bluuebunny/crossref_metadata_2025 huggingface dataset:
Observability of ENA emissions at Europa and Callisto: predictions for the JUICE mission
Authors: Haynes C. Michael , Tippens Tyler , Simon Sven , Liuzzo Lucas
Published: July 2024

We analyze the emission of energetic neutral atom (ENA) flux from Callisto and Europa as a tool to probe moon-plasma interactions on a global scale. In situ ENA detectors sample a two-dimensional snapshot of the entire interaction region, as opposed to observations that provide magnetic field and plasma data only along one-dimensional trajectories. Charge exchange between energetic magnetospheric ions and cold atmospheric neutrals results in ENAs that propagate along rectilinear trajectories. Since the distribution of ENA flux is resultant from the interaction between the ambient plasma, the magnetospheric field configuration and the neutral gas distribution, ENA images can contextualize and quantitatively constrain these aspects of the moon-magnetosphere interaction on a local as well as a global scale. We combine the perturbed electromagnetic fields from a hybrid plasma model with a particle tracing tool to model ENA generation for the energetic ions interacting with Europa's and Callisto's neutral envelopes. By taking into account the point-like size (on scales of the plasma interaction) and limited field of view of a spacecraft detector, we apply our model to investigate which features of the emitted ENA flux will be observable by the JUICE spacecraft during its close flybys of both moons.
The origin of Insoluble Organic Matter: Formation of macromolecules from heavily irradiated simple ices
Authors: Kipfer Kristina , Ligterink Niels Frank Willem , Riebe My , Allen Nicola Margaret
Published: July 2024

Comets and asteroids are among the most pristine objects in the Solar System, being formed out of the materials available in the proto-Solar Nebula [1]. Especially interesting are the complex organic molecules in these bodies, as they likely contribute towards the elemental composition of forming planets, as well as potentially being delivered after accretion of planetary bodies via impacts and thus contribute to their molecular inventory [2, 3].Many primitive solar system objects, such as carbonaceous chondrites or interplanetary dust particles (IDPs), contain organic matter, which itself can be divided into a solvent-soluble (soluble organic matter, SOM) and insoluble fraction (Insoluble Organic Matter, IOM) [4, 5]. The soluble fraction can contain PAHs, sugars, nucleobases, and amino acids [6, 7, 8, 9]. The insoluble fraction is a mix of large macromolecules with numerous molecular links and functional groups [3, 14]. The formation environment of the IOM is an area of ongoing research and IOM could have formed either in the interstellar medium or in the proto-Solar Nebula [3].In the proto-Solar Nebula, interstellar space, and protoplanetary disks, microscopic ice-coated dust grains are readily available. Laboratory experiments on the energetic processing of extraterrestrial and interstellar ice analogues show that a number of complex molecules form, including prebiotic molecules [e.g., 10, 11, 12, 13, 14], therefore focussing on recreating the chemical inventory observed in SOM. Even though it makes up the majority of the organic carbon in solar system objects, IOM has not been extensively studied in the laboratory. However, the formation pathways of IOM are crucial to understand the complex – insoluble – organic molecules available for the formation of planetary bodies.MethodsIn this study, irradiation experiments on ice are performed with the ICEBEAR setup [15]. The setup consists of a stainless-steel vacuum chamber with base pressures of
CALICO - a Mission Proposal to Explore Ceres In Situ
Authors: Hagermann Axel , Schroeder Stefan , Buchwald Robert , Bründl Tara-Marie , Küppers Michael , Benkhoff Johannes , Otto Katharina , Grott Matthias , Pilorget Cédric , Olsson-Francis Karen , Sheridan Simon , Morgan Geraint , Schröder Christian , Barabash Stas , Fatemi Shahab , Reiss Philipp , Palomba Ernesto , Longobardo Andrea , Van Hoolst Tim , Kindracki Jan ,   The CALICO Consortium
Published: July 2024

The Ceres Autonomous Lander Into Crater Occator (CALICO) was proposed in response to ESA’s M7-call for future space missions. CALICO is a mission to study the surface and interior of dwarf planet Ceres, the closest ocean world to Earth. Ceres’ accessible location in the main belt makes it a compelling target for exploration since it was classified as an ocean world in the wake of NASA’s Dawn mission, which provided a wealth of data. DAWN also left open many questions, such as whether the interior of Ceres ever had the potential for habitability.CALICO’s space segment consists of two components: the CALICO surface element is to land in Occator crater to analyse the salt- and organic-rich deposits of Vinalia Faculae, where building blocks of life might be accessible on the surface. The CALICO orbital element will characterize Ceres’ magnetic and particle environment to establish the presence of subsurface volatile reservoirs.We present an overview of CALICO’s science objectives, instrument payload and a possible mission scenario.  Although not selected to go forward into Phase A, CALICO - or any CALICO-like mission - has great potential to answer such fundamental questions about our place in the Solar System. The CALICO consortium will continue its efforts to realize a mission to Ceres.
Revealing tectonic processes at large coronae on Venus by joint analysis of modelled topography and gravity
Authors: Cascioli Gael , Gülcher Anna , Mazarico Erwan , Smrekar Suzanne
Published: July 2024

Understanding the interior processes shaping Venus surface is one of the fundamental tasks for the next decade of Venus science. Even in the absence of plate tectonics, Venus’ surface is covered with many tectonic and/or volcanic structures, including the so-called “coronae” (Latin for crown). Coronae range in diameter from 60 km to up to 2600 km and are defined by rings of closely spaced concentric fractures.  These enigmatic structures are widely distributed across the surface and are considered crucial to understanding the planet's geodynamic regime and resurfacing history. Coronae showcase diverse topographic morphologies, volcanic features, and fracture patterns. Geodynamic modelling studies have provided various scenarios for corona formation, often involving some type of plume-lithosphere interaction.In this work, four end-member geodynamic cases for large coronae formation from  Gülcher et al. (2020) are used to compute the expected gravity signal for different scenarios through time. Results demonstrate that the addition of gravity field constraints helps to distinguish different formation scenarios that may lead to similar surface expressions. A detailed classification of coronae based on gravity requires a resolution that is greater than currently available. By carefully rescaling our models to Magellan resolution we assess a set of macro-characteristics allowing us to apply this methodology to current datasets, notably pertaining the end-member formation class and the evolution stage of the corona. By applying these concepts to the Magellan topography and gravity maps of Venus we classify several coronae as active/inactive and assess whether their formation could imply crustal recycling. Importantly, we find that 47 coronae bear signatures of present-day plume-induced activity with various styles of tectonic processes at play.The next decade will be marked by multiple missions flying to Venus aiming to gather updated, and fundamentally more accurate gravity. Anticipating the future VERITAS mission’s gravity data, we provide an overview of the resolving power of the higher resolution dataset and what additional information on coronae formation may be forthcoming.  Gülcher, A. J. P., Gerya, T. V., Montési, L. G. J., and Munch, J. (2020). Corona structures driven by plume–lithosphere interactions and evidence for ongoing plume activity on Venus. Nature Geoscience, 13(8):547–554. https://doi.org/10.1038/s41561-020-0606-1 
Use of the Europlanet network by a group of amateur astronomers
Authors: Correa Mercè
Published: July 2024

Since 2021, a small group of amateurs from the Sabadell Astronomical Group have requested and obtained several observation projects to be carried out with the telescope network (ETN) that Europlanet has made available to the planetary observation community.Our group has focused on the observation of Exoplanets, collaborating with the ExoClock project. A successful platform initiated and led by Anastasia Kokori and Angelos Tsiaras from the University of Thessaloniki, to monitor exoplanet transits that will be observed by the Ariel space mission, which will be launched in 2029, and will observe known exoplanets to obtain their spectrum and characterize their atmosphere. ExoClock is a platform with double scope: To monitor Ariel's goals to increase mission efficiency and open exoplanet science to diverse communities and facilitate collaborations.For this project we have used three telescopes offered in Europlanet's ETN network. The most used telescope has been the IAC80 located at the Teide observatory in Canary Islands and equipped with the Camelot 2 CCD or, failing that, with the CARONTE camera. With this telescope we have made more than 27 observations as of January 31, 2024 and with 23 published transits. This telescope is used in service mode.The second most used is the 1.23m telescope located in Calar Alto Observatory in Andalusia. It is equipped with the DLR-MKIII CCD camera. This telescope is used remotely and for this we have previously had to carry out in-person observations, to learn its subsequent use remotely. With this telescope we have made 10 observations, of which 8 have been published. All these observations have been funded by Europlanet.In parallel, we have also used the Joan Oró telescope, located at the Montsec Observatory, in Catalonia. This telescope is used in robotic mode and its nights have been achieved through the relationship with the observatory manager who showed his interest in participating in the EcoClock project. In this case, Europlanet funding was not needed. With this telescope, 16 observations have been made, 11 published. It will be briefly explained how this experience has turned out and the current state of collaboration with these observatories. (10 minutes needed) Mercè Correa is technical engineer in Food Industries. Vice-president of Sabadell Astronomical Group. Member of GEOS group, European Star Observing Group, and member of Europlanet Society. She is a member of the Advisory Commission of the FAAE (Spanish Federation of Astronomical amateurs’ groups). She is focused on observation and photometry of variable stars, mainly RR Lyrae stars type, and exoplanets.
Size, albedo and rotational period of the Hayabusa2# target (98943) 2001 CC21 from SPITZER and groundbased observations
Authors: Fornasier Sonia , Dotto Elisabetta , Panuzzo Pasquale , Delbo Marco , Belskaya Irina , Krugly Yuri , Inasaridze Raguli , Barucci Maria Antonietta , Perna Davide , Brucato John , Birlan Mirel
Published: July 2024

The Japan Aerospace Exploration Agency's (JAXA) Hayabusa2 mission, following the successful return of samples of the near-Earth asteroid (NEA, 162173) Ryugu, in December 2020, has been extended to explore two more NEAs. These are (98943) 2001 CC21, which is scheduled for a flyby in 2026, and the fast-spinning 1998 KY26, for a rendez-vous on 2031. The extended mission has been named Hayabusa2#, where the # character stands for "SHARP" (Small Hazardous Asteroid Reconnaissance Probe). Several observing campaigns of these two targets have been and will be carried out to better understand their physical properties in support of the Hayabusa2# mission, and to optimize the observing strategy.In this work we present a new estimate of the size, albedo and rotational period of 2001 CC21. This is based on observations of 2001 CC21 spectral energy distribution in the thermal infrared obtained by NASA’s Spitzer Space Telescope and new ground-based photometric observations carried out at the 3.5m New Technology Telescope of ESO, at the 1.2m Haute Provence Observatory, and at the 0.7m Abastumani telescope. In the optical, we obtained three complete lightcurves in 2023-2024. The Spitzer observations of (98943) 2001 CC21 were obtained on November 20, 2005 from 10:17 to 12:26 UT with the Infrared Spectrograph (IRS). Data were acquired in low resolution mode covering the 5.2-38 micron range in 4 IRS long slit segments. The data were reduced starting from the basic calibrated data generated by the Spitzer Space Center automated pipeline, and  the sky background was removed by differencing two consecutive images taken at different nodding positions for each spectral segment. Finally, spectra were extracted using the Spitzer IRS Custom Extraction (SPICE) software. Data were modeled with the Near Earth Asteroid Thermal Model  to determine the asteroid size and albedo.From ground-based observations, we determine an absolute magnitude of H=18.94±0.05, and a rotational period of 5.02124±0.00001 hours, with a large lightcurve amplitude of ˜0.8 magnitude at a phase angle of 22o, indicating a very elongated shape with estimated a/b semiaxis ratio > 1.8, or a close-contact binary body.  The emissivity of 2001 CC21 is consistent with that of silicates, and its albedo is 21.6+1.1-1.0 %.  Finally, the spherical-equivalent diameter of 2001 CC21 is 465±15 m.The albedo value and emissivity here determined, coupled with results from polarimetry and spectroscopy from the literature, confirm that 2001 CC21 is an S-complex asteroid, and not a L-type, as previously suggested. The size of 2001 CC21 is less than 500 m, which is smaller than its first size estimation (˜700 m). These results are relevant in preparation of the observing strategy of 2001 CC21 by Hayabusa2 extended mission.
Ocean-sourced CO2 inflates radiolytic H2O2 at Europa’s Chaos
Authors: Raut Ujjwal , Protopapa Silvia , Mamo Bereket D , Teolis Benjamin D , Villanueva Geronimo , Cartwright Richard , Nordheim Tom , Retherford Kurt D , Blaney Diana L , Kammer Josh
Published: July 2024

JWST observations of Europa’s leading hemisphere show excess CO2 over chaos terrains where the ocean is likely to have breached the ice shell. Analysis of the 3.5 µm peroxide absorption reveals elevated amounts of H2O2 in these chaos regions. Laboratory experiments motivated by these observations show that trace inclusions of CO2 can substantially inflate the radiolytic peroxide yield, more so than in pure water ice. These experiments suggest that endogenic CO2 amplifies H2O2 synthesis in the chaos terrain when processed by Jupiter’s magnetospheric particles. We combine the CO2-enhanced H2O2 yields with the energy dose delivered by the magnetospheric particles onto the leading hemisphere to generate a peroxide distribution map to compare with the observed distribution. Our results suggest that geologic activity at Europa’s chaos conspires with precipitating radiation to contribute to the excess peroxide observed by Webb. The rapid transport of the peroxide to the underlying ocean via brine-percolated conduits underscores strong implications for Europa’s habitability. Additionally, these JWST observations combined with laboratory measurements set the stage for detailed mapping of CO2 (via its 2.7 and ~4.23-4.29 µm absorptions) and H2O2 (via its 3.5 µm absorption) with MISE (Europa Clipper) and MAJIS (JUICE) at unprecedented spatial resolution.
Elemental Composition of Uranus and Neptune: Insights from Building Blocks
Authors: Mousis Olivier , Schneeberger Antoine , Cavalié Thibault , Mandt Kathleen , Aguichine Artyom , Lunine Jonathan , Benest Couzinou Tom , Hue Vincent , Moreno Raphael
Published: July 2024

This study aims to predict the bulk volatile compositions of Uranus and Neptune, aligning with the preparatory framework for the Uranus Orbiter Probe mission. We employ a protoplanetary disk model to trace the evolution of volatile species through vapor, dust, and pebble transport. It is assumed that both planets formed near the CO iceline in the protosolar nebula, in a way consistent with interior models reconciling heavy element abundances with measured atmospheric D/H ratios.The time-dependent abundances of primary volatile species are calculated at the CO iceline location, gradually evolving inward. This yields abundance ratios of key elements, including heavy noble gases, within Uranus and Neptune's feeding zones. Predictions for their deep compositions are formulated, assuming negligible compositional gradients in the envelope.Despite potential interior heterogeneity, estimates of the Xe/Ar or Kr/Ar abundance ratios prove valuable for evaluating our model. This is due to the absence of known differentiation mechanisms among these noble gases while they remain in vapor form within the atmospheres.
Observing comets with the upcoming CUBES near-UV spectrograph
Authors: Opitom Cyrielle , La Forgia Fiorangela , Snodgrass Colin , Migliorini Alessandra
Published: July 2024

High-resolution spectroscopy of the near-UV regime provides access to a tremendous diversity of iron-peak and heavy elements in stellar spectra, is critical in extragalactic observations, such as studies of the circumgalacticmedium of distant galaxies, and is an extremely interesting regime for the study of small bodies of the solar system.  The Cassegrain U-Band Efficient Spectrograph (CUBES), to be installed on the Very Large Telescope in 2028, has been designed to cover this very exciting part of the electromagnetic spectrum at the edge of the atmospheric cut-off.CUBES will open-up exciting new scientific opportunities for ESO’s Paranal Observatory, providing a world-leading capability well into the 2030s. Looking ahead to the start of ELT operations, we note that the VLT will be competitive for observations shortwards of ~400 nm (e.g. Evans et al. 2016) because of the protected silver coatings of four of the five ELT mirrors, that result in diminished performance at 20 for targets of  U=18 mag at 313 nm in 0.007nm wavelength bin. The instrument will also be equipped with an autoguider combined to a set of broad-band filters, allowing the user to obtain images of the target immediately before performing the spectroscopy. The combination of high spectral resolution and efficiency of CUBES will enable ground-breaking results in various fields, from extragalactic astronomy to stellar nucleosynthesis.CUBES will also be particularly interesting for the observation of solar system object as the gas coma of comets contains a large number of emission features in range covered by CUBES, which are diagnostic of the composition of the ices in its nucleus and the chemistry in the coma. Production rates and relative ratios between different species reveal how much ice is present and inform models of the conditions in the early solar system. In particular, CUBES will lead to advances in detection of water from very faint comets, (through the OH emission band at 310 nm), revealing how much ice may be hidden in the main asteroid belt.  CUBES will allow us to constrain key molecular abundances in cometary ices, such as the N2/CO ratio through observation of ions and will be sensitive to emissions from gaseous metals (e.g., FeI and NiI), which have recently been identified in comets and offer an entirely new area of investigation to understand these enigmatic objects. Finally, CUBES will be used to measure the D/H ratio in comets providing an unprecedented homogeneous sample of measurements in a range of comets, that will allow us to constrain their formation temperature and the origin of water on Earth.
Platform for Controlled Ultra Low Gravity Profiles
Authors: Joeris Kolja , Keulen Matthias , Teiser Jens , Kollmer Jonathan
Published: July 2024

After conducting our own experiments, we propose the platform we developed as a tool for other users. Designed for ultra low velocity impacts in granular beds simulating asteroid surfaces [1], the main requirement in platform design was a clean partial gravity generation without any coriolis forces. This is achieved by using a two stage approach: First, earth gravity is reduced to microgravity using the ZARM drop tower at Bremen. Second, microgravity is converted to the desired level of partial gravity. This is done by using a linear stage, driven at a constant acceleration inside of the drop tower capsule. The acceleration imposed by the moving experiment volume onto the drop tower capsule is supposed to be neglected, because of the vastly different inertial masses of approximately 2-3 kg for the experiment and several hundred kg for the drop tower capsule. As required for its original purpose, our platform is optimized for providing accelerations in the milligravity regime, but not limited to that. Partial gravities in the cm/s^2 regime were succesfully tested and our platform has also proven to be able to induce oscillations to agitate the experiment. Arbitrary trajectories are possible, respecting available microgravity time and the maximum travel of 30 cm.In detail, we evaluate our platforms capabilities, performance and compliance. The drop tower provides 9.3 s of microgravity in catapult mode. Because of an initial equilibration time and the necessity to return our system to a safe resting position, our platform can forward a usable duration of approximately 7 s to the experiment. Expected values g-jitter, meaning the unwanted residual acceleration, lie in the range of 10^-6 g. Vacuum supply, power and remote control are supplied by ZARM until just before launch. The experiment can be made accessible after a delay after each launch. The capsules are compatible, so our system may be used in the Gravitower Bremen Pro as well.[1] Joeris, K., Schönau, L., Keulen, M., Born, P., & Kollmer, J. E. (2022). The influence of Interparticle cohesion on rebounding slow impacts on rubble pile asteroids. npj Microgravity, 8(1), 36.[2] Von Kampen, P., Kaczmarczik, U., & Rath, H. J. (2006). The new drop tower catapult system. Acta Astronautica, 59(1-5), 278-283.
Astrotourism as a tool for astronomy and planetary science outreach - The case study of Ikaria island
Authors: Kokori Anastasia
Published: July 2024

Astrotourism has been used in several locations as a model for business development. Astrotourism is an umbrella term including activities that focus on the night sky such as stargazing and astronomical phenomena such as aurora, eclipses, meteor shower etc.  Although astrotourism has been studied in the literature, many themes have not been covered yet. Usually astrotourism is connected to the protection of the night sky from light pollution. Astrotourism research is focused also on how astrotouristic activities can be combined with regional tourism. This presentation will focus on the aspect of using astrotouristic activities as a vehicle for outreach of astronomy and planetary science. Particularly, I will share practices, challenges and lessons learned from my experience on performing astrotouristic activities on the Greek island of Ikaria. Ikaria is a place where light pollution is almost absent. Additionally, the high altitudes of the mountainous areas in combination with the low level of industrialisation, give room for experimental efforts of astotourism. The power of the clear dark skies in combination with the pristine nature of Ikaria island lead to the creation of ideal conditions for experience-based activities which create to people unique feelings. 
Influence of secondary ionisation by photoelectrons on exoplanetary atmospheres
Authors: Gillet Alexandre
Published: July 2024

Planetary mass-loss is governed by several physical mechanisms such as: thermal hydrodynamic escape, photochemical escape, ionospheric outflow, interaction with the stellar wind and dynamical events such as flares. All these processes affect the model-estimated atmospheric mass loss rates. The phenomenon of hydrodynamic escape has long been postulated to have acted upon Earth, Venus and Mars in their early lives. The ongoing detection and characterisation of exoplanets offers a new window into the underlying physics. With this new insight, we expect to offer new clues into the formation of planets near and afar. Moreover, the stellar radiation energy deposited as heat depends strongly on the energy of the primary electrons following photoionisation and on the local fractional ionisation. We perform 1D spherical and 2D Cartesian HD simulations with the PLUTO code of an atomic hydrogen planetary atmosphere. We assess the impact of the shape of different XUV spectra taken from the MUSCLES survey of type K and M type stars on the mass loss rate and the impact of flare events on the planetary atmosphere. For the first time, we take into account the effect of secondary ionisation by photoelectrons self-consistently in different Exosystems. In our explored sample, we also vary the planetary masses and report a significant diminution up to 54% of the planetary mass loss rate for a planet with a mass of 0.02 Mj.
Aerosol optical properties observed by MEDA Radiation an Dust Sensor (RDS) at Jezero Crater, Mars
Authors: Rodriguez-Veloso Raúl , Toledo Daniel , Apéstigue Víctor , Arruego Ignacio , Lemmon Mark T. , Smith Michael D. , Martínez Germán , Vicente-Retortillo Álvaro , Jiménez-Martín Juan J. , García-Menéndez Elisa , Viudez-Moreiras Daniel , Sánchez-Lavega Agustín , Pérez-Hoyos Santiago , Sebastian Eduardo , de la Torre-Juárez Manuel , Rodríguez-Manfredi José Antonio
Published: July 2024

Aerosols on Mars are a primary elements for studying the interaction between the solar radiation and the atmosphere and surface. Depending on properties such as aerosol number density, particle radius, or refractive index, the impact of the aerosols can provide positive or negative radiative feedbacks on the dynamics of the atmosphere. Previous studies have revealed large temporal and spatial variability in the aerosol optical properties, emphasizing the necessity for continuous monitoring of these properties throughout the day and at multiple locations. To address these measurements, the Radiation and Dust Sensor (RDS) [1] is part of the Mars Environmental Dynamics Analyzer (MEDA) [2] payload onboard of the Mars 2020 rover Perseverance. RDS instrument compromises two sets of 8 photodiodes (RDS-DP) and a camera (RDS-SkyCam). One set of photodiodes is pointed upward, with each one covering a different wavelength range between 190-1200 nm. The other set is pointed sideways, 20 degrees above the horizon, and they are spaced 45 degrees apart in azimuth to sample all directions at a single wavelength. The analysis of these observations with a radiative transfer model [3] (Fig. 1) allow us to fit aerosol parameters such as the aerosol opacity at different wavelengths or the aerosol particle radius. In this work we will discuss some preliminary results for the first 100 sols of Mars 2020 mission.References:[1] Apestigue, V., et al. “Radiation and Dust Sensor for Mars Environmental Dynamic Analyzer Onboard M2020 Rover”. Sensor 22.8 (2022): 2907.[2] Rodriguez-Manfredi, Jose Antonio, et al. “The Mars Enviromental Dynamics Analyzer, MEDA. Asuite of enviromental sensors for the Mars 2020 mission.” Space science reviews 217.3 (2021): 1-86.[3] Toledo, D., et al. “Measurement of aerosol optical depth and sub-visual cloud detection using the optical depth sensor (ODS)”. Atmospheric Measurement Techniques 9.2 (2016): 455-467.
One formula to describe the struggle between planetesimals and gas drag: Insights from microgravity experiments
Authors: Schönau Laurent , Teiser Jens , Wurm Gerhard
Published: July 2024

Wind erosion is a serious threat to the evolution of planetesimals in the early stages of planet formation. Since they move around the star at a different orbital velocity than the surrounding gas, they feel a permanent headwind of at least 50 m/s [1]. In the case of eccentric orbits, this difference in velocity can increase significantly. Planetesimals are not solid rocks, but rather a collection of loosely bound dust aggregates [2] that are held together by the low self-gravity. Although the pressure in protoplanetary disks is very low, wind erosion can dismantle planetesimals. As a result, their existence is ruled out in some areas close to the star [3,4].In a series of wind tunnel experiments in the laboratory and on microgravity platforms such as the drop tower Bremen and parabolic flights, we have recreated the conditions on planetesimals more and more realistically. Under pressures down to 1 Pa and gravity down to 10-5g, we observed and analysed wind-induced erosion of granular particles. Starting with simple glass spheres, we finally recreated the surface of a pebble pile planetesimal with millimetre sized SiO2 dust aggregates. These aggregates were produced by the collision of micrometre sized SiO2 particles in analogy to the dust growth up to the bouncing barrier in protoplanetary disks.As a result of our experiments, we found a single formula that predicts the erosion threshold of granular particles on the surface of a planetesimal. Its overall size, the volume and density of the pebbles forming it and its position in the protoplanetary disk can be set as parameters. Together with a suitable disk model, this allows us to define stable and unstable orbits for the evolution of planetesimals into full grown planets. References[1]        Weidenschilling S. J., 1977, MNRAS, 180, 57[2]        Wahlberg Jansson K., Johansen A., Bukhari Syed M., Blum J., 2017, ApJ, 835, 109[3]        Cedenblad L., Schaffer N., Johansen A., Mehlig B., Mitra D., 2021, ApJ, 921, 123[4]        Schönau, L., Teiser, J., Demirci, T., Joeris, K., Onyeagusi, F.C., Fritscher, M., Wurm, G., 2023, A&A, 672 A169
Investigation of Mercury exosphere from ground-based observations: the cases of BepiColombo’s flybys 2 and 3 
Authors: Mangano Valeria , Massetti Stefano , Milillo Anna , Di Bartolomeo Pier Paolo , Del Moro Dario , Moroni Martina , Orsini Stefano , Leblanc Francois , Heyner Daniel , Varsani Ali , Laky Gunter , Aronica Alessandro , Kazakov Adrian
Published: July 2024

The ground-based observations over years have shown to be a crucial mean to study the exosphere of Mercury and to investigate the complex environment of the planet and its interactions with the solar wind and the embedded interplanetary magnetic field.In fact, the Na exospheric pattern have shown to map the magnetic cusp and to be very sensitive to the IMF-planetary magnetic field coupling.Now, with the era of space mission at Mercury (MESSENGER in the last decade, and now BepiColombo), the ground-based observations are playing the new role of complementary observation to the in-situ, high resolution measurements of exospheric components, but also ion population and magnetic field.In this frame, we present the observations performed from the ground-based solar telescope THEMIS during the second and third flyby of BepiColombo at Mercury in June 2022 and 2023. Exospheric data were acquired in a period of 4-5 days around the flybys dates during all daytime hours with a high resolution spectrograph able to adequately image both the D2 and D1 emission lines of sodium.We will highlight analogies and differences in the morphology and how they relate to the IMF experienced by the spacecraft during its approach. Ion populations encountered will also be investigated.Space- and Earth-based coordinated observations will have to be performed also during BepiColombo nominal mission because they are an outstanding tool for making contemporary detailed and global investigations of the exosphere.
Space Weathering Provides a Lower Limit on the Age of Saturn’s Rings
Authors: Esposito Larry W. , Elliott Joshua P. , Bradley E. Todd
Published: July 2024

Cassini observations of the micrometeoroid bombardment flux, ring mass and fractional pollution constrain the origin and history of Saturn’s rings. In the simplest model, the age of the rings can be estimated by assuming the rings are a closed system with constant bombardment at the current rate. However, the rings are not a closed system and Cassini spectroscopy is consistent with space weathering of the cosmic dust polluting the rings. The remote sensing of the rings shows a red slope, with higher pollution at the shortest wavelengths, consistent with reddening due to space weathering of atmosphereless bodies. If processes at the time of the micrometeorite impacts or subsequent chemical and physical weathering can degrade the original pollutants, this means that laboratory spectra are not appropriate to determine the total extrinsic material that has struck the rings over their lifetime. Laboratory results for irradiation of icy outer solar system analogues indicate oxidation of organics and other pollutants over time. It is now generally agreed that the radiolysis of ice by energetic ions, electrons and solar UV photons produces the oxygen, ozone and peroxide seen at many icy satellites. The porosity of ice provides sufficient space for chemical reactions and mobility. The ring particle surfaces are in addition continually gardened by particle collisions and meteoritic impacts. Because of the loss processes, the current fractional pollution provides only a lower limit on the total integrated pollution flux, and thus a lower limit for the ring age. Rosetta data on the dust composition and surface reflectivity of Comet 67P provide our starting point for the composition of the bombarding material: Two independent analyses of Cassini UVIS spectra of Saturn’s rings give fractional pollution in the outer B ring of 1.4 -3%. This provides a lower limit of 400 to 1600 million years for the most opaque parts of Saturn’s B ring, depending on whether we use the maximum or minimum values for the bombardment rate reported by Cassini CDA. This result shows Saturn’s rings may be as old as the planet Saturn itself, consistent with the estimates for the orbital evolution of ring moons Atlas and Epimetheus. The A and C rings may have formed more recently.  
Exploring the Solar System beyond Neptune with the ESO/Extremely Large Telescope HARMONI Integral Field Spectrograph
Authors: Delsanti Audrey , Douté Sylvain , Groussin Olivier , Carme Bellana , Bodereau Éloïse , Neichel Benoît
Published: July 2024

The European Southern Observatory (ESO) 39m-Extremely Large Telescope will be on sky before the end of this decade, and will enable unprecedented spatially resolved observations. HARMONI (High Angular Resolution Monolithic Optical and Near-Infrared Integral field spectrograph) is a first-light instrument that covers the 0.47-2.45 micron range with a spectral resolution R of 3300-18000. Four Fields of View (FOV) sizes are available with "spaxels" scales from 30x60 down to 4x4  milli-arcsecond (mas). HARMONI will operate in two Adaptive Optics (AO) modes: single conjugate adaptive optics (SCAO) and laser tomography adaptive optics (LTAO). In this work, we explore the performances of the near infrared gratings (0.8-2.4 microns, R=3300) in LTAO mode to obtain the surface reflectance spectra of Trans-Neptunian Objects of various apparent diameters and of various surface compositions. We use a complete set of image rendering tools and laboratory data as well as the HSIM simulation pipeline (Zieleniewski et al 2015, MNRAS 453, Issue 4, 3754, which was further enhanced by M. Pereira-Santaella) to produce the observed data cubes. We present the resulting simulations and related performances for the exploration of the very first surface composition constrast maps of dwarf planets beyond Neptune.
Modeling the internal composition and evolution of warm Jupiters with MESA
Authors: Jones Matias , Brahm Rafael , Tala Marcelo
Published: July 2024

Giant planets (Mp > 0.3 Mjup) with orbital periods between ~10-200 days (a.k.a warm-Jupiters), are excellent targets to measure their bulk composition, to characterize their atmospheric abundances and to study their formation and evolution mechanisms. In particular, they are less affected by the strong stellar irradiation and tidal interactions with the host star, that their innermost siblings, the so-called hot-Jupiters, suffer.In this talk I will first describe our MESA (Paxton et al. 2011) based interior/evolutionary modelsof gas giants, which include a rocky-icy core, sorrounded by a H/He gaseous envelope, and with metals homogeneously mixed in the envelope. In addition, our models include the effect of the stellar irradiation in the cooling evolution of the planet. For this, we also include the host star evolution in our models, which translates into an increasing insolation level since the zero age main-sequence to present. This is particularly important for planet orbiting stars that are close to the terminal age main-sequence, whose luminosity have significantly increased since their formation.  A few examples of our models are presented in Figures 1.Then, I will present different models of a sample of selected systems, which were validated, and  homogeneously characterized (both the stellar and planetary properties) in the context of the Warm gIaNts with TESS collaboration (WINE; Brahm et al. 2019).Finally, I will compare their internal composition and metallicity with the planet mass and host star properties, and I will discuss these results in the context of planet formation scenarios for gas giants. Figure 1: Position of TOI-2529 b in the age-radius diagram (black dot). Planet evolutionary models with different envelope composition and insolation level are overplotted. For comparison, a simple model of Jupiter is also shown. Figure from Jones et al. (2024).
Io Source of Heavy Ions in Jupiter’s Equatorial Ionosphere
Authors: Bagenal Fran , Dols Vincent , Valek Phil , Waite Hunter
Published: July 2024

The JADE instrument on Juno has measured cold (
Small-ELF (SELF): a powerful telescope for high-contrast astronomy and a prototype for the future >30-meter ExoLife Finder (ELF) hybrid optical telescope
Authors: Lodieu Nicolas , Kuhn Jeff , Rebolo Rafael , Fernandez Patricia , Sola La Serna Paula , Padron Maria Auxiliadora , Arteaga Marrero Natalia , Ruiz Sabina Alejandro , Tamayo Diego Alberto , Moretto Gil , Langlois Maud
Published: July 2024

Ground-breaking science like the search for life in the atmospheres of exoplanets requires telescopes with extemely large diameters (>35m). Emergingtechnology can build competing and complementary to the large astronomical telescopes being built and designed to achieve some specific science cases such as the detection and study of life-bearing exoplanets in the nearest 100 star systems. In particular, Fizeau optics, non-subtractive shaping of thin mirrors, photonics and neural-network wavefront sensing, active/adaptive optics, integral robotics and tensegrity structures, are key.Our team is currently working on the design and construction of a 3.5m precursor telescope, using some of these disruptive technologies. The so-called Small ExoLife Finder (Small-ELF) costs about 5Me and can be finished within the next 5 years to detect nearby large exoplanets. This research and development was recently fundedby the European Union to create a new sustainable "Laboratory for Innovation in Optomechanics"  at the IAC (Tenerife) led by Prof Jeff Kuhn. LIOM plans for a 50m ExoLife Finder to be built within 10 years for about 200Meur - more than an order of magnitude less than the Keck-era and ELT telescopes. LIOM aims at (1) developing ultra-thin light mirrors with novel engineered materials to reduce the cost and weight of future telescopes. Moreover, our team is developing (2) designing lighter structures with pre-tensioned cables to support mirrors and lighten structures, and (3) integrating photonic devices that allow more thermal and mechanical stability cost savings with high replicability.The talk will review our progress on all these fronts.
Just how different are NEO and meteoroid impactors from an orbital point of view?
Authors: Devillepoix Hadrien , Shober Patrick , Deam Sophie
Published: July 2024

Potentially Hazardous Asteroids and meteorites are delivered to near-Earth space via the same mechanisms, and for modelling purposes it is often assumed that they are similarly distributed across orbital space. Thanks to 9 years of large meteoroid impact monitoring by the Desert Fireball Network, we have direct evidence that the two populations are dynamically different. We find that a key transition happens in the unobserved gap between meteoroids that regularly drop meteorites (0.1-1 m) and the sizes covered by Near-Earth Objects models (>35 m). Asteroids are preferentially on evolved and inclined orbits, whilst meteoroids tend to have larger semi-major axes and retain a better orbital connection to their main asteroid belt origin. The cause for this is the size-dependent strength of the Yarkovsky effect, much stronger on smaller objects, that effectively shortens the delivery time from the main asteroid belt to Earth impacting orbits for meteoroids. We find that the meteoroid/meteorite population is more sensitive to short-term main belt weather (moderate size collisions). Whereas the larger asteroid population is only sensitive to the biggest storms (family forming events). This implies that the meteorite mix currently falling onto Earth is not in a steady state over more than a few million years.
M-MATISSE MaCro: an intersatellite link in Mars orbit
Authors: Martin Pätzold , Andert Tom , Imamura Takeshi , Ando Hiroki , Genova Antonio , Hahn Matthias , Noguchi Katsuyuki , Oschlisniok Janusz , Peter Kerstin , Tellmann Silvia , Sanchez-Cano Beatriz , Leblanc Francois
Published: July 2024

The "Mars Magnetosphere ATmosphere Ionosphere and Space-weather SciencE (M-MATISSE)" mission, currently in Phase A study by the European Space Agency (ESA), is a Medium-class (M7) candidate. M-MATISSE aims to unravel the intricate and dynamic couplings of the Martian magnetosphere, ionosphere, and thermosphere (MIT coupling) in relation to the solar wind (i.e., space weather) and the lower atmosphere. This two-spacecraft mission involves both spacecraft carrying an identical payload suite, each following different orbits with an apocenter at 3,000 km and 10,000 km altitude, and a pericenter at 250 km altitude. The intersatellite radio link, MaCro, operates at two frequencies to probe the ionosphere and atmosphere of Mars during occultations, as one spacecraft disappears behind the planetary disk as seen from the other spacecraft. The instrumentation comprises two transceivers at UHF and S-band, stabilized by an ultrastable oscillator on both spacecraft each. The observables include the shift of the carrier frequencies caused by the bending of the radio ray path in the atmosphere/ionosphere. Onboard data pre-processing precedes the transmission of telemetry to Earth. The orbits allow about eight occultations events (ingress or egress) on average per day starting at an altitude of 1000 km.
The Structure of the Martian Ionosphere
Authors: Andersson Laila , Pilinski Marcin , Bark Duncan , Shaver Skylar , Hesse Troy , Shuvalov Sergey , Andrews David
Published: July 2024

After multiple Martian years and almost one full solar cycle in orbit, measurements from the MAVEN mission can now allow us to study the ionosphere. The statistical structure of the Martian ionosphere is assessed and presented here as a step towards a new empirical Martian Ionospheric Model for electron density and temperature. The ionosphere is assessed based on the most likely density and temperature and the variability of these numbers determined by many different conditions. The data will be presented as function of season, altitude, neutral pressure, solar location, and aerographic latitude. The influence of solar activity through solar irradiation and solar wind conditions are also considered. Furthermore, the data is examined based on local magnetic field strength, light versus heavy ionosphere composition, and the uniformity of the ionosphere. This work will identify effective approaches to characterizing the Martian ionosphere and thereby identify when and where different drivers influence its structure.
Characterization of Exoplanets with LIFE (Large Interferometer For Exoplanets)
Authors: Noack Lena , Lichtenberg Tim , Alei Eleonora , Angerhausen Daniel , Quanz Sascha ,   LIFE team
Published: July 2024

The ESA Voyage 2050 report (https://www.cosmos.esa.int/web/voyage-2050) names the “characterisation of temperate exoplanets in the mid-infrared, through a first spectrum of direct thermal emission from exoplanet atmospheres to better understand if they harbour truly habitable surface conditions” as one of the top three priorities for future large-scale missions. This is the goal of the mission concept LIFE - Large Interferometer For Exoplanets (https://life-space-mission.com/). The LIFE initiative is currently investigating the scientific potential and technological challenges of an ambitious mission using a formation-flying nulling interferometer in space operating at mid-infrared wavelengths. The poster will outline the basic concept of the LIFE mission and present predictions for the discovery yield of exoplanets in our neighborhood as well as recent key results regarding the detectability of biosignatures and indicators of habitability. 
Miniaturized Wideband Ultraviolet Imaging Spectrograph for Deep Space Exploration
Authors: Fu Liping
Published: July 2024

Deep space exploration is the main means for mankind to study the origin, evolution and current situation of the solar system and the universe, to further understand the formation and evolution of the earth's environment, and to understand the relationship between space phenomena and the earth's natural system. Deep space exploration, which mainly includes lunar exploration, planetary exploration, interplanetary exploration and interplanetary exploration, has become a new growth point and research hotspot, and is also the international research direction. Ultraviolet optical remote sensing (50-380 nm) load mainly detect targets include planets (include satellite of the planet, such as the moon, etc.),atmosphere and magnetosphere object surface, can obtain the traditional field and the particles in place observation is difficult to capture the full picture of the material and energy transport. UV remote sensing is an new important technology to study the solar system and its evolution, and it also can be used for searching extraterrestrial life information . Explorations on the probe of the project will focus on miniaturization, large dynamic, intelligent processing on-board and other special requirements. This project will study the miniaturization of wide spectrum of ultraviolet detection technology, submit a miniaturized wide spectrum imaging spectrometer prototype, spectrum covered 50-200 nm, 2-3 nm spectral resolution, weighing less than 4 kg. This project will fill the blank of the detection of deep space small ultraviolet imaging spectrometry in China, provides technical reserves for subsequent including planet detection, solar system marginal deep space exploration program.