bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of ozone reactivity scales for volatile organic compounds in a Chinese megacity
Authors: Zhang Yingnan , Xue Likun , Carter William P. L. , Pei Chenglei , Chen Tianshu , Mu Jiangshan , Wang Yujun , Zhang Qingzhu , Wang Wenxing
Published: July 2021

Abstract. We developed incremental reactivity (IR) scales for 116 volatile organic compounds (VOCs) in a Chinese megacity (Guangzhou) and elucidated their
application in calculating the ozone (O3) formation potential (OFP) in China. Two sets of model inputs (emission-based and observation-based) were designed to localize the IR scales in Guangzhou using the Master Chemical Mechanism (MCM) box model and were also compared with those of the US. The two inputs differed in how primary pollutant inputs in the model were derived, with one based on emission data and the
other based on observed pollutant levels, but the maximum incremental reactivity (MIR) scales derived from them were fairly similar. The IR scales showed a strong dependence on the chemical mechanism (MCM vs. Statewide Air Pollution Research Center), and a higher consistency was found in IR scales between China and the US using a similar chemical mechanism. With a given chemical mechanism, the MIR scale for most VOCs showed a relatively small dependence on environmental conditions. However, when the NOx availability decreased, the IR scales became more sensitive to environmental conditions and the discrepancy between the IR scales obtained from emission-based and observation-based inputs increased, thereby implying the necessity to localize IR scales over mixed-limited or NOx-limited areas. This study provides recommendations for the application of IR scales, which has great significance for VOC control in China and other countries suffering from serious O3 air pollution.
Revealing Mercury’s surface properties through data mining of the MESSENGER datasets with MeSS
Authors: Besse Sébastien , Munoz Claudio , Cornet Thomas
Published: July 2021

Introduction: The MESSENGER spacecraft has returned a wealth of data from Mercury that offers infinite research opportunities. The objective of our modest science team, the Mercury Surface Spectroscopy (MeSS) group, is to enable and maximise the science exploitation of the visible to near-infrared spectrometer (MASCS) onboard the MESSENGER mission to unravel Mercury’s surface.The MeSS project is currently collecting research investigations of Mercury’s surface through data mining, knowing that the output of this work is of paramount importance for the preparation of BepiColombo’s exploration of Mercury.Scientific topics for Mercury’s surface: In preparation for the next Decadal Survey, the Mercury science community defined in 2019 a list of high priority science at Mercury. The MeSS approach is supporting many of those high priority questions, and in particular those related to surface analysis. Are geological processes (e.g. formation of hollows and scarps) actively taking place today? How and why has volcanism changed so dramatically through time? To what degree have secondary processes affected the surface composition and mineralogy of Mercury? With the use of the MeSS, scientific users can explore those science questions with the MASCS observations.The MeSS infrastructure: The MeSS database is a PostgreSQL relational database. This MeSS database contains the entire set of observations acquired by MASCS (i.e. >4.000.000 footprints) with all the relevant metadata to evaluate the MASCS data. Additionally, the MeSS database provide access to a product that combine the UV-visible and near channels of the spectrometer following the approach described in [1]. A view of the various parameters available in the MeSS database is presented in Fig 1. A python interface is available to provide query access to the database and explore the products of interest based on various criteria. Spectral parameters defined in [2] are also added as a table in the MeSS database. With the various information provided in the MeSS database, users can explore a combination of parameters of interest to explore the properties of Mercury’s surface. Fig 1: Illustration of the various parameters and their relationships in the MeSS Fig 2: Output of a query in the MeSS Database for the footprints with an incidence angle
Rapoc: the Rosseland and Planck opacity converter. A user-friendly and fast opacity program for Python
Authors: Mugnai Lorenzo V. , Modirrousta-Galian Darius
Published: July 2021

We present a novel code that converts the widely-used wavelength-dependent opacities of gaseous species into Rosseland and Planck mean opacities (RPMs). RAPOC (Rosseland and Planck Opacity Converter) is a straightforward and efficient Python code that makes use of ExoMol and DACE data as well as any other user-defined data, provided that it is within the correct format. Furthermore, RAPOC has the useful ability of rapidly interpolating between discrete data points, therefore allowing for a complete incorporation in atmospheric models. Whereas RPMs should not be used as a replacement for more rigorous opacity analyses, they have certain benefits. For example, RPMs  allow  one  to  use  Grey  or  semi-Grey  models  when  analysing  gaseous environments;  which  are  simpler,  have  exact  solutions,  and  can  be  used  as benchmarks  for  more  rigorous  approaches. By incorporating the pressure and temperature dependence of RPMs, RAPOC provides a more complex treatment of the mean opacities than what is sometimes used within the literature, notably assuming constant values or adopting simple analytic formulations.  We report  examples  of RAPOC opacities  that  are  incorporated  into  a  semi-Grey  model  to produce the temperature profile of HD 209458 b that is then compared to the realisations of the more rigorous POSEIDON code.The RAPOC code will provide the exoplanetary community a new tool for atmospheric modelling. For a quick installation in one's machinery, the “pip install rapoc” command can be used.
Redox hysteresis of super-Earth exoplanets from magma ocean circulation
Authors: Lichtenberg Tim
Published: July 2021

Internal redox reactions may irreversibly alter the mantle composition and volatile inventory of terrestrial and super-Earth exoplanets and affect the prospects for atmospheric observations. The global efficacy of these mechanisms, however, hinges on the transfer of reduced iron from the molten silicate mantle to the metal core. Scaling analysis indicates that turbulent diffusion in the internal magma oceans of sub- Neptunes can kinetically entrain liquid iron droplets and quench core formation. This suggests that the chemical equilibration between core, mantle, and atmosphere may be energetically limited by convective overturn in the magma flow. Hence, molten super-Earths possibly retain a compositional memory of their accretion path. Redox control by magma ocean circulation is positively correlated with planetary heat flow, internal gravity, and planet size. The presence and speciation of remanent atmospheres, surface mineralogy, and core mass fraction of atmosphere-stripped exoplanets may thus constrain magma ocean dynamics.
Feature Detector on the Moon Trek Portal
Authors: Law Emily , Gallegos Natalie , Nainan Charles , Malhotra Shan
Published: July 2021

The Moon Trek portal (https://trek.nasa.gov/moon) aims to provide the scientific community as well as the general public access to lunar data collected from various lunar missions. The portal also offers a suite of tools with the goal of allowing users to analyze the data for the purposes of education, mission planning, and research. Such tools include elevation profilers, crater and rock detection, lighting analysis, and slope analysis to name a few. Moon Trek is further expanding its analytic capabilities by adding feature detection to its toolset.The feature detector, similar to the rock and crater detection tools, seeks to detect features on the lunar surface using orbital imagery. Unlike the detection tools currently available on the Moon Trek, the feature detector is built to be generic, trainable, and able to seek out any feature when provided a training set for the feature in question. The tool currently supports detection of craters, rocks, and lunar pits.The feature detector takes a deep learning approach in finding features from orbital imagery. The model used in the latest detection tool is a Faster Region Based Convolutional Neural Network (Faster-RCNN) with a finetuning approach. More succinctly, the finetuning approach uses a model which has been developed and trained on a different and larger training set. The classification layer is replaced to detect features of the chosen domain (rocks, pits, craters, etc.) The model is then trained with smaller training sets.Currently we use panchromatic Narrow Angle Camera (NAC) images from the Lunar Reconnaissance Orbiter Camera (LROC) as input. However, the model can be trained on orbital imagery from any mission. The tool’s output includes the NAC image with bounding boxes over detected and an ascii file showing pixel coordinates of each detected feature.
Update on CO2 and temperature profiles retrievals from NOMAD-SO on board ExoMars TGO
Authors: Trompet Loïc , Vandaele Ann Carine , Aoki Shohei , Erwin Justin , Thomas Ian , Piccialli Arianna , Daerden Frank , Neary Lori , Villanueva Geronimo , Liuzzi Giuliano , Crismani Matteo , Lopez-Valverde Miguel Angel , Ristic Bojan , Lopez-Moreno José Juan , Bellucci Giancarlo , Patel Manish ,   NOMAD team
Published: July 2021

The SO channel of the NOMAD instrument
The NOMAD-SO channel [1] is an infrared spectrometer working in the 2.2 to 4.3 µm spectral range (2200-4500 cm-1) and started to perform solar occultation measurement on April 21, 2018. The instrument is composed of an echelle grating coupled to an Acousto-Optical Tunable Filter for the diffraction order selection. As TGO is on a quasi-circular orbit at around 400 km of altitude, it performs one orbit every two hours. During a solar occultation measurement, SO scans six diffraction orders each second. These diffraction orders are recorded on four bins leading to a vertical sampling lower than one km. The calibration of the SO channel is described in [2] and is still being fine-tuned.CO2 density and temperature profiles retrievals
Several diffraction orders probe different altitude ranges as they contain CO2 lines with different intensities that appear and saturate at different altitudes. Correct temperature profiles are necessary for the retrieval of several species and the profiles have to be carefully retrieved as their inversion is very sensitive to noise. We use the following retrieval scheme:For each solar occultation measurement, we derive a slant column profile of CO2 using ASIMUT-ALVL [3]. ASIMUT is a radiative transfer program developed at BIRA-IASB and uses the Optimal Estimation Method for regularization [4]. The GEM-Mars GCM provides the a priori profiles of CO2 local density, pressure and temperature. We then apply an iterated Tikhonov regularization to derive a regularized local density profile using an improved version of the algorithm described in [5]. This method requires the selection of a regularization parameter to reduce as much as possible the presence of noise in the profile while keeping the real variations. This retrieval scheme allows a fine-tuning of the reguralization parameter. We finally apply the hydrostatic equilibrium equation to derive the temperature profiles [6]. We derived the NOMAD-SO CO2 and temperature profiles for MY34 and 35.
Does Leakage of Charge in Particle Collisions Kill the Concept of Deadzones?
Authors: Wurm Gerhard , Jungmann Felix , van Unen Hannah , Voellings Nils , Schoenau Laurent , Teiser Jens
Published: July 2021

Protoplanetary disks are thought to harbor deadzones, regions in their interior, where the ionization fraction is too low to trigger MRI turbulence. This has quite severe consequences for accretion and planet formation. So far, the dominant source considered for ionization is high energy radiation from external cosmic rays over stellar radiation to radioactive decay. Especially, external radiation might indeed be attenuated too much before reaching parts of the midplane in disks. Radiation might not be the only source of ionization though.In recent years, we carried out a number of laboratory experiments on collisional charging (tribocharging) of grains related to planet formation. Being mm-size, in a range where fragmentation and bouncing dominate, these particles are large and, although charged, might not be relevant in the context of MRI themselves directly. An underlying assumption though is that triboelectric charge generated in collisions among grains stays on the grains. In this case, grain charging and aggregation as part of early particle growth on one side and MRI building on gas ionization on the other side would be distinct processes. However, what we recently found in a number of different experiments, is that tribocharging of grains also charges the ambient gas.In one set of microgravity experiments, we observed that the charge on two particles before and after a collision is not conserved. On the order of 20\% of the pre-charge on a grain is discharged into the environment. To mention a second experiment, the number of ions detected in a gas flow after passing a granular medium increases strongly if the particles undergo collisions, i.e. are charged. There are experiments with further evidence but these two clearly show that charge is leaking into the ambient atmosphere during collisions.In detail, the charging depends on the collision frequencies and particle sizes, which are model dependent. We also caution that these are only first experiments in this direction, but, in any case, estimates suggest that ionization rates within the gas might regularly be way larger than e.g. provided by radiation at the surface of a disk. If this holds, the charge balance in the midplane of protoplanetary disks might be quite different than previously assumed. The obvious and severe consequence might simply be that there are just no deadzones.
Automatic Detection and Classification of Boundary Crossings in Spacecraft in situ Data
Authors: Ruedisser Hannah , Windisch Andreas , Amerstorfer Ute V. , Píša David , Soucek Jan
Published: July 2021

Planetary magnetospheres create multiple sharp boundaries, such as the bow shock, where the solar wind plasma is decelerated and compressed, or the magnetopause, a transition between solar wind field and planetary field.We attempt to use convolutional neural networks (CNNs) to identify magnetospheric boundaries, i.e.  planetary and interplanetary shocks crossings and magnetopause crossings in spacecraft in situ data. The boundaries are identified by a discontinuity in a magnetic field, plasma density, and in the spectrum of high-frequency waves. These measurements are available on many planetary missions. Data from Earth's missions Cluster and THEMIS are used for CNN training. We ultimately strive for successful classification of boundaries (shock, magnetopause, inbound, outbound) and the correct handling of multiple crossings.
LONSCAPE: Light Optical Nephelometer Sizer and Counter for Aerosols in Planetary Environments
Authors: Vivien Hugo , Renard Jean-Baptiste , Olivier Mousis , Nicolas Verdier
Published: July 2021

The LONSCAPE - Light Optical NephelometerSizer and Counter for Aerosols in Planetary Envi-ronments (Renard et al., 2020) has been proposed asa concept combining a particle counter with a neph-elometer at several phase angles to characterize thescattering function and obtain precise aerosol prop-erties (see Figure 1).LONSCAPE is currently considered as part ofthe science payload of a balloon designed to flyin the Venusian atmosphere (Baines et al., 2021).LONSCAPE has also been proposed to be partof the science payload of several Saturn descentprobe concepts submitted to the ESA M4 and M5calls (Mousis et al., 2016). This instrument is alsoconsidered as part of the science payload of an ESAconcept of ice giant probe to be carried by a NASAspacecraft (Mousis et al., 2018).There are currently two major improvementsunder investigation that could be included to theinstrument’s design.The first major improvement is the reduction ofthe wavelength at which the instrument operates(650→405nm). Such a change would allow thedetection of particles as small as∼0.1μm.Detectors tend to be less efficient towards theUV, but the light scattered by diffusion is directlyproportional to the ratiod/λ, withdthe particlediameter. This leads to more flux recovered towardsthe blue than in the red, even accounting fordetector efficiency (see Figure 2).The second improvements concerns the shape ofthe beam. Making use of a thin nappe rather thana dot will increase the counting accuracy by (i) in-creasing the chance a particle will hit the beam, and(ii) reducing the time it takes to cross it.Both of these points play in favor of counting thesmaller, more numerous, particles. This modificationis quite favorable to be included to LONSCAPE, as itcould significantly enhance its detection capabilitiesfor minimal hardware changes. 
Analysis of meteors observed in the UV by the Mini-EUSO telescope onboard the International Space Station
Authors: Barghini Dario , Battisti Matteo , Belov Alexander , Bertaina Mario Edoardo , Bertone Sara , Bisconti Francesca , Capel Francesca , Casolino Marco , Cellino Alberto , Ebisuzaki Toshikazu , Gardiol Daniele , Klimov Pavel , Marcelli Laura , Miyamoto Hiroko , Picozza Piergiorgio , Piotrowski Lech Wiktor , Prévot Guillaume , Reali Enzo , Sakaki Naoto , Takizawa Yoshiyuki ,   Mini-EUSO collaboration
Published: July 2021

During its first six months of operations onboard the Zvezda module of the International Space Station, the Mini-EUSO wide-field telescope detected more than two thousand meteors in approximately 40 hours of data taking. Mini-EUSO observes the Earth’s atmosphere in the UV range (290 – 430 nm) with a field of view of about 44° x 44° through a nadir-facing, UV-transparent window with a focal surface of 48 x 48 pixels and a resolution of about 6.3 km on ground. While temporal resolution and triggering are at the timescales of 2.5 μs to potentially record UHECR showers and TLEs, Mini-EUSO performs a continuous monitoring of the UV emission at a 40.96 ms timescale, where meteors are recorded. We developed an analysis pipeline able to offline detect, track and characterize meteor events and subsequently compute their physical parameters, such as tangential speed, magnitude, duration and trajectory azimuth. In this contribution, we present the implemented reduction methods and the results of the analysis of the sample, providing comparisons with existing databases of meteors observed in the optical band.
MOMSTER, a Europlanet-funded public engagement project
Authors: Calders Stijn , Lamy Hervé , Anciaux Michel , Lefever Karolien , Kolenberg Katrien , Sterken Mieke , Kochuyt Anne-Lize
Published: July 2021

In May 2020, Europlanet Society launched a call to fund projects to engage the public with planetary science. Our project proposal called MOMSTER: MObile Meteor STation for Education & outReach was amongst the three projects that were granted.MOMSTER aims at developing a Meteor Education Kit as a resource for STEAM (Science, Technology, Engineering, Arts, Mathematics) teachers in secondary schools. The kit includes a mobile radio meteor station consisting of a dedicated antenna and radio receiver, as well as an educational package to learn all about meteors and their detection methods, while at the same time conveying a fascination for the ephemeral beauty and complexity of these natural light shows. The project goals are stimulating STEAM (ultimately resulting in nudging future career choices towards science or engineering career paths) and the use of citizen science (especially the Radio Meteor Zoo initiative on the online citizen science platform Zooniverse) at schools, and reaching the general public.The development of educational resources builds upon preliminary experiences we gained by participating in an Erasmus+ project called BRITEC (Bringing Research into ThE Classroom), in which teachers and pupils participated in the Radio Meteor Zoo activity.  We are presently in a pilot phase where three Belgian schools (two Dutch speaking and one French speaking) test the mobile radio meteor station and the educational resources, and give their feedback.We are using STEAM-education as an approach to broaden our target group towards less scientifically oriented students. We do this by developing an educational resource on visual (science) communication. We also organized an art & design competition for high school students with more than 30 submissions. The best piece of art will decorate the ‘MOMSTER boxes’ we use for transport of the radio receivers.
A new framework to explain changes in Io's footprint tail electron fluxes in the Juno era
Authors: Szalay Jamey , Allegrini Frederic , Bagenal Fran , Bolton Scott , Bonfond Bertrand , Clark George , Connerney Jack , Ebert Robert , Hue Vincent , McComas David , Saur Joachim , Sulaiman Ali , Wilson Robert
Published: July 2021

Jupiter’s aurora is complex and dynamic, with a large number of distinct auroral features and regions generated by multiple phenomena. Of these features, Io’s auroral signature is one of the most persistent and identifiable aurora, with a rich observational history spanning decades of remote observations. Since Juno arrived at Jupiter, providing in-situ transits through flux tubes directly connected to Io’s auroral emissions, its diverse set of instruments have revealed an even more complex and dynamic picture of Io’s auroral interaction. In this presentation, we report on Juno observations of precipitating electron fluxes connected to 18 crossings of Io’s footprint tail aurora, over altitudes of 0.15 to 1.1 Jovian radii (RJ). We will highlight how the strength of precipitating electron fluxes is dominantly organized by “Io-Alfvén tail distance”, the angle along Io’s orbit between Io and an Alfvén wave trajectory connected to the tail aurora. We will discuss how these fluxes were best fit with an exponential as a function of down-tail extent with an e-folding distance of 21˚, the acceleration region altitude likely increases down-tail, and most of the parallel electron acceleration sustaining the tail aurora occurs above 1 RJ in altitude. Finally, we will highlight how Juno has likely transited Io’s Main Alfvén Wing fluxtube, observing a characteristically distinct signature with precipitating electron fluxes ~600 mW/m2 and an acceleration region extending as low as 0.4 RJ in altitude.
Seasonal variability of Mars atmospheric turbulence studied from InSight high-frequency pressure measurements
Authors: Chatain Audrey , Spiga Aymeric ,   InSight team
Published: July 2021

I- IntroductionThe Martian surface is prone to atmospheric turbulence. Its thin atmosphere allows strong near-surface temperature gradients, especially during daytime, which result in conductive and convective instabilities in the Planetary Boundary Layer1. Atmospheric turbulence have different forms: convection cells during daytime and possibly convection rolls during the night, vortexes, waves or local turbulence. These phenomena induce high-frequency variations in the atmospheric pressure, wind and temperature, with different time scales. Most processes happen during the day, and are sensitive to seasons. On the opposite, nighttime conditions at the surface of Mars are usually highly-stable, though not much studied.The InSight NASA mission, arrived on Mars in November 2018, recently brought new knowledge on surface atmospheric turbulence. InSight is the first lander operating an advanced geophysical station on Mars. It also has many accurate meteorological sensors and acts as a fixed weather station. Previous studies on the first 400 sols of the mission2,3 observed a high vortex activity during the day, though no detection of dust devils, detected nigttime gravity waves, and discovered the presence of a quiet regime 2 to 4 hours after sunset, which they attributed to the development time of the nocturnal low-level jet.The aim of this work is to complete the study the atmospheric turbulence measured by the InSight mission over more than one Martian year and investigate its diurnal and seasonal variations. We observe many unexpected events with the arrival of autumn, with a burst of daytime vortexes, the apparition of nighttime vortexes and the development of a nighttime local turbulence nearly as intense as during daytime. Observational results are afterwards compared to Large Eddy Simulation (LES) outputs to bring new insights on the origin of the turbulent phenomena observed. II- Investigation of the atmospheric turbulence with InSight pressure dataII.1- VortexesPrevious studies4,5 observed vortexes during the first 400 sols of the mission, corresponding to a half year, spanning from the end of northern winter to midsummer. We extended their study to more than a complete Martian year. Vortexes are detected in the pressure data as sudden pressure drops of 0.1 to 10 Pa amplitude. We used the same detection algorithm as described in 4.II.2- Local and non-local turbulenceAside from vortexes, atmospheric turbulence can be observed through high-frequency pressure variations. We classified the turbulent phenomena in two groups depending on their timescales. ‘Local turbulence’ is due to small scale and high frequency phenomena (
Microlensing survey combining  Roman and Euclid Space Telescopes
Authors: Beaulieu Jean-Philippe , Bachelet Etienne
Published: July 2021

As the Kepler mission has done for hot exoplanets, the ESA Euclid and NASA Roman missions have the potential to create a breakthrough in our understanding of the demographics of cool exoplanets, including planets on very wide orbits, unbound, or "free-floating", planets (FFPs). Current ground-based microlensing observations have provided preliminary evidence for a potentially significant population of Super-Earth FFPs. Roman will dedicate part of its core survey program to the detection of cool exoplanets via microlensing, while Euclid may undertake a microlensing program as an ancillary science goal. We argue that simultaneous observations of short-duration microlensing events by Roman and Euclid will enable not just the verification of FFPs, but also a direct measurement of their masses, distances and transverse motions, via the detection of microlens parallax between Euclid and Roman. We use simulations of the joint-mission detection capabilities to show that parallax detections will be possible down to Earth-mass FFPs. The mass and phase-space measurements from a joint survey could thus provide strong clues to the primary mode of FFP formation.We also demonstrate that an early brief Euclid survey (∼5 h) of the Roman fields shortly after the Euclid launch would be also very valuable. It would allow the measurement of at least 10% of the events’  relative proper motions and 35% of the lens magnitudes very early on the life of the Roman Survey. We further discuss additional valuable science that will be facilitated by a joint Roman-Euclid microlensing campaign.
Digital 3D shapes suitable for the description of meteoroids
Authors: Čapek David , Kohout Tomáš , Pachman Jiří , Macke Robert , Koten Pavel
Published: July 2021

Some processes in the physics of small solar system bodies depend on the detailed shape of the body. One of them is the YORP effect, which affects the rotation of asteroids and can lead to rotational bursting. The YORP effect can be modelled because the shape of asteroids can be determined from spacecraft images, radar observations, or inversions of asteroid light curves. A similar effect, caused by the reflection of solar radiation from an irregularly shaped body, affects the rotation of meteoroids. However, this effect is very difficult to model because we are not able to determine the shapes of meteoroids.In this presentation we show our approach to obtain shapes suitable for characterizing meteoroids. For meteoroids of asteroidal origin, we simulated their formation during a collision in the main belt by fragmentation a sample of an ordinary meteorite using explosive charge technique and performed the digitization of fragments. To describe the cometary meteoroids, we used the shapes of interplanetary dust particles determined by X-ray microtomography. Finally, we show a comparison of the ability of the two types of shapes (asteroidal vs. cometary) to be spun up by the solar radiation.
Global 3D modelling of Martian CO2 clouds
Authors: Mathé Christophe , Määttänen Anni , Audouard Joachim , Listowski Constantino , Millour Ehouarn , Forget François , Spiga Aymeric , Bardet Déborah , Teinturier Lucas , Falletti Lola , Vals Margaux , González-Galindo Franscico , Montmessin Franck
Published: July 2021

In the Martian atmosphere, carbon dioxide (CO2) clouds have been revealed by numerous instruments around Mars from the beginning of the XXI century. These observed clouds can be distinguished by two kinds involving different formation processes: those formed during the winter in polar regions located in the troposphere, and those formed during the Martian year at low- and mid-northern latitudes located in the mesosphere (Määattänen et al, 2013). Microphysical processes of formation of theses clouds are still not fully understood. However, modeling studies revealed processes necessary for their formation: the requirement of waves that perturb the atmosphere leading to a temperature below the condensation of CO2 (transient planetary waves for tropospheric clouds (Kuroda et al., 20123), thermal tides (Gonzalez-Galindo et al., 2011) and gravity waves for mesospheric clouds (Spiga et al., 2012)). In the last decade, a state-of-the-art microphysical column (1D) model for CO2 clouds in a Martian atmosphere was developed at Laboratoire Atmosphères, Observations Spatiales (LATMOS) (Listowski et al., 2013, 2014). We use our full microphysical model of CO2 clouds formation to investigate the occurrence of these CO2 clouds by coupling it with the Global Climate Model (GCM) of the Laboratoire de Météorologie Dynamique (LMD) (Forget et al., 1999). Last modeling results on Martian CO2 clouds properties and their impacts on the atmosphere will be presented and be compared to observational data.
Virtual Methods for Teaching Educational Astronomy
Authors: Boldea Afrodita Liliana
Published: July 2021

In the didactic activity, in order to carry out the teaching-learning process, the teacher uses different methods, depending on the specifics and the topics taught. The introduction of virtual learning information technologies in the educational environment has had a strong impact on teaching strategies and forms of training in the educational process. The computer together with the sources of information and documentation (Internet, encyclopedias, etc.) are the elements that make the interaction with the pupils and students. This paper aims to present and implement modern training methods, as efficiently as possible, through the online platforms Googleclass and Moodle, in our case, to teach an Astronomy course to students and pupils. We aim to highlight the content of an online course, with interactive assessment tests, scientific documentation, dictionaries and homework, coming to the support of distance students, respectively for the diversification of astronomy teaching methods. By accessing such online courses, students deepen the knowledge gained in the teaching-learning-assessment process. A whole set of information technologies facilitates the transmission of information, in which an efficient combination of classical teaching methods with modern virtual methods must be used, as well as an efficient use of didactic principles and forms of student organization to achieve high performance. Given the rapid pace at which electronic methods of storing, processing and transmitting information have evolved in recent decades, we expect the future to bring about equally dramatic transformations in the education process, with the further development of information technologies and their penetration. massive in everyday life. Starting from the theoretical and applied aspects, we performed in this paper a comparative statistical study between different teaching methods and their performance, depending on the results obtained by students following the application of new assessment methods. Each online learning platform contains different assessment methods, depending on the type of lessons taught. It is very important to promote virtual teaching methods, which have a lower share in the classical lessons, so the online assessment and self-assessment methods become efficient.
Solar wind protons in the diamagnetic cavity at comet 67P/Churyumov-Gerasimenko
Authors: Goetz Charlotte , Scharre Lucie , Simon-Wedlund Cyril , Nilsson Hans , Odelstad Elias , Taylor Matthew , Volwerk Martin
Published: July 2021

Against expectations, the Rosetta spacecraft was able to observe protons of solar wind origin in the diamagnetic cavity at comet 67P/Churyumov-Gerasimenko. This study investigates these unexpected observations and gives a working hypothesis on what could be the underlying cause.The cometary plasma environment of a comet is shaped by two distinct plasma populations: the solar wind, consisting of protons, alpha particles, electrons and a magnetic field, and the cometary plasma, consisting of heavy ions such as water ions or carbon dioxide ions and electrons. As the comet follows its orbit through the solar system, the amount of cometary ions that is produced varies significantly. This means that the plasma environment of the comet and the boundaries that form there are also dependent on the comet's heliocentric distance. For example, at sufficiently high gas production rates (close to the Sun) the protons from the solar wind are prevented from entering the inner coma entirely. The region where no protons (and other solar wind origin ions) can be detected is referred to as the solar wind ion cavity. A second example is the diamagnetic cavity, a region very close to the nucleus of the comet, where the interplanetary magnetic field, which is carried by the solar wind electrons, cannot penetrate the densest part of the cometary plasma. The Rosetta mission clearly showed that the solar wind ion cavity is larger than the diamagnetic cavity at a comet such as 67P/Churyumov-Gerasimenko. However, this new study finds that in isolated incidences this order can be reversed and ions of solar wind origin (mostly protons, but also helium) can be detected inside the diamagnetic cavity. We present the observations pertaining to these events and list and discard possible mechanisms that could lead to such a configuration. Only one mechanism cannot be discarded: that of a solar wind configuration where the solar wind velocity is aligned with the magnetic field. We show evidence that fits this hypothesis as well as solar wind models in support. 
The Young Suns Exoplanet Survey: imaging infant planets around young, solar analogs
Authors: Kenworthy Matthew , Bohn Alexander , Ginski Christian , Reggiani Maddalena , Meshkat Tiffany , Mamajek Eric , Pecaut Mark , Snik Frans
Published: July 2021

Within the Young Suns Exoplanet Survey (YSES) we are observing a homogeneous sample of 70 solar-mass members of the approximately 16 Myr-old Lower Centaurus-Crux subgroup of the Scorpius-Centaurus association to search for sub-stellar companions.High-contrast imaging observations with VLT/SPHERE/IRDIS revealed (i) a shadowed transition disk around Wray 15-788 that shows significant signs of ongoing planet formation and (ii) one of the lowest-mass companions imaged to date: YSES-2 b has a mass of 6.5 Jupiter masses and is orbiting its solar-mass primary at a separation of 110 au. Most intriguing, though, was (iii) the discovery of the first directly imaged multi-planet system around a Sun-like star. The detection of two gas-giant companions of 14±3 and 6±1 Jupiter masses that are orbiting YSES-1 (TYC 8998-760-1) at separations of 160 au and 320 au, respectively, provides important implications for the outer architecture of planetary systems and the underlying formation mechanisms.In addition to the SPHERE observations, we identified further companions to our ‘Young Suns’ outside the instrument’s field of view in the third early data release of the Gaia mission. Based on parallaxes and proper motions provided in this catalogue, we detected eight additional sub-stellar companions at separations larger than 500 au amongst our sample.By combining Gaia astrometry with the high-contrast imaging capabilities of SPHERE, our survey will provide a complete census of wide-orbit sub-stellar companions for a statistically highly significant sample of young, solar analogues. From the current results we derived a preliminary probability of 14.3±3.1% for our solar-type stars to host wide-orbit, sub-stellar companions. As follow-up observations of 45 YSES targets are still pending, this ratio can be interpreted as a lower limit, which is tentatively indicating a higher companion yield than previous surveys.
Cruise and flyby operations of BepiColombo – first results and planned activities
Authors: Benkhoff Johannes
Published: July 2021

BepiColombo was launched on 20 October 2018 from the European spaceport Kourou in French Guyana and is now on route to Mercury to unveil Mercury’s secrets. BepiColombo with its state of the art and very comprehensive payload will perform measurements to increase our knowledge on the fundamental questions about Mercury’s evolution, composition, interior, magnetosphere, and exosphere. BepiColombo is a joint project between the European Space Agency (ESA) and the Japanese Aerospace Exploration Agency (JAXA) and consists of two orbiters, the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (Mio). On its way BepiColombo will travel 18 times around the Sun until the spacecraft will be put into an polar orbit around Mercury. During its long way through the inner solar system, BepiColombo will perform nine flybys (one at Earth, two at Venus and six at Mercury). However, since the spacecraft is in a stacked configuration during the flybys only some of the instruments on both spacecraft will perform scientific observations. In addition there are plenty of opportunities for further science operations (testing Einstein’s theory during solar conjunctions, listening to gamma ray bursts, or investigation of the solar environment).A status of the mission and instruments, science operations plans during cruise, and first results of measurements taken in the first three years since launch will be given.
The EU Project NEOROCKS — NEO Rapid Observation, Characterization, and Key Simulations Project
Authors: Dotto Elisabetta , Banaszkiewicz Marek , Banchi Sara , Barucci Maria Antonietta , Bernardi Fabrizio , Birlan Mirel , Carry Benoit , Cellino Alberto , De Léon Julia , Lazzarin Monica , Mazzotta Epifani Elena , Mediavilla Anabel , Nomen Torres Jaime , Perna Davide , Perozzi Ettore , Pravec Petr , Snodgrass Colin , Teodorescu Claudiu ,   NEOROCKS team
Published: July 2021

The knowledge of even some basic physical properties of a NEO such as the composition and the internal structure has strong implications for both science and impact mitigation. Depending on its composition and internal structure a meter-size object can completely burn in the atmosphere or reach the ground excavating an impact crater. To date, only 20% of the known NEO population has been characterized. The percentage rises 30% when considering only objects larger than 1 km. The reason is that physical characterization requires availability of large aperture telescopes, accurate ephemerides, and can be performed only if the object is sufficiently bright.International efforts devoted to NEO physical characterization have undoubtedly succeeded in the last decade in addressing this problem through the organization of extensive observational campaigns within the framework of international cooperative programs. Yet the observational work and the associated modelling and simulation research is far from being exhausted in particular as far as the physical characterization of PHOs and smaller objects (D
Characterisation of the hydrodynamic atmospheric escape of HD 209458 b, HD 189733 b, and GJ 3470 b
Authors: Lampón Manuel , López-Puertas Manuel , Sánchez-López Alejandro , Czesla Stefan , Sanz-Forcada Jorge ,   CARMENES Consortium
Published: July 2021

Hydrodynamic escape is the most efficient atmospheric mechanism of planetary mass loss and has a large impact on planetary evolution. However, the lack of observations remained this mechanism poorly understood. Therefore, new observations of the He I triplet at 10830 Å provide key information to advance hydrodynamic escape knowledge. In this work, we analyse the hydrodynamic escape of three exoplanets, HD209458 b, HD189733 b, and GJ 3470 b via an analysis of He triplet absorptions recently observed by the CARMENES high-resolution spectrograph, and their available Ly-alpha measurements, involving a 1D hydrodynamic model. We characterise the main upper atmospheric parameters, e.g.,  the temperature, the composition (H/He ratio), and the radial outflow velocity. We also study their hydrodynamic regime and show that HD209458 b is in the energy-limited regime, HD189733 b is in the recombination-limited regime, and GJ 3470 b is in the photon-limited regime. Details of this work can be found in [1], [2], [3].References[1] Lampón, M., López-Puertas, M., Lara, L.M., et al. 2020, A&A, 636, A13[2] Lampón, M., López-Puertas, M., Sanz-Forcada, J., et al. 2021, A&A, 647, A129[3] Lampón, M., López-Puertas, M., Czesla, S., et al. 2021, A&A, 648, L7
EnVision: Understanding why Earth's closest neighbour is so different
Authors: Widemann Thomas , Ghail Richard , Wilson Colin , Titov Dmitri
Published: July 2021

EnVision is a proposed orbiter mission aiming at determining the nature and current state of Venus' geological evolution and its relationship with the atmosphere, to understand how and why Venus and Earth evolved so differently. It is is one of two M5 mission concepts in Phase A study with a final down-selection expected in June 2021. EnVision’s overall science goals are- to characterise the sequence of events that generated the regional and global surface features of Venus, and characterize the geodynamics framework that controls the release of internal heat over Venus history; - to search for ongoing geological processes and determine whether the planet is active in the present era;- to characterise regional and local geological units, to better assess whether Venus once had condensed liquid water on its surface and was thus perhaps hospitable for life in its early history.EnVision will deliver new insights into geological history through complementary imagery, polarimetry, radiometry and spectroscopy of the surface coupled with subsurface sounding and gravity mapping; it will search for thermal, morphological, and gaseous signs of volcanic and other geological activity; and it will trace the fate of key volatile species from their sources and sinks at the surface through the clouds up to the mesosphere.EnVision’s science payload consists of VenSAR, a dual polarization S-band radar also operating as microwave radiometer, three spectrometers VenSpec-M, VenSpec-U and VenSpec-H designed to observe the surface and atmosphere of Venus, and the Subsurface Radar Sounder (SRS), a High Frequency (HF) sounding radar to probe the subsurface. These are complemented by a radio science investigation which achieves gravity mapping and radio occultation of the atmosphere, for a comprehensive investigation of the Venusian surface, interior and atmosphere and their interactions.
Preparing for the future of direct imaging exoplanets through combining other exoplanet detection techniques
Authors: Rickman Emily
Published: July 2021

Very little is known about giant planets and brown dwarfs at an orbital separation great than 5 AU. And yet, these are important puzzle pieces needed for constraining the uncertainties that exist in giant planet formation and evolutionary models that are plagued by a lack of observational constraints. In order to observationally probe this mass-separation parameter space, direct imaging is necessary but faces the difficulty of low detection efficiency.
To utilise the power of direct imaging, pre-selecting companion candidates with long-period radial velocities, coupled with proper anomalies from Hipparcos and Gaia, provide a powerful tool to hunt for the most promising candidates for direct imaging. Not only does this increase the detection efficiency, but this wealth of information removes the degeneracy of unknown orbital parameters, like the inclination, leading to derived dynamical masses which can serve as benchmark objects to test models of formation and evolution.
With upcoming missions like JWST and Roman, as well as ground-based facilities like the ELT, observing time is valuable and the strategy of direct imaging needs to be re-defined to pre-select targets. Looking further ahead, perfecting these strategies will be necessary as we look toward HabEx and LUVOIR to pinpoint the location of terrestrial planets amenable to direct imaging.
I present the ongoing work towards creating a tool to use this information to select candidates for direct imaging with upcoming and future instruments. Ultimately this will lead us to a catalogue of benchmark objects that can be used to test models of planet formation and evolution.
High-resolution Automated Crater Detection of Small Lunar Craters on LRO-NAC Images
Authors: Fairweather John , Lagain Anthony , Servis Kosta , Benedix Gretchen , Bland Phil
Published: July 2021

Introduction: The Moon’s bombarded surface acts as a 4 Ga cratering record due to the lack of any significant crustal renewal or erosional processes. This extensive record is analysed by studying the spatial densities of craters on the Moon’s surface across different geological landscapes. These differences in relative cratering densities are quantified and linked to radiometrically dated samples collected during the Apollo and Luna missions. Through all this, one can derive a model age of a cratered surface [1]. This technique is referred to as crater counting. Over the years, this technique has grown to be utilised in dating the surfaces of rocky bodies throughout the solar system [1]. The accuracy of this technique still lies in the ability to detect and measure impact craters. The availability of the Lunar Reconnaissance Orbiter (LRO) Narrow-Angle Camera (NAC) images, with a 0.5-2m/px resolution [2], allows us to see craters at the metre-scale. The leading lunar crater database, consisting of ~1.3 million manually counted craters, is complete down to 1km [3]. To utilise the high-resolution NAC imagery, we need to count ever-smaller craters. The number of smaller craters scale as a power law, meaning there are tens of millions of craters 80%) (Tab. 1). True crater diameters across both terrains were mostly overestimated by the CDA (Tab. 1) but are still within the error margins (±20%) of human manual detections [8].  18 ‘fresh craters’ (craters with clear and easily identifiable rims), with D≥25m, were chosen across both images (Tab. 1*). The CDA has excellent TP detection rates (100%) and diameter estimations (~±10%) for the fresh craters (Tab. 1*).Prospects of the Lunar CDA: With further analysis and evaluation of the lunar CDA across broader lunar terrains, we want to create an accurate small crater lunar dataset. This dataset will fill the gap for craters