bluuebunny/crossref_metadata_2025 huggingface dataset:
Google Dataset Search and DOI for data in the ESA Space Science Archives
Authors: Masson Arnaud , De Marchi Guido , Merin Bruno , Henar Maria , Wenzel David
Published: October 2020

The ESAC Science Data Centre (ESDC) is in the process of registering Digital Object Identifiers (DOIs) for datasets or group of datasets accessible across the ESA Space Science Archives managed by ESDC. These DOIs are persistent URL that point to DOI landing pages setup and managed by ESDC, actually located at https://www.cosmos.esa.int/web/esdc/doiIn the heliophysics domain, the first step has been to register DOIs related to the datasets measured by experiments onboard ESA heliophysics spacecraft. Around 60 experiments are flying or have been flown so far onboard ESA heliophysics missions. At the moment, 47 DOI have been registered with CrossRef pointing to DOI landing pages for each experiment onboard SOHO, Proba-2, Cluster, Double Star, Ulysses and ISS-Solaces and are publicly accessible at https://www.cosmos.esa.int/web/esdc/doi/heliophysics. Discussions are on-going with editors of major journal to promote and acknowledge the use of data from any of these experiments by citing these DOIs. Eventually, this would improve the traceability of the usage of datasets from these experiments.Additionally, a JavaScript Object Notation (JSON) script has been added to these DOI landing pages to make them discoverable through Google Dataset Search (GDS). GDS is a new search engine that helps users to find datasets online. Twenty five millions datasets were already indexed and searchable when this service was launched in early 2020, after a beta version released in late 2018. Thanks to a close interaction with the PI teams, DOIs for ESA heliophysics experiments are now easily discoverable through GDS and not only by looking for a particular experiment name. The use of structured metadata, based on schema.org, has enabled the search through physical processes investigated by these experiments, the type of experiments, the time coverage, the PI names or their affiliation… Various examples will be provided while the next steps of development will be outlined.
How waves and turbulence maintain the super-rotation of Venus' atmosphere – results from Akatsuki
Authors: Horinouchi Takeshi , Hayashi Yoshi-Yuki , Watanabe Shigeto , Yamada Manabu , Yamazaki Atsushi , Kouyama Toru , Taguchi Makoto , Fukuhara Tetsuya , Takagi Masahiro , Ogohara Kazunori , Murakami Shin-ya , Peralta Javier , Limaye Sanjay S. , Imamura Takeshi , Nakamura Masato , Sato Takao M. , Satoh Takehiko
Published: October 2020

How the super-rotation of the Venusian atmosphere is maintained is an outstanding question of the Venus science and geophysical fluid dynamics. We tackled it by using data from Akatsuki. Prior to that, we revisited the meridional circulation by using past observational data: downward solar flux from entry probe and satellite-based radiation observation. With a very simple assumption, we obtained a meridional circulation consistent with the earlier studies based on radiative transfer computation. The result allowed us to order-estimate the eddy angular-momentum forcing needed to maintain the present super-rotation. We derived the eddy forcing by using cloud-tracking winds and thermal infrared data from Akatsuki. In particular, we focused on the pivotal question on the maintenance of the presentation, which is how the angular momentum (per unit mass) is supplied at its peak around the equatorial cloud top to compensate the deceleration by the meridional circulation. It was revealed that the thermal tides provide it, acting to accelerate the super-rotation, through both the horizontal and the vertical angular-momentum transport. Other waves and large-scale horizontal turbulence are found to counteract it to a weaker degree, in contrast to the earlier expectation from the classical Gierasch-Rossow-Williams mechanism. This study provided a number of by-products, such as the detection of turbulent motion and spectra of wind disturbances. This study was published recently as Horinouchi et al. 2020, Science, 368 (6489), 405-409 and its online supplementary material.
Martian visible and ultraviolet dayglow: altitude, latitudinal and seasonal variations observed with NOMAD/TGO
Authors: Gérard Jean-Claude , Aoki Shohei , Gkouvelis Leonardos , Willame Yannick , Depiesse Cédric , Thomas Ian R. , Risctic Bojan , Vandaele Ann Carine , Daerden Frank , Hubert Benoît , Mason Jon , Patel Manish , López-Moreno Jose , López-Valverde Miguel , Belluci Giancarlo
Published: October 2020

The OI 557.7 nm green line has been measured in the Martian dayglow for the first time with the UVIS visible-ultraviolet spectrograph on board ESA’s Trace Gas Orbiter (Gérard et al., 2020). The first observations started in April 2019 in a special mode where the spacecraft is tilted to observe the limb with the UVIS nadir channel (Vandaele et al., 2015, Patel et al., 2017). The instrument detected the presence of bright green dayglow emission on every of those observations. The main peak altitude is located near 80 km, and its intensity varies as a result of the changing distance from sun, the local time and latitude of the observations. A second, less pronounced, emission peak is observed near 110 km. Photochemical model simulations (Gkouvelis et al., 2018) used the MCD density distribution (Forget et al., 1999) have been made to understand the sources of this airglow emission. It is able to reproduce the altitude and the brightness of the airglow layer. It indicates that the green line dayglow on Mars is essentially produced by photodissociation of CO2 molecules by solar far ultraviolet radiation (Fox & Dalgarno, 1979). A fraction of the oxygen atoms is formed in the 1S metastable state that produces the green emission.In this presentation, we describe additional dayside observations obtained since December 2019. For this purpose, the spacecraft has been used in a special mode where it is re-oriented so that the UVIS channel observed the sunlit limb (Lopez-Valverde et al., 2018). We analyse the observed limb profile variations and the changing altitude of the peak emission resulting from the variations of the pressure levels in the mesosphere (Gkouvelis et al., 2020). The measured intensities are compared with model calculations of the O(1S) density in the conditions of the observations. The ratio of ultraviolet spectral features relative to the oxygen emission also observed with UVIS will also be analysed. REFERENCESForget, F. et al., J. Geophys. Res. 104(E10), 24155-24175 (1999).Fox, J.L. & Dalgarno, J. Geophys. Res. 84(A12), 7315-7333 (1979).Gérard, J.C. et al., Nature Astronomy, 1-4 (2020), https://doi.org/10.1038/s41550-020-1123-2Gkouvelis, L. et al., J. Geophys.Res., 123(12), 3119-3132. (2018).Gkouvelis, L. et al.,  Icarus, 341, 113666 (2020).López-Valverde M. et al.,  Space Science Reviews, 214(1), 29 (2018).Patel, M. R. et al.,  Applied optics, 56(10), 2771-2782 (2017).Vandaele, A. C. et al.,  Optics Express, 23(23), 30028-30042 (2015).
The SPECULOOS Project: New targets to hunt planets of Ultra-cool dwarfs.
Authors: Sebastian Daniel , Gillon Michael , Ducrot Elsa , Pozuelos Francisco J. , Garcia Lionel J. ,   SPECULOOS science team
Published: October 2020

One of the most promising roads for detailed analysis of temperate Earth-sized exoplanets is their detection in transit of small stars. If close enough, upcoming giant telescopes like ELT or JWST will make possible their thorough atmospheric characterisation. In this context, the TRAPPIST-1 planets form an unique benchmark system that has gathered broad interest in and out of the scientific community.The SPECULOOS survey is a transit-search survey, targeting a volume-limited (40 pc) sample of ultracool dwarf stars (spectral type M7 and later). The survey is powered by a global network of dedicated robotic 1 m telescopes, and its strategy leverages on the synergy with TESS for its brighter and earlier targets. Given its detection potential, once completed, it will not only provide targets for atmospheric characterisation, but will also deliver robust constraints on the structure of planetary systems of ultracool dwarf stars. In this talk, I will detail the SPECULOOS target selection process, including new ultracool dwarf candidates, and introduce to its observing strategy. 
ASMODEUS Meteor Simulation Tool
Authors: Baláž Martin , Tóth Juraj , Vereš Peter , Jedicke Robert
Published: October 2020

We describe a universal meteor simulation tool set named ASMODEUS and present several of its possible use cases. The toolset consists of a Monte-Carlo simulator of meteoroids entering the Earth’s atmosphere, functions for transformation to observer-centred coordinate frames representing virtual views of the sky, application of observational bias effects and a number of statistical tools for analyses of produced data sets and comparison to real-world data. The simulation has already been used in several areas of research, most notably estimates of meteoroid flux and de-biasing of real-world meteor observations and in investigation of how varying the initial properties of meteoroids affects the resulting meteors. It lends itself to many more possible applications, such as assessment of selection bias in ground-based observing systems, investigation of models of meteor flight and ablation, and evaluation of mass and population indices of meteor showers.
Compositional analysis of rocky material in Saturn’s C and D Rings as seen by CDA during Cassini’s Grand Finale Orbits
Authors: Linti Simon , Hillier Jon , Postberg Frank
Published: October 2020

The gap between Saturn and its innermost D ring is populated with dust particles which primarily originate from the main rings. These particles were sampled by Cassini’s Cosmic Dust Analyzer (CDA) during the final mission phase, providing individual high-speed time-of-flight mass spectra. Compositionally, two main groups were observed, water ice and silicate particles. The relative frequencies of these spectral types vary with distance to Saturn’s ring plane (Hsu et al. 2018).In this study we present an approach to infer the composition of the silicate particles, which make up nearly 30% of the evaluated spectra, with the aim of deriving the elemental composition of minerals stemming from Saturn’s C and D rings. Owing to CDA’s relatively low mass resolution, spectral peaks from important mineral-forming ions such as Mg+, Al+ and Si+ are often unresolvable individually, forming a single broad peak. To remove this effect, we apply manual deconvolution, enabling the interferences to be disentangled and allowing the relative abundances of the different constituents to be measured. After combining the results of the deconvolution with experimentally-determined relative sensitivity factors (RSFs), converting ion abundances to elemental abundances (Fiege et al. 2014), we are able to infer elemental ratios within the particles and thus quantitatively measure their compositions. The grain detection locations allow C or D ring sources to be discriminated between, and this work represents the first in situ analysis of the rocky fraction in Saturn’s main rings, which until now was only accessible via remote sensing.  Fiege, K., Trieloff, M., Hillier, J. K., Guglielmino, M., Postberg, F., Srama, R., Kempf, S., Blum, J.: Calibration of relative sensitivity factors for impact ionization detectors with high-velocity silicate microparticles, Icarus 241, 2014. Hsu, H.-W., Schmidt, J., Kempf, S., Postberg, F., Moragas-Klostermeyer, G., Seiß, M., Hoffmann, H., Burton, M., Ye, S.-Y., Kurth, W. S., Horányi, M., Khawaja, N., Spahn, F., Schirdewahn, D., O’Donoghue, J., Moore, L., Cuzzi, J., Jones, G. H., Srama, R.: In situ collection of dust grains falling from Saturn’s rings into its atmosphere, Science 362, 2018. 
On the detection of a high-altitude peak of atmospheric ozone by the NOMAD/UVIS onboard the ExoMars TGO
Authors: Khayat Alain , Smith Michael , Wolff Michael , Daerden Frank , Patel Manish , Piccialli Arianna , Vandaele Anne C. , Thomas Ian , Mason Jon , Willame Yannick , Bellucci Giancarlo , Depiesse Cedric , Lopez-Moreno Jose Juan
Published: October 2020

The Nadir and Occultation for MArs Discovery (NOMAD) is a spectrometer suite onboard the ExoMars Trace Gas Orbiter (TGO), providing observations in the nadir, limb, and solar occultation modes since April 2018. UVIS, a single spectrometer unit within NOMAD spans the ultraviolet-visible range between 200 nm and 650 nm. It obtained ~ 4000 vertically resolved (< 1 km) solar occultation observations of the martian atmosphere for over a full Mars year (MY, 687 days) starting at MY 34 during late northern summer at Ls = 163°. Ozone (O3), a principal component of the martian atmosphere, is highly responsive to the incoming UV flux, and is a sensitive tracer of the odd hydrogen chemistry. Transmittance spectra returned by UVIS sampled the O3 Hartley band around 250 nm and provided unique insights into understanding the vertical, latitudinal and temporal behavior of O3. UVIS detected a high-altitude peak of O3 between 40 and 60 km that is mostly persistent between Ls = 340° and ~ 200° at polar latitudes, and is found to be highly dependent on latitude and season. We will present high-resolution results tracking the vertical, latitudinal, diurnal and seasonal evolution of the secondary peak of ozone for a full Mars year. In comparison, we will also provide O3 simulations from the GEM-Mars General Circulation Model (GCM) with the purpose of shedding light into understanding the photochemical processes that lead to the presence and disappearance of the high-altitude peak of atmospheric ozone. 
Morphological study of landforms in the Northern Polar Region of Mars
Authors: Sánchez-Bayton Marina , Treguier Erwan , Herraiz Miguel , Martin Patrick , Kereszturi Akos , Sánchez-Cano Beatriz
Published: October 2020

AbstractThis work focuses on the study of the characteristics and possible origin of distinct positive topographic landforms located in Scandia Cavi and Olympia Undae [1]. These are two regions close to the northern polar cap of Mars and which are of special interest because of the potential joint presence of volcanism, glacial processes and gypsum deposits which could be related to the past presence of liquid water there. Such processes can cast light on the geological evolution of the area.We use images from Mars Express and Mars Reconnaissance Orbiter, as well as MOLA topographic profiles from Mars Global Surveyor to investigate 201 small and medium-size landforms in these two regions. These landforms have a priori similar characteristics, such as similar sizes and forms, but their origin might not be the same. A detailed analysis of images and morphometric parameters has allowed their classification into 6 groups, which are the so-called cratered cones, impact craters, ambiguous craters, simple and peaked domes, and irregular structures.Different possible origins for these landforms are discussed such as impact, aeolian, glacial and volcanic processes. The possible implications for relationships between an available volcanic heat source nearby water ice and gypsum deposits make the area particularly interesting toward further constraining the region’s geology. References[1] Sánchez-Bayton et al., Morphological analyses of small and medium size landforms in Scandia Cavi and Olympia Undae, North Polar Region of Mars, under review at Journal of Geophysical Research: Planets 
Possible case of exoplanetary rings around HIP 41378 f
Authors: Akinsanmi Babatunde , Santos Nuno , Faria Joao , Oshagh Mahmoud , Barros Susana , Santerne Alexandre , Charnoz Sebastien
Published: October 2020

Planetary rings are exciting features yet to be detected around exoplanets despite their prevalence around the giant planets and other rocky bodies of the solar system. A number of studies have proposed methods to identify and characterise the signatures of rings mostly from transit light curves. Probing for the presence of rings in transit light curves is very useful as the rings can cause a number of effects both on the light curve shape and the inferred parameters of the planet.The presence of rings around a transiting planet can cause it to appear larger and lead to an underestimation of its density if the mass is known. Therefore, a class of planets with extremely low densities, called Super puffs, can be planets with yet undetected rings. A Bayesian framework is employed here to show that the anomalously low density (~0.09 g/cm3) of the transiting long-period planet HIP 41378f might be due to the presence of opaque circum-planetary rings. Analysing the light curve data from the K2 mission, we construct physically motivated model priors and found that the statistical evidence for the ringed planet scenario is  comparable to that of the planet-only scenario. The ringed planet solution suggests a larger planetary density of ~1.23 g/cm3 similar to Uranus. The associated ring extends from 1.05 to 2.59 times the planetary radius and is inclined away from the sky-plane by ~25 degrees. However, the computed ring material density is lower than is expected for a planet with an equilibrium temperature of 294K so future high-precision transit observations of HIP 41378f would be necessary to confirm/dismiss the presence of planetary rings.
Near-Simultaneous Optical + NIR Photometry of Interstellar Comet 2I/Borisov
Authors: Schwamb Megan , Bannister Michele , Marsset Michael , Fraser Wesley , Pike Rosemary , Snodgrass Colin , Kavelaars JohnJ , Benecchi Susan , Lehner Matthew , Peixinho Nuno , Fitzimmons Alan
Published: October 2020

In August 2019, 2I/Borisov, the second interstellar object and first visibly active interstellar comet, was discovered on a trajectory nearly perpendicular to the ecliptic. Observations of planet forming disks and debris disks serve as probes of the ensemble properties of extrasolar planetesimals, but the passage of an active interstellar comet through our Solar System provides a rare opportunity to individually study these small bodies up close in the same ways in which we investigate objects originating from our own Outer Solar System. Ground-based observations of short period comet 67P/Churyumov–Gerasimenko revealed a coma dust composition indistinguishable from what was measured on its nucleus by the orbiting Rosetta spacecraft. Therefore when 2/I Borisov had a dust dominated tail, we attempted to study its composition with near-simultaneous griJ photometry with the Gemini North Telescope. We obtained two epochs of GMOS-N and NIRI observations in November 2019, separated by two weeks. We will report on the inferred optical-near-IR colors of 2I/I Borisov’s dust coma/tail and nucleus. We will compare our measurements to other observations of 2I/Borisov and place the interstellar comet in context with the Col-OSSOS (Colours of the Outer Solar System Survey) sample of small KBOs and interstellar object ʻOumuamua observed in grJ with Gemini North, using the same setup.
Effects of phosphorus on Martian magmas: an experimental study
Authors: Payre Valerie , Dasgupta Rajdeep
Published: October 2020

Introduction: Experimental studies showed that elevated phosphorus concentrations (> 1 wt. %) in terrestrial basaltic magmas have significant effects on the crystallization sequence, the composition and physical properties of melts [1-2]. [1] demonstrated that the polyvalent nature of P5+ favors the polymerization of silica tetrahedra, promoting the silica liquidus boundary in favor of that of pyroxene and the pyroxene liquidus boundary in favor of that of olivine. The enhancement of polymerized minerals can have significant implications regarding the petrogenesis of igneous rocks and mineralogy of the crust. Mars’ primitive mantle contains >10 times more phosphorus than Earth’s [3], which could result in considerable differences in magma compositions and crustal mineralogy between Earth and Mars.Preliminary thermodynamical partial melting models based on a martian mantle composition using pMELTS software showed that phosphorus likely have implications in terms of magma compositions [4]. This study aims to explore with piston-cylinder experiments the effects of phosphorus on martian melt compositions and residual mineral assemblages when considering partial melting of a primitive mantle composition [6].Methods: A set of nominally anhydrous partial melting experiments has been run on a primitive mantle composition [5] with two P2O5 contents (0 wt.% and 0.5 wt.%). We followed the exact same procedure as [6], which considered partial melting experiments in the same laboratory of a primitive mantle composition [5] with P2O5=0.2 wt.%, the actual mantle content. We will compare our results with those from [6].Using oxides and carbonates, all reagents were fired to avoid any water contaminations, and mixed together using an agate motar for 2 hours. The mixture was then loaded in a graphite inner capsule, which was placed into a platinum outer capsule. Before welding shut the platinum capsule, the loaded capsule was dried at 300°C during 24 hours to minimize water contamination. The welded shut capsule was then emplaced into a crushable MgO internal spacers, cylindrical graphite furnaces, BaCO3 pressure sleeve, and the whole assembly was wrapped within a Pb-foil. A half-inch piston cylinder apparatus at Rice University has been used at a pressure of 2GPa and temperatures between 1210 and 1450°C during 24-72 hours. Texture and composition have been analyzed using an electron probe microanalyzer at Rice university, and quantitative elemental maps have been acquired using Wavelength Dispersive Spectrometers (WDS). Phase proportions have been calculated by mass balance calculations.Equilibrium: Equilibrium conditions are likely met according to the defined delimitations between grain boundaries, exchange coefficients between Fe and Mg KD mostly varying from 0.30 to 0.40 (accepted value 0.35 [7]), the high quality of mass balance calculations (sum of squared residuals
Hiding resonant planets behind a big friend
Authors: Rodet Laetitia , Lai Dong
Published: October 2020

The characterization of the interplay between the inner and outer parts of planetary systems has long been impractical due to the separated detection ranges of the corresponding observation techniques. However, this gap is closing thanks to the technical improvements of the instruments and the longer observational baselines, and statistical insights are already within reach on the impact of cold Jupiters on super Earths. In this talk, I would like to present a theoretical study on the influence of an external giant planet misaligned with inner resonant planets, within the circular restricted problem. The behavior of the system depends on the relative strength between the coupling of the planets and the perturbations from the outer body. We demonstrated that mean-motion resonance strengthens the inner coupling and is very resilient to the perturbation, surviving periodic relative inclination increases of tens of degrees between the inner planets. This study has applications for the indirect detection of exoplanets, as well as the understanding of their formation and evolution, in particular the role of mean-motion resonance and relative inclinations.
VISIR Characterization of the Nucleus, Morphology, Activity, Spin-Pole Orientation & Rotation of Interstellar Comet 2I/Borisov by Earth- and Space-based Facilities
Authors: Bolin Bryce , Lisse Carey , Kasliwal Mansi , Quimby Robert , Bodewits Dennis , Morbidelli Alessandro , Helou George
Published: October 2020

VISIR Characterization of the Nucleus, Morphology, Activity, Spin-Pole Orientation & Rotation of Interstellar Comet 2I/Borisov by Earth- and Space-based Facilities
Bryce T. Bolin (1,2), Carey M. Lisse (3), Mansi M. Kasliwal (1), Robert Quimby (4,5), Dennis Bodewits (6), Alessandro Morbidelli (7), George Helou (2)
(1) Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA (bbolin@caltech.edu)
(2) IPAC, Mail Code 100-22, Caltech, 1200 E. California Blvd., Pasadena, CA 91125, USA
(3) Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
(4) Department of Astronomy, San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA
(5) Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
(6) Physics Department, Leach Science Center, Auburn University, Auburn, AL 36832, USA
(7) Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Boulevard de l’Observatoire, CS 34229, F-06304 Nice cedex 4, France
We present visible and near-infrared photometric and spectroscopic observations of interstellar object 2I/Borisov taken from 2019 September 10 to 2020 January 27 using ground-based facilities FROM the ZTF, the Keck Telescope, the GROWTH network, the APO ARC 3.5m, & the NASA/IRTF 3.0m combined high-resolution observations from HST. The photometry, taken in filters spanning the visible and NIR range shows 2I having a reddish object becoming neutral in the NIR. The lightcurve from recent and pre-discovery data reveals a brightness trend suggesting the recent onset of significant H2O sublimation with the comet being active with super volatiles such as CO at heliocentric distances >6 au consistent with its extended morphology (Fig. 1., left panel). Using the advanced capability to significantly reduce the scattered light from the coma enabled by high-resolution NIR images from Keck adaptive optics taken on 2019 October 04, we estimate a diameter of 2I's nucleus of
The InSight Mars lander’s meteor search
Authors: Lemmon Mark , Daubar Ingrid , Banks Maria , Vaubaillon Jeremie , Sansom Ellie , Maki Justin
Published: October 2020

The InSight lander (Banerdt et al. 2020) on Mars is equipped with two cameras capable of sky imaging both of which have been used opportunistically to search for meteors. The rate of occurrence of Martian meteors has not been directly measured and initial reports of an imaged meteor by Selsis et al. 2005 were likely incorrect (Domokos et al. 2007). The meteor search is part of the investigation into the flux of impactors at Mars (Daubar et al. 2018).The InSight cameras have been described by Maki et al. (2018). The Instrument Deployment Camera (IDC) can be aimed by a robotic arm and has a 45-degree square field of view (FOV). However, this camera was typically unavailable, and has only been used twice. The Instrument Context Camera (ICC) has a 120-degree fisheye FOV. It is aimed downward, but sees a broad section of the southern sky to around 20-degrees elevation angle.IDC images are shown in Fig. 1. They were aimed to the southwest at an elevation of about 35 degrees, and on sols 126 and 176 (5 April and 27 May 2019), four 5-minute exposures were acquired. Stars are visible in the images, and will be used to determine the sensitivity. Many cosmic rays were seen (e.g., Fig. 2)—long ones can be mistaken for meteors, but they have a distinctive morphology with a narrow end and a diffuse end due to the charge diffusion process after the charged particles pass through the detector (Fisher-Levine and Nomerotski, 2015). Despite the Sun being 60 degrees down, diffuse sky brightness was visible (Banfield et al. 2020). No meteors were detected.ICC images are shown in Fig. 3—about 75% of the images do not include sky. On 25 sols from 254 to 432 (15 August 2019 to 6 February 2020), the ICC acquired four, 5-minute exposures. No meteors were seen.We will present an analysis of the results and their implication for the meteor rate at Mars. While no meteors were seen, the upper limit is likely to be constraining. Total exposure time is 540 minutes, using cameras more sensitive than the limiting exposures of Domokos et al. (2007) and with wider FOVs. However, the complex geometry and the time variable atmospheric dust extinction will be considered.References. Banerdt et al. 2020. Nature Geoscience, 13, 183-189. Banfield et al. 2020. Nature Geoscience, 13, 190-198. Daubar et al. 2018. Space Science Rev. 214, 132. Domokos et al. 2007. Icarus 191, 141-150. Fisher-Levine and Nomerotski 2015. BNL-108381-2015-JA. Maki et al. 2018. Space Sci. Rev. 214, 105. Selsis et al. 2005. Nature 435, 581.
Seeing Effects on Ground-Based Images of Mercury's Sodium Exosphere
Authors: Killen Rosemary
Published: October 2020

ReferencesLeblanc, F. et al., 2009. Short-term variations of Mercury's Na exosphere observed with very high spectral resolution. Geophys. Res. Lett. 36, 7.Mangano, V. et al., 2015. THEMIS Na exosphere observations of Mercury and their correlation with in-situ magnetic field measurements by MESSENGER, Planet. Space Sci. 115, 102-109.Potter, A. E., R. M. Killen and M. Sarantos. 2006. Spatial distribution of sodium on Mercury. Icarus 181, 1 -12.Potter, A. E., R. M. Killen and T. H. Morgan, 1999. Rapid changes in the sodium exosphere of Mercury. Planet. Space Sci. 47, 1441-1448.Potter, A. E. and T. H. Morgan, 1985. Discovery of sodium in the atmosphere of Mercury. Geophys. Res. Lett. 22, 3289-3292.Sprague, A. L. et al., 1998. Mercury sodium atmosphere enhancements, Radar bright spots, and visible surface features. Icarus 136, 60-68.   
Tridymite in Gale crater, Mars: Witness of explosive volcanism in Early Mars?
Authors: Payre Valerie , Siebach Kirsten L. , Thorpe Michael T. , Antoshechkina Paula , Rampe Elizabeth B.
Published: October 2020

Introduction: Tridymite, cristobalite, and quartz are silica polymorphs, i.e., they share the same chemical formula SiO2 but their crystalline structures differ [1]. On Earth, tridymite is stable as a high-temperature hexagonal phase (870
Stopping Super-Earths from growing into Jupiters
Authors: Ali-Dib Mohamad , Cumming Andrew , Lin Doug
Published: October 2020

Super-Earths are by far the most dominant type of exoplanet, yet their formation isstill not well understood. In particular, planet formation models predict that manyof them should have accreted enough gas to become gas giants. Here we examine therole of the protoplanetary disk in the cooling and contraction of the protoplanetaryenvelope. In particular, we investigate the effects of 1) the thermal state of the disk asset by the relative size of heating by accretion or irradiation, and whether its energy istransported by radiation or convection, and 2) advection of entropy into the outer envelope by disk flows that penetrate the Hill sphere, as found in 3D global simulations.We find that, at 0.1 AU, the envelope quickly becomes fully radiative, nearly isothermal, and thus cannot cool down, stalling gas accretion. Thiseffect is significantly more pronounced in convective disks, leading to envelope mass or-ders of magnitude lower. Entropy advection at 0.1 AU in either radiative or convectivedisks could therefore explain why super-Earths failed to undergo runaway accretion.Ali-Dib, Cumming, & Lin (MNRAS 2020)
The lower dayside ionosphere of Mars in light of MEX MaRS radio science observations
Authors: Peter Kerstin , Pätzold Martin , Molina-Cuberos Gregorio , González-Galindo Francisco , Witasse Olivier , Tellmann Silvia , Häusler Bernd , Bird Michael
Published: October 2020

         Figure 1: MEX-MaRS X-band observations of the dayside ionosphere of Mars for (a) Day of Year (DoY) 343 (2005) and (b) DoY 215 (2014).  Combined X- and S-band (differential Doppler) observations for (c) DoY 011 (2014) and (d) DoY 006 (2006). The gray dashed line indicates the noise level, while the black dashed line marks the lowest valid altitude of the individual observation (details about the parameter derivation in [2]).The Mars Express Radio Science experiment (MaRS) on board the Mars Express spacecraft has observed the Mars atmosphere and ionosphere since 2004. More than 900 high-resolution MaRS height profiles of the ionospheric electron density from the topside down to the ionospheric base are available.The two dominant features of the undisturbed Martian dayside ionosphere are the main peak (M2), caused mainly by solar radiation in the Extreme Ultraviolet, and the secondary layer (M1), mostly formed by primary and secondary impact ionization of short solar X-rays < 10 nm [1]. The region below the M1 peak is highly variable and regularly contains merged excess electron density regions (Mm) in various shapes [2] (Figures 1).More than 15 years of MaRS radio science observations are used to study the behavior of the lowest region of the Martian dayside ionosphere. Categories for the identified Mm shapes are defined and statistics of the individual Mm shape occurrences are provided. The 1-D photochemical model IonA-2 (Ionization in Atmospheres 2 [2]) is applied to investigate which of the identified Mm shapes can be reproduced by solar radiation of the quiet Sun and under solar M- and X-flare conditions. References  [1] Fox J. L. et al. (1996), Adv. Space Res., 17, 11, 203-218.  [2] Peter K. (2018), PhD Dissertation, https://kups.ub.uni-koeln.de/8110/.
VIS-NIR and Raman analyses of acid altered volcanic rocks
Authors: De Angelis Simone , Ferrari Marco , De Sanctis Maria Cristina , Altieri Francesca , Ammannito Eleonora , Fonte Sergio , Formisano Michelangelo , Frigeri Alessandro , Giardino Marco
Published: October 2020

IntroductionAlteration of mafic and ultramafic rocks on Mars surface and shallow subsurface has been postulated to have occurred throughout its history by means of different mechanisms, among which acid groundwater circulation (mainly sulfuric) is one of the most important [1,2,3,4]. This hypothesis is based on the high Fe and S concentration observed at various landing sites and strengthened by remote-sensing infrared detection of Fe/Al-bearing sulfates such as alunite, jarosite and Fe3+SO4(OH) [4,5]. These sulfates typically form as alteration of K-rich volcanic rocks and Fe-sulfides in low-pH environments. Additionally the occurrence of perchlorates could be related to the action of other acids (perchloric) [6]. The investigation in laboratory of acidic alteration of volcanic rocks is thus an essential step in order to provide constraints in the interpretation of remote-sensing and in-situ data from Mars missions of the next future (Mars-2020, ExoMars-2022). Several works recently have explored the processes of acid alteration of minerals and rocks both in the field and in laboratory by using different spectroscopic and microscopy techniques [7,8].MethodsIn our work we studied by Visible-Near Infrared reflectance and Raman spectroscopy the acid alteration of two volcanic samples, a basalt from Aeolian Islands (FCD1) and a rhyodacite from Alps (RDO). These two samples have been chosen with the aim of investigating the action of acids on both a mafic and a felsic rock. Four acids have been used for the treatment of samples, namely hydrochloric (HCl 37 vol%), nitric (HNO3 65 vol%), sulfuric (H2SO4 96 vol%) and phosphoric (H3PO4 85 vol%), in order to contemplate a diversity of acid environments. Samples were acid-treated both in the form of fine powders (d
Uniform Retrieval Analysis of Brown Dwarfs
Authors: Saboi Kezman , Line Michael R. , Zalesky Joseph , Schneider Adam , Zhang Zhoujian , Liu Michael C. , Best William M. J. , Marley Mark S.
Published: October 2020

Spectra of brown dwarfs are key to exploring the chemistry and physics that take place in their atmospheres. Late T dwarf (850 - 500 K) spectra are particularly diagnostic due to their relatively cloud free atmospheres and deep molecular bands. With the use of powerful atmospheric retrieval tools, these properties permit proper allocation of constraints on the molecular/atomic abundances and temperature profiles. These constraints can be used to derive the elemental abundances (metallicity, C/O), chemical disequilibrium, and non-radiative-convective equilibrium temperature perturbations. Building upon previous analyses on T and Y dwarfs (Line et al. 2017; Zalesky et al. 2019), we present a uniform retrieval analysis of 52 T dwarfs via their low-resolution near-infrared spectra. This analysis more than doubles the sample of T dwarfs with retrieved properties. We present updates on current compositional trends and thermal profile constraints amongst the T dwarf population.
Giant planet formation models with a self-consistent treatment of heavy-element.
Authors: Valletta Claudio , Helled Ravit
Published: October 2020

We present a new numerical framework to model the formation and evolution of giant planets. The code is based on the further development of the stellar evolution toolkit Modules for Experiments in Stellar Astrophysics (MESA). The model includes the dissolution of the accreted planetesimals/pebbles in the planetary gaseous envelope, and the effect of envelope enrichment on the planetary growth and internal structure is computed self-consistently. We apply our simulations to Jupiter and investigate the impact of different heavy-element and gas accretion rates on its formation history. We show that the assumed runaway gas accretion rate significantly affect the planetary radius and luminosity.It is confirmed that heavy-element enrichment leads to shorter formation timescales due to more efficient gas accretion. We find that with heavy-element enrichment Jupiter's formation timescale is compatible with typical disks' lifetimes even when assuming a low heavy-element accretion rate (oligarchic regime). Finally, we provide an approximation for the heavy-element profile in the innermost part of the planet, providing a link between the internal structure and the planetary growth history.
Bennu and Ryugu: Dynamical modelling of ejected particles to the Earth
Authors: Kováčová Martina , Nagy Roman , Kornoš Leonard , Tóth Juraj
Published: October 2020

Apollo-type asteroids Bennu and Ryugu are currently targets of sample-return missions. The goal of OSIRIS-REx mission (NASA) is to explore asteroid Bennu and Ryugu is being probed by JAXA’s Hayabusa2 mission. Observations of Bennu in January 2019 revealed ejecting material in the close proximity of the asteroid. Here we peresent our results of studying orbital evolution of potential meteoroid streams along the orbits of Bennu and Ryugu by integrating over 5000 test particles each for 1000 yr. We searched for their approaches to the Earth and we were also interested in evolution of their Earth MOIDs in order to estimate possible activity of potential meteor showers. Our results indicate possible observability from the Earth approximately for next 400 - 500 yr in both cases. Theoretical radiants for both asteroids and their potential meteor showers were also calculated.
Observational evidence for heat transfer from Jupiter's polar auroral region to lower latitudes
Authors: O'Donoghue James , Moore Luke , Melin Henrik , Stallard Tom
Published: October 2020

Jupiter, Saturn and Uranus have non-auroral ionospheres that are measurably 100s of Kelvin hotter than models can explain by solar heating alone. This problem has existed for many decades and is generally termed in literature as the "energy crisis". One way to cause heating in the non-auroral ionosphere is to redistribute heat from the auroral ionosphere at the poles down to lower latitudes (the auroral region itself is heated thermally by collisions as a result of the auroral mechanism). Most models of global circulation suggest that heat within the polar/auroral is confined there by Coriolis forces, such that auroral energy cannot be communicated to lower latitudes, but until now there have been no high spatial resolution observations of temperature in the auroral region simultaneous with non-auroral regions to confirm it. Today we will present ground-based observations of Jupiter's ionospheric H3+ temperature at high spatial resolution (~1000km per pixel). H3+ is a major ion at Jupiter, considered in quasi-thermodynamic equilibrium with its surroundings, and therefore a good proxy for energy balance of the ionosphere. These observations, taken by the 10-meter Keck telescope on April 14, 2016 and Jan 25, 2017, strongly suggest heat from the auroral region is spreading to lower latitudes, such that the missing heat source causing the "energy crisis" may ultimately be auroral in nature.
Design of a MOOC and augmented reality applications about exoplanets
Authors: Peralta Raphael , Minier Vincent
Published: October 2020

The European Exoplanets-A project is aimed at providing a comprehensive view of the nature of exoplanet atmospheres, through an interdisciplinary approach, which includes the integration of state of the art models of the star-planet interaction, atmospheric chemistry and dynamics and planet formation.
 
The Exoplanets-A has a knowledge server: www.explore-exoplanets.eu. It provides scientific and educational resources through two main pages: a Science page and a Learning page.
The science page includes a knowledge base with a direct access to all the scientific products of the project (Archival data, methods and tools, databases and publications).
The Learning page was designed for the public with educational resources based on the science products: Data visualization (exoplanetary system, space instruments, set of data…), online courses (MOOC and SPOC) and serious games (applications in augmented reality).
 
During this talk, we would like to present the MOOC on exoplanets that we have developed as well as other outreach resources, such as an augmented reality (AR) application about exoplanets, JWST and the solar system.
The impact of exoplanets' measured parameters on the inferred internal structure.
Authors: Fernandez Otegi Jon , Dorn Caroline , Helled Ravit , Bouchy François , Haldemann Jonas , Alibert Yann
Published: October 2020

Exoplanet characterization is one of the main foci of current exoplanetary science. For super-Earths and sub-Neptunes, we mostly rely on mass and radius measurements, which allow to derive the body’s mean density and give a rough estimate of the planet’s bulk composition. However, the determination of planetary interiors is a very challenging task. In addition to the uncertainty in the observed fundamental parameters, theoretical models are limited due to the degeneracy in determining the planetary composition. We aim to study several aspects that affect internal characterization of super-Earths and sub-Neptunes: observational uncertainties, location on the M-R diagram, impact of additional constraints as bulk abundances or irradiation, and model assumptions.We use a full probabilistic Bayesian inference analysis that accounts for observational and model uncertainties. We employ a Nested Sampling scheme to efficiently produce the posterior probability distributions for all the planetary structural parameter of interest. We include a structural model based on self-consistent thermodynamics of core, mantle, high-pressure ice, liquid water, and H-He envelope.  Regarding the effect of mass and radius uncertainties on the determination of the internal structure, we find three different regimes: below the Earth-like composition line and above the pure-water composition line smaller observational uncertainties lead to better determination of the core and atmosphere mass respectively, and between them internal structure characterization only weakly depends on the observational uncertainties. We also find that using the stellar Fe/Si and Mg/Si abundances as a proxy for the bulk planetary abundances does not always provide additional constraints on the internal structure. Finally we show that small variations in the temperature or entropy profiles lead to radius variations that are comparable to the observational uncertainty. This suggests that uncertainties linked to model assumptions can eventually become more relevant to determine the internal structure than observational uncertainties.
New estimates of the mass and density of asteroid (16) Psyche
Authors: Siltala Lauri , Granvik Mikael
Published: October 2020

Asteroid mass determination is performed by analyzing an asteroid's gravitational interaction with another object, such as a spacecraft, Mars, a companion in the case of binary asteroids, or a separate asteroid during a close encounter. During asteroid-asteroid close encounters, perturbations caused by the masses of larger asteroids can be detected in the post-encounter orbits of the smaller test asteroid involved in such an encounter. This can be described as an inverse problem where the aim is to fit six orbital elements for each asteroid and mass(es) for the perturbing asteroid(s), for a total of 13 parameters at minimum unless more asteroid-asteroid encounters are modeled simultaneously.To solve this inverse problem, which is traditionally done with least-squares methods, we have implemented a Markov-chain Monte Carlo (MCMC) based solution and recently (Siltala & Granvik 2020) reported, among others, significantly lower than expected masses and densities for the asteroid (16) Psyche in particular. Psyche is an interesting, and topical, object as it is the target of NASA's eponymous Psyche mission and is commonly thought to be of metallic or stony-iron composition, which our previous density estimates disagreed with. In our previous work our two separate mass estimates for Psyche were based on modeling encounters with two separate test asteroids in both cases. Since then we have further refined our mass estimate for Psyche by simultaneously using eight separate test asteroids for this object, significantly increasing the amount of observational data included on the model which, in turn, will narrow down the uncertainties of our results at the cost of additional model complexity. Here we report and discuss our latest results for the mass of Psyche based on this case and compute corresponding densities based on existing literature values for the volume. We obtain a mass of (0.972 ± 0.148) * 10^-11 solar masses for Psyche corresponding to a bulk density of (3.37 ± 0.58) g/cm³ which is higher than our previous results while remaining consistent with them considering the uncertainties involved. It still remains lower than other previous literature values. We compare our results to these previous literature values and briefly discuss possible physical implications of these results.In addition, due to previous interest from the scientific community, we have also computed mass estimates for Ceres and Vesta, both of which already have very precisely known masses from the Dawn mission. As such, our results for these two asteroids are not of direct scientific interest but they serve as an useful benchmark to verify that our algorithm provides realistic results as we have 'ground truth' values to compare our results to. We find that for both cases, our results are in line with those of Dawn.
Ganymede-induced decametric emission: in-situ measurements by Juno.
Authors: Louis Corentin , Louarn Philippe , Kurth William , Allegrini Frederic , Szalay Jamey
Published: October 2020

At Jupiter, part of the auroral radio emissions are controlled by the Galilean moons Io, Europa and Ganymede. Until now, they have been remotely detected using ground-based radio-telescope or electric antenna aboard spacecraft. The polar trajectory of the Juno orbiter leads to cross the magnetic flux tube connected to these moons, or their tail, and gives a direct in-situ measurements of the characteristics of these decametric moon induced radio emissions (such as the electron population, size of the source, and beaming angle and growth rate of the emission). In this study, we focus on the crossing of the Ganymede flux tube. The study of Juno/JADE-E and Juno/Waves data leads to an estimated source size of a few 100s km, an electron population of energy E= 8±2 keV and an emission beaming angle of θ= 80±2° from the magnetic field lines. Finally, this crossing of a decametric radio emission induced by a moon brings us new constrains on the Cyclotron Maser Instability process