test spectra using laboratory‐quality data. We then extend this analysis to degraded test spectra with reduced SNRs and sampling rates and find a range of data qualities required to predict olivine composition within ±11 Mg# (molar Mg/[Mg + Fe] × 100) for the test spectra explored here. Spectra for the sample most relevant to lunar exploration, an Apollo 74002 drive tube consisting of microcrystalline olivine and glass‐rich pyroclastics, required SNRs ≥ 200 for sampling rates ≤25 nm to predict composition within ±11 Mg# of the sample's true composition. Derived limits on SNRs and sampling rates will serve as valuable inputs for the development of IMIR spectrometers, enabling comprehensive knowledge of olivine composition on the lunar surface. Plain Language Summary: An understanding of olivine composition can reveal the history of large‐ and small‐scale magmatic processes, offering key insights into a planet's thermal and chemical evolution. Here we explore olivine spectra in the intermediate infrared region (IMIR), where systematic trends in olivine's absorption bands are indicative of composition. We degrade laboratory olivine spectra to data qualities that are more realistic of spectrometers used in planetary exploration and derive constraints on the signal‐to‐noise ratio and sampling rates required to accurately predict olivine composition. These constraints will be useful in the development of IMIR spectrometers. Key Points: We use a feature fitting routine to predict olivine composition from degraded spectral data in the intermediate infrared region (4–8 μm)Accurate prediction of olivine composition is observed at data qualities expected of spectrometers designed for space exploration [ABSTRACT FROM AUTHOR]

This editorial titled "Enhancing the right to science: the triple planetary crisis and the need for comprehensive approaches" emphasizes the importance of the right to science in addressing global challenges such as climate change and biodiversity loss. It discusses the role of the right to science in promoting access to scientific knowledge, protecting against harm, and ensuring academic freedom. The editorial also highlights the need to address global inequalities in scientific practice, decolonize scholarship, and address gender inequalities in the field. It calls for international cooperation and the protection of scientific integrity in the face of disinformation and anti-science sentiment. The article acknowledges the efforts of organizations like UNESCO and the UN Human Rights Council in promoting the right to science but recognizes the obstacles and inequalities that need to be addressed for effective implementation. [Extracted from the article]

The Mars Reconnaissance Orbiter and its Context Camera (CTX) have acquired more than 100,000 separate panchromatic images that capture nearly the entire surface of Mars at ∼5–6 m/pixel. This paper describes a data processing workflow used to generate the first contiguous global mosaic of CTX data, which represents a large improvement in spatial resolution over existing 100 m/pixel contiguous global mosaics. We describe the overarching strategy for the mosaic's construction, which was to maximize the scientific utility of a continuous mosaic that is 5.7 trillion pixels in size. The pipeline used for data processing prioritized traceability and reproducibility of the final mosaic, such that the provenance of all pixels is reported, equipping scientists with information to differentiate mosaic artifacts from surface landforms and to incorporate critical image metadata into their analyses. The CTX data set synthesized into a global CTX mosaic facilitates ready analysis and provides a new capability in transitioning global studies of Mars from high‐resolution investigations of individual images to systematic studies of the entire Martian surface at outcrop‐resolving quality without regard to image boundaries. Plain Language Summary: We generated a global mosaic of Mars using Context Camera satellite imagery at 5.0 m/pixel, a substantial improvement in spatial resolution over the previous global mosaic at 100 m/pixel. This paper describes a new technique for merging overlapping images together in a way that preserves all information from each component image and produces a map of all image boundaries that is included with the mosaic. This makes scientific analyses that are facilitated by the mosaic fully traceable and reproducible. With this mosaic, scientists can now readily analyze landforms without the overhead of downloading individual images and perform complete global analyses of Mars at a resolution capable of seeing rock outcrops on the surface. Key Points: A global mosaic of Mars at 5.0 m/pixel has been created from 86,571 Context Camera images that are co‐registered to each other and seam‐correctedNon‐destructive image processing was used to preserve all image metadata and map seamsThe new mosaic will facilitate systematic studies of Mars at 5.0 m/pixel spatial resolution [ABSTRACT FROM AUTHOR]

Granular solids in planetary science are found in the regolith that covers planetary surfaces as well as in the bulk of rubble-pile asteroids, comets and planetesimals. To help understand the physics of these planetary bodies, we aim at deriving the structural properties of granular packings over a large range of porosities. Relevant to fluid flow and gas diffusion are the void spaces inside the granular packings so that we analyze the mean free path of point-like particles, their diffusion constant and their total traveled path lengths. For mechanical and heat-transport properties, the coordination number and the absolute chain length of the inter-connected particles are important. Generally, we also derive the homogeneity and isotropy of the granular solids. We compare granular packings generated by four algorithms for porosities in the range between 85 and 42%, which are the upper and lower limits for natural packings of equal-sized spheres. All produced sphere packings arrive at very similar quantities for the mean free path, the free path probability distribution function, the diffusion constant and the total traveled path length for the entire range of porosities. Hence, transport processes governed by the void-space properties are independent of the specific generation algorithm for the granular packing. In contrast, heat conduction or mechanical stresses almost exclusively depend on the existence and properties of particle contacts and particle chains in the network of spheres. In this case, the four algorithms deliver very different results. [ABSTRACT FROM AUTHOR]

Micrometeorites are estimated to represent the main part of the present flux of extraterrestrial matter found on the Earth's surface and provide valuable samples to probe the interplanetary medium. Here, we describe large and representative collections of micrometeorites currently available to the scientific community. These include Antarctic collections from surface ice and snow, as well as glacial sediments from the eroded top of nunataks—summits outcropping from the icesheet—and moraines. Collections extracted from deep-sea sediments (DSS) produced a large number of micrometeorites, in particular, iron-rich cosmic spherules that are rarer in other collections. Collections from the old and stable surface of the Atacama Desert show that finding large numbers of micrometeorites is not restricted to polar regions or DSS. The advent of rooftop collections marks an important step into involving citizen science in the study of micrometeorites, as well as providing potential sampling locations over all latitudes to explore the modern flux. We explore their strengths of the collections to address specific scientific questions and their potential weaknesses. The future of micrometeorite research will involve the finding of large fossil micrometeorite collections and benefit from recent advances in sampling cosmic dust directly from the air. This article is part of the theme issue 'Dust in the Solar System and beyond'. [ABSTRACT FROM AUTHOR]

Euclid, a space telescope, is facing issues with ice accumulation on its optics, affecting its vision. The mission teams are testing a new procedure to de-ice the optics and find a long-term solution. A study has found that thermal stresses break up large meteoroids near Earth, observed when multiple meteors are detected in a short period. A star from the second generation in the Large Magellanic Cloud has been discovered, shedding light on element formation in other galaxies. The impact of NASA's DART mission on the asteroid Dimorphos changed its motion and shape, suggesting it is a loosely packed object. [Extracted from the article]

Terrestrial planets currently in the habitable zone around M dwarfs are estimated to have been in runaway greenhouse conditions for up to ∼1 Gyr due to the long-term pre-main-sequence phase of M dwarfs. These planets likely lose a significant portion of water during the pre-main-sequence phase owing to H2O photolysis followed by hydrogen and oxygen loss to space. However, the effects of H2O reproduction reactions and UV shielding by chemical products that reduce photolysis-induced water loss have yet to be estimated. Here, we apply a 1D photochemical model to a H2O-dominated atmosphere of an Earth-like planet around a pre-main-sequence M dwarf to estimate these effects. We find that water loss is suppressed by efficient H2O reproduction reactions and by UV shielding due to O2. The water loss rate decreases by several to several hundred times compared to that in previous studies, with the assumption that the water loss rate is limited by stellar X-ray and extreme-ultraviolet flux or hydrogen diffusion through the atmosphere. Our results imply that terrestrial planets currently in the habitable zone around M dwarfs are more likely to retain surface water than previously estimated. [ABSTRACT FROM AUTHOR]

Detecting near-Earth asteroids (NEAs) is crucial for research in solar system and planetary science. In recent year, deep-learning methods have almost dominated the task. Since NEAs represent only one-thousandth of the pixels in images, we proposed an ICC-BiFormer model that includes an image compression and contrast enhancement block and a BiFormer model to capture local features in input images, which is different from previous models based on Convolutional Neural Network (CNN). Furthermore, we utilize a larger input size of the model, which corresponds to the side length of the input image matrix, and design a cropping algorithm to prevent NEAs from being truncated and better divide NEAs and satellites. We apply our ICC-BiFormer model into a dataset of approximately 20,000 streak and 40,000 non-streak images to train a binary classification model. The ICC-BiFormer achieves 99.88% accuracy, which is superior to existing models. Focusing on local features has been proven effective in detecting NEAs. [ABSTRACT FROM AUTHOR]

Updated formation and structure models of Jupiter predict a metal-poor envelope. This is at odds with the two to three times solar metallicity measured by the Galileo probe. Additionally, Juno data imply that water and ammonia are enriched. Here, we explore whether Jupiter could have a deep radiative layer separating the atmosphere from the deeper interior. The radiative layer could be caused by a hydrogen-transparency window or depletion of alkali metals. We show that heavy-element accretion during Jupiter's evolution could lead to the desired atmospheric enrichment and that this configuration would be stable over billions of years. The origin of the heavy elements could be cumulative small impacts or one large impact. The preferred scenario requires a deep radiative zone, due to a local reduction of the opacity at ∼2000 K by ∼90%, which is supported by Juno data, and vertical mixing through the boundary with an efficiency similar to that of molecular diffusion (D ≲ 10−2 cm2 s−1). Therefore, most of Jupiter's molecular envelope could have solar composition while its uppermost atmosphere is enriched with heavier elements. The enrichment likely originates from the accretion of solid objects. This possibility resolves the long-standing mismatch between Jupiter's interior models and atmospheric composition measurements. Furthermore, our results imply that the measured atmospheric composition of exoplanets does not necessarily reflect their bulk compositions. We also investigate whether the enrichment could be due to the erosion of a dilute core and show that this is highly unlikely. The core-erosion scenario is inconsistent with evolution calculations, the deep radiative layer, and published interior models. [ABSTRACT FROM AUTHOR]

With the advent of toroidal and double-stage diamond anvil cells (DACs), pressures between 4 and 10 Mbar can be achieved under static compression, however, the ability to explore diverse sample assemblies is limited on these micron-scale anvils. Adapting the toroidal DAC to support larger sample volumes offers expanded capabilities in physics, chemistry, and planetary science: including, characterizing materials in soft pressure media to multi-megabar pressures, synthesizing novel phases, and probing planetary assemblages at the interior pressures and temperatures of super-Earths and sub-Neptunes. Here we have continued the exploration of larger toroidal DAC profiles by iteratively testing various torus and shoulder depths with central culet diameters in the 30–50 µm range. We present a 30 µm culet profile that reached a maximum pressure of 414(1) GPa based on a Pt scale. The 300 K equations of state fit to our P–V data collected on gold and rhenium are compatible with extrapolated hydrostatic equations of state within 1% up to 4 Mbar. This work validates the performance of these large-culet toroidal anvils to > 4 Mbar and provides a promising foundation to develop toroidal DACs for diverse sample loading and laser heating. [ABSTRACT FROM AUTHOR]

The detection of low-mass planets orbiting the nearest stars is a central stake of exoplanetary science, as they can be directly characterized much more easily than their distant counterparts. Here, we present the results of our long-term astrometric observations of the nearest binary M-dwarf Gliese 65 AB (GJ65), located at a distance of only 2.67 pc. We monitored the relative astrometry of the two components from 2016 to 2023 with the VLTI/GRAVITY interferometric instrument. We derived highly accurate orbital parameters for the stellar system, along with the dynamical masses of the two red dwarfs. The GRAVITY measurements exhibit a mean accuracy per epoch of 50−60 ms in 1.5 h of observing time using the 1.8 m Auxiliary Telescopes. The residuals of the two-body orbital fit enable us to search for the presence of companions orbiting one of the two stars (S-type orbit) through the reflex motion they imprint on the differential A–B astrometry. We detected a Neptune-mass candidate companion with an orbital period of p = 156 ± 1 d and a mass of mp = 36 ± 7 M⊕. The best-fit orbit is within the dynamical stability region of the stellar pair. It has a low eccentricity, e = 0.1 − 0.3, and the planetary orbit plane has a moderate-to-high inclination of i > 30° with respect to the stellar pair, with further observations required to confirm these values. These observations demonstrate the capability of interferometric astrometry to reach microarcsecond accuracy in the narrow-angle regime for planet detection by reflex motion from the ground. This capability offers new perspectives and potential synergies with Gaia in the pursuit of low-mass exoplanets in the solar neighborhood. [ABSTRACT FROM AUTHOR]

Deep space exploration has become the commanding heights of science and technology competition. Since the beginning of the 21st century, China has successfully completed the lunar exploration missions of "orbiting, landing, and returning" in just twenty years, and upgraded to a new roadmap of "survey, construction, and utilization". Meanwhile, lunar exploration worldwide has shown a trend towards normalization and commercialization. The research on lunar water resources has sparked widespread interest and intense competition among countries and space agencies, marking a new focus in human's deep space exploration. The exploration of lunar water can help reveal crucial processes in the formation and evolution of the Earth-Moon system and even the entire solar system. It stands as a forefront in planetary science research and a key focus in discipline construction. The development of lunar water resources can provide fuel for future deep space exploration missions and ensure the long-term survival of humans on the Moon. It is an inevitable choice for countries and organizations worldwide to expand and deepen international cooperation, jointly utilizing extraterrestrial resources for the benefit of humanity. Combining the status and future trends of lunar water resource exploration, this study analyzes the opportunities and challenges in China's deep space exploration program and the development of planetary science disciplines. It proposes strategies and suggestions based on the national context to seize the commanding heights of science and technology competition. [ABSTRACT FROM AUTHOR]

This article is an interview between Sara Seager and Diana Valencia, discussing Diana's work in the field of exoplanet interiors. They discuss the importance of thinking outside the norm in scientific discoveries and how Diana's ability to see connections between disparate ideas contributes to her original thinking. Diana shares her journey from being fascinated by the sky as a child to becoming a professor of planetary science, and how her work has focused on combining geophysics and astrophysics to understand exoplanets. Sara Seager praises Diana's work and acknowledges its impact on the field of exoplanet characterization. They also touch on the culture clash between astronomers and geophysicists, the study of super Earths, the possibility of water worlds, and the uniqueness of Earth. They discuss the challenges and experiences of being a woman in academia and balancing a career with motherhood, and emphasize the importance of interacting with successful women for guidance and support. [Extracted from the article]

• Microbes were the only lifeform for almost three quarters of Earth's history. • Microbes form the main target for extraterrestrial search for past or extant life. • The fossilised breath of microbes is a large and durable sign of life. • Ways to convey complex science to the general public could be valuable for forensics. • Similar techniques can be used in both spoken and written presentations. A new method for looking for life outside the Earth is used as an example to demonstrate how ways of presenting complex scientific concepts to the general public, used in planetary science, could be used in forensic science. The work led to a pared down, practical definition of detectable Life for planetary exploration, An organised system capable of processing energy sources to its advantage. For nearly three quarters of Earth's history the only lifeforms were microbes, which are the target for looking for extraterrestrial life. Microbes are microscopic and may be sparsely distributed, but their metabolic products can form large, durable rocks, much easier to find and which may contain the organisms or their remains. There are similar challenges in presenting astrobiological and forensic science. Both may have to deal with very large or very small numbers which are not immediately comprehensible but can be understood by analogy. To increase the impact on the listener or reader, dramatic analogues are valuable, for example, referring to the mineralised microbial metabolic products as, "fossilised breath of bacteria" demands the audience's attention and engages them before more detailed explanations are given. The power of practical experiments or demonstrations is most important to reinforce what might otherwise be a fairly abstract concept. Surprisingly, most of these approaches can be made to work equally well in both spoken and written forms as well as in both sciences. [ABSTRACT FROM AUTHOR]

The Earth is no longer the only known celestial body containing one or more liquid phases. The Cassini spacecraft has discovered seas of hydrocarbons at the surface of Titan, while a series of corroborating evidences argue in favor of the existence of an aqueous ocean beneath the icy crust of several moons. Capillarity embraces a family of physical processes occurring at the free surface of a liquid. These phenomena depend on the liquid properties and on the local planetary conditions. Capillarity may have important direct or indirect implications on the geoscientific and astrobiological points of view. In this paper, we discuss capillarity physics among solar system objects and expected consequences for planetary science. Plain Language Summary: The formation of raindrops, the production of tiny liquid droplets by bubble bursting at the surface of an ocean, or even the floatation of small solid particles at this surface, are examples of capillarity effects, physical processes which can be observed in everyday life. In this work, we discuss such phenomena in extraterrestrial contexts where large amount of liquids have be detected during past decades by space exploration. Key Points: Capillarity is involved in numberless natural processesDuring past decades, the presence of liquid phase of different nature has been detected on several extraterrestrial bodies of the solar systemWe review and discuss physical processes that may have important consequences in planetary science like the transport of organic material between planetary interior and the atmosphere [ABSTRACT FROM AUTHOR]

As a natural satellite of the Earth, the moon is a prime target for planetary remote sensing exploration. However, lunar polarization studies are not popular in the planetary science community. Polarimetry of the lunar surface had not been carried out from a spacecraft until the Korean lunar exploration program was initiated. In previous polarization observations of the moon, images of different polarization states were obtained by a rotating linear polarizer. This method is not well suited for future polarization observations from space-based spacecraft. To this end, we present a new kind of polarized observation of the moon using a division of a focal-plane polarization camera and propose a pipeline on the processing method of the polarization observation of the moon. We obtain a map of the degree of white-light polarization on the nearside of the moon through polarization observation, data processing, and correction. The observation and data processing methods presented in this study have the potential to serve as a reference for analyzing polarization observation data from future orbiting spacecraft. These are expected to lead to new discoveries in the fields of astronomy and planetary science. [ABSTRACT FROM AUTHOR]

(99942) Apophis is a potentially hazardous asteroid that will closely approach the Earth on April 13, 2029. Although the likelihood of an impact has been ruled out, this close encounter represents a unique opportunity for planetary science and defense. By investigating the physical and dynamical changes induced by this interaction, valuable insights into asteroid cohesion, strength, and internal structure can be obtained. In light of these circumstances, a fast mission to Apophis holds great scientific importance and potential for understanding potentially hazardous asteroids. To this aim, ESA proposed the mission RAMSES (Rapid Apophis Mission for SEcurity and Safety) to reach Apophis before its close encounter. In this context, the paper focuses on the reachability analysis of (99942) Apophis, examining thousands of trajectories departing from Earth and reaching the asteroid before the fly-by, using a low-thrust spacecraft. A two-layer approach combining direct sequential convex programming and an indirect method is employed for fast and reliable trajectory optimization. The results reveal multiple feasible launch windows and provide essential information for mission planning and system design. [ABSTRACT FROM AUTHOR]

Venus is Earth's closest neighbor, hosting a similar size, density, and location in the Solar System. Due to these similarities, Venus has been suggested as a premier location for particular mission sets to include: near-Venus communications and positioning, navigation, and timing (PNT); planetary science; heliophysics; space weather monitoring; and planetary defense. This paper, for the first time in literature, presents 37 unique planar periodic orbits discovered in the Sun–Venus system that may be used for such missions. The Circular Restricted Three-Body Problem (CR3BP) is the primary dynamical model utilized to generate all periodic orbits in the Sun–Venus system. The discovered orbits are grouped into four categories based on their shape: Near-Venus periodic orbits, Sun–Venus touring periodic orbits, Sun–Venus touring periodic orbits featuring near-Sun flybys, and Sun–Venus touring periodic orbits featuring near-Mercury flybys. Each orbit is discussed in terms of its respective Jacobi constant and stability within the context of the CR3BP. The stability of the orbits provides a preliminary analysis of station-keeping costs related to propellant expenditure, thereby determining the feasibility of implementing these trajectories. Specifically, this research shows that most of the identified orbits possess stability indices below 2, suggesting that minimal propellant is necessary for station-keeping maneuvers to sustain the preferred trajectory. For all orbits, specific initial position and velocity states conditions are provided, accompanied by recommendations for their potential mission applications. This research aims to advance ongoing astrodynamics research by filling a catalog hole and providing a Sun–Venus CR3BP orbit baseline. [ABSTRACT FROM AUTHOR]

The exploration of Uranus, a key archetype for ice giant planets and a gateway to understanding distant exoplanets, is acquiring increasing interest in recent years, especially after the Uranus Orbiter and Probe (UOP) mission has been prioritized in the Planetary Science Decadal Survey 2023–2032. This paper presents the results of numerical simulations aimed at providing experimental constraints on the parameterized post-Newtonian (PPN) parameter γ , a measure of space–time curvature in general relativity (GR), during the cruise phase of a spacecraft travelling to Uranus. Leveraging advanced radio tracking systems akin to those aboard the JUICE and BepiColombo missions, we explore the potential of solar conjunction experiments (SCEs) to refine current measurements of γ by exploiting the spacecraft's long journey in the outer Solar System. We discuss the anticipated enhancements over previous estimates, underscoring the prospect of detecting violations of GR. Our simulations predict that by using an advanced radio tracking system, it is possible to obtain an improvement in the estimation of γ up to more than an order of magnitude with respect to the latest measurement performed by the Cassini–Huygens mission in 2002, contingent on the calibration capabilities against solar plasma noise. The results reveal that a number of SCEs during the mission can substantially strengthen the validation of GR. In tandem with fundamental physics tests, the use of radio links during SCEs presents a valuable opportunity to dissect the solar corona's plasma dynamics, contributing to solar physics and space weather forecasting. This paper also enumerates methodologies to analyze electron density, localize plasma features, and deduce solar wind velocity, enriching the scientific yield of the experiments beyond the primary objective of testing GR during the cruise phase of a mission to Uranus. [ABSTRACT FROM AUTHOR]