bluuebunny/crossref_metadata_2025 huggingface dataset:
Coupling the Spacecraft-Plasma Interaction Software to the Space Environment Databases
Authors: Hess Sebastien , Leclercq Ludivine
Published: September 2022

Spacecraft in the space environment plasma collect and emit charged particles ending charging themselves. Even with the best specification, the spacecraft potential charge to a potential of the order of the ambient electron temperature, which impact the instrument ability to investigate the thermal plasma characteristics. The most impacted instruments are the particle detector which see a distortion both in arrival direction and energy, and the plasma and field sensors which are perturbed by the electrostatic sheath around the spacecraft. In order to improve the space mission data analysis, the Spacecraft-Plasma Interaction Software (SPIS) has been developed by ONERA and Artenum, with support from the ESA, the CNES and the SPINE Community which gathers European academic and industrial partners and the charging issues. However, the precision of its modelings depends on the accuracy of its inputs, particularly concerning the plasma environment populations. In the frame of the Europlanet 2024 RI project funded by the European Commission, we developed a connection between SPIS and the main environment databases through the SPASE framework. Using the Simulation extension to SPASE, the IMPEX planetary environment simulation databases are also accesible. In addition, this extension allowed us to develop algorithms that allow to retrieve semi-automatically the data of interest (i.e. that can be exploited by software) in a whole database and to handle them properly. We will demonstrate the capability of the software - database connection to analyze instrument measurements and show the capability of SPASE to provide the metadata needed for the automatic processing of the data by client tools.
ALMA observations of the spatial distribution of CO and HCN in the stratosphere of Jupiter
Authors: Cavalié Thibault , Rezac Ladislav , Moreno Raphael , Lellouch Emmanuel , Fouchet Thierry , Benmahi Bilal , Greathouse Thomas K. , Sinclair James A. , Hue Vincent , Hartogh Paul , Dobrijevic Michel , Carrasco Nathalie , Perrin Zoé
Published: September 2022

Jupiter's stratospheric chemistry and dynamics are poorly understood as a function of latitude. The Shoemaker-Levy 9 comet impacts in Jupiter's atmosphere in 1994 have offered us with a unique means to characterize Jupiter's stratospheric chemistry and dynamics. We can indeed use the delivery at 44°S of the long-lived species HCN, CO, H2O, and CS and the subsequent temporal evolution of their spatial distribution as constraints for vertical and meridional mixing, zonal winds and chemistry as a function of latitude. 
We mapped HCN and CO in Jupiter's stratosphere with ALMA in March 2017. These observations have already been used in Cavalié et al. (2021) and Benmahi et al. (2021) to derive the stratospheric zonal wind field. In this paper, we use the same observations to retrieve the vertical and meridional distributions of HCN and CO, almost 25 years after the comet impacts. We will present the spatial distributions of both species and discuss the implications on Jupiter's stratospheric chemistry, and vertical and horizontal mixing.
ExoSim 2. The new time-domain simulator applied to the Ariel space mission
Authors: Mugnai Lorenzo V. , Pascale Enzo , Al-Refaie Ahmed F. , Bocchieri Andrea , Papageorgiou Andreas , Sarkar Subhajit
Published: September 2022

ExoSim 2 is a time-domain simulator for exoplanet observations. The software can simulate exoplanetary transit, eclipse and phase curve observations from ground and space-based instruments. Such simulation can capture temporal effects, such as correlated noise and systematics on the light curve. The simulator will produce spectral images like those produced by an actual observation.

ExoSim 2 has been developed for the Ariel Space Mission, to assess the impact of astronomical and instrumental systematic on astrophysical measurement, and to prepare the data reduction pipeline against realistic data sets. ExoSim 2 output can be utilised by different data reduction methods, not only to determine the best pipeline strategy to remove the systematics in the measurements but also to assess the confidence level of retrieved quantities.

ExoSim 2 is a refactored version of ExoSim: an end-to-end simulator that models noise and systematics in a dynamical simulation. The first version of ExoSim (Sarkar et al. 2020) was developed for the Ariel Space Mission, then adapted to the James Webb Telescope and presented to the community as JexoSim (Sarkar et al. 2019 and Sarkar et al. 2021).

ExoSim 2 is meant to be easier to use than its predecessor and largely customizable. It is completely written in Python, tested against Python 3.7+, and follows the object-oriented philosophy. It comes with an installer, documented examples, a comprehensive guide, and almost every part of the code can be replaced by a user-defined function, which allows the user to include new functionalities to the simulator.

We believe that ExoSim 2 is a versatile tool, which can be used for the development of instruments other than Ariel, or to assess the impact of different astronomical or instrumental systematics.
A planetary-scale heat wave in Jupiter's mid-latitude upper atmosphere
Authors: O'Donoghue James , Moore Luke , Bhakyapaibul Tanapat , Johnson Rosie , Melin Henrik , Stallard Tom
Published: September 2022

At Jupiter, magnetosphere-ionosphere coupling gives rise to intense auroral emissions and enormous energy deposition in the magnetic polar regions. Here we show ground-based maps of Jupiter's upper atmosphere temperatures obtained via the emissions of the major upper-atmospheric ion, H3+. The maps have a spatial resolution of 2o longitude and latitude from pole to equator and trace the global temperature gradient. We find that temperatures decrease steadily from the auroral polar regions to the equator, indicating that the aurora act as a planet-wide heating source. However, during a period of enhanced activity in the auroral region which models imply was due to a solar wind compression, a high-temperature planetary-scale-sized structure was also observed on top of this gradient. This presentation reports on the particulars of this feature, including how it appears to be propagating away from the main auroral oval (as determined by estimates of the features' velocity at several longitudes) and its subsequent implications for global energy circulation at Jupiter and other planets.
Re-activation of main-belt comet 288P in 2021
Authors: Agarwal Jessica , Kim Yoonyoung , Jewitt David , Mutchler Max , Weaver Harold , Larson Stephen
Published: September 2022

The binary main-belt comet 288P is peculiar both because of its comet-like activity and because of its unusual system properties, combining near-equal component sizes with a wide separation of about 100 times the primary radius. The system likely formed by rotational disruption after YORP spin-up and subsequently widened, possibly by radiative or outgassing torques.
We present Hubble Space Telescope data obtained in 2021 while 288P re-approached perihelion and activity re-kindled. The data show a developing dust tail. We constrain the time of activity onset and investigate whether one or both components were active, which is key to understanding whether the splitting was the cause of the activity.
The Atmospheric Remote-sensing Infrared Exoplanet Large-survey (Ariel) sensitivity and performance
Authors: Pascale Enzo , Eccleston Paul , Savini Giorgio , Tinetti Giovanna
Published: September 2022

The Ariel space mission will characterise spectroscopically the atmospheres of a large and diverse sample of hundreds of exoplanets. Targets will be chosen to cover a wide range of masses, densities, equilibrium temperatures and host stellar types to study the physical mechanisms behind the observed diversity in the population of known exoplanets. With a 1-m class telescope, Ariel will detect the atmospheric signatures from the small, <100ppm, modulation induced by exoplanets on the bright host-star signals, using transit, eclipse and phase curve spectroscopy. Three photometric and three spectroscopic channels, with Niquist sampled focal planes, simultaneously cover the 0.5-7.8 micron region of the electromagnetic spectrum, to maximise observing efficiency and to reduce systematics of astrophysical and instrumental origin. This contribution reviews the predicted Ariel performance as well as the design solutions implemented that will allow Ariel to reach the required sensitivity and control of systematics.
Update of seasonal gravity field and k2 love number of Mars from MGS, Mars Odyssey and MRO radio science 
Authors: levesque maeva , rosenblatt pascal , marty jean-charles , dumoulin caroline
Published: September 2022

The Mars Global Surveyor (MGS), Mars Odyssey (MO), and Mars reconnaissance Orbiter (MRO) Doppler tracking data from 1999 to end of 2021 have been reprocessed, offering the longest time series ever obtained for the gravity field of a planet.

 

The process, called Precise Orbit Determination (POD), uses the Doppler radio-tracking data acquired at the Deep Space Network (DSN) ground stations, and an accurate dynamical model for each spacecraft. This model employs identical up-to-date standards and state-of-the-art of the force models, both surface forces and gravitational forces. A macromodel of each spacecraft (surface area and optical properties of the faces of the probe) is taken into account. It is oriented in space at any time given telemered quaternions. This attitude information of the bus of the spacecraft is completed by the attitude of the articulated solar array and of the steerable high gain antenna with respect to the spacecraft body. In addition, the  self-shadowing effect is introduced for each surface force, atmospheric drag and radiation pressure form the Sun and the planet (albedo and infra-red emission). The angular momentum desaturation maneuvers are taken into account by solving for empirical accelerations at the epoch of each maneuver.

 

This force model allows to compute theoretical Doppler tracking data, then the difference of these predicted data with the tracking data collected at ground stations is computed. Least square fit of this difference is processed over successive data-arcs with a duration of 4 days for each spacecraft. This least squares filter allows to adjust a scale factor of the drag and solar pressure force for each data-arc as well as residual accelerations at each angular momentum desaturation event. The least squares fit results in normal matrices for each data-arc and for each spacecraft. It contains partial derivatives for each coefficient of the force model (scale factors, residual accelerations) as well as for the time series the first zonal gravity field coefficients and for the degree 2 tidal Love number, k2. All the normal matrices are stacked together in order to retrieve a time series of the gravity field from 1999 to 2021 (about 10 Martian year), which has never been obtained before. The k2 Love number solution is also re-estimated.  We analyze the error on the obtained solution depending on the number of satellite we used (1 to 3) and the data timespan used.

 

The retrieved time-varying gravity coefficients and the Love number k2 are then use to tightly constrain the seasonal variations in the mass of the polar caps and the solid tides of Mars, respectively
The circulation at the nightside lower clouds of Venus with high-precision winds
Authors: Peralta Javier , Galeote Antonio , Lee Yeon Joo , Bullock Mark , Young Eliot , Machado Pedro , Espadinha Daniela , Baena Roberto
Published: September 2022

The study of the atmospheric circulation in the planets and moons of our solar system and exoplanets is critical for the advances in Meteorology. In slowly rotators like Venus, Titan and tidally-locked exoplanets, the Coriolis effect is too weak to balance the pressure gradients and other metric terms (centrifugal forces) generate a different balance called “cyclostrophic”. For reasons yet not fully understood, these slowly rotating bodies tend to exhibit atmospheres which rotate much faster than the solid globe, a phenomenon called atmospheric “superrotation”. Venus constitutes the most extreme case known in our solar system, with its clouds rotating up to 60 times faster than the surface, although numerical models yet fail to accurately reproduce this superrotation, especially at the deeper atmosphere. Besides, despite the richness of information provided by the space missions that explored Venus in the past and the varied and numerous Earth-based observations, accuracy in wind measurements at present is yet insufficient to isolate and characterize the several contributors of the observed speeds of the lower clouds of Venus located within 48-60 km. As a result, the net meridional circulation, influence of the solar tides or the magnitude of transient waves and eddied are yet uncertain.

In this work we intend to provide new insights about the circulation at the deeper atmosphere of Venus obtaining wind speeds with an accuracy better than 1 m·s-1 taking advantage of the long-term coherence of the lower clouds’ patterns, which enables confidently tracking cloud tracers in images separated by more than 5 hours. These high-precision winds were obtained from sequences of images taken at 1.74, 2.26 and 2.32 µm by space missions Venus Express/VIRTIS-M (2006-2008) and Akatsuki/IR2 (2016), as well as with pairs of images acquired co-ordinately by Earth-based telescopes located at different geographical locations: IRTF/SpeX in Hawaii and HCT/IRCAM in India (May and July 2004, December 2010), IRTF/SpeX in Hawaii and NOT/NOTCam (July 2020). Our results extend those from VIRTIS-M recently published by Gorinov et al. (Atmosphere 2021, 12, 186) and confirm some of their results.
Probing Atmospheric Chemical Processes with Warm Jupiter Observations
Authors: Cubillos Patricio E.
Published: September 2022

Transmission observations of transiting exoplanets allow us to constrain the composition of their atmospheres.  In particular, the GIANO-B high-resolution spectrograph can probe a wide range of the near-infrared spectrum with unprecedented detail (0.9--2.45 microns), being able to test for the presence of several molecular species such as H2O, CO, CO2, CH4, HCN, NH3, and C2H2. The simultaneous detection of multiple carbon-, oxygen-, and nitrogen-bearing species places direct constraints to infer which chemical processes shape the observed composition of a planetary atmosphere, allowing us to study them in an unprecedented manner.
Warm Jupiters, having equilibrium temperatures near the CO--CH4 equal-abundance boundary (~1000 K), have atmospheric compositions particularly sensitive to temperature, and are thus favorable for characterization. Here we will employ physically motivated models to explore the atmospheric condition and chemical processes of recent GIANO-B observations that show a rich chemistry in carbon, nitrogen, and oxygen species.  In particular we will contrast the impact of equilibrium/disequilibrium processes and variable C/O ratios, and their consequences on the planet observable spectra.
Transmission spectroscopy of the aligned hot Jupiter KELT-10b using HARPS
Authors: Steiner Michal , Attia Omar , Ehrenreich David , Bourrier Vincent
Published: September 2022

Context

High-resolution spectrographs provide an excellent opportunity for probing exoplanetary atmospheres, utilizing the transmission spectroscopy method (among others). This method allows us to explore deep into the atmosphere, detecting multiple atomic and molecular species. We can also study the atmospheric wind patterns by characterizing the line profile. So far, dozens of exoplanets, mainly hot Jupiters and warm Neptunes, have their atmosphere successfully observed with this method. Most studies so far have focussed on exoplanets showcasing easily detectable signatures (in particular, sodium); however, it is important, not to bias the sample of studied planets, to enquire about more challenging cases, which could feature different atmospheric conditions.

KELT-10b

Using the HARPS spectrograph, I will show my work on transmission spectroscopy of KELT-10b, a standard hot Jupiter-type planet, utilizing data from two transit nights. We used spectra from the HEARTS survey, which aims to study exoplanetary atmospheres using transmission spectroscopy with HARPS. I have been mainly focusing on the sodium lines and Balmer lines in the transmission spectrum of KELT-10b. Sodium has not been detected in KELT-10b with HARPS, although recently detected by UVES. I will discuss how high-quality non-detections can further strengthen our confidence in detected signals and how precise rectification of stellar effects is necessary for detections. Two photometric light curves have been observed complementary to the two transit night observations with HARPS. This allows us to monitor the star for potential stellar variation, and, by including the already public dataset, improve the ephemeris of this system.

Rossiter-McLaughlin effect

Since HARPS allows for precise observations of radial velocities, we analyzed the Rossiter-McLaughlin effect during the transits. We measured the obliquity and stellar projected equatorial velocity, finding the system to be aligned.

Transmission spectroscopy

Searching for sodium in the transmission spectroscopy has been unsuccessful, as KELT-10b is quite a faint target. However, due to the characteristics of the system, the effect of the Rossiter-McLaughlin effect is significant, possibly explaining the signature previously detected in UVES data.

 
Ground-based HDO and SO2 thermal mapping on Venus between 2012 and 2022: : An update 
Authors: Encrenaz Therese , Greathouse Thomas , Giles Rohini , Widemann Thomas , Bézard Bruno , Fouchet Thierry
Published: September 2022

Since 2012, we have been monitoring SO2 and H2O (using HDO as a proxy) at the cloud top of Venus, using the TEXES high-resolution imaging spectrometer at the NASA InfraRed Telescope Facility (IRTF) at Maunakea Observatory. Sixteen runs have been performed between 2012 and 2022. Maps have been recorded around 1345 cm-1 (7.4 microns, z = 62 km), where SO2, CO2 and HDO are observed, and around 530 cm-1 (19 microns, z = 57 km) where SO2 and CO2 are observed, as well as around 1162 cm-1 (8.6 microns, z = 66 km) where CO2 is observed. From the early beginning, SO2 plumes have been identified with an evolution time scale of a few hours. In 2020, an anti-correlation has been found in the long-term evolution of H2O and SO2; in addition,  the SO2 plume appearance as a function of local time seems to show two maxima around the terminator, indicating the possible presence of a semi-diurnal wave (Encrenaz et al. A&A 639, A69, 2020). After two years of interruption due to the pandemia, new observations have been performed in July 2021, September 2021, November 2021, and February 2022.   The main results of the new observations are listed below. (1)The SO2 abundance, which had been globally increasing from 2014 until 2019, has now decreased with respect to its maximum value. (2) The anti-correlation between H2O and SO2, which was maximum between 2014 and 2019 (cc = - 0.9) does not appear clearly in the recent observations. (3) The maximum appearance of the SO2 plumes at the equator and the terminators is confirmed, but appears stronger on the morning side.(4) A strong activity of the SO2 plumes is observed in September and November 2021, at a time when the disk-integrated SO2 abundance is low. At the same time, thermal maps at 1162 cm-1 (8.6 microns, z = 66 km) show a polar enhancement. This behavior could possibly be associated with the topography.

 

 

 
Meteor clusters observed by the video technique
Authors: Koten Pavel , Čapek David
Published: September 2022

Several meteor clusters were observed by the video cameras deployed within the Czech Republic in recent years. Moreover, we also obtained data on another cluster which was detected above the Southern America.

In this talk the basic data on the selected meteor clusters, their atmospheric trajectories, and 3D distribution of the fragments will be provided. For example, a cluster consisting from a fireball and four fainter meteors was observed on August 23, 2020. It was a relatively compact cluster with smaller meteoroids up to 30 kilometres from the main body. Possible origin of the clusters will be discussed, too.
Phyllosilicates as a source of water in the Trappist-1 protoplanetary disk
Authors: Schneeberger Antoine , Mousis Olivier
Published: September 2022

In many ways the architecture of the Trappist-1 system resembles that of the Galilean moons orbiting around Jupiter. With seven conﬁrmed planet, including three terrestrial planets in the habitable zone, it is a unique laboratory to study planetary formation scenarios. Recent results derived from interior modelling show a gradient in the planets’ water mass fractions (WMF). From little to no water to an estimated WMF of 10%, this gradient is puzzling formation models considering that all planets’ orbits are inside the system’s snow line. A mean to bring water inside the snow line is to consider the dihydroxylation of hydrated minerals. Phyllosilicates are good candidates as they can carry up to 10% of water in mass. With a 1+1D proto- stellar nebula toy model (PSN), we study the eﬀect of a water vapor source at the location of the dehydroxylation of particles dominated by phyllosilicates. One major unknown remains however the dehydroxylation temperature of phyllosilicates under PSN thermodynamic conditions. We have then used three plausible devolatilization temperatures, namely 400 K, 600 K and 800 K. We show that the water vapor released from phyllosilicates can increase the water ice abundance located at the snowline. Those enrichments range from 2 to 5 times the initial water abundance in phyllosilicates.
The Importance of Noble Gas Isotopic Composition for Understanding the Origins of the Ice Giants 
Authors: Mandt Kathleen , Mousis Olivier , Lunine Jonathan , Simon Amy , Hofstadter Mark , May Erin , Mayorga Laura
Published: September 2022

The 2023 Planetary Science Decadal Survey recommended a Uranus Orbiter and Probe as the top priority flagship for NASA and encourages collaboration with ESA in this mission. One of the primary science objectives of this mission would be to determine how this class of planets formed. The current composition, particularly the abundances and isotopes of noble gases, in the atmosphere of Uranus will provide information on how the planet formed, and on the origin of the solid building blocks that contributed to its formation.

Noble gas abundances and their isotope ratios are among the most valuable pieces of evidence for tracing the origin of the materials from which the giant planets formed. We will outline the current state of knowledge for heavy element abundances in the giant planets and explain what is currently understood about the reservoirs of icy building blocks that could have contributed to the formation of the Uranus. We then outline how noble gas isotope ratios have provided details on the original sources of noble gases in various materials throughout the solar system. We follow this with a discussion on how noble gases are trapped in ice and rock that later became the building blocks for the giant planets and how the heavy element abundances could have been locally enriched in the protosolar nebula. We then provide a review of the current state of knowledge of noble gas abundances and isotope ratios in various solar system reservoirs, and discuss measurements needed to understand the origin of Uranus. Finally, we outline how formation and interior evolution will influence the noble gas abundances and isotope ratios observed in Uranus today. The measurements required to understand the origin of Uranus can only be made by an atmospheric probe, and include (1) the 3He/4He isotope ratio to help constrain the protosolar D/H and 3He/4He; (2) the 20Ne/22Ne and 21Ne/22Ne to separate primordial noble gas reservoirs similar to the approach used in studying meteorites; (3) the Kr/Ar and Xe/Ar to determine if the building blocks were Jupiter-like or similar to 67P/C-G and Chondrites; (4) the krypton isotope ratios for the first giant planet observations of these isotopes; and (5) the xenon isotopes for comparison with the wide range of values represented by solar system reservoirs.

 

Mandt, K. E., Mousis, O., Lunine, J., Marty, B., Smith, T., Luspay-Kuti, A., & Aguichine, A. (2020). Tracing the origins of the ice giants through noble gas isotopic composition. Space Science Reviews, 216(5), 1-37.

 
Reappraising the Production and Transfer of Hydrogen to the Upper Atmosphere at Times of Elevated Water Vapor  
Authors: Montmessin Franck , Belyaev Denis , Lefevre Franck , Alday Juan , Fedorova Anna , Korablev Oleg , Trokhimovskiy Alexander , Chaffin Mike , Schneider Nick
Published: September 2022

We have used a 1D hybrid model to represent the ascent of a wet air parcel at times of intense dust and transport activity. This model combines observations of the ACS instrument that measured, for the first time, water vapor abundance from 20 to 120 km. These observations enable the in-depth study of how the water vapor penetration to high altitude contributes to hydrogen production above 80 km. In contrast with other 1D models that have been used to explore Mars’ photochemistry, our model represents the vertical transport through advection with a constant velocity of 10 cm/s up to 100 km. Our results imply that, contrary to a common assumption made in models used to study Mars’ photochemistry and escape processes, the region between 60 and 80 km cannot be neglected in the production and migration of hydrogen to the upper atmosphere. In particular, these results imply that upper atmosphere photochemistry models intending to capture Southern Summer conditions need to carefully consider the flux boundary condition for H at the lower boundary if it is higher than 80 km. Testing a variety of configurations, from the MY34 GDS to the recent MY35 perihelion period, we have been able to assess how the hydrogen upward flux from above 60 km varies with events. Stochastic events (GDS and A, B, C- storms) have a strong imprint on the escape budget, but our results suggest perihelion remains the dominant escape component on the long term.
Least Squares Estimates of Earthlike Exoplanet Temperatures from Infrared Emission Spectra
Authors: Schreier Franz , Wunderlich Fabian , Grenfell Lee
Published: September 2022

Detailed characterization of exoplanets lies at the forefront of exoplanetary science.
Temperature is a key quantity to understand atmospheric physics and chemistry.
We retrieved temperatures of N2-O2 dominated atmospheres from thermal emission secondary eclipse spectroscopic observations of Earth-like exoplanets orbiting G-, K-, and M-stars.
A line-by-line (lbl) radiative transfer code (Py4CAtS) is used to generate synthetic thermal infrared (TIR) observations.
The atmospheric temperature is approximated by a function expansion with base vectors defined by a singular value decomposition of a matrix comprising representative profiles.
A standard nonlinear least squares solver coupled to the lbl code is used to estimate the unknown expansion coefficients.

Results suggest that even low signal-to-noise ratios (=5) and medium resolution fits of the shortwave and longwave CO2 bands in the TIR spectra allow the inference of
reasonable temperature profiles. Deviations from the true temperature in the upper troposphere and lower-to-mid stratosphere are mostly in the range of a few Kelvin, with larger deviations in the upper atmosphere and, less often, in the lower troposphere.
Although the performance of the two bands is equivalent in most cases, the longwave TIR is more favorable than the shortwave due to increased star-planet contrast and higher intensities.
Elemental Composition and Optical Properties of Cometary Dust Particles in the Coma of Comet 67P
Authors: Hilchenbach Martin , Stenzel Oliver , Fischer Henning
Published: September 2022

The COmetary Secondary Ion Mass Analyser (COSIMA) instrument on board ESA's Rosetta mission to comet 67P/Churyumov–Gerasimenko has collected and analysed dust particles in the inner coma from August 2014 to September 2016 between 1.25 and 3.8 AU solar distance and 4 to 1000 km off the comet nucleus. The dust particles were identified with optical microscopy and analysed with secondary ion mass spectrometry (SIMS). The elemental composition of the dust particles collected and analysed with SIMS is heterogeneous for the mineral forming elements within a factor of 2. The potential relation between optical properties and dust particle elemental ratio of carbon and silicon has been studied. 
ExoClock project: a pro-am collaboration to monitor the exoplanet ephemerides for the Ariel space mission
Authors: Kokori Anastasia
Published: September 2022

ExoClock (exoclock.space) is a project aiming to monitor transiting exoplanets through regular observations using small and medium scale telescopes. The project is part of the ephemerides working group of ESA's Ariel space mission and the main scope is to maximise the mission efficiency. This effort was launched in EPSC2019 and we are actively collaborating with both professional and amateur astronomers coming from various countries across the world. In this talk, I will talk about the organisation of the project and the main tools that are used to achieve an effective pro-am collaboration. I will also present the current status of the project and the results of the publications we have produced so far. Our research includes a collective analysis of light-curves aquired by ground telescopes most of which belong to amateur astronomers. This data are used in combination with other resources (literature data, space data and light curves from other networks) to update the ephemerides of exoplanets that are candidates for the Ariel space mission. The ExoClock network currently consists of 550 participants out of whom 420 are amateur astronomers, a number that highlights the significant contribution of amateurs in our project. 
ELT-METIS: estimating the constraining power of high-resolution exoplanet spectra with Bayesian inference
Authors: Blain Doriann , Sánchez López Alejandro , van Boekel Roy , Mollière Paul
Published: September 2022

Ground-based high-resolution spectroscopic observations of exoplanet atmosphere is a rapidly-evolving field with already significant successes, mainly in species detection using a cross-correlation approach. Since a few years new techniques are developed to tackle down the obstacles to not only detect species, but also retrieve abundances and other properties (e.g the temperature profile), a deed that was so far essentially reserved to low-resolution (R ~100) observations. 
The Mid-infrared Extremely Large Telescope (ELT) Imager and Spectrograph (METIS) features a high-resolution (resolving power of ~100,000) spectrograph in the L- and M-bands (2.90 to 5.30 $\mu$m). For exoplanet atmospheric characterisation, this instrument will represent a major leap forward. It will enable the observation of fainter and smaller objects and will drastically improve the quality of data from brighter objects due to the dependence of the Signal-to-Noise Ratio in the background-limited regime on the square of the telescope diameter. At these wavelengths the obscuring effects of hazes and/or clouds are much reduced.

We present here realistic simulated observations of several exoplanets of interest with METIS. We notably included telluric lines, and time-dependent airmass and Doppler shift of the planet spectra relative to the instrument. We also included realistic noise and uncertainties from the METIS dedicated radiometric code. We performed Bayesian analysis (using PyMultiNest) of these observations with a newly developed extension of petitRADTRANS, our atmospheric modelling software. We investigated which species could be retrieved, and how well, on these selected targets. We will also discuss the detection and abundance retrieving of trace species and isotopologues, as well as the retrieving of other key atmospheric properties. Finally, we will briefly introduce the new and robust atmospheric retrieval framework we developed for petitRADTRANS, which we tested on existing high-resolution data.
Investigating dust devils on Mars through the Makadikadi Salt Pans analogue (Botswana)
Authors: Toledo Daniel , Apéstigue Victor , Arruego Ignacio , Montoro Francisco , Martinez-Oter Javier , Serrano Felipe , Yela Margarita , Carrasco-Blázquez Isaias , Franchi Fulvio
Published: September 2022

In the framework of Europlanet 2024 Research Infrastructure (RI) Transnational Access (TA) programme, from 29 September to 6 October 2021 a field campaign was conducted at the Makgadikgadi Salt Pans (Botswana) [1] with the spare units of the radiometers RDS [3] (part of MEDA meteo station [2] onboard on the NASA Mars 2020 Perseverance rover) and SIS (originally selected for ExoMars 2022 METEO package).The main goal of the campaign was to characterize the impact of dust devils on the observations made by these sensors, and so to evaluate the capabilities of this instrumentation to constrain the dust lifting activity on Mars (RDS is currently operating on Mars). For each day of the campaign, RDS and SIS were set at two different locations with the following instrumentation: 1) Two cameras to record panoramic videos; 2) A Vaisala weather station to perform measurements of pressure, wind direction and intensity, temperature and relative humidity; 3) A ZEN radiometer to measure how much light was absorbed by the dust at different wavelengths.

In this work we will present the different results obtained during this campaign for which a large number of dust devils and dust lifting events produced by wind gusts were analysed. For each dust lifting, we recorded the dust devil distance, the size, duration and direction. This information along with the videos made by the cameras, helped us to establish the amount of dust lifted by the dust devil as well as their distances from the instruments. We will also discuss the implication of our results for establishing the RDS and SIS capabilities for dust lifting characterisation on Mars.
Responses of eukaryotic photosynthetic organisms to simulated M-dwarf star light. 
Authors: La Rocca Nicoletta , Battistuzzi Mariano , Claudi Riccardo , Cocola Lorenzo , Poletto Luca
Published: September 2022

Recently discovered Earth-like exoplanets are orbiting the Habitable Zone of M-dwarf stars, the most abundant and long-lived stars known in the Milky Way. Such stars have different spectral characteristics respect to the Sun, being less luminous and generating a light spectrum with a major component in far-red and infrared, while emitting very low in the visible. Many researchers discussed the possibility of oxygenic photosynthesis in these worlds, as the characteristics of M-dwarf stars do not seem suitable for most oxygenic photosynthetic organisms evolved on Earth to absorb the only visible light. However, no experimental research has been done testing organisms under simulated M-dwarf spectra. At the university of Padova, a collaboration between the Department of Biology, the Astronomical Observatory (INAF) and the Institute of Photonics and Nanotechnology (IFN-CNR) led to the construction and the development of a new experimental tool. The setup is composed by two main components: a Star Light Simulator, able to generate different light intensities and spectra, including those of M-dwarf stars and an Atmosphere Simulator Chamber where different gas compositions can be set, allowing to grow photosynthetic organisms under selected non-terrestrial conditions. We initially focused on cyanobacteria as target microorganisms, due to their extraordinary capacities to withstand every kind of environment on the Earth as well as their ability to acclimate to Far-Red light. We are now testing the responses of different species of microalgae and mosses by analysing their ability to acclimate to Far-Red light and M-dwarf simulated spectra.
A search for transiting planets around hot subdwarfs - Results from TESS Cycle I
Authors: Thuillier Antoine , Van Grootel Valérie , Pozuelos Francisco , Devora-Pajares Martín , Siess Lionel , Charpinet Stephane
Published: September 2022

In this talk I will present our project that is dedicated to the search for transiting planets around hot subdwarfs (sdOB). These peculiar bodies are evolved stars that lost most of their envelope at the tip of the Red-Giant-Branch (RGB). They are small, hot and short-lived stars which have the interesting particularity to have no confirmed planets around them. In this project we perform a wide analysis of all the sdOB observed by the missions Kepler, K2, TESS and CHEOPS in order to, firstly, find transiting planets and compute their occurrence rates and secondly, bring observational constraints for the survival of close-in planets while their host star goes through the RGB. With our current technological means it is often impossible to reach Earth-sized bodies around post-RGB stars, but thanks to the small size of sdOB stars, we are able to do it here. Moreover, the short lifetime of sdOB would most likely not allow for planetary migration or the formation of second-generation planets, which means that short-period planets around them would correspond to planets that were engulfed during the RGB phase. This make them pristine candidates to understand the fate of close-orbiting exoplanets after the RGB phase of their host. In this talk I will present the method we set to analyse the data, from the initial search run to the confirmation steps of interesting signals. I will put an emphasis on the analysis of the 792 sdOB observed during the cycle 1 of the mission TESS as this part is now finished and is the topic of a submitted paper (Thuillier et al. 2022).
Planetesimal Formation (or Lack Thereof) in Pressure Bumps and Implications for Early Planet Formation
Authors: Simon Jacob B. , Carrera Daniel
Published: September 2022

A crucial step in the planet formation process is the formation of smaller bodies known as planetesimals.  However, how these small bodies formed is one of the largest outstanding issues in planetary science and astronomy. One promising route is a process known as the streaming instability, the end product of which is enhanced concentration of dust grains in the gaseous planet-forming disk.  However, even this instability requires an initial enhancement in grain concentration to get started. This initial enhancement can occur in axisymmetric regions of relatively high gas pressure known as pressure bumps; inwardly drifting dust grains slow down as they enter the bump, leading to a localized enhancement. 

Here, I present a series of very high-resolution simulations of grain concentration + streaming instability in axisymmetric pressure bumps at stellar distances equivalent to the Cold Classical Kuiper Belt.  We find that planetesimal formation via this process is extremely robust for cm-sized grains, but completely fails for mm-sized grains unless the pressure bump is sufficiently large in amplitude to completely trap the inwardly drifting grains. However, such large pressure bumps are likely to be themselves unstable and break down into vortices. Furthermore, models suggest that grains cannot grow beyond mm sizes at these distances.

Our main conclusion is that either planet-forming disks form grains larger than ~1 mm , or planetesimals do not form by the streaming instability in pressure bumps.  This result has a number of important implications for early planet formation, including alternative routes towards planetesimal formation.  I will conclude with a brief discussion of these implications.
Effect of magnetospheric disturbances on Jovian radio emissions: an in situ case study from Juno data
Authors: Louis Corentin , Jackman Caitriona , O’Kane Hackett Aoife , Devon-Hurley Elliot , Kurth William , Hospodarsky George , Louarn Philippe , Allegrini Frederic , Connerney John , Weigt Dale , McEntee Sean , Fogg Alexandra , Waters James , Bolton Scott
Published: September 2022

During its 53-day polar orbit around Jupiter, Juno often crosses the boundaries of the Jovian magnetosphere, namely the magnetopause and bow shock, as well as the plasma disc (located at the centrifugal equator). The positions of the magnetopause and bow shock allow us to determine the dynamic pressure of the solar wind (using both the updated model of Joy et al. 2002 by Ranquist et al., 2020 and/or in situ data) which allows us to infer magnetospheric compression or relaxation, while the observations of plasma disc perturbations allows us to infer magnetospheric reconfigurations.

The aim of this study is to examine Jovian radio emissions during magnetospheric perturbations. We then use our analysis to determine the relationship between the solar wind and Jovian radio emissions (observed and emitted from different regions of the magnetosphere, from different mechanisms, and at different wavelengths from kilometers to decameters).

In this presentation, we show case studies for each typical case (bow shock, magnetopause and plasma disk crossings) and show that the activation of new radio sources is related to magnetospheric disturbances. By performing a statistical study of these crossings, we hope to be able to show the relationship between the activation of new radio sources (emission intensity and extension, source positions) and the solar wind (dynamic pressure, magnetic intensity, ...), with the aim of being able to use observations of planetary radio emission as a proxy for the solar wind.
Measurement of micron-sized ejecta generated from oblique impact experiments with regolith simulant targets
Authors: Li Yanwei , Yang Jianqun , Sommer Maximilian , Li Xingji , Srama Ralf
Published: September 2022

The surface of the Moon and other airless planetary bodies is usually covered by a regolith layer. The meteoroids and interplanetary dust particles bombarding such highly pulverized layer may excavate with a yield up to 1000 times of the impactor’s own mass. The excavated ejecta grains with relatively high speeds are the main components of the dust cloud around airless bodies. Faster grains with speeds exceeding the escape velocity of a planetary body contribute to the interplanetary dust environment.

In order to understand the formation of the dust cloud around airless planetary bodies, it is necessary to deeply understand how ejecta grains are launched from regolith surfaces. We performed new oblique impact experiments on particulate targets to determine the angular and size distributions of ejecta. The spherical Aluminum projectiles of 4 mm were fired by a light gas gun at speeds of around 4.1 km/s. The targets were B4C powders with median diameters of 17 µm and the incident angles were 15°, 30°, and 45° to the target surface. Around the target, arrays of thin Al foils with thicknesses of 15 µm were installed, which were penetrated by high speed ejecta grains. The resulting holes were analyzed with computer vision methods. Our preliminary result is that we found (1) the sizes of major ejecta grains are comparable with median diameters of the target powder; (2) the angular distributions of ejecta varies with the incident angle of the impactor.
The photochemical evolution of meteoritic polycyclic aromatic hydrocarbons in clay environments on prebiotic Earth and Mars
Authors: Kopacz Nina , Corazzi Maria Angela , Poggiali Giovanni , Camprubi-Casas Eloi , von Essen Ayla , Fornaro Teresa , Brucato John , ten Kate Inge Loes
Published: September 2022

Polycyclic aromatic hydrocarbons (PAHs) represent ~20% of cosmically available carbon [1, 2]. The further photochemical evolution of PAHs on planetary surfaces is of interest to early Earth origin-of-life studies and Mars origin-of-life speculations. Much of the literature has focused on small molecules contained in meteorites, such as amino acids and nucleic acid bases, and their potential as a carbon source for prebiotic chemistry on early Earth. However, 75% of extraterrestrial organic matter in meteorites is in aromatic form [3], and is more likely to survive the journey to a planetary surface, during which much of the small molecules can be destroyed. These stable carbon compounds could later be broken down into smaller, more biologically relevant molecules by photocatalysis on clay mineral surfaces in the ultraviolet radiation regime of early Earth and Mars.

Here we experimentally test whether PAHs degrade when adsorbed to nontronite clay and exposed to ultraviolet radiation. Experiments were performed at the INAF Observatory of Arcetri and in the PALLAS chamber at Utrecht University and were monitored with in-situ diffuse reflectance infrared spectrometry (DRIFTS) measurements. PAHs and any degradation products were extracted post-irradiation and analyzed with nuclear magnetic resonance (NMR).

[1] Allamandola, L. J., Tielens, A. G. G. M., & Barker, J. R. (1989). The Astrophysical Journal Supplement Series, 71, 733-775.

[2] Puget, J. L., & Léger, A. (1989). Annual review of astronomy and astrophysics, 27(1), 161-198.

[3] Sephton, M. A. (2002). Natural product reports, 19(3), 292-311.
Statistical analysis of manually segmented linear surface features in Galileo images of Europa
Authors: Haslebacher Caroline , Thomas Nicolas
Published: September 2022

The solid-state imaging experiment onboard the Galileo mission returned around 700 images of Jupiter’s icy moon Europa [1]. These images revealed a young surface that seems to have undergone resurfacing processes, mainly caused by ridges that overprint older ridged terrains [2]. Tidal stress fields from resonances with other Galilean moons and non-synchronous rotation seem to drive geophysical surface processes. Although the Galileo images have undergone substantial study, formation mechanisms of linear surface features and connected to that, the thickness of the ice layer, are not well constrained, but many hypotheses are proposed [3]. However, a statistical analysis of linear surface features in terms of photometric properties has not yet been done.
With this work, we aim to provide a deeper understanding of geophysical processes on the surface of Europa. Furthermore, it is valuable for future mission design and planning, e.g. for the upcoming Europa Clipper mission [4], to find places that show anomalies or that would benefit from further investigations.
We analyse manually segmented linear surface features in selected Galileo images of intermediate resolution (150 - 600 m/px). The surface feature categories we investigate are 1) bands, 2) double ridges, 3) ridge complexes and 4) undifferentiated lineae. Additionally, we also segment cusps, which indicate cycloidal features. Since the cross-cutting relationships are preserved during segmentation, we can gain insights into the geological history. With these segmentations, we can retrieve the length, width and the main direction of each linear feature, while taking the number of overprints into account, in order to analyse the tidal stress field and its development over time. We look into differences in radiance between the different linear surface features with respect to the geological history to learn about endogenic and exogenic processes. More specifically, we extract radiance profiles along the direction of maximal change. For double ridges for example, we extract a w-shaped profile that let’s us investigate symmetry and differences between instances of double ridges. These analyses could turn out useful in constraining formation mechanisms for linear surface features and in reconstructing the geological history of Europa’s surface. The current status of our work is presented.
References:
[1] Belton, M. J. S., et al., The Galileo solid-state imaging experiment, Space Sci. Rev., 60, No. 1/4, 413-455.
[2] Greeley, R., et al., Europa: Initial Galileo Geological Observations, Icarus, Vol. 135, No. 1, 4-24, 1998
[3] Daubar, I., et al., Planned Geological Investigations of the Europa Clipper Mission, in prep.
[4] Richey, C., et al., The Europa Clipper Mission: Science Objectives and Mission Status Update, AGU Fall Meeting Abstracts, 2018