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1. The Biological Role of Platelet Derivatives in Regenerative Aesthetics

Author: Lorena Cristina Santos, Giselle Lobo Lana, Gabriel Silva Santos, Silvia Beatriz Coutinho Visoni, Rayssa Junqueira Brigagão, Napoliane Santos, Rafaela Sobreiro, Andreza da Cruz Silva Reis, Bruno Lima Rodrigues, Sabrina Ferrari, Claudia Herrera Tambeli, and José Fábio Lana
Subjects: platelet-rich plasma, platelet-rich fibrin, growth factors, tissue regeneration, aesthetic medicine, Biology (General), QH301-705.5, Chemistry, QD1-999
Abstract: Bioproducts derived from platelets have been extensively used across various medical fields, with a recent notable surge in their application in dermatology and aesthetic procedures. These products, such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), play crucial roles in inducing blood vessel proliferation through growth factors derived from peripheral blood. PRP and PRF, in particular, facilitate fibrin polymerization, creating a robust structure that serves as a reservoir for numerous growth factors. These factors contribute to tissue regeneration by promoting cell proliferation, differentiation, and migration and collagen/elastin production. Aesthetic medicine harnesses these effects for diverse purposes, including hair restoration, scar treatment, striae management, and wound healing. Furthermore, these biological products can act as adjuvants with other treatment modalities, such as laser therapy, radiofrequency, and microneedling. This review synthesizes the existing evidence, offering insights into the applications and benefits of biological products in aesthetic medicine.
Published: 2024
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2. Laboratory Emissivity Spectra of Sulphide-Bearing Samples, New Constraints for the Surface of Mercury: Oldhamite in Mafic Aggregates

Author: Cristian Carli, Sabrina Ferrari, Alessandro Maturilli, Giovanna Serventi, Maria Sgavetti, Arianna Secchiari, Alessandra Montanini, and Jörn Helbert
Subjects: planetary, silicate, sulphide, emissivity, temperature, Mercury, Mineralogy, QE351-399.2
Abstract: Exploration of Mercury will continue in the near future with ESA/JAXA’s BepiColombo mission, which will increase the number and the type of datasets, and it will take advantage of the results from NASA’s MESSENGER (MErcury Surface, Space ENviroment, GEochemistry and Ranging) mission. One of the main discoveries from MESSENGER was the finding of a relatively high abundance of volatiles, and in particular of sulphur, on the surface. This discovery correlates well with the morphological evidence of pyroclastic activity and with features attributable to degassing processes like the hollows. BepiColombo will return compositional results from different spectral ranges and instruments, and, in particular, among them the first results from the orbit of emissivity in the thermal infrared. Here, we investigate the results from the emissivity spectra of different samples between a binary mixture of a volcanic regolith-like for Mercury and oldhamite (CaS). The acquisitions are taken at different temperatures in order to highlight potential shifts due to both mineral variation and temperature dependence on these materials that potentially could be present in hollows. Different absorption features are present for the two endmembers, making it possible to distinguish the oldhamite with respect to the regolith bulk analogue. We show how, in the mixtures, the Christiansen feature is strongly driven by the oldhamite, whereas the Reststrahlen minima are mainly dominated by mafic composition. The spectral contrast is strongly reduced in the mixtures with respect to the endmembers. The variations of spectral features are strong enough to be measured via MERTIS, and the spectral variations are stronger in relation to the mineralogy with respect to temperature dependence.
Published: 2024
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3. Geologic Mapping and Age Determinations of Tsiolkovskiy Crater

Author: Gloria Tognon, Riccardo Pozzobon, Matteo Massironi, and Sabrina Ferrari
Subjects: geologic mapping, Tsiolkovskiy, moon, morphology, crater size-frequency distributions (CSFDs), stratigraphy, Science
Abstract: Tsiolkovskiy is a ~200 km diameter crater presenting one of the few mare deposits of the lunar far side. In this work, we perform a geological study of the crater by means of morpho-stratigraphic and color-based spectral mappings, and a detailed crater counting age determination. The work aims at characterizing the surface morphology and compositional variation observed from orbital data including the Lunar Reconnaissance Orbiter Wide Angle Camera and Clementine UVVIS Warped Color Ratio mosaics, and attempts a reconstruction of the evolutionary history of the Tsiolkovskiy crater through both relative and absolute model age determinations. The results show a clear correlation between the geologic and spectral units and an asymmetric distribution of these units reflecting the oblique impact origin of the crater. Crater counts performed using the spectral units identified on the smooth crater floor returned distinct age ranges, suggesting the occurrence of at least three different igneous events, generating units characterized by particular compositions and/or degree of maturity. This work demonstrates the scientific value of Tsiolkovskiy crater for a better understanding of the volcanic evolution of the Moon and, in particular, of its far side.
Published: 2021
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4. An Integrated Geologic Map of the Rembrandt Basin, on Mercury, as a Starting Point for Stratigraphic Analysis

Author: Andrea Semenzato, Matteo Massironi, Sabrina Ferrari, Valentina Galluzzi, David A. Rothery, David L. Pegg, Riccardo Pozzobon, and Simone Marchi
Subjects: geologic mapping, Mercury, stratigraphy, morphology, volcanism, impact basin, Science
Abstract: Planetary geologic maps are usually carried out following a morpho-stratigraphic approach where morphology is the dominant character guiding the remote sensing image interpretation. On the other hand, on Earth a more comprehensive stratigraphic approach is preferred, using lithology, overlapping relationship, genetic source, and ages as the main discriminants among the different geologic units. In this work we produced two different geologic maps of the Rembrandt basin of Mercury, following the morpho-stratigraphic methods and symbology adopted by many authors while mapping quadrangles on Mercury, and an integrated geo-stratigraphic approach, where geologic units were distinguished also on the basis of their false colors (derived by multispectral image data of the NASA MESSENGER mission), subsurface stratigraphic position (inferred by crater excavation) and model ages. We distinguished two different resurfacing events within the Rembrandt basin, after the impact event, and four other smooth plains units outside the basin itself. This provided the basis to estimate thicknesses, volumes, and ages of the smooth plains inside the basin. Results from thickness estimates obtained using different methodologies confirm the presence of two distinct volcanic events inside the Rembrandt basin, with a total thickness ranging between 1–1.5 km. Furthermore, model ages suggest that the volcanic infilling of the Rembrandt basin is among the ones that extended well into the mid-Calorian period, when Mercury’s effusive volcanism was previously thought to be largely over.
Published: 2020
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5. Mapping and Monitoring Urban Environment through Sentinel-1 SAR Data: A Case Study in the Veneto Region (Italy)

Author: Andrea Semenzato, Salvatore Eugenio Pappalardo, Daniele Codato, Umberto Trivelloni, Silvano De Zorzi, Sabrina Ferrari, Massimo De Marchi, and Matteo Massironi
Subjects: urban environment, urban planning, Sentinel, SAR, urban footprint, land cover, Geography (General), G1-922
Abstract: Focusing on a sustainable and strategic urban development, local governments and public administrations, such as the Veneto Region in Italy, are increasingly addressing their urban and territorial planning to meet national and European policies, along with the principles and goals of the 2030 Agenda for the Sustainable Development. In this regard, we aim at testing a methodology based on a semi-automatic approach able to extract the spatial extent of urban areas, referred to as “urban footprint”, from satellite data. In particular, we exploited Sentinel-1 radar imagery through multitemporal analysis of interferometric coherence as well as supervised and non-supervised classification algorithms. Lastly, we compared the results with the land cover map of the Veneto Region for accuracy assessments. Once properly processed and classified, the radar images resulted in high accuracy values, with an overall accuracy ranging between 85% and 90% and percentages of urban footprint differing by less than 1%–2% with respect to the values extracted from the reference land cover map. These results provide not only a reliable and useful support for strategic urban planning and monitoring, but also potentially identify a solid organizational dataflow process to prepare geographic indicators that will help answering the needs of the 2030 Agenda (in particular the goal 11 “Sustainable Cities and Communities”).
Published: 2020
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6. Leaving child and adolescent mental health services in the MILESTONE cohort: a longitudinal cohort study on young people's mental health indicators, care pathways, and outcomes in Europe

Author: Suzanne E Gerritsen, Larissa S van Bodegom, Mathilde M Overbeek, Athanasios Maras, Frank C Verhulst, Dieter Wolke, Dimitris Rizopoulos, Giovanni de Girolamo, Tomislav Franić, Jason Madan, Fiona McNicholas, Moli Paul, Diane Purper-Ouakil, Paramala J Santosh, Ulrike M E Schulze, Swaran P Singh, Cathy Street, Sabine Tremmery, Helena Tuomainen, Gwendolyn C Dieleman, Rebecca Appleton, Nikolina Davidović, Sabrina Ferrari, Federico Fiori, Charlotte Gatherer, Gaëlle Hendrickx, Ingrid Holme, Renaud Jardri, Alfred Kolozsvari, Kate Lievesley, Mathilde Mastroianni, Virginie Maurice, Giorgia Morini, Aesa Parenti, Frédérick Russet, Melanie Saam, Ilyas Sagar-Ouriaghli, Anne Sartor, Giulia Signorini, Jatinder Singh, Priya Tah, Amanda Tuffrey, Therese AMJ van Amelsvoort, Pamela Varvara, Stefano Vicari, Leanne Walker, Anna Wilson, Helena Jerkovic, Clinical Child and Family Studies, LEARN! - Child rearing, APH - Mental Health, Child and Adolescent Psychiatry / Psychology, and Epidemiology
Subjects: Adult, Male, Mental Health Services, Adolescent, Infant, Cohort Studies, Europe, Young Adult, Psychiatry and Mental health, Mental Health, SDG 3 - Good Health and Well-being, Critical Pathways, Humans, Female, Longitudinal Studies, Child, Europe-epidemiology, Biological Psychiatry
Abstract: Background: The configuration of having separate mental health services by age, namely child and adolescent mental health services (CAMHS) and adult mental health services (AMHS), might be a barrier to continuity of care that adversely affects young people's mental health. However, no studies have investigated whether discontinuity of care in the transition period affects mental health. We aimed to discern the type of care young people receive after reaching the upper age limit of their CAMHS and examine differences in outcomes at 24-month follow-up between young people receiving different types of care. Methods: To assess mental health in young people from 39 CAMHS in eight European countries (Belgium, Croatia, France, Germany, Italy, Ireland, the Netherlands, and the UK), we did a longitudinal cohort study. Eligible young people were CAMHS users up to 1 year younger than the upper age limit of their CAMHS or up to 3 months older, if they were still in CAMHS. Information on mental health service use, mental health problems (ie, using the Health of the Nation Outcome Scale for Children and Adolescents, Youth Self-Report and Adult Self-Report, DSM-5, and ICD-10), and sociodemographic characteristics were collected using self-reported, parent-reported, and clinician-reported interviews and questionnaires. Mixed models were applied to assess relationships between baseline characteristics, mental health service use, and outcomes. Findings: The MILESTONE cohort included 763 young people. The participants were 60·0% female (n=458) and 40·0% male (n=305), 90·3% White (n=578), and had a mean age of 17·5 years (range 15·2–19·6 years). Over the 24-month follow-up period, 48 young people (6·3%) actively withdrew from the study. For young people, the higher their scores on the Health of the Nation Outcome Scale for Children and Adolescents (p=0·0009) and Youth Self-Report and Adult Self-Report (p=0·046), and who had a clinical classification of severe mental illness (p=0·0033), had suicidal thoughts or behaviours or self-harm (p=0·034), used psychotropic medication (p=0·0014), and had a self-reported or parent-reported need for continued treatment (p
Published: 2022

7. Thermal expansion of oldhamite, CaS: Implication for the surface of Mercury

Author: Anna Barbaro, Federico Zorzi, Alessandra Lorenzetti, Sabrina Ferrari, Cristina Tubaro, and Fabrizio Nestola
Subjects: Space and Planetary Science, Mercury, surface, Mineralogy, Terrestrial planets, surface, Astronomy and Astrophysics, Mercury
Published: 2023

8. Compositional and subsurface analysis of an outcrop close to Olympia Planum on Mars

Author: Nicole Costa, Matteo Massironi, Luca Penasa, Jacopo Nava, Riccardo Pozzobon, and Sabrina Ferrari
Abstract: Introduction: In the Martian North Polar Cap, troughs are formed and enlarged by the erosive action of katabatic winds, blowing perpendicularly with respect to steep edges of the cap. Along these valleys deeper layering of the polar deposits are often exposed making it possible to study the stratigraphy of the upper part of the polar cap [1]. We focused our attention on a 140 km long and 500 m high scarp located in the North-Western edge, facing Olympia Planum, and where part of the North Polar Layered Deposits (NPLD) are exposed. NPLD deposits are finely layered and laterally continuous sequence of light and dark strata with sporadic unconformities in between, whose periodicity has been attributed to climatic and orbital variations [2]. In the polar cap, Tanaka et al. [3] has distinguished different polar units by means of surface image interpretation, hence our scarp exposes Planum Boreum 1 unit overlapped by Planum Boreum 3 unit, both composed of variable ice/dust content, but different thickness. Putzig et al. [4] identified instead seven units inside the polar cap on the basis of the pattern of radar reflections in the radargram-based stratigraphy thanks to the data provided by SHARAD. The stratigraphic sequence of our interest correlates with the upper part of the packet-inter-packet sequence of the unit G by Putzig et al. [4]. The aim of our work is to relate the composition and stratigraphy of the visible layered deposits with the subsurface radar reflectors, using the data acquired by the NASA Mars Reconnaissance Orbiter instruments. Data selection: We performed stratigraphic and geomorphologic interpretation on images of the Context Camera (CTX) and High Resolution Imaging Science Experiment (HiRISE); band ratios and spectral signatures on a hyperspectral cube of the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM); subsurface reconstructions on radar reflectors obtained by the Shallow Radar (SHARAD). The integration of the results obtained by such a multi-score data-set underlies the possibility to join the SHARAD stratigraphy with the stratigraphic record recognisable at the surface including its compositional variability (Fig.1). Fig.1 – Data-set: MOLA DEM (a), CTX image (b), CRISM cube (c), HiRISE images (d, e) and SHARAD radargram tracks (f, g, h, i). Black rectangle in the North Polar Cap region shows the study area. Spectral analysis: Spectra for five Regions of Interest (ROIs) of about 50 pixels were acquired and are shown in Fig.2a-b. Fig.2 – (a) Regions of Interest over CRISM image detail; (b) Plot of five ROI average spectra: each colour line represents a ROI spectrum (continuum is removed). The exposed stratigraphy is composed of different amount of dry ice, water ice and basaltic dust [3]. Spectra A and B are well distinguishable, whereas the signatures of C, D and E appear similar, indicating comparable compositions. Spectrum A exhibits well developed water-ice absorption bands (1.5 and 1.95 µm), less development of same peaks might imply an increase of dry ice content. The 1 µm peak (water ice) is well visible in both A and B spectra, but less evident in C, D and E. Multiple absorptions at 1.65 and 2.06 µm, associated to CO2, are well visible in C, D and E. Other absorption bands (at 0.50, 1.02 and 2.30 µm for example) can be related to femic and aqueous alteration minerals. Spectrum A is similar to the signature of pure water ice, with less altered minerals, while C, D and E appear to be characterized by dry ice and femic minerals. Spectrum B appear to be transitional between these two end-members. Spectral indexes: Spectral indexes were produced using CRISM Analysis Toolkit (CAT) [5]. Indexes allowed us to create false colour images to highlight the presence/absence of specific minerals. Example of these are shown in Fig. 3 (see FED for the index definition). Fig.3 – Two false colour images created with spectral indexes (a) BDI1000VIS_BD15002_BD1435 representing ice compositions and (b) OLINDEX3_LCPINEX2_RBR to highlight mineral composition. Mapping and correlation to radar reflectors: Geological units were identified on CRISM and CTX data on the basis of morphology, composition, albedo and their stratigraphic relationship. Fig.4 displays the mapped units. Fig.4 – Geological map and relative units. WI-units: water-ice-rich deposits (blue), WF-unit: water ice and femic minerals deposits (light blue); DF-units: dry ice and femic minerals deposits (green); DI-units: dry-ice-rich deposits (yellow); Aeolian deposits (red); Gravitational deposits (purple). Fig.5 shows the geological units correlated with radargrams features. Variations of dielectric constant among strata are due firstly to presence of water ice in the surficial layers and dry ice in deeper ones, secondly to different amount of dust in radar units. These affect the signal reflectance: stronger if it is from water-ice layers. Additionally, high content of dust significantly decrease the radar signal, so units appear darker [4] [6]. The lines in Fig.5 represent lower contact of the geological units. Fig.5 – Correlation between geological units and radar reflectors. The colours of units are the same of geological map (vertical axis in time). Section track is shown in Fig.1. Discussion and conclusions: We provide a detailed compositional and geometrical characterization (using CRISM, HiRISE, CTX) of outcropping layered deposits of the North Polar Cap, to evaluate the potential for performing sound stratigraphic correlations with the subsurface reflectors identified in SHARAD radargrams. At a scale of single layers, compositional variations of basaltic dust content in the stratigraphic sequence were identified. This variability is visible especially in dry-ice-rich layers. Basaltic dust showed aqueous alteration, especially in water-ice-rich strata. Acknowledgments: We acknowledge support from the EU’s H2020 research and innovation program under grant agreement N° 871149 (GMAP). References: [1] Masse, M. et al. (2012) Earth and Planetary Science Letters, 317, doi: 10.1016/j.epsl.2011.11.035; [2] Byrne, S. (2009) Annual Review of Earth and Planetary Science, 37, doi: 10.1146/annurev.earth.031208.100101; [3] Tanaka, K. et al. (2008) Icarus, 196(2), doi: 10.1016/j.icarus.2008.01.021; [4] Putzig, N. et al. (2009), Icarus, 204(2), doi: 10.1016/j.icarus.2009.07.034; [5] Viviano-Beck, C. et al (2014), Journal of Geophysical Research, 119(6), doi: 10.1002/2014JE004627; [6] Lauro, S. et al. (2012), Icarus, 219(1), doi: 10.1016/j.icarus.2012.03.011.
Published: 2022

9. Dating long thrust systems on Mercury: New clues on the thermal evolution of the planet

Author: Matteo Massironi, Lorenza Giacomini, Sabrina Ferrari, Pasquale Palumbo, Valentina Galluzzi, and ITA
Subjects: 010504 meteorology & atmospheric sciences, lcsh:QE1-996.5, Planetary geology, 010502 geochemistry & geophysics, Fault scarp, 01 natural sciences, Crater counting, lcsh:Geology, Paleontology, Tectonics, Impact crater, Planet, Mercury Thrust systems Crater counting Thermal evolution Planetary geology Structural geology, General Earth and Planetary Sciences, Thrust fault, Structural geology, Geology, 0105 earth and related environmental sciences
Abstract: The global tectonics of Mercury is dominated by contractional features mainly represented by lobate scarps, high relief ridges, and wrinkle ridges. These structures are the expression of thrust faults and are linear or arcuate features widely distributed on Mercury. Locally, these structures are arranged in long systems characterized by a preferential orientation and non-random spatial distribution. In this work we identified five thrust systems, generally longer than 1000 km. They were named after the main structure or crater encompassed by the system as: Thakur, Victoria, Villa Lobos, Al-Hamadhani, and Enterprise. In order to gain clues about their formation, we dated them using the buffered crater counting technique, which can be applied to derive the ages of linear landforms such as faults, ridges and channels. To estimate the absolute age for the end of the thrust system’s activity, we applied both Le Feuvre and Wieczorek Production Function and Neukum Production Functions. Moreover, to further confirm the results obtained with the buffered crater counting method, the classic stratigraphic approach has been adopted, in which a faulted and an unfaulted craters were dated for each system. The results gave consistent ages and suggested that the most movements along major structures all over Mercury most likely ended at about 3.6–3.8 Ga. This gives new clues to better understand the tectonics of the planet and, therefore, its thermal evolution. Indeed, the early occurrence of tectonic activity in the planet’s history, well before than predicted by the thermophysical models, coupled with the orientation and spatial distribution of the thrust systems, suggests that other processes beside global contraction, like mantle downwelling or tidal despinning, could have contributed to the first stage of the planet’s history. Keywords: Mercury, Thrust systems, Crater counting, Thermal evolution, Planetary geology, Structural geology
Published: 2020

10. Application of Implicit Modelling to Reconstruct the Layered Structure of the Comet 67P

Author: Luca, Penasa, Matteo, Massironi, Emanuele, Simioni, Franceschi, Marco, Giampiero, Naletto, Sabrina, Ferrari, Bertini, Ivano, Pamela, Cambianica, Elisa, Frattin, Fiorangela La Forgia, Alice, Lucchetti, Maurizio, Pajola, Frank, Preusker, Frank, Scholten, Laurent, Jorda, Robert, Gaskell, Holger, Sierks, Andrea Bistacchi, Matteo Massironi, Sophie Viseur, Penasa, Luca, Massironi, Matteo, Simioni, Emanuele, Franceschi, Marco, Naletto, Giampiero, Ferrari, Sabrina, Bertini, Ivano, Cambianica, Pamela, Frattin, Elisa, La Forgia, Fiorangela, Lucchetti, Alice, Pajola, Maurizio, Preusker, Frank, Scholten, Frank, Jorda, Laurent, Gaskell, Robert, and Sierks, Holger
Abstract: We provide details about the procedure employed for the three-dimensional geological modelling of the lobes of comet Churyumov-Gerasimenko (67P). The two lobes of 67P are characterized by well visible terraces and elongated cliffs that revealed a pervasive layering arranged in an onion-like fashion. None of the layers can be traced for a continuity large enough to provide a means of stratigraphic correlation. Therefore, an explicit modelling approach of the layered structure is not easily applicable. We show how a very simple modelling strategy based on implicitly-defined analytical surfaces (spheres or ellipsoids), and requiring very limited operator decision-making, can be successfully applied to produce a geological model that easily fits the available scattered attitude observations. Our formulation has the advantage of providing a small set of parameters with a precise geometrical meaning that can be compared with other parameters of the lobes (i.e. center of ellipsoids and center of mass). The presented method originates outside commercial geological modelling software packages and required devising some ad-hoc solutions for the visualization of the resulting models in comparison with observations made on OSIRIS images. Some extracts of the visualization code, helpful for applying this procedure in similar operational contexts, are also presented.
Published: 2022

11. Ralstonia insidiosa Bacteremia in Patients with Solid Cancer Treated by Means of a Central Venous Catheter

Author: Lorenzo Ruggieri, Anna Lisa Ridolfo, Sara Giordana Rimoldi, Maria Silvia Cona, Davide Dalu, Pietro Olivieri, Giuliano Rizzardini, Spinello Antinori, Anna Gambaro, Sabrina Ferrario, Cinzia Fasola, Maria Antista, Carmen Giusy Rea, and Nicla La Verde
Subjects: Ralstonia, catheters, bacteremia, cancer, outbreak, Industrial medicine. Industrial hygiene, RC963-969, Industrial hygiene. Industrial welfare, HD7260-7780.8
Abstract: Ralstonia spp. are low-virulent environmental Gram-negative bacteria that can cause serious nosocomial infections in immunocompromised patients. We report the characteristics of a cluster of R. insidiosa bacteremia cases occurring in our oncology day ward in Milan, Italy, between January and March 2022. A case was defined as a cancer patient attending our day ward and whose blood culture (performed because of bacteremia symptoms) led to the isolation of Ralstonia insidiosa. An epidemiological investigation was conducted in order to seek the possible source of infection. Seven adult patients received curative or palliative treatment via infusion through a Port-a-Cath (PAC). All developed symptoms within 24 h of the infusion (three during the infusion itself). Ralstonia insidiosa was isolated in the blood drawn from the PAC in all patients. All of the isolates were susceptible to carbapenems, fluoroquinolones, and piperacillin/tazobactam but resistant to aminoglycosides and cephalosporins. Systemic and/or lock antibiotic therapy led to stable symptom resolution and negative blood cultures in five patients, whereas bacteremia recurred in two patients. An epidemiological investigation suggested that extrinsic contamination of antiseptic solutions was the possible cause of the R. insidiosa infections. Although R. insidiosa is not considered a virulent pathogen, clinicians, microbiologists, and infection control teams should be aware about its potential to cause outbreaks of nosocomial bloodstream infections, especially in immunocompromised patients bearing central venous catheters.
Published: 2024
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12. 3D geological model of Rembrandt basin on Mercury and calculation basin infilling volumes

Author: Riccardo Pozzobon, Matteo Massironi, Luca Penasa, and Sabrina Ferrari
Abstract: Rembrandt is a 715 km-diameter basin on Mercury centered at 32.89°S latitude and 87.86°E longitude. This crater constitutes a remarkable example of the stratigraphic variability on Mercury. The uppermost smooth plains of volcanic origin, which are temporally unrelated to the impact event, have been distinguished by the surrounding smooth plains utilizing spectral information. The basin is crosscut by a prominent NE-SW thrust system more than 1000 km long, named Enterprise Rupes (Ferrari et al., 2015; Galluzzi et al., 2015; Semenzato et al., 2020), attributed mainly to crustal shortening induced by global contraction (see Semenzato et al., 2020 and references therein). This consists of a set of lobate scarps and wrinkle ridges with inverse to transpressional kinematics (Massironi et al., 2015). The aim of this work, as part of the PLANMAP Horizon 2020 project, is to use all the available information on the site to provide a comprehensive 3D model of both the structural setting and the thicknesses of the main units of the Rembrandt basin infilling using explicit modeling approach. The principle of three-dimensional explicit modelling relies on the creation of 3D surfaces based on geologic observations and constraints. While implicit modelling and its effectiveness rely on the amount of available data both on the surface and the subsurface to provide a mathematical solution that satisfies all the constraints, the explicit geological modelling implies a more extended geologic interpretation based on the available data which is subject to the operator’s experience and is essentially based on the construction of several interpreted cross-sections to be then interpolated generating mesh surfaces. The advantage is that such type of geologic modelling can be applied in areas with scarcity of data, especially related to subsurface constraints. In the case of the Rembrandt basin, we mainly based our reconstruction on the geo-stratigraphic map and geologic cross-section from Semenzato et al. (2020). Additional constraints, regarding fault kinematics and fault plane geometry, were provided by Galluzzi et al. (2015) and Crane (2020). As a basemap, we used the MESSENGER MDIS global mosaic at 166 m/pixel together with the MDIS global DEM (665 m/pixel), both of them available in the USGS repositories, with the same Lambert Conformal Conic (LCC) projection of the geo-stratigraphic map. In Rembrandt basin two different infillings - the YIP (Young Interior smooth Plains) and OIP (Older Interior smooth Plains) units - overlay the IT (para-autochtonous intracrater plains) base unit. The thickness of these units was estimated with several methods in Semenzato et al., (2020), among which the presence of impact craters excavating and exposing the inner basin stratigraphy. We used such craters for the construction of the interpreted cross-sections in complement to the one by Semenzato et al., (2020). These were subdivided into two intersecting sub-parallel sets. The interpreted subsurface horizons were used for mesh interpolation together with the geologic contacts between the different units on the surface creating meshes representin ghte top of the YIP, OIP and IT basin infilling units. The volume between them was then calculated. The structural modelling was carried out using the structural mapping from Semenzato et al., (2020) and Ferrari et al., (2015). The faults’ vergence and their angles were extracted both thanks to the illumination conditions on the image mosaic and topography, to the measurements provided by Galluzzi et al., (2015) on displaced impact craters and to the work by Crane (2020) and Massironi et al., (2015). This way we were able to model the Enterprise rupes thrust geometry, its splays and backthrusts as well as contractional lobate scarps and extensional radial features within the basin infilling units. Although requiring a certain degree of assumptions especially on planetary bodies, the 3D geomodelling proves to be a useful tool in order to check surface interpretations that might change once set into 3D environment and refine volume calculations and 3D shape of geologic units. Follow up investigations will focus on forward and backwards modeling work on the activity of the Enterprise Rupes system. Figure 1: in a) the mesh construction for the main Enterprise rupes structure, constrained with surface mapped lineaments and anchored on the geologic cross-section. In b) the tetrahedral volumetric mesh representing the two events of Rembrandt basin infilling. In c) the structural and stratigraphic geomodel of Rembrandt basin (https://skfb.ly/6ZqtI). Acknowlegements: This research was supported by the European Union’s Horizon 2020 under grant agreement No 776276‐PLANMAP. References: Crane, K., 2020. Structural interpretation of thrust fault-related landforms on Mercury using Earth analogue fault models. Geomorphology 369, 107366. https://doi.org/10.1016/j.geomorph.2020.107366 Ferrari, S., Massironi, M., Marchi, S., Byrne, P. K., Klimczak, C., Martellato, E., & Cremonese, G. (2015). Age relationships of the Rembrandt basin and Enterprise Rupes, Mercury. Geological Society, London, Special Publications, 401(1), 159–172. https://doi.org/10.1144/SP401.20 Galluzzi, V., Di Achille, G., Ferranti, L., Popa, C., & Palumbo, P. (2015). Faulted craters as indicators for thrust motions on Mercury. Geological Society, London, Special Publications, 401(1), 313–325. https://doi.org/10.1144/SP401.17 Massironi, M., Di Achille, G., Rothery, D. A., Galluzzi, V., Giacomini, L., Ferrari, S., Zusi, M., Cremonese, G., & Palumbo, P. (2015). Lateral ramps and strike-slip kinematics on Mercury. Geological Society, London, Special Publications, 401(1), 269–290. https://doi.org/10.1144/SP401.16 Semenzato, A., Massironi, M., Ferrari, S., Galluzzi, V., Rothery, D. A., Pegg, D. L., Pozzobon, R., & Marchi, S. (2020). An Integrated Geologic Map of the Rembrandt Basin, on Mercury, as a Starting Point for Stratigraphic Analysis. Remote Sensing, 12(19), 3213. https://doi.org/10.3390/rs12193213
Published: 2021

13. Analysis of the MESSENGER MASCS photometric targets part II: Photometric variability between geomorphological units

Author: Sabrina Ferrari, Mario D'Amore, Jörn Helbert, Noam R. Izenberg, and Deborah L. Domingue
Subjects: photometry, 010504 meteorology & atmospheric sciences, Spectrometer, variability, Scattering, Mineralogy, Astronomy and Astrophysics, MASCS, 01 natural sciences, Regolith, Atmosphere of Mercury, Photometry (optics), Space and Planetary Science, 0103 physical sciences, Surface roughness, MESSENGER, Millimeter, geomorphological units, Mercury MESSENGER photometric correction spectroscopy, Ejecta, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: This study examines the level of structural uniformity within Mercury's regolith as a function of geomorphological unit. Using two categories of photometric models (Hapke versus Kaasalainen–Shkuratov), the variation between and within similar geomorphological units are examined with the Mercury Atmosphere and Surface Composition Spectrometer (MASCS) photometry sequence data sets. The results show evidence for variations in the spectral and photometric scattering properties both within similar geomorphological units and between different geomorphological units. The ejecta and cratering units show the largest differences between the modeling results, each indicating variations in different properties. The results for the intercrater materials, smooth materials, and dark materials show consistent results between both models. The variations include possible differences in grain structures, regolith compaction, and surface roughness on micron to millimeter scales.
Published: 2019

14. The volcanic provinces of the Lennon-Picasso basin (Mercury)

Author: Riccardo Pozzobon, Simone Bedon, Matteo Massironi, and Sabrina Ferrari
Subjects: geography, geography.geographical_feature_category, chemistry, Volcano, Geochemistry, PICASSO, chemistry.chemical_element, Structural basin, Geology, Mercury (element)
Abstract: The volcanic provinces are embedded between the NE margin of b56 /Lennon-Picasso basin and high terrain bounding structures. Resulting plains are interested by endogenic pits associated with pyroclastic activity, in agreement with the observation that Mercury's explosive volcanic vents tend to be located along major fold and thrust belts (Byrne et al 2014) and around large impact basins. Recent large scale mapping defined them intercrater plains partly covered by smooth plains (Malliband et al 2019; Whitten et al 2020). In addition to endogenic pits, these provinces display several 10-km diameter prominent cones, sometimes aligned forming high-relief ridges, resembling constructional edifices. In colour composite images, cone tops are peculiarly darker (blue) or, alternatively, brighter (and yellow) with respect to the surrounding material. On the surface Mercury, Wright et al. (2019) interpreted two randomly located constructional edifices of similar size, attributing their origin to a late highly viscous stage of volcanism that followed lower-viscous stage that are thought to provide typical smooth plains. Wider et al. (2016) proposed that the encounter of highly-viscous lavas with C-rich material during the magma ascent can easily provide volatiles (Zolotov et al. 2011) that progressively accumulate and lead to explosive eruptions. The resulting high reflectance of pyroclastic deposits would arise from removal of graphite as it was consumed during oxidation. The study aims to reveal the nature of cones at the margin of the Lennon-Picasso basin and to explain the relationship between a potential long-lasting volcanic activity and the concurrent global contractional regime.Authors received funding from the Italian Space Agency (ASI) under ASI-INAF agreement 2017-47 and from European Union’s Horizon 2020 research grant under agreement 776276- PLANMAP.
Published: 2021

15. The best temperature range to acquire reliable thermal infrared spectra from orbit

Author: M. G. Pamato, M. C. Domeneghetti, Matteo Alvaro, Fabrizio Nestola, Günther J. Redhammer, Sabrina Ferrari, and Joern Helbert
Subjects: Diffraction, Solar System, Materials science, Science, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Spectral line, Thermal expansion, Article, chemistry.chemical_compound, 0103 physical sciences, Planetary science, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Multidisciplinary, Olivine, Atmospheric temperature range, Mineralogy, Silicate, Volume (thermodynamics), chemistry, 13. Climate action, Chemical physics, engineering, Medicine, Astrophysics::Earth and Planetary Astrophysics
Abstract: Solar System bodies undergo to daily and periodical variations of temperature that mainly depend on their closeness to the Sun. It is known that mineral expansion and contraction due to such variations modify the thermal infrared spectra acquired on solid surfaces. Therefore, it becomes crucial to know the best temperature range at which the acquisition itself should be carried out to get reliable information on the mineralogy of such bodies. Here we provide the thermal expansion of olivine between 20 and 298 K determined by X-ray diffraction. Our data reveal the non-linear behaviour of silicates that undergo to low temperatures, where volume variations appear positively correlated with temperatures. Subtle bond-length variations occurring at low temperatures are then expected to minimally affect vibrational absorption positions. We suggest that thermal infrared spectra of those Solar-System surfaces that are not exceeding 300 K provide reliable information about not only the silicate mineral identification but also on their chemical composition, regardless of the instantaneous temperature.
Published: 2021

16. Observational constraints to the dynamics of dust particles in the coma of comet 67P/Churyumov–Gerasimenko

Author: Pamela Cambianica, Giampiero Naletto, G. Cremonese, Francesco Marzari, F. La Forgia, I. Bertini, Carsten Güttler, Marco Fulle, Monica Lazzarin, Fernando Moreno, Sabrina Ferrari, Stavro Ivanovski, Alessandra Rotundi, Francesca Ferri, Holger Sierks, Alice Lucchetti, Cecilia Tubiana, V.V. Zakharov, Maurizio Pajola, E. Frattin, Luca Penasa, Agenzia Spaziale Italiana, European Commission, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), and Junta de Andalucía
Subjects: Physics, Comets: individual, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, Dust particles, photometric [Techniques], Library science, Techniques: image processing, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, individual [Comets], 01 natural sciences, Space and Planetary Science, Methods: data analysis, 0103 physical sciences, image processing [Techniques], Christian ministry, Techniques: photometric, Astrophysics::Earth and Planetary Astrophysics, data analysis [Methods], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: In this work, we aim to characterize the dust motion in the inner coma of comet 67P/Churyumov-Gerasimenko to provide constraints for theoretical 3D coma models. The OSIRIS camera on-board the Rosetta mission was able for the first time to acquire images of single dust particles from inside the cometary coma, very close to the nucleus. We analyse a large number of particles, performing a significant statistic of their behaviour during the post-perihelion period, when the spacecraft covered distances from the nucleus ranging between 80 and 400 km. We describe the particle trajectories, investigating their orientation and finding highly radial motion with respect to the nucleus. Then, from the particle brightness profiles, we derive a particle rotational frequency of ν < 3.6 Hz, revealing that they are slow rotators and do not undergo fragmentation. We use scattering models to compare the observed spectral radiance of the particles with the simulated ones in order to estimate their size, finding values that range from millimetres up to centimetres. The statistics performed in this paper provide useful parameters to constrain the cometary coma dynamical models. © 2021 The Author(s)., OSIRIS was built by a consortium of the Max-Planck-Institut fur Sonnensystemforschung in Gottingen, Germany; CISAS-University of Padova, Italy; the Laboratoire d'Astrophysique de Marseille, France; the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain; the Research and Scientic Support Department of the European Space Agency, Noordwijk, The Netherlands; the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain; the Universidad Politechnica de Madrid, Spain; the Department of Physics and Astronomy of Uppsala University, Sweden; and the Institut fur Datentechnik und Kommunikationsnetze der Technischen Universit at Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), Italy (ASI), France (CNES), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. GIADA was built by a consortium led by the Univ. Napoli Parthenope INAF-Oss. Astr. Capodimonte, in collaboration with the Inst. de Astrofisica de Andalucia, Selex-ES, FI and SENER. GIADA was managed and operated at INAF-IAPS. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with the support of the Spanish Ministry of Education and Science MEC, ES. We thank the ESA teams at ESAC, ESOC, and ESTEC for their work in support of the Rosetta mission. This research has been supported by the Italian Space Agency (ASI) within the ASI-INAF agreements I/032/05/0, I/024/12/0, and ASI 2020-4-HH.0. Fernando Moreno acknowledges financial support from the Spanish plan National de Astrofisica y Astronomia LEONIDAS project RTI2018-095330-B-100, project P18-RT-1854 from Junta de Andalucia, and the Centro de Excelencia Severo Ochoa Program under grant SEV-2017-0709. Elisa Frattin acknowledges funding from Italian Ministry of Education, University and Research (MIUR) through the `Dipartimenti di eccellenza' project Science of the Universe.
Published: 2021

17. From morpho-stratigraphic to geo-stratigraphic units: the PLANMAP contribution

Author: Carolyn H. van der Bogert, Andrea Semenzato, David A. Rothery, C. M. Poehler, John Wright, Francesca Zambon, Riccardo Pozzobon, Cristian Carli, Lorenza Giacomini, Francesca Altieri, Matteo Massironi, Erica Luzzi, Sabrina Ferrari, Angelo Pio Rossi, and Gloria Tognon
Subjects: Paleontology, biology, Morpho, biology.organism_classification, Geology
Abstract: Geological units on Earth are defined by several parameters besides the stratigraphic ones, such as rock textures, lithology, composition, and environmental conditions of their origin (numerous and diverse magmatic, volcanic, metamorphic and sedimentary environments). On the other hand, from the Apollo era onward, planetary ‘geologic’ mapping has been carried out using a photo-interpretative approach mainly on panchromatic and monochromatic images. This limited the definition of geological units to morpho-stratigraphic considerations so that units were mainly defined by their stratigraphic position, surface textures and morphology, and attribution to general emplacement processes (a few related to magmatism, some broad sedimentary environments, some diverse impact domains, and all with uncertainties of interpretation). Hence, the two products are still separated by an important conceptual and effective gap which makes the traditional planetary morpho-stratigraphic maps unable to satisfy fully the needs of modern planetary exploration, i.e. an optimised product to define mission strategy in terms of target selection, exploration traverse definition and resource evaluation for ISRU purposes. One of the approaches that might close this gap is to integrate spectral, color and compositional information into morpho-stratigraphic maps, thus generating spectro-morphic or geo-stratigraphic maps.The PLANMAP team has explored diverse methods for the integration of color variation and spectral information into planetary geological maps that diverge on the bases of the data available, the planetary surface under consideration (Moon, Mars and Mercury),the geological environments and the scale of mapping. PLANMAP received funding from the European Union Horizon 2020 research and innovation program under grant agreement N. 776276.
Published: 2021

18. Spectral variability of brigth regions whitin Kuiper quadrangle: spectral indication for integrated geostratigraphic maps

Author: Cristian Carli, Lorenza Giacomini, Francesca Zambon, Valentina Galluzzi, Sabrina Ferrari, Matteo Massironi, Francesca Altieri, Luigi Ferranti, Pasquale Palumbo, and Fabrizio Capaccioni
Published: 2021
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19. Kuiper Quadrangle spectral analysis: looking forward to integrated geological map

Author: Cristian Carli, Lorenza Giacomini, Francesca Zambon, Sabrina Ferrari, Matteo Massironi, Valentina Galluzzi, Francesca Altieri, Fabrizio Capaccioni, Luigi Ferranti, and Pasquale Palumbo
Abstract: Mercury geology reached a new era after the MESSENGER mission, which has allowed not only to acquire global information but also to study the geological history of the planet with multiple techniques. The orbital BepiColombo mission will be the next step to fix some of the Hermean paradigm because more techniques, coupled with the higher resolution of the instruments onboard Mio and Bepi.Integration of compositional data and morpho-stratigraphic maps generally produced from camera data, will be one of the main issue to improve the understanding of Mercury geological evolution. This goal is also correlated with the efforts of other projects such as PLANMAP European H2020 and GMAP Europlanet 20-24.Several morpho-stratigraphic maps of Mercury quadrangles have been produced, or are ongoing (e.g. Galluzzi et al. 2018), and a global map has been realized (e.g. Kinczyk et al. 2019). Discussion or integration at quadrangle level of Mercury is recently beginning (e.g. Bott et al. 2019; Zambon et al. 2019) and here we report activity done in the Kuiper H06.Kuiper (H06) is an equatorial quadrangle, and it encompasses the area between longitudes 72°W –0° and latitudes 22.5°N – 22.5°S. H06 morpho-stratigraphic mapping is still ongoing (Giacomini et al. 2018; 2019), it evidences a high variegation of units, from older intercrater plains to younger smooth plains, to craters. Several craters show pyroclastic deposits (e.g. Kerber et al. 2011; Pajola et al. 2020), in some cases with putative vents, and hollows. Some of the hollows look like very peculiar from spectral point of view, e.g. in Dominici Crater (Vilas et al. 2016; Lucchetti et al. 2018), showing possible indication of mineralogical phases. Whereas most smooth plains are limited in extension and confined on the floor of the largest craters, a wide smooth plain has been detected that surrounds Rudaki crater. Some of these plains show clearly color variegation (e.g. two color units within Renoir Basin, see Giacomini et al. 2018).Due to the low latitudes, the coverage from MDIS data with high spatial resolution is lower than the northern quadrangles (e.g. Bott et al. 2019; Zambon et al. 2019) and we approach the study in a multiple-stage passages. This has been done to investigate the region with the best detail from a spectral point of view. Following the mosaic product procedure used by Zambon et al. (2019), we generate a homogeneous 8 color global mosaic at 1600 m/px scale (average scale taking into account the average resolution) and at 665 m/px pushing the resolution. Moreover, we considered the partial quadrangle coverage mosaics at 385 m/px and 246 m/px to exploit the presence of higher resolution color images.We will show spectral variations considering specific indices and color combinations (example on Figure 1), discussing the possibility to define some spectral units which could be later integrated with the morpho-stratigraphic mapping. Furthermore, we will locally investigate the spectral variation of specific cases, e.g. fresh craters, hollows and pyroclastic material, to infer some indication on material composition, or within some blue dark regions to understand the possible darkening material.This activity could be also helpful in the definition of indicators improving the selection procedure for regions of interest (see also Giacomini et al. 2020) to be studied for covering the science goals of the BepiColombo mission (e.g. Rothery et al. 2020).Acknowledgements:We gratefully acknowledge funding from the Italian Space Agency (ASI) under ASI-INAF agreement 2017-47-H.0. MM, CC, FZ, FA were also supported by European Union’s Horizon 2020 research grant agreement No 776276- PLANMAP. MM, CC, FA were also supported by Europlanet 20-24 GMAP, EPN-RI-2024.References:Bott N., et al. 2019. Global Spectral Properties and Lithology of Mercury: The Example of the Shakespeare (H‐03) Quadrangle. JGR-Planets, 124, 2326-2346.Zambon F., et al. 2019. Spectral properties of the H05 Hokusai quadrangle on Mercury and relationship with the morpho-stratigraphic units. EGU 7796.Giacomini L., et al. 2018. Updates on geologic mapping of Kuiper (H06) quadrangle. EPSC 721-1.Giacomini L., et al. 2019. GEOLOGICAL MAPPING OF THE KUIPER (H06) QUADRANGLE OF MERCURY. XV Congresso delle Scienze Planetarie, pg. 71.Giacomini L., et al. 2020. Scientific sites of interest in Kuiper Quadrangle (H06). EPSC this meeting.Kerber L., et al. 2011. The global distribution of pyroclastic deposits on Mercury: The view from MESSENGER flybys 1–3. PSS, 59, 1895–1909.Kinczyk M.J., et al. 2019. The First Global Geological Map of Mercury. EPSC-DPS 1045-1.Lucchetti A., et al. 2018. Mercury Hollows as Remnants of Original Bedrock Materials and Devolatilization Processes: A Spectral Clustering and Geomorphological Analysis. JGR-Planets, 123, 2365-2379.Pajola M., et al. 2020. MULTIDISCIPLINARY ANALYSIS OF LERMONTOV CRATER ON MERCURY. 51 LPSC 1402.Rothery et al. 2020. Rationale for BepiColombo studies of Mercury’s surface and composition. Spa.Sci.Review. in press.Vilas F., et al. 2016. Mineralogical indicators of Mercury's hollows composition in MESSENGER color observations. JGR 43, 1450-1456.
Published: 2020

20. Global-scale brittle plastic rheology at the cometesimals merging of comet 67P/Churyumov–Gerasimenko

Author: Carsten Güttler, Holger Sierks, Matteo Massironi, Maurizio Pajola, Dennis Bodewits, Marco Franceschi, Luca Penasa, Giampiero Naletto, Imre Tóth, Stefano Mottola, Michele Fondriest, J. Deller, Alice Lucchetti, Cecilia Tubiana, Sabrina Ferrari, Franceschi, Marco, Penasa, Luca, Massironi, Matteo, Naletto, Giampiero, Ferrari, Sabrina, Fondriest, Michele, Bodewits, Denni, Güttler, Carsten, Lucchetti, Alice, Mottola, Stefano, Pajola, Maurizio, Toth, Imre, Deller, Jacob, Sierks, Holger, and Tubiana, Cecilia
Subjects: 010504 meteorology & atmospheric sciences, Comet, Bent molecular geometry, 67P/Churyumov–Gerasimenko, Deformation, Impact, Rheology, Geometry, 01 natural sciences, comet, Brittleness, 0103 physical sciences, Porosity, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Multidisciplinary, Deformation (mechanics), deformation, impact, rheology, Sinistral and dextral, 13. Climate action, Physical Sciences, Contact area, Geology
Abstract: Observations of comet nuclei indicate that the main constituent is a mix of ice and refractory materials characterized by high porosity (70–75%) and low bulk strength (10 −4 –10 −6 MPa); however, the nature and physical properties of these materials remain largely unknown. By combining surface inspection of comet 67P/Churyumov–Gerasimenko and three-dimensional (3D) modeling of the independent concentric sets of layers that make up the structure of its two lobes, we provide clues about the large-scale rheological behavior of the nucleus and the kinematics of the impact that originated it. Large folds in the layered structure indicate that the merging of the two cometesimals involved reciprocal motion with dextral strike–slip kinematics that bent the layers in the contact area without obliterating them. Widespread long cracks and the evidence of relevant mass loss in absence of large density variations within the comet’s body testify that large-scale deformation occurred in a brittle-plastic regime and was accommodated through folding and fracturing. Comparison of refined 3D geologic models of the lobes with triaxial ellipsoids that suitably represent the overall layers arrangement reveals characteristics that are consistent with an impact between two roughly ellipsoidal cometesimals that produced large-scale axial compression and transversal elongation. The observed features imply global transfer of impact-related shortening into transversal strain. These elements delineate a model for the global rheology of cometesimals that could be possible evoking a prominent bonding action of ice and, to a minor extent, organics.
Published: 2020

21. Thermal infrared emissivity of felsic-rich to mafic-rich analogues of hot planetary regoliths

Author: Harald Hiesinger, Alessandro Maturilli, Fabrizio Nestola, Cristian Carli, Mario D'Amore, Sabrina Ferrari, and Jörn Helbert
Subjects: 010504 meteorology & atmospheric sciences, Planetare Labore, Mineralogy, Pyroxene, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Thermal expansion, pyroxene, Geochemistry and Petrology, Thermal, Earth and Planetary Sciences (miscellaneous), Emissivity, Plagioclase, 0105 earth and related environmental sciences, Felsic, silicate, temperature, Temperature gradient, Geophysics, Space and Planetary Science, emissivity, engineering, plagioclase, planetary, Mafic, Geology
Abstract: Inner Solar System bodies with absent or extremely tenuous atmospheres such as Mercury and several high-eccentricity Near Earth Objects (NEOs) are subject to a wide range of surface temperatures. Here we show how the thermal expansion induced by strong diurnal insolation variations affects the thermal infrared spectra of felsic-rich to mafic-rich regoliths. 1400-700 cm−1 spectra of granular plagioclase-pyroxene mixtures were measured in the laboratory at four temperatures between 425 K and 725 K, simulating different daily surface temperatures within the Solar System. At the same time, we describe for the first time how two minerals with different thermal expansion coefficients combined in the same granular sample appear in a non-ambient (i.e., non-298 K) thermal infrared spectrum. The spectra of plagioclase-rich analogues appear to be dominated by felsic features regardless of the daily surface temperature, and do not exhibit any of the short-wavelength absorptions of pyroxenes. When detectable, on the other hand, the 870-cm−1 pyroxene absorption, which is not affected by thermal variations, functions instead as a proxy for the solid-solution composition (i.e., the Mg-Fe relative contents). In contrast, indications of the plagioclase solid solution occurring at ambient temperatures (i.e., Ca-Na relative contents) disappear at temperatures over 525 K. Christiansen feature position and spectral contrast, which show a clear dependency on composition even at high temperatures, require an accurate reproduction of the shallow thermal gradient in order to be used as indices. In general, in order to decipher planetary hyperspectral data, surface temperature acquisition seems to be a prerequisite, as well as a comparison with analogue spectra obtained under realistic environmental conditions.
Published: 2020

22. FLY-SPEC prototype: UV-VIS-NIR reflectometry and laser induced breakdown spectroscopy

Author: P. Chioetto, Paola Zuppella, S. S. Zehra, Sabrina Ferrari, Piergiorgio Nicolosi, M. Fedel, Matteo Massironi, Jacopo Nava, Fabrizio Nestola, Christine Meyzen, V. Da Deppo, and A. Slemer
Subjects: spectroscopy, Ultraviolet visible spectroscopy, LIBS, Hyperspectral imaging, Waste recycling, Laser-induced breakdown spectroscopy, NIR reflectometry, space, Reflectometry, Spectroscopy, Remote sensing
Abstract: Development of efficient, non-destructive, time-saving and innovative instruments for material identification surveying is urgently requested in several fields, including solid-state physics, industrial processing, waste recycling and environmental contamination detection. In this respect, coupling laser-induced breakdown spectroscopy (LIBS) and (near-infrared unit) NIR reflectometry with hyperspectral imaging spectroscopy (HIS), owing to its power and versatility, is key to more efficient and time-saving diagnostic of chemical and physical properties of rocks and unconsolidated materials. Here we present the FLY-SPEC instrument conceived to combine these three relevant techniques for space exploration surveying. The recent assemblage of its LIBS unit has allowed us to conduct our first pilot experiments.
Published: 2020

23. Mapping and Monitoring Urban Environment through Sentinel-1 SAR Data: A Case Study in the Veneto Region (Italy)

Author: Daniele Codato, Salvatore Pappalardo, Andrea Semenzato, Massimo De Marchi, Silvano De Zorzi, Umberto Trivelloni, Matteo Massironi, and Sabrina Ferrari
Subjects: 010504 meteorology & atmospheric sciences, Process (engineering), Geography, Planning and Development, 0211 other engineering and technologies, lcsh:G1-922, SDG, 02 engineering and technology, Land cover, 01 natural sciences, urban planning, Footprint, land cover, Urban planning, Radar imaging, Earth and Planetary Sciences (miscellaneous), Computers in Earth Sciences, Sentinel, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Sustainable development, Strategic urban planning, business.industry, Environmental resource management, 2030 Agenda, urban environment, SAR, urban footprint, Statistical classification, Geography, business, lcsh:Geography (General)
Abstract: Focusing on a sustainable and strategic urban development, local governments and public administrations, such as the Veneto Region in Italy, are increasingly addressing their urban and territorial planning to meet national and European policies, along with the principles and goals of the 2030 Agenda for the Sustainable Development. In this regard, we aim at testing a methodology based on a semi-automatic approach able to extract the spatial extent of urban areas, referred to as &ldquo, urban footprint&rdquo, from satellite data. In particular, we exploited Sentinel-1 radar imagery through multitemporal analysis of interferometric coherence as well as supervised and non-supervised classification algorithms. Lastly, we compared the results with the land cover map of the Veneto Region for accuracy assessments. Once properly processed and classified, the radar images resulted in high accuracy values, with an overall accuracy ranging between 85% and 90% and percentages of urban footprint differing by less than 1%&ndash, 2% with respect to the values extracted from the reference land cover map. These results provide not only a reliable and useful support for strategic urban planning and monitoring, but also potentially identify a solid organizational dataflow process to prepare geographic indicators that will help answering the needs of the 2030 Agenda (in particular the goal 11 &ldquo, Sustainable Cities and Communities&rdquo, ).
Published: 2020

24. SIMBIO-SYS: Scientific Cameras and Spectrometer for the BepiColombo Mission

Author: Marilena Amoroso, Francesca Esposito, Giancarlo Bellucci, Y. Langevin, Marco Baroni, Océane Barraud, Francesca Altieri, Giacomo Colombatti, Michael Mendillo, M. I. Blecka, M. T. Capria, Romolo Politi, Ernesto Palomba, Pasquale Palumbo, Olivier Forni, Gianfranco Forlani, E. Flamini, Francesca Ferri, P. Borin, Lionel Wilson, Andrea Cicchetti, Vito Mennella, Carlo Bettanini, Riccardo Paolinetti, Alice Lucchetti, Davide Perna, Nicolas Thomas, Marcello Fulchignoni, V. Della Corte, Maria Sgavetti, Daniela Fantinel, M. El yazidi, A. Doressoundiram, Luigi Ferranti, Simone Marchi, John Robert Brucato, T. Van Hoolst, Cedric Leyrat, Sebastien Besse, Stéphane Erard, Elena Martellato, Y. Li, Diego Turrini, Francesco Marzari, W-H. Ip, Maurizio Pajola, Cristian Carli, Raffaella Noschese, Matteo Massironi, Sabrina Ferrari, Alessio Aboudan, Giuseppe Salemi, I. Ficai Veltroni, Lorenza Giacomini, Karri Muinonen, Emanuele Simioni, Jessica Flahaut, Priscilla Cerroni, Mathieu Vincendon, V. Da Deppo, Alessandra Slemer, L. M. Lara, M. C. De Sanctis, Raffaele Mugnuolo, M. Dami, Francesca Zambon, G. Piccioni, L. Guzzetta, Fabrizio Capaccioni, Giampiero Naletto, E. Mazzotta Epifani, G. Aroldi, Andrea Turella, Michele Zusi, Maurizio Rossi, Stefano Debei, Gabriele Cremonese, A. Barucci, Johannes Benkhoff, Gloria Tognon, Cristina Re, François Poulet, Donato Borrelli, Sonia Fornasier, Valentina Galluzzi, Gianrico Filacchione, Leonardo Tommasi, François Leblanc, Laurent Jorda, Lucia Marinangeli, Roberto Ragazzoni, V. Carlier, Alessandra Rotundi, N. Bott, Luigi Colangeli, Klaus Gwinner, Cremonese, G., Capaccioni, F., Capria, M. T., Doressoundiram, A., Palumbo, P., Vincendon, M., Massironi, M., Debei, S., Zusi, M., Altieri, F., Amoroso, M., Aroldi, G., Baroni, M., Barucci, A., Bellucci, G., Benkhoff, J., Besse, S., Bettanini, C., Blecka, M., Borrelli, D., Brucato, J. R., Carli, C., Carlier, V., Cerroni, P., Cicchetti, A., Colangeli, L., Dami, M., Da Deppo, V., Della Corte, V., De Sanctis, M. C., Erard, S., Esposito, F., Fantinel, D., Ferranti, L., Ferri, F., Ficaiveltroni, I., Filacchione, G., Flamini, E., Forlani, G., Fornasier, S., Forni, O., Fulchignoni, M., Galluzzi, V., Gwinner, K., Ip, W., Jorda, L., Langevin, Y., Lara, L., Leblanc, F., Leyrat, C., Li, Y., Marchi, S., Marinangeli, L., Marzari, F., Mazzottaepifani, E., Mendillo, M., Mennella, V., Mugnuolo, R., Muinonen, K., Naletto, G., Noschese, R., Palomba, E., Paolinetti, R., Perna, D., Piccioni, G., Politi, R., Poulet, F., Ragazzoni, R., Re, C., Rossi, M., Rotundi, A., Salemi, G., Sgavetti, M., Simioni, E., Thomas, N., Tommasi, L., Turella, A., Van Hoolst, T., Wilson, L., Zambon, F., Aboudan, A., Barraud, O., Bott, N., Borin, P., Colombatti, G., Elyazidi, M., Ferrari, S., Flahaut, J., Giacomini, L., Guzzetta, L., Lucchetti, A., Martellato, E., Pajola, M., Slemer, A., Tognon, G., Turrini, D., INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Dipartimento di Fisica 'Ettore Pancini', University of Naples Federico II = Università degli studi di Napoli Federico II, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Dipartimento di Geoscienze [Padova], Università degli Studi di Padova = University of Padua (Unipd), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Agenzia Spaziale Italiana (ASI), Leonardo SpA, European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), European Space Astronomy Centre (ESAC), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), INAF - Osservatorio Astronomico di Capodimonte (OAC), Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A), Department og Engineering and Architecture [Parma] (DIA), Università degli studi di Parma = University of Parma (UNIPR), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), DLR Institute of Planetary Research, German Aerospace Center (DLR), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Suzhou Vocational University, Southwest Research Institute [Boulder] (SwRI), International Research School of Planetary Sciences [Pescara] (IRSPS), Dipartimento di Fisica e Astronomia 'Galileo Galilei', INAF - Osservatorio Astronomico di Roma (OAR), Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), Department of Physics [Helsinki], Falculty of Science [Helsinki], Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Finnish Geospatial Research Institute (FGI), Università degli Studi di Napoli 'Parthenope' = University of Naples (PARTHENOPE), Department of Cultural Heritage [Padova], Dipartimento di Scienze della Terra [Parma], Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Royal Observatory of Belgium [Brussels] (ROB), Environmental Sciences [Lancaster], Lancaster University, Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Università degli studi di Napoli Federico II, Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universita degli Studi di Padova, European Space Agency (ESA), Consiglio Nazionale delle Ricerche [Roma] (CNR), University of Parma = Università degli studi di Parma [Parme, Italie], Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), University of Helsinki-University of Helsinki, Universita degli studi di Napoli 'Parthenope' [Napoli], Universität Bern [Bern], and Agenzia Spaziale Italiana
Subjects: 010504 meteorology & atmospheric sciences, Computer science, BepiColombo, MPO, Astronomy & Astrophysics, INFRARED REFLECTANCE SPECTRA, 01 natural sciences, 7. Clean energy, Spectrometer, MECHANISMS, law.invention, Orbiter, EXPLOSIVE VOLCANISM, law, 0103 physical sciences, instrument, Spectral resolution, 010303 astronomy & astrophysics, Image resolution, BASIN, 0105 earth and related environmental sciences, Remote sensing, SIMBIO-SYS, ONBOARD, Science & Technology, SPECTROSCOPY, GRAVITY-FIELD, 520 Astronomy, Hyperspectral imaging, MERCURYS SURFACE, Astronomy and Astrophysics, Spectral bands, Mercury, 620 Engineering, HOLLOWS, Imageur, Stereo imaging, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Physical Sciences, MESSENGER, Stereo camera
Abstract: Full list of authors: Cremonese, G.; Capaccioni, F.; Capria, M. T.; Doressoundiram, A.; Palumbo, P.; Vincendon, M.; Massironi, M.; Debei, S.; Zusi, M.; Altieri, F.; Amoroso, M.; Aroldi, G.; Baroni, M.; Barucci, A.; Bellucci, G.; Benkhoff, J.; Besse, S.; Bettanini, C.; Blecka, M.; Borrelli, D.; Brucato, J. R.; Carli, C.; Carlier, V.; Cerroni, P.; Cicchetti, A.; Colangeli, L.; Dami, M.; Da Deppo, V.; Della Corte, V.; De Sanctis, M. C.; Erard, S.; Esposito, F.; Fantinel, D.; Ferranti, L.; Ferri, F.; FicaiÂ Veltroni, I.; Filacchione, G.; Flamini, E.; Forlani, G.; Fornasier, S.; Forni, O.; Fulchignoni, M.; Galluzzi, V.; Gwinner, K.; Ip, W.; Jorda, L.; Langevin, Y.; Lara, L.; Leblanc, F.; Leyrat, C.; Li, Y.; Marchi, S.; Marinangeli, L.; Marzari, F.; MazzottaÂ Epifani, E.; Mendillo, M.; Mennella, V.; Mugnuolo, R.; Muinonen, K.; Naletto, G.; Noschese, R.; Palomba, E.; Paolinetti, R.; Perna, D.; Piccioni, G.; Politi, R.; Poulet, F.; Ragazzoni, R.; Re, C.; Rossi, M.; Rotundi, A.; Salemi, G.; Sgavetti, M.; Simioni, E.; Thomas, N.; Tommasi, L.; Turella, A.; Van Hoolst, T.; Wilson, L.; Zambon, F.; Aboudan, A.; Barraud, O.; Bott, N.; Borin, P.; Colombatti, G.; ElÂ Yazidi, M.; Ferrari, S.; Flahaut, J.; Giacomini, L.; Guzzetta, L.; Lucchetti, A.; Martellato, E.; Pajola, M.; Slemer, A.; Tognon, G.; Turrini, D. -- This is an open access article, The SIMBIO-SYS (Spectrometer and Imaging for MPO BepiColombo Integrated Observatory SYStem) is a complex instrument suite part of the scientific payload of the Mercury Planetary Orbiter for the BepiColombo mission, the last of the cornerstone missions of the European Space Agency (ESA) Horizon + science program. The SIMBIO-SYS instrument will provide all the science imaging capability of the BepiColombo MPO spacecraft. It consists of three channels: the STereo imaging Channel (STC), with a broad spectral band in the 400-950 nm range and medium spatial resolution (at best 58 m/px), that will provide Digital Terrain Model of the entire surface of the planet with an accuracy better than 80 m; the High Resolution Imaging Channel (HRIC), with broad spectral bands in the 400-900 nm range and high spatial resolution (at best 6 m/px), that will provide high-resolution images of about 20% of the surface, and the Visible and near-Infrared Hyperspectral Imaging channel (VIHI), with high spectral resolution (6 nm at finest) in the 400-2000 nm range and spatial resolution reaching 120 m/px, it will provide global coverage at 480 m/px with the spectral information, assuming the first orbit around Mercury with periherm at 480 km from the surface. SIMBIO-SYS will provide high-resolution images, the Digital Terrain Model of the entire surface, and the surface composition using a wide spectral range, as for instance detecting sulphides or material derived by sulphur and carbon oxidation, at resolutions and coverage higher than the MESSENGER mission with a full co-alignment of the three channels. All the data that will be acquired will allow to cover a wide range of scientific objectives, from the surface processes and cartography up to the internal structure, contributing to the libration experiment, and the surface-exosphere interaction. The global 3D and spectral mapping will allow to study the morphology and the composition of any surface feature. In this work, we describe the on-ground calibrations and the results obtained, providing an important overview of the instrument performances. The calibrations have been performed at channel and at system levels, utilizing specific setup in most of the cases realized for SIMBIO-SYS. In the case of the stereo camera (STC), it has been necessary to have a validation of the new stereo concept adopted, based on the push-frame. This work describes also the results of the Near-Earth Commissioning Phase performed few weeks after the Launch (20 October 2018). According to the calibration results and the first commissioning the three channels are working very well. © 2020, The Author(s)., We gratefully acknowledge funding from the Italian Space Agency (ASI) under ASI-INAF agreement 2017-47-H.0. The SIMBIO-SYS instrument has been developed by Leonardo under ASI contract I/054/10/0.
Published: 2020

25. Spectrophotometric variegation of the layering in comet 67P/Churyumov-Gerasimenko as seen by OSIRIS

Author: Cesare Barbieri, W-H. Ip, Pedro J. Gutiérrez, Jakob Deller, Björn Davidsson, D. Bodewits, Gloria Tognon, R. Rodrigo, F. La Forgia, V. Petropoulou, Philippe Lamy, Prasanna Deshapriya, H. U. Keller, Cecilia Tubiana, M. A. Barucci, Holger Sierks, V. Da Deppo, Carsten Güttler, Matteo Massironi, Marco Fulle, Imre Toth, Michel Franceschi, Sabrina Ferrari, Giampiero Naletto, Alice Lucchetti, Detlef Koschny, M. De Cecco, E. Frattin, Sonia Fornasier, J. J. Lopez-Moreno, Monica Lazzarin, Maurizio Pajola, Ivano Bertini, Luca Penasa, Luisa Lara, Francesca Ferri, Francesco Marzari, Pamela Cambianica, Jean-Loup Bertaux, Gabriele Cremonese, Stefano Debei, Xian Shi, Stefano Mottola, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Dipartimento di Geoscienze [Padova], CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), International Space Science Institute [Bern] (ISSI), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Department of Physics [Auburn], Auburn University (AU), CNR Institute for Photonics and Nanotechnologies (IFN), Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Università degli Studi di Padova = University of Padua (Unipd), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), NASA-California Institute of Technology (CALTECH), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), German Centre for Air and Space Travel, Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Agencia Estatal de Investigación (España), European Space Agency, Swedish National Space Agency, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), IMPEC - LATMOS, Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), Technische Universität Braunschweig [Braunschweig], Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Tognon, Gloria, Ferrari, S., Penasa, L., La Forgia, F., Massironi, M., Naletto, G., Lazzarin, M., Cambianica, P., Lucchetti, A., Pajola, M., Ferri, F., Güttler, C., Davidsson, B., Deshapriya, P., Fornasier, S., Mottola, S., Tóth, I., Sierks, H., Lamy, P. L., Rodrigo, R., Koschny, D., Barbieri, C., Barucci, M. A., Bertaux, J. -L., Bertini, I., Bodewits, D., Cremonese, G., Da Deppo, V., Debei, S., De Cecco, M., Deller, J., Franceschi, M., Frattin, E., Fulle, M., Gutiérrez, P. J., Ip, W. -H., Keller, H. U., Lara, L. M., López-Moreno, J. J., Marzari, F., Petropoulou, V., Shi, X., and Tubiana, C.
Subjects: Brightness, 010504 meteorology & atmospheric sciences, Outcrop, Multispectral image, Narrow angle, Astrophysics, 01 natural sciences, WATER ICE, NUCLEUS, individual: 67P/Churyumov-Gerasimenko [Comets], Methods: data analysis, 0103 physical sciences, data analysis [methods], medicine, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Comets: individual: 67P/Churyumov-Gerasimenko, Physics, Multispectral data, biology, general [Comets], Astronomy and Astrophysics, biology.organism_classification, Lobe, Comets: general, medicine.anatomical_structure, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], comets: general – comets: individual: 67P/Churyumov-Gerasimenko – methods: data analysis, Osiris, Layering, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Between August 2014 and September 2016, the ESA space mission Rosetta escorted comet 67P/Churyumov-Gerasimenko (67P) during its perihelion passage. The onboard OSIRIS Narrow Angle Camera (NAC) acquired high-resolution multispectral images of the cometary surface. These datasets allowed a characterization of the spectrophotometric variegation of the layering of the large lobe, correlated with the layer structural elevation. Aims. We perform a spectrophotometric characterization of the outcropping stratification of the small lobe of 67P as a function of its structural elevation, and consequently, a spectrophotometric comparison of the layered outcrops of the two lobes. Methods. We selected two sequences of post-perihelion OSIRIS NAC images (similar to 2.4 au outbound to the Sun), from which we built up two multispectral images, framing an extended geological section of the onion-like stratification of the small lobe. Then we classified the consolidated areas of the outcropping and the relative coarse deposits that were identified in the multispectral data with a two-class maximum likelihood method. For this, we defined the classes as a function of the structural elevation of the surface. Results. As a result, we identified a brightness variegation of the surface reflectance that is correlated with the structural elevation. The outer class, which is located at higher elevations, appears darker than the inner class. This fits previously obtained results for the large lobe. The reflectance values of the nucleus of 67P tend to decrease with increasing structural elevation. Conclusions. The observed spectrophotometric variegation can be due to a different texture as well as to a different content of volatiles and refractories. We suggest that the outer outcrops appear darker because they have been exposed longer, and the inner outcrops appear brighter because the surface has been more effectively rejuvenated. We interpret this variegation as the result of an evolutionary process.© ESO 2019, We are grateful to Andrea Longobardo for suggestions and corrections that improved our paper. OSIRIS was built by a consortium of the Max-Planck-Institut fur Sonnensystemforschung, Gottingen, Germany, CISAS - University of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, the Research and Scientific Support Department of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut fur Datentechnik und Kommunikationsnetze der Technischen Universitat Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged.
Published: 2019

26. Multidisciplinary analysis of the Hapi region located on Comet 67P/Churyumov–Gerasimenko

Author: Wing-Huen Ip, Philippe Lamy, Carsten Güttler, F. La Forgia, Nilda Oklay, R. Rodrigo, Z. Y. Lin, Dennis Bodewits, Stefano Debei, V. Da Deppo, H. U. Keller, Luca Penasa, Jakob Deller, Maurizio Pajola, Alice Lucchetti, Gabriele Cremonese, Giampiero Naletto, Sonia Fornasier, Detlef Koschny, Marco Fulle, P. J. Gutierrez, M. De Cecco, Holger Sierks, J. J. Lopez Moreno, Francesco Marzari, J.-C. Lee, Matteo Massironi, F. Preusker, Ivano Bertini, Stubbe F. Hviid, Sabrina Ferrari, Imre Tóth, Jessica Agarwal, Pamela Cambianica, Xian Shi, Frank Scholten, Lorenza Giacomini, Jean-Loup Bertaux, M. A. Barucci, Stefano Mottola, Luisa Lara, Björn Davidsson, M. R. El Maarry, Clement Feller, Cecilia Tubiana, Monica Lazzarin, Jean-Baptiste Vincent, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Department of Atmospheric Sciences [Taoyuan City], National Central University [Taiwan] (NCU), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Dipartimento di Geoscienze [Padova], Dipartimento di Fisica e Astronomia 'Galileo Galilei', CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Institute of Space Science [Taiwan], Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Department of Physics [Auburn], Auburn University (AU), Department of Mechanical Engineering [Padova], Department of Industrial Engineering [Padova], Universita degli Studi di Padova-Universita degli Studi di Padova, University of Trento [Trento], Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], INAF - Osservatorio Astronomico di Trieste (OAT), Institut d'Astronomie et d'Astrophysique [Bruxelles] (IAA), Université Libre de Bruxelles [Bruxelles] (ULB), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), European Space Agency, Swedish National Space Board, Ministerio de Educación y Ciencia (España), Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, German Centre for Air and Space Travel, Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Pajola, M. [0000-0002-3144-1277], Penasa, L. [0000-0002-6394-3108], Fornasier, S. [0000-0001-7678-3310], Lucchetti, A. [0000-0001-7413-3058], Vicent, J. B. [0000-0001-6575-3079], Naletto, G. [0000-0003-2007-3138], Barucci, M. A. [0000-0002-1345-0890], Bertaux, J. L. [0000-0003-0333-229X], Deller, J. [0000-0001-8341-007X], Fulle, M. [0000-0001-8435-5287], Güttler, C. [0000-0003-4277-1738], Tubiana, C. [0000-0001-8475-9898], Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH)-NASA, PLANETO - LATMOS, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Université libre de Bruxelles (ULB), Agenzia Spaziale Italiana (ASI), Swedish National Space Agency (SNSA), Deutsches Zentrum für Luft- und Raumfahrt (DLR), and Centre National D'Etudes Spatiales (CNES)
Subjects: Asteroiden und Kometen, statistical [Methods], Comet, individual (67P C-G) [Comets], Comets: individual (67P C-G), Methods: data analysis, Methods: statistical, 01 natural sciences, Methods statistical, Gravitational potential, 0103 physical sciences, data analysis [Methods], 010303 astronomy & astrophysics, Southern Hemisphere, Physics, geography, geography.geographical_feature_category, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Multidisciplinary analysis, Planetengeodäsie, 67P/Churyumov–Gerasimenko Comets Rosetta Hapi, Northern Hemisphere, Astronomy, Astronomy and Astrophysics, methods: data analysis –methods: statistical – comets: individual (67P C-G), Space and Planetary Science, Ridge, individual: 67P C-G [Comets], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: By using the Rosetta/OSIRIS-NAC data set taken in 2014 August, we focus on the neck region, called Hapi, located on 67P Churyumov-Gerasimenko's Northern hemisphere. The gravitational potential and slopes of Hapi, coupled with the geological unit identification and the boulder size-frequency distributions, support the interpretation that both taluses and gravitational accumulation deposits observable on Hapi are the result of multiple cliff collapses that occurred at different times. By contrast, the fine-particle deposits observable in the central part of the study area are made of aggregates coming from the Southern hemisphere and deposited during each perihelion passage. Both the consolidated terrains on the western part of Hapi, as well as the centrally aligned ridge made of boulder-like features, suggest that Hapi is in structural continuity with the onion-like structure of the main lobe of 67P. Despite the dusty blanket observable on Hapi, its terrains are characterized by water-ice-rich components that, once repeatedly and rapidly illuminated, sublimate, hence resulting in the strong jet activity observed in 2014 August.© 2019 The Author(s)., The support of the national funding agencies of Germany (DLR), Italy (ASI), France (CNES), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged.
Published: 2019

27. Future science goals of in situ Lunar explorations

Author: Sabrina Ferrari and Matteo Massironi
Subjects: 010504 meteorology & atmospheric sciences, Situation awareness, Lunar regolith, Moon volcanism, Exploration of Mars, 01 natural sciences, Regolith, Subsurface structures, Human exploration, Mantle (API), In situ activities, Moon interior, 0103 physical sciences, Cratering processes, Earth-Moon impact history, Lunar crust, Lunar volatiles, Ground segment, 010303 astronomy & astrophysics, Environmental planning, 0105 earth and related environmental sciences
Abstract: Many space agencies have now consolidated road-maps foreseeing intensive Lunar exploration during this and the next decades. The new era of Moon exploration is seen as a precursor of future more ambitious Mars missions and as such will imply intensive in situ activities involving both humans and rovers. Although the operational concepts will substantially change with respect to the Apollo era and a more immersive situation awareness even of scintists on the ground segment can be easily foreseeable, the main science goals will be largely represented by the open questions leaved behind in the Seventies and only partly covered by the following orbital and limited rover missions. They include the understanding of Lunar crustal and mantle evolutions, a better definition of its inner structure, volcanism and cratering history and the assessment of the regolith properties. To these subjects can be added some important ones more related to future settlements such as the Lunar volatiles and in situ resources. All these goals will greatly benefit of the involvement of astronauts and the use of flexible and managiable instrumention that should guarantee a prompt and correct sampling although not a comprehensive catherization of the Lunar materials.
Published: 2019

28. The backscattering ratio of comet 67P/Churyumov-Gerasimenko dust coma as seen by OSIRIS onboard Rosetta

Author: Pamela Cambianica, F. La Forgia, Jean-Loup Bertaux, P. J. Gutierrez, Alice Lucchetti, E. Frattin, Alessandra Rotundi, Detlef Koschny, Pedro Hasselmann, Xian Shi, Wing-Huen Ip, Giovanna Rinaldi, Philippe Lamy, Carsten Güttler, Giampiero Naletto, Stefano Mottola, Monica Lazzarin, Marco Fulle, J. J. Lopez Moreno, Sabrina Ferrari, Nafiseh Masoumzadeh, M. A. Barucci, H. U. Keller, D. Guirado, Imre Toth, V. Petropoulou, Gábor L. Kovács, Holger Sierks, Gabriele Cremonese, M. De Cecco, Cesare Barbieri, L. M. Lara, Björn Davidsson, Jakob Deller, Dennis Bodewits, S. Ivanovsky, Francesca Ferri, Cecilia Tubiana, Luca Penasa, Jessica Agarwal, Stefano Debei, Ivano Bertini, Maurizio Pajola, Olga Muñoz, Francesco Marzari, S. Fornasier, Matteo Massironi, F. Moreno, R. Rodrigo, V. Da Deppo, German Centre for Air and Space Travel, Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Ministerio de Educación y Ciencia (España), Swedish National Space Agency, European Space Agency, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Dipartimento di Scienze e Tecnologie [Napoli] (DIST), Universita degli studi di Napoli 'Parthenope' [Napoli], INAF - Osservatorio Astronomico di Padova (OAPD), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Department of Physics [Auburn], Auburn University (AU), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), CNR Institute for Photonics and Nanotechnologies (IFN), Department of Industrial Engineering [Padova], University of Trento [Trento], Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Dipartimento di Geoscienze [Padova], Fulle, M. [0000-0001-8435-5287], Tubiana, C. [0000-0001-8475-9898], Güttler, C. [0000-0003-4277-1738], Pajola, M. [0000-0002-3144-1277], Rinaldi, G. [0000-0002-2968-0455], Naletto, G. [0000-0003-2007-3138], Barucci, M. A. [0000-0002-1345-0890], Bertaux, J. L. [0000-0003-0333-229X], Deller, J. [0000-0001-8341-007X], Fornasier, S. [0000-0001-7678-3310], Penasa, L. [0000-0002-6394-3108], Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), IMPEC - LATMOS, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), NASA-California Institute of Technology (CALTECH), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Braunschweig [Braunschweig], Università degli Studi di Padova = University of Padua (Unipd), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Napoli 'Parthenope' = University of Naples (PARTHENOPE), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA), and Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Subjects: 67P/Churyumov-Gerasimenko, Asteroiden und Kometen, 010504 meteorology & atmospheric sciences, photometry, Comet, data analysis, scattering –methods: data analysis – techniques: image processing – techniques: photometric – comets: individual: 67P/Churyumov-Gerasimenko, techniques: image processing, Astrophysics, 01 natural sciences, Photometry (optics), Scattering, techniques: photometric, individual: 67P/Churyumov-Gerasimenko [Comets], 0103 physical sciences, Churyumov–Gerasimenko, image processing [Techniques], data analysis [Methods], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], scattering, methods: data analysis, techniques: image processing, techniques: photometric, comets: individual: 67P/Churyumov-Gerasimenko, Phase angle, scattering, photometric [Techniques], comets: individual: 67P/Churyumov-Gerasimenko, Astronomy and Astrophysics, biology.organism_classification, methods: data analysis, image processing, 13. Climate action, Space and Planetary Science, Drag, Temporal resolution, Inverse scattering problem, Osiris, individual: 67P [Comets], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Remote sensing observations of dust particles ejected from comets provide important hints on the intimate nature of the materials composing these primitive objects. The measurement of dust coma backscattering ratio, BSR, defined as the ratio of the reflectance at phase angle 0 ◦ and 30 ◦ , helps tuning theoretical models aimed at solving the inverse scattering problem deriving information on the nature of the ejected particles. The Rosetta/OSIRIS camera sampled the coma phase function of comet 67P, with four series acquired at low phase angles from 2015 January to 2016 May. We also added previously published data to our analysis to increase the temporal resolution of our findings. We measured a BSR in the range ∼ [1.7-3.6], broader than the range found in literature from ground-based observations of other comets. We found that during the post-perihelion phase, the BSR is systematically larger than the classical cometary dust values only for nucleocentric distances smaller than ∼ 100 km. We explain this trend in terms of a cloud of chunks orbiting the nucleus at distances < 100 km ejected during perihelion and slowly collapsing on the nucleus over a few months because of the coma gas drag. This also implies that the threshold particle size for the dust phase function to become similar to the nucleus phase function is between 2.5 mm and 0.1 m, taking into account previous Rosetta findings. © 2018 The Author(s)., The support of the national funding agencies of Germany (DLR: Deutschen Zentrums fur Luft-und Raumfahrt), France (CNES: Centre national d' etudes spatiales), Italy (ASI: Agenzia Spaziale Italiana), Spain (MEC: Ministry of Education& Science), Sweden (SNSB: Swedish National Space Board), and the European Space Agency (ESA) Technical Directorate is gratefully acknowledged.
Published: 2019

29. Quantitative analysis of isolated boulder fields on comet 67P/Churyumov-Gerasimenko

Author: Philippe Lamy, G. Cremonese, W.-H. Ip, Pamela Cambianica, Marco Fulle, Sabrina Ferrari, Dennis Bodewits, Matteo Massironi, Alice Lucchetti, Frank Scholten, Jean-Loup Bertaux, P. J. Gutierrez, F. La Forgia, Björn Davidsson, Francesco Marzari, Carsten Güttler, Z. Y. Lin, Jakob Deller, Cecilia Tubiana, Ivano Bertini, Detlef Koschny, M. De Cecco, Monica Lazzarin, M. A. Barucci, Holger Sierks, Emanuele Simioni, H. U. Keller, S. Fornasier, R. Rodrigo, Stefano Debei, L. M. Lara, V. Da Deppo, Xian Shi, Stefano Mottola, J.-B. Vincent, Giampiero Naletto, Luca Penasa, Maurizio Pajola, Imre Tóth, J. J. Lopez-Moreno, Cambianica, P. [https://orcid.org/0000-0002-8091-4915], European Space Agency (ESA), Centre National D'Etudes Spatiales (CNES), Agencia Estatal de Investigación (AEI), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Agenzia Spaziale Italiana (ASI), Swedish National Space Agency (SNSA), German Centre for Air and Space Travel, Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Agencia Estatal de Investigación (España), European Space Agency, Swedish National Space Agency, Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Dipartimento di Fisica e Astronomia 'Galileo Galilei', CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Dipartimento di Geoscienze [Padova], Department of Physics [Auburn], Auburn University (AU), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), IMPEC - LATMOS, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), NASA-California Institute of Technology (CALTECH), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), and Technische Universität Braunschweig [Braunschweig]
Subjects: 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, Comets, Data analysis, General, Individual, Methods, Population, Comet, Narrow angle, Geometry, Astrophysics, 01 natural sciences, Power law, Fractal, individual: 67P/Churyumov-Gerasimenko [Comets], Power index, 0103 physical sciences, education, data analysis [Methods], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, [PHYS]Physics [physics], Physics, Comets: individual: 67P/Churyumov-Gerasimenko, education.field_of_study, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], general [Comets], Astronomy and Astrophysics, methods: data analysis, Comets: general, Space and Planetary Science, Spatial ecology, comets: general – comets: individual: 67P/Churyumov-Gerasimenko – methods: data analysis, Sublimation (phase transition), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: We provide a detailed quantitative analysis of isolated boulder fields situated in three different regions of comet 67P/Churyumov-Gerasimenko: Imhotep, Hapi, and Hatmehit. This is done to supply a useful method for analyzing the morphology of the boulders and to characterize the regions themselves. Methods. We used OSIRIS Narrow Angle Camera images with a spatial scale smaller than 2 mpx(-1) and analyzed the size-frequency distribution and the cumulative fractional area per boulder population. In addition, we correlated shape parameters, such as circularity and solidity, with both the spatial and the size-frequency distribution of the three populations. Results. We identified 11 811 boulders in the Imhotep, Hapi, and Hatmehit regions. We found that the Hatmehit and Imhotep areas show power indices in the range of -2.3/-2.7. These values could represent a transition between gravitational events caused by thermal weathering and sublimation, and material formed during collapses that has undergone sublimation. The Hapi area is characterized by a lower power index (-1.2/-1.7), suggesting that those boulders have a different origin. They can be the result of material formed during gravitational events and collapses that has undergone continuous fragmentation. We calculated the cumulative fractional area (CFA) in order to investigate how the area is covered by boulders as a function of their sizes. The Hatmehit and Imhotep regions show a CFA that is well fit by a power law. In contrast, the Hapi area does not show the same trend. We analyzed the fractal distributions, finding that the populations seem to be fractal at all dimensions, except for the Hapi distribution, which shows a possible fractal behavior for small dimensions only. Finally, the average values of the shape parameters reveal solid and roundish boulders in all populations we studied.© ESO 2019, OSIRIS was built by a consortium of the Max-Planck Institut fur Sonnensystemforschung, in Guttingen, Germany, CISAS University of Padova, Italy, the Laboratoire de Astrophysique de Marseille, France, the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, the Research and Scientific Support Department of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut fur Datentechnik und Kommunikationsnetze der Technischen Universitat Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. We thank the ESA teams at ESAC, ESOC and ESTEC for their work in support of the Rosetta mission. We made use of Arcgis 10.3.1 software together with the Matlab, Java, and ImageJ software to perform our analysis. I thank Frederic Moisy for sharing the box-count work.
Published: 2019

30. Rosetta/OSIRIS observations of the 67P nucleus during the April 2016 flyby: High-resolution spectrophotometry

Author: H. U. Keller, Alice Lucchetti, M. De Cecco, Giampiero Naletto, D. Bodewits, Monica Lazzarin, Francesco Marzari, R. Rodrigo, P. J. Gutiérrez, Maurizio Pajola, Sonia Fornasier, J. D. P. Deshapriya, Stefano Debei, F. La Forgia, A. Barucci, J. J. López-Moreno, V. Da Deppo, Frank Preusker, Wing-Huen Ip, Philippe Lamy, Matteo Massironi, C. Feller, Holger Sierks, Pedro Hasselmann, Gabriele Cremonese, Björn Davidsson, Cecilia Tubiana, Luisa Lara, B. Gaskell, Carsten Güttler, Frank Scholten, Ivano Bertini, Marco Fulle, Sabrina Ferrari, Xian Shi, Stefano Mottola, Jean-Loup Bertaux, Detlef Koschny, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), International Space Science Institute [Bern] (ISSI), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Department of Physics [Auburn], Auburn University (AU), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Planetary Science Institute [Tucson] (PSI), Feller, C. [0000-0002-2941-3875], Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, German Centre for Air and Space Travel, Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Agencia Estatal de Investigación (España), European Space Agency, Swedish National Space Agency, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), NASA-California Institute of Technology (CALTECH), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), and Technische Universität Braunschweig [Braunschweig]
Subjects: Asteroiden und Kometen, 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, techniques: image processing, Astrophysics, 01 natural sciences, individual: 67P/Churyumov-Gerasimenko [Comets], Frost line, Spectrophotometry, Spectral slope, Methods, Churyumov–Gerasimenko, image processing [Techniques], space vehicles: instruments, data analysis [Methods], 010303 astronomy & astrophysics, Earth and Planetary Astrophysics (astro-ph.EP), Comets: individual: 67P/Churyumov-Gerasimenko, Physics, [PHYS]Physics [physics], biology, medicine.diagnostic_test, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Resolution (electron density), Comets, Data analysis, Image processing, Individual, Instruments, Space vehicles, Techniques, individual: 67P [Comets], Comet, FOS: Physical sciences, Terrain, Context (language use), instruments [Space vehicles], 0103 physical sciences, medicine, 0105 earth and related environmental sciences, Planetengeodäsie, space vehicles – space vehicles: instruments – comets: individual: 67P/Churyumov–Gerasimenko – techniques: image processing – methods: data analysis, Astronomy and Astrophysics, biology.organism_classification, methods: data analysis, 13. Climate action, Space and Planetary Science, Osiris, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: From August 2014 to September 2016, the Rosetta spacecraft followed comet 67P/Churyumov-Gerasimenko along its orbit. After the comet passed perihelion, Rosetta performed a flyby manoeuvre over the Imhotep-Khepry transition in April 2016. The OSIRIS/Narrow-Angle-Camera (NAC) acquired 112 observations with mainly three broadband filters (centered at 480, 649, and 743 nm) at a resolution of up to 0.53 m/px and for phase angles between 0.095 degrees and 62 degrees. Aims. We have investigated the morphological and spectrophotometrical properties of this area using the OSIRIS/NAC high-resolution observations. Methods. We assembled the observations into coregistered color cubes. Using a 3D shape model, we produced the illumination conditions and georeference for each observation. We mapped the observations of the transition to investigate its geomorphology. Observations were photometrically corrected using the Lommel-Seeliger disk law. Spectrophotometric analyses were performed on the coregistered color cubes. These data were used to estimate the local phase reddening. Results. The Imhotep-Khepry transition hosts numerous and varied types of terrains and features. We observe an association between a feature's nature, its reflectance, and its spectral slopes. Fine material deposits exhibit an average reflectance and spectral slope, while terrains with diamictons, consolidated material, degraded outcrops, or features such as somber boulders present a lower-than-average reflectance and higher-than-average spectral slope. Bright surfaces present here a spectral behavior consistent with terrains enriched in water-ice. We find a phase-reddening slope of 0.064 +/- 0.001%/100 nm/degrees at 2.7 au outbound, similar to the one obtained at 2.3 au inbound during the February 2015 flyby. Conclusions. Identified as the source region of multiple jets and a host of water-ice material, the Imhotep-Khepry transition appeared in April 2016, close to the frost line, to further harbor several potential locations with exposed water-ice material among its numerous different morphological terrain units.© ESO 2019, OSIRIS was built by a consortium of the Max-Planck-Institut fur Sonnensystemforschung, Gottingen, Germany, CISAS-University of Padova, Italy, Laboratoire d'Astrophysique de Marseille, France, Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, Research and Scientific Support Department of the European Space Agency, Noordwijk, The Netherlands, Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, Universidad Politechnica de Madrid, Spain, Department of Physics and Astronomy of Uppsala University, Sweden, and Institut fur Datentechnik und Kommunikationsnetze der Technischen Universitat Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. Rosetta is an ESA mission with contributions from its member states and NASA. Rosetta's Philae lander is provided by a consortium led by DLR, MPS, CNES, and ASI. The SPICE libraries and PDS resources are developed and maintained by NASA. The authors thank the referee and editors for their questions, remarks, and advices for the improvement of this article.
Published: 2019

31. Linking surface morphology, composition, and activity on the nucleus of 67P/Churyumov-Gerasimenko

Author: Jessica Agarwal, J. Deller, Pedro J. Gutiérrez, R. Rodrigo, Monica Lazzarin, Gabriele Cremonese, Holger Sierks, J. D. P. Deshapriya, Stefano Debei, D. Bodewits, Björn Davidsson, Cecilia Tubiana, Imre Toth, Pedro Hasselmann, Giampiero Naletto, Marco Fulle, Sabrina Ferrari, M. A. Barucci, Sonia Fornasier, Carsten Güttler, J. J. Lopez Moreno, Wing-Huen Ip, Philippe Lamy, Cesare Barbieri, Jean-Loup Bertaux, M. De Cecco, F. La Forgia, M. Küppers, Z. Y. Lin, Maurizio Pajola, M. L. Lara, Ivano Bertini, H. U. Keller, V. Da Deppo, Francesco Marzari, C. Feller, Van H. Hoang, Detlef Koschny, Xian Shi, Stefano Mottola, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Hanoi], Vietnam Academy of Science and Technology (VAST), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Dipartimento di Fisica e Astronomia 'Galileo Galilei', CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Department of Mechanical Engineering [Padova], Department of Industrial Engineering [Padova], Universita degli Studi di Padova-Universita degli Studi di Padova, University of Trento [Trento], Dipartimento di Geoscienze [Padova], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Institute of Astronomy [Taiwan] (IANCU), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], European Space Astronomy Centre (ESAC), European Space Agency (ESA), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), NASA-California Institute of Technology (CALTECH), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Technische Universität Braunschweig [Braunschweig], ITA, USA, GBR, FRA, DEU, Federal Ministry of Education and Research (Germany), Agence Nationale de la Recherche (France), Agenzia Spaziale Italiana, Ministerio de Ciencia, Innovación y Universidades (España), and Government of Sweden
Subjects: Asteroiden und Kometen, 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, Comet, observational [methods], Data analysis, FOS: Physical sciences, Coma (optics), Individual, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Photometric, 01 natural sciences, photometric [techniques], techniques: photometric, individual: 67P/Churyumov-Gerasimenko [Comets], Comet nucleus, 0103 physical sciences, medicine, data analysis [methods], Comets, Methods, 010303 astronomy & astrophysics, Observational, Optical depth, 0105 earth and related environmental sciences, Physics, Comets: individual: 67P/Churyumov-Gerasimenko, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Techniques, Resolution (electron density), Astronomy and Astrophysics, methods: data analysis, Plume, medicine.anatomical_structure, 13. Climate action, Space and Planetary Science, comets: individual: 67P/Churyumov-Gerasimenko – methods: data analysis – methods: observational – techniques: photometric, Radiance, Astrophysics::Earth and Planetary Astrophysics, methods: observational, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Nucleus, Astrophysics - Earth and Planetary Astrophysics
Abstract: Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., The Rosetta space probe accompanied comet 67P/Churyumov-Gerasimenko for more than two years, obtaining an unprecedented amount of unique data of the comet nucleus and inner coma. This has enabled us to study its activity almost continuously from 4 au inbound to 3.6 au outbound, including the perihelion passage at 1.24 au. This work focuses identifying the source regions of faint jets and outbursts and on studying the spectrophotometric properties of some outbursts. We use observations acquired with the OSIRIS/NAC camera during July-October 2015, that is, close to perihelion. Methods. We analyzed more than 2000 images from NAC color sequences acquired with 7-11 filters covering the 250-1000 nm wavelength range. The OSIRIS images were processed with the OSIRIS standard pipeline up to level 3, that is, converted in radiance factor, then corrected for the illumination conditions. For each color sequence, color cubes were produced by stacking registered and illumination-corrected images. Results. More than 200 jets of different intensities were identified directly on the nucleus. Some of the more intense outbursts appear spectrally bluer than the comet dark terrain in the visible-to-near-infrared region. We attribute this spectral behavior to icy grains mixed with the ejected dust. Some of the jets have an extremely short lifetime. They appear on the cometary surface during the color sequence observations, and vanish in less than some few minutes after reaching their peak. We also report a resolved dust plume observed in May 2016 at a resolution of 55 cm pixel(-1), which allowed us to estimate an optical depth of similar to 0.65 and an ejected mass of similar to 2200 kg, assuming a grain bulk density of similar to 800 kg m(-3). We present the results on the location, duration, and colors of active sources on the nucleus of 67P from the medium-resolution (i.e., 6-10 m pixel(-1)) images acquired close to perihelion passage. The observed jets are mainly located close to boundaries between different morphological regions. Some of these active areas were observed and investigated at higher resolution (up to a few decimeter per pixel) during the last months of operations of the Rosetta mission. Conclusions. These observations allow us to investigate the link between morphology, composition, and activity of cometary nuclei. Jets depart not only from cliffs, but also from smooth and dust-covered areas, from fractures, pits, or cavities that cast shadows and favor the recondensation of volatiles. This study shows that faint jets or outbursts continuously contribute to the cometary activity close to perihelion passage, and that these events are triggered by illumination conditions. Faint jets or outbursts are not associated with a particular terrain type or morphology.© S. Fornasier et al. 2019, OSIRIS was built by a consortium led by the Max-Planck-Institut fur Sonnensystemforschung, Goettingen, Germany, in collaboration with CISAS, University of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, the Scientific Support Office of the European Space Agency, Noordwijk, the Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut fur Datentechnik und Kommunikationsnetze der Technischen Universitat Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. We thank the Rosetta Science Ground Segment at ESAC, the Rosetta Mission Operations Centre at ESOC and the Rosetta Project at ESTEC for their outstanding work enabling the science return of the Rosetta Mission. S.F. acknowledges the financial support from the France Agence Nationale de la Recherche (programme Classy, ANR-17-CE31-0004). The authors thank H. Campins for his comments that helped us improve this article. The authors would like to thank Andrew Cooper and Marco Parigi for spotting the inconsistencies in regional boundaried of Fig. 1 in the online preprint version of the paper.
Published: 2019

32. Gaining a global perspective on the surface composition of Venus from orbit through near infrared observations – with a little help from machine learning approaches

Author: Jörn Helbert, Melinda Dyar, Alessandro Maturilli, Mario D'Amore, Sabrina Ferrari, and Indhu Varatharajan
Published: 2018

33. Hospital-Based Influenza and Pneumococcal Vaccination for Cancer Patients on Active Treatment and Their Family Members during the COVID-19 Pandemic in Italy: A Single-Center Experience

Author: Davide Dalu, Anna Lisa Ridolfo, Lorenzo Ruggieri, Maria Silvia Cona, Agostino Riva, Davide De Francesco, Chiara Tricella, Cinzia Fasola, Sabrina Ferrario, Anna Gambaro, Benedetta Lombardi Stocchetti, Valeria Smiroldo, Gaia Rebecchi, Sheila Piva, Giorgia Carrozzo, Spinello Antinori, and Nicla La Verde
Subjects: hospital vaccination, influenza, pneumococcal, cancer, Medicine
Abstract: In patients with cancer, tumor- and treatment-induced immunosuppression are responsible for a four-fold increase in morbidity and mortality caused by influenza and invasive Streptococcus pneumoniae infections compared to the general population. The main oncology societies strongly recommend vaccination in patients with cancer to prevent these infections. However, vaccine hesitancy is a main concern in this population. The aim of this study was to assess the feasibility of in-hospital vaccination for patients under anticancer treatment and their family members (FMs) against influenza and pneumococcal infections during the COVID-19 pandemic in order to increase vaccine coverage. This was a single-center, prospective, observational study conducted at the Department of Oncology of Luigi Sacco University Hospital (Milan, Italy) between October 2020 and April 2021. The main primary outcome was the incidence of influenza-like illness (ILI) and pneumococcal infections. The main secondary outcome was safety. A total of 341 subjects were enrolled, including 194 patients with cancer and 147 FMs. The incidence of ILI was higher among patients than among FMs (9% vs. 2.7%, OR 3.92, p = 0.02). Moreover, two subjects were diagnosed with pneumococcal pneumonia. The most frequent vaccine-related AEs were pain in the injection site (31%) and fatigue (8.7%). In conclusion, this hospital-based vaccination strategy was feasible during the COVID-19 pandemic, representing a potential model to maximize vaccine coverage during a public health emergency.
Published: 2024
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34. Clinical efficacy of the first two doses of anti‐SARS‐CoV‐2 mRNA vaccines in solid cancer patients

Author: Maria Silvia Cona, Agostino Riva, Davide Dalu, Arianna Gabrieli, Cinzia Fasola, Giuseppe Lipari, Giacomo Pozza, Eliana Rulli, Francesca Galli, Lorenzo Ruggieri, Elsa Masedu, Gaia Parma, Davide Chizzoniti, Anna Gambaro, Sabrina Ferrario, Maria Antista, Matteo De Monte, Maciej S. Tarkowski, and Nicla La Verde
Subjects: Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract: Abstract Introduction Cancer patients are frail individuals, thus the prevention of SARS‐CoV‐2 infection is essential. To date, vaccination is the most effective tool to prevent COVID‐19. In a previous study, we evaluated the immunogenicity of two doses of mRNA‐based vaccines (BNT162b2 or mRNA‐1273) in solid cancer patients. We found that seroconversion rate in cancer patients without a previous exposure to SARS‐CoV‐2 was lower than in healthy controls (66.7% vs. 95%, p = 0.0020). The present study aimed to evaluate the clinical efficacy of the vaccination in the same population. Methods This is a single‐institution, prospective observational study. Data were collected through a predefined questionnaire through phone call in the period between the second and third vaccine dose. The primary objective was to describe the clinical efficacy of the vaccination, defined as the percentage of vaccinated subjects who did not develop symptomatic COVID‐19 within 6 months after the second dose. The secondary objective was to describe the clinical features of patients who developed COVID‐19. Results From January to June 2021, 195 cancer patients were enrolled. Considering that 7 (3.59%) patients tested positive for SARS‐CoV‐2 and 5 developed symptomatic disease, the clinical efficacy of the vaccination was 97.4%. COVID‐19 disease in most patients was mild and managed at home; only one hospitalization was recorded and no patient required hospitalization in the intensive care unit. Discussion Our study suggests that increasing vaccination coverage, including booster doses, could improve the prevention of infection, hospitalization, serious illness, and death in the frail population of cancer patients.
Published: 2023
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35. Shallow crustal composition of Mercury as revealed by spectral properties and geological units of two impact craters

Author: Noam R. Izenberg, Jörn Helbert, Piero D'Incecco, Rachel L. Klima, William E. McClintock, Sabrina Ferrari, Harald Hiesinger, James W. Head, Mario D'Amore, and Alessandro Maturilli
Subjects: Spectrometer, Stratigraphy, Leitungsbereich PF, Mineralogy, chemistry.chemical_element, Astronomy and Astrophysics, Crust, Mercury, Geophysics, MASCS, Spectral line, Mercury (element), Wavelength, Impact crater, chemistry, Impact craters, Space and Planetary Science, Spectral slope, MESSENGER, MDIS, Spectrograph, Geology
Abstract: We have performed a combined geological and spectral analysis of two impact craters on Mercury: the 15 km diameter Waters crater (106°W; 9°S) and the 62.3 km diameter Kuiper crater (30°W; 11°S). Using the Mercury Dual Imaging System (MDIS) Narrow Angle Camera (NAC) dataset we defined and mapped several units for each crater and for an external reference area far from any impact related deposits. For each of these units we extracted all spectra from the MESSENGER Atmosphere and Surface Composition Spectrometer (MASCS) Visible-InfraRed Spectrograph (VIRS) applying a first order photometric correction. For all the mapped units, we analyzed the spectral slope in two wavelength ranges, 350–450 nm and 450–650 nm, and the absolute reflectance in the 700–750 nm range. Normalized spectra of Waters crater display a generally bluer spectral slope than the external reference area over both wavelength windows. Normalized spectra of Kuiper crater generally display a redder slope than the external reference area in the 350–450 nm window, while they display a bluer slope than the external reference area in the 450–650 nm wavelength range. The combined use of geological and spectral analyses enables reconstruction of the local scale stratigraphy beneath the two craters, providing insight into the properties of the shallower crust of Mercury. Kuiper crater, being ~4 times larger than Waters crater, exposes deeper layers with distinctive composition, while the result for Waters crater might indicate substantial compositional homogeneity with the surrounding intercrater plains, though we cannot exclude the occurrence of horizontal compositional heterogeneities in the shallow sub-surface.
Published: 2015

36. The Venus Emissivity Mapper (VEM): Obtaining global mineralogy of Venus from orbit

Author: Constantine Tsang, Dennis Wendler, Gabriel Guignan, Emmanuel Marcq, Joern Helbert, Judit Jaenchen, Gabriele Arnold, Nils Mueller, Darby Dyar, Anko Boerner, Mario D'Amore, Suzanne E. Smrekar, Ingo Walter, Alessandro Maturilli, David Kappel, Sabrina Ferrari, Thomas Widemann, DLR Institute of Planetary Research, German Aerospace Center (DLR), Mount Holyoke College, DLR Institute for Optical Sensorsystems, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), DLR Institut für Planetenforschung, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Università di Pavia, Southwest Research Institute [Boulder] (SwRI), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Marija Strojnik, Maureen S. Kirk (eds.), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Università degli Studi di Pavia, California Institute of Technology (CALTECH)-NASA, Imperial College London, DLR Institute of Optical Sensor Systems, and Università degli Studi di Pavia = University of Pavia (UNIPV)
Subjects: Asteroiden und Kometen, spectroscopy, Weltrauminstrumente, 010504 meteorology & atmospheric sciences, Multispectral image, Venus, 01 natural sciences, law.invention, remote sensing, Planetenphysik, law, 0103 physical sciences, Emissivity, Radar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing, Echtzeit-Datenprozessierung, Venus Emissivity Mapper, biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Near-infrared spectroscopy, Leitungsbereich PF, Global Map, biology.organism_classification, Planetary science, 13. Climate action, composition, Orbit (dynamics), Environmental science, Planetare Sensorsysteme
Abstract: The Venus Emissivity Mapper is the first flight instrument designed to focus on mapping the surface of Venus using atmospheric windows around 1 micron. After several years of development, VEM has a mature design with an existing laboratory prototype verifying an achievable instrument SNR of well above 1000, as well as predicted error in retrieval of relative emissivity of better than 1%, assuming the availability of an improved Venus topography. It will provide a global map of rock type, iron contents and redox state of the surface by observing the surface with six narrow band filters, ranging from 0.86 to 1.18 micron. Three additional windows allow corrections for cloud composition and variability, two measure water abundance, and three compensate for stray light. Continuous observation of Venus' thermal emission will also place tighter constraints on current day volcanic activity. Eight of the channels provide measurements of atmospheric water vapor abundance as well as cloud microphysics and dynamics and permit accurate correction of atmospheric interference on the surface data. Combining VEM with a high-resolution radar mapper, such as on the ESA EnVision or NASA VERITAS mission proposals, will provide key insights into the divergent evolution of Venus and Earth.
Published: 2018

37. Analysis of the MESSENGER MASCS photometric targets part I: Photometric standardization for examining spectral variability across mercury's surface

Author: Noam R. Izenberg, Deborah L. Domingue, Mario D'Amore, Sabrina Ferrari, and Jörn Helbert
Subjects: photometry, 010504 meteorology & atmospheric sciences, Standardization, Astrophysics::Cosmology and Extragalactic Astrophysics, MASCS, 01 natural sciences, Atmosphere of Mercury, Photometry (optics), 0103 physical sciences, surface, Astrophysics::Solar and Stellar Astrophysics, spectroscopy Mercury, 010303 astronomy & astrophysics, Spectrograph, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Remote sensing, Spectrometer, Astrophysics::Instrumentation and Methods for Astrophysics, Solution set, Astronomy and Astrophysics, Planetary Data System, Data set, Mercury photometric corrrection hapke MESSENGER Shkuratov, Space and Planetary Science, MESSENGER, Environmental science, Astrophysics::Earth and Planetary Astrophysics
Abstract: Examination of the Mercury Atmosphere and Surface Composition Spectrometer (MASCS) photometry sequence data sets, and comparison of modeling results using both the Hapke and Kaasalainen–Shkuratov models show that these models can provide an improved photometric standardization to the MASCS's Visible and InfraRed Spectrograph (VIRS) data sets over the current empirical correction. Properties of the MASCS photometric data set are less constraining of the Hapke model, producing more than one mathematically viable solution set of parameters. The Kaasalainen–Shkuratov model, while simpler, produces a single mathematically viable solution set to the global MASCS photometric data set, and was selected by the MASCS instrument team to provide an updated photometric standardization for the team's final delivery to the Planetary Data System archive.
Published: 2018

38. Morphological and spectrophotometric investigation of the layering of comet 67P/Churyumov-Gerasimenko

Author: Sabrina Ferrari, Matteo Massironi, Luca Penasa, Gloria Tognon, Monica Lazzarin, Fiorangela La Forgia, and Giampiero Naletto
Subjects: Comet, Layering, Geology, Astrobiology
Published: 2018

39. The big lobe of 67P/Churyumov–Gerasimenko comet: morphological and spectrophotometric evidences of layering as from OSIRIS data

Author: P. J. Gutierrez, Xian Shi, Carsten Güttler, Pedro Hasselmann, J. J. López-Moreno, Matteo Massironi, Monica Lazzarin, Detlef Koschny, Stubbe F. Hviid, M. A. Barucci, Björn Davidsson, Cecilia Tubiana, Ivano Bertini, Pamela Cambianica, Nicolas Thomas, Michael Küppers, Francesca Ferri, Luca Penasa, Francesco Marzari, M. De Cecco, W-H. Ip, J. L. Bertaux, Marco Franceschi, Laurent Jorda, Holger Sierks, J.-B. Vincent, Olivier Groussin, E. Frattin, F. La Forgia, Stefano Debei, Philippe Lamy, Jakob Deller, Maurizio Pajola, Nilda Oklay, Giampiero Naletto, Ekkehard Kührt, Sonia Fornasier, L. M. Lara, V. Da Deppo, Marco Fulle, Jörg Knollenberg, Emanuele Simioni, Sabrina Ferrari, R. Rodrigo, Gabriele Cremonese, Alice Lucchetti, H. U. Keller, Dennis Bodewits, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Dipartimento di Fisica e Astronomia 'Galileo Galilei', CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Fundacion Galileo Galilei, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, CNR Institute for Photonics and Nanotechnologies (IFN), Department of Industrial Engineering [Padova], Dipartimento di Geoscienze [Padova], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Operations Department (ESAC), European Space Astronomy Centre (ESAC), Physikalisches Institut [Bern], Universität Bern [Bern], Center for Space and Habitability (CSH), University of Bern, German Centre for Air and Space Travel, Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Agencia Estatal de Investigación (España), European Space Agency, Swedish National Space Agency, Ferrari, Sabrina, Penasa, L., La Forgia, F., Massironi, M., Naletto, G., Lazzarin, M., Fornasier, S., Hasselmann, P. H., Lucchetti, A., Pajola, M., Ferri, F., Cambianica, Pamela, Oklay, N., Tubiana, C., Sierks, H., Lamy, P. L., Rodrigo, R., Koschny, D., Davidsson, B., Barucci, M. A., Bertaux, J. -L., Bertini, I., Bodewits, D., Cremonese, G., Da Deppo, V., Debei, S., De Cecco, M., Deller, J., Franceschi, M., Frattin, Elisa, Fulle, M., Groussin, O., Gutiérrez, P. J., Güttler, C., Hviid, S. F., Ip, W. -H., Jorda, L., Keller, H. U., Knollenberg, J., Kührt, E., Küppers, M., Lara, L. M., López-Moreno, J. J., Marzari, F., Shi, X., Simioni, E., Thomas, N., Vincent, J. -B., Università degli Studi di Padova = University of Padua (Unipd), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), NASA-California Institute of Technology (CALTECH), Universität Bern [Bern] (UNIBE), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), and Technische Universität Braunschweig [Braunschweig]
Subjects: 67P/Churyumov-Gerasimenko, Brightness, Comets: general, Comets: individual: 67P/Churyumov-Gerasimenko, Methods: data analysis, Techniques: image processing, Astronomy and Astrophysics, Space and Planetary Science, 010504 meteorology & atmospheric sciences, Multispectral image, Comet, Data analysis, Mineralogy, Spatial distribution, 01 natural sciences, Texture (geology), Image processing, individual: 67P/Churyumov-Gerasimenko [Comets], 0103 physical sciences, medicine, Comets, image processing [Techniques], spectral variegation, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], biology, OSIRIS cameras, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 520 Astronomy, general [Comets], Astronomy and Astrophysic, biology.organism_classification, 620 Engineering, Lobe, data analysi [Methods], medicine.anatomical_structure, multiple-filters, Variegation (histology), Osiris
Abstract: Between 2014 and 2016, ESA's Rosetta OSIRIS cameras acquired multiple-filters images of the layered nucleus of comet 67P/Churyumov-Gerasimenko, ranging from ultraviolet to near-infrared wavelengths. No correlation between layers disposition and surface spectral variegation has been observed so far. This paper investigates possible spectral differences among decametre-thickness outcropping layers of the biggest lobe of the comet by means of OSIRIS image dataset. A two-classes maximum likelihood classification was applied on consolidated outcrops and relative deposits identified on post-perihelion multispectral images of the big lobe. We distinguished multispectral data on the basis of the structural elevation of the onion-shell Ellipsoidal Model of 67P. The spatial distribution of the two classes displays a clear dependence on the structural elevation, with the innermost class resulting over 50 per cent brighter than the outermost one. Consolidated cometarymaterials located at different structural levels are characterized by different brightness and revealed due to the selective removal of large volumes. This variegation can be attributed to a different texture of the outcrop surface and/or to a different content of refractory materials.© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society., We are grateful to Paul Helfenstein for corrections that improved our paper. OSIRIS was built by a consortium of the Max-Planck-Institut fur Sonnensystemforschung, in Goottingen, Germany, CISAS-University of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, the Research and Scientific Support Department of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut fur Datentechnik und Kommunikationsnetze der Technischen Universitat Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), Italy (ASI), France (CNES), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. We thank the ESA teams at ESAC, ESOC, and ESTEC for their work in support of the Rosetta mission.
Published: 2018

40. Mercury Hollows as Remnants of Original Bedrock Materials and Devolatilization Processes: A Spectral Clustering and Geomorphological Analysis

Author: Valentina Galluzzi, Lorenza Giacomini, Maurizio Pajola, Alice Lucchetti, G. A. Marzo, G. Cremonese, Sabrina Ferrari, Matteo Massironi, Pasquale Palumbo, Cristian Carli, Marzo, G. A., and ITA
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, tatistical analysi, Geochemistry, chemistry.chemical_element, Soil Science, Aquatic Science, Oceanography, 01 natural sciences, Mineralogical composition, mineralogical composition, hollows, statistical analysis, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Statistical analysis, spectral clustering, geomorphology, Mercury, Geomorphological analysis, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Geophysics, Forestry, Ecology, Water Science and Technology, Earth-Surface Processes, Space and Planetary Science, Paleontology, geography, geography.geographical_feature_category, Bedrock, hollow, Spectral clustering, Mercury (element), chemistry, Geology
Abstract: We perform a detailed geomorphological and compositional analysis on three craters hosting hollows located in the Victoria and Kuiper Quadrangles of Mercury. Based on Mercury Dual Imaging System data, high-resolution detailed geomorphological mapping is provided in order to fully characterize the geological framework where hollows formed. In addition, we apply an unsupervised spectral clustering, based on a K-mean algorithm, to separate in clusters our data sets. The comparison between the spectral and the well-defined geomorphological units reveals a spatially coherent distribution. In particular, all hollows are uniquely identified by a well-defined spectrum showing a wide absorption band between 0.558 and 0.828, with a possible hint of absorption toward 1 μm. Our analysis suggests that the composition of hollows may be characterized by a mixture of different minerals contributing to the absorptions found in our spectra. Indeed, sulfides alone (CaS, MnS, and MgS) cannot explain the spectrum behavior of hollows, even if the mechanism forming hollows likely involves the loss of volatiles from the surface. Hence, we have to consider bedrock-forming material as partial responsible of the absorptions. For the studied hollows we suggest that the bedrock-forming minerals are pyroxenes presenting transitional elements, like Cr, Ti, and Ni in substitution of Mg and/or Fe. Therefore, we suggest that the spectral characteristics of hollows are related to both remnant material produced by devolatilization process and to bedrock in which the hollows formed. ©2018. American Geophysical Union. All Rights Reserved.
Published: 2018

41. The Venus Emissivity Mapper concept

Author: Alessandro Maturilli, M. Darby Dyar, Gabriel Guignan, Nils Mueller, Mario D'Amore, Anko Boerner, Jörn Helbert, David Kappel, Thomas Widemann, Emmanuel Marcq, Judit Jaenchen, Suzanne E. Smrekar, Dennis Wendler, Gabriele Arnold, Sabrina Ferrari, Ingo Walter, Strojnik, Marija, Kirk, Maureen, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), DLR Institute for Optical Sensorsystems, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Pavia, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Department of Astronomy of the Mount Holyoke College, Mount Holyoke College, Marija Strojnik, Maureen S. Kirk (eds.), DLR Institute of Optical Sensor Systems, and Università degli Studi di Pavia = University of Pavia (UNIPV)
Subjects: Asteroiden und Kometen, spectroscopy, 010504 meteorology & atmospheric sciences, near infrared, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Venus, 01 natural sciences, law.invention, Hochgeschwindigkeitselektronik, Interference (communication), law, 0103 physical sciences, Emissivity, Circular orbit, Radar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing, Echtzeit-Datenprozessierung, geography, geography.geographical_feature_category, biology, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Leitungsbereich PF, Global Map, biology.organism_classification, Volcano, 13. Climate action, Planetare Sensorsysteme, Flight instruments
Abstract: International audience; The Venus Emissivity Mapper (VEM) is the first flight instrument specially designed with a sole focus on mapping the surface of Venus using the narrow atmospheric windows around 1μm. VEM will provide a global map of surface composition as well as redox state of the surface, providing a comprehensive picture of surface-atmosphere interaction on Venus. In addition, continuous observation of the thermal emission of the Venus will provide tight constraints on current day volcanic activity. These capabilities are complemented by measurements of atmospheric water vapor abundance as well as cloud microphysics and dynamic. Atmospheric data will allow for the accurate correction of atmospheric interference on the surface measurements and represent highly valuable science on their own. A mission combining VEM with a high-resolution radar mapper such as the NASA VOX or the ESA EnVision mission proposals in a low circular orbit will provide key insights in the divergent evolution of Venus.
Published: 2017

42. A three-dimensional modelling of the layered structure of comet 67P/Churyumov-Gerasimenko

Author: Hans Rickman, Matteo Massironi, J.-R. Kramm, Ivano Bertini, Stubbe F. Hviid, Francesco Marzari, P. J. Gutierrez, M. De Cecco, Emanuele Simioni, Ekkehard Kührt, L. M. Lara, Frank Scholten, Detlef Koschny, Cesare Barbieri, Maurizio Pajola, R. Rodrigo, V. Da Deppo, Jakob Deller, Frank Preusker, S. Fornasier, Monica Lazzarin, Jean-Baptiste Vincent, Giampiero Naletto, Francesca Ferri, Robert Gaskell, Jessica Agarwal, Wing-Huen Ip, J-C. Lee, Laurent Jorda, N. Thomas, M. A. Barucci, Björn Davidsson, Michael Küppers, Alice Lucchetti, M. F. A'Hearn, Clement Feller, Marc Hofmann, Cecilia Tubiana, Olivier Groussin, Stefano Debei, Gabriele Cremonese, Holger Sierks, Marco Fulle, Philippe Lamy, Sabrina Ferrari, J. J. Lopez Moreno, F. La Forgia, Nilda Oklay, Carsten Güttler, E. Frattin, Luca Penasa, J. L. Bertaux, H. U. Keller, Jörg Knollenberg, Xian Shi, Stefano Mottola, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Università degli Studi di Padova = University of Padua (Unipd), Dipartimento di Astronomia [Padova], INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), NASA Ames Research Center (ARC), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Planetary Science Institute [Tucson] (PSI), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Department of Physics and Astronomy [Uppsala], Uppsala University, Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Mechanical Engineering [Padova], Department of Industrial Engineering [Padova], Università degli Studi di Padova = University of Padua (Unipd)-Università degli Studi di Padova = University of Padua (Unipd), Università degli Studi di Trento (UNITN), INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Department of Earth Sciences [Chung-Li City], National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), DLR Institute of Planetary Research, German Aerospace Center (DLR), Operations Department (ESAC), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Universita degli Studi di Padova, Consiglio Nazionale delle Ricerche [Roma] (CNR), California Institute of Technology (CALTECH)-NASA, Max-Planck-Institut für Sonnensystemforschung (MPS), European Space Agency (ESA), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Universita degli Studi di Padova-Universita degli Studi di Padova, European Space Agency (ESA)-European Space Agency (ESA), and Universität Bern [Bern]
Subjects: 010504 meteorology & atmospheric sciences, Geometry, Concentric, Classification of discontinuities, 01 natural sciences, Layered structure, 0103 physical sciences, medicine, 010303 astronomy & astrophysics, Comets: individual: 67P/Churyumov, Gerasimenko, 0105 earth and related environmental sciences, Comets: general, Methods: data analysis, Physics, [PHYS]Physics [physics], comets: individual: 67P/Churyumov–Gerasimenko, comets: general, Astronomy and Astrophysics, Dimensional modeling, Ellipsoid, methods: data analysis, Lobe, medicine.anatomical_structure, Space and Planetary Science, Layering, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Free parameter
Abstract: International audience; We provide a three-dimensional model of the inner layered structure of comet 67P based on the hypothesis of an extended layering independently wrapping each lobe. A large set of terrace orientations was collected on the latest shape model and then used as a proxy for the local orientation of the surfaces of discontinuity which defines the layers. We modelled the terraces as a family of concentric ellipsoidal shells with fixed axis ratios, producing a model that is completely defined by just eight free parameters. Each lobe of 67P has been modelled independently, and the two sets of parameters have been estimated by means of non-linear optimization of the measured terrace orientations. The proposed model is able to predict the orientation of terraces, the elongation of cliffs, the linear traces observed in the Wosret and Hathor regions and the peculiar alignment of boulder-like features which has been observed in the Hapi region, which appears to be related to the inner layering of the big lobe. Our analysis allowed us to identify a plane of junction between the two lobes, further confirming the independent nature of the lobes. Our layering models differ from the best-fitting topographic ellipsoids of the surface, demonstrating that the terraces are aligned to an internal structure of discontinuities, which is unevenly exposed on the surface, suggesting a complex history of localized material removal from the nucleus.
Published: 2017

43. The pristine interior of comet 67P revealed by the combined Aswan outburst and cliff collapse

Author: Frank Scholten, Frank Preusker, M. F. A'Hearn, Monica Lazzarin, Ekkehard Kührt, Harald Michalik, Olivier Groussin, Nilda Oklay, Jean-Baptiste Vincent, Luca Penasa, Detlef Koschny, M. De Cecco, Nicolas Thomas, Matteo Massironi, Imre Toth, V. Da Deppo, J. L. Bertaux, Laurent Jorda, Holger Sierks, Björn Davidsson, Carsten Güttler, Emanuele Simioni, Steve Boudreault, Stubbe F. Hviid, S. Höfner, Géza Kovács, Cecilia Tubiana, Sonia Fornasier, Marc Hofmann, Mohamed Ramy El-Maarry, Francesco Marzari, J.-R. Kramm, J. J. Lopez Moreno, Hans Rickman, Maurizio Pajola, Gabriele Cremonese, Giampiero Naletto, Sebastien Besse, M. A. Barucci, Pedro Hasselmann, Michael Küppers, Jörg Knollenberg, Luisa Lara, J. D. P. Deshapriya, Stefano Debei, Francesca Ferri, Rafael Rodrigo, Antoine Pommerol, Jessica Agarwal, H. U. Keller, Cesare Barbieri, Philippe Lamy, Jakob Deller, Zhong-Yi Lin, Stephen C. Lowry, P. J. Gutierrez, Ivano Bertini, W-H. Ip, Clement Feller, Emanuele Baratti, Marco Fulle, Sabrina Ferrari, Alice Lucchetti, Stefano Mottola, NASA Ames Research Center (ARC), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Università degli Studi di Padova = University of Padua (Unipd), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Department of Information Engineering [Padova] (DEI), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), School of Physical Sciences [Canterbury], University of Kent [Canterbury], Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Department of Physics and Astronomy [Uppsala], Uppsala University, Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Operations Department (ESAC), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Department of Industrial Engineering [Padova], University of Trento [Trento], Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Dipartimento di Geoscienze [Padova], Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Department of Civil Chemical Environmental and Materials Engineering [Bologna] (DICAM), University of Bologna/Università di Bologna, Universita degli Studi di Padova, Max-Planck-Institut für Sonnensystemforschung (MPS), Consiglio Nazionale delle Ricerche [Roma] (CNR), European Space Agency (ESA), European Space Agency (ESA)-European Space Agency (ESA), Universität Bern [Bern], and University of Bologna
Subjects: outburst, 010504 meteorology & atmospheric sciences, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Escarpment, 01 natural sciences, Aswan, comet, Rosetta, 0103 physical sciences, Cliff, Table (landform), 010303 astronomy & astrophysics, QB, 0105 earth and related environmental sciences, Physics, geography, 67P, geography.geographical_feature_category, biology, cliff, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy, Astronomy and Astrophysics, Crust, Landslide, Albedo, biology.organism_classification, collapse, WAC, 13. Climate action, Osiris, Comet 67/P
Abstract: International audience; Outbursts occur commonly on comets1 with different frequencies and scales2,3. Despite multiple observations suggesting various triggering processes4,5, the driving mechanism of such outbursts is still poorly understood. Landslides have been invoked6 to explain some outbursts on comet 103P/Hartley 2, although the process required a pre-existing dust layer on the verge of failure. The Rosetta mission observed several outbursts from its target comet 67P/Churyumov–Gerasimenko, which were attributed to dust generated by the crumbling of materials from collapsing cliffs7,8. However, none of the aforementioned works included definitive evidence that landslides occur on comets. Amongst the many features observed by Rosetta on the nucleus of the comet, one peculiar fracture, 70 m long and 1 m wide, was identified on images obtained in September 2014 at the edge of a cliff named Aswan9. On 10 July 2015, the Rosetta Navigation Camera captured a large plume of dust that could be traced back to an area encompassing the Aswan escarpment7. Five days later, the OSIRIS camera observed a fresh, sharp and bright edge on the Aswan cliff. Here we report the first unambiguous link between an outburst and a cliff collapse on a comet. We establish a new dust-plume formation mechanism that does not necessarily require the breakup of pressurized crust or the presence of supervolatile material, as suggested by previous studies7. Moreover, the collapse revealed the fresh icy interior of the comet, which is characterized by an albedo >0.4, and provided the opportunity to study how the crumbling wall settled down to form a new talus.The evolution of the collapse of the Aswan cliff9, observed by the OSIRIS Narrow Angle Camera (NAC)10 and the Rosetta Navigation camera (NavCam), is shown in Fig. 1. We estimated a total outburst ejected mass of cometary material between 0.5 × 106 and 1.0 × 106 kg for the 10 July event. By applying stereo-photogrammetric methods11 using multiple OSIRIS images (Supplementary Table 1), we determined the total volume of material that collapsed from the Aswan cliff. In Fig. 2, the dataset that depicts the aspect of the cliff before and after the collapse is presented. By using pre- and post-collapse three-dimensional (3D) models (see Methods), we have been able to measure the dimensions of the collapsed overhang (Supplementary Figs 1–2), deriving a total volume of 2.20 × 104 m3, with a 1σ uncertainty of 0.34 × 104 m3.
Published: 2017

44. Post-perihelion photometry of dust grains in the coma of 67P Churyumov-Gerasimenko

Author: Carsten Güttler, Xian Shi, Ekkehard Kührt, L. M. Lara, Alice Lucchetti, Cesare Barbieri, J. B. Vincent, Stefano Mottola, P. Lamy, Hans Rickman, P. J. Gutierrez, Theresa Ott, Jakob Deller, Matteo Massironi, Jörg Knollenberg, Luca Penasa, Stubbe F. Hviid, Holger Sierks, Michael Küppers, F. La Forgia, J.-R. Kramm, J. L. Bertaux, Nilda Oklay, Ivano Bertini, Gabriele Cremonese, Wing-Huen Ip, Laurent Jorda, M. A. Barucci, Monica Lazzarin, J. J. Lopez Moreno, M. F. A'Hearn, Stefano Debei, Olivier Groussin, E. Frattin, V. Da Deppo, Emanuele Simioni, B. J. R. Davidsson, Horst Uwe Keller, Marc Hofmann, R. Rodrigo, Maurizio Pajola, A. Gicquel, Cecilia Tubiana, Sonia Fornasier, M. De Cecco, Giampiero Naletto, Francesco Marzari, Francesca Ferri, Jessica Agarwal, Marco Fulle, Detlef Koschny, Esther Drolshagen, Sabrina Ferrari, Nicolas Thomas, ITA, USA, GBR, FRA, DEU, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Università degli Studi di Padova = University of Padua (Unipd), CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), University of Oldenburg, Carl Von Ossietzky Universität Oldenburg = Carl von Ossietzky University of Oldenburg (OFFIS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), International Space Science Institute [Bern] (ISSI), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics and Astronomy [Uppsala], Uppsala University, Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Industrial Engineering [Padova], University of Trento [Trento], Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), European Space Astronomy Centre (ESAC), Dipartimento di Geoscienze [Padova], Department of Information Engineering [Padova] (DEI), NASA Ames Research Center (ARC), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Universita degli Studi di Padova, Consiglio Nazionale delle Ricerche [Roma] (CNR), Carl Von Ossietzky Universität Oldenburg, Max-Planck-Institut für Sonnensystemforschung (MPS), European Space Agency (ESA), Universität Bern [Bern], Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA)
Subjects: Asteroiden und Kometen, 010504 meteorology & atmospheric sciences, Comet, Data analysis, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astrophysics, 01 natural sciences, Spectral line, Photometry (optics), Photometry, Methods: data analysis, 0103 physical sciences, Spectral slope, Rosetta, Comets, OSIRIS, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, Zodiacal dust, Astronomy and Astrophysics, 620 Engineering, Comets: general, Wavelength, Techniques: photometric, Space and Planetary Science, Water ice, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Automated method
Abstract: International audience; We present a photometric analysis of individual dust grains in the coma of comet 67P/Churyumov–Gerasimenko using OSIRIS images taken from 2015 July to 2016 January. We analysed a sample of 555 taken during 18 d at heliocentric distances ranging between 1.25 and 2.04 au and at nucleocentric distances between 80 and 437 km. An automated method to detect the tracks was specifically developed. The images were taken by OSIRIS NAC in four different filters: Near-IR (882 nm), Orange (649 nm), FarOrange (649 nm) and Blue (480 nm). It was not always possible to recognize all the grains in the four filters, hence we measured the spectral slope in two wavelengths ranges: in the interval [480–649] nm, for 1179 grains, and in the interval [649–882] nm, for 746 grains. We studied the evolution of the two populations’ average spectral slopes. The data result scattered around the average value in the range [480–649] nm, while in the [649–882] nm we observe a slight decreasing moving away from the Sun as well as a slight increasing with the nucleocentric distance. A spectrophotometric analysis was performed on a subsample of 339 grains. Three major groups were defined, based on the spectral slope between [535–882] nm: (i) the steep spectra that may be related with organic material, (ii) the spectra with an intermediate slope, likely a mixture of silicates and organics and (iii) flat spectra that may be associated with a high abundance of water ice.
Published: 2017

45. Geomorphological and spectrophotometric analysis of Seth's circular niches on comet 67P/Churyumov–Gerasimenko using OSIRIS images

Author: Monica Lazzarin, M. F. A'Hearn, Björn Davidsson, Cecilia Tubiana, Marco Fulle, Olivier Groussin, Frank Scholten, J.-B. Vincent, Sabrina Ferrari, Ekkehard Kührt, Xian Shi, Horst Uwe Keller, Stefano Mottola, L. M. Lara, Ivano Bertini, Michael Küppers, P. J. Gutierrez, Steve Boudreault, R. Rodrigo, Alice Lucchetti, Carsten Güttler, L. Z. Lin, F. La Forgia, Cesare Barbieri, Nilda Oklay, Jakob Deller, Holger Sierks, Sonia Fornasier, Detlef Koschny, Nicolas Thomas, V. Da Deppo, Maurizio Pajola, Clement Feller, Wing-Huen Ip, Laurent Jorda, M. Hoffman, Giampiero Naletto, Pedro Hasselmann, Jörg Knollenberg, J.-R. Kramm, Luca Penasa, G. Cremonese, Stefano Debei, M. De Cecco, J. L. Bertaux, J. J. Lopez Moreno, Philippe Lamy, M. A. Barucci, Matteo Massironi, Stubbe F. Hviid, Jessica Agarwal, Francesco Marzari, Hans Rickman, Frank Preusker, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), NASA Ames Research Center (ARC), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Università degli Studi di Padova = University of Padua (Unipd), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Geoscienze [Padova], CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Department of Information Engineering [Padova] (DEI), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', International Space Science Institute [Bern] (ISSI), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics and Astronomy [Uppsala], Uppsala University, Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), European Space Astronomy Centre (ESAC), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Universita degli Studi di Padova, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Consiglio Nazionale delle Ricerche [Roma] (CNR), Max-Planck-Institut für Sonnensystemforschung (MPS), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), European Space Agency (ESA), Universität Bern [Bern], and California Institute of Technology (CALTECH)-NASA
Subjects: 010504 meteorology & atmospheric sciences, comets: general-comets, Comet, Data analysis, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Terrain, 67P/Churyumov–Gerasimenko, 01 natural sciences, individual: 67P/Churyumov-Gerasimenko-methods:data analysis, Methods: data analysis, 0103 physical sciences, Size frequency, Cliff, 010303 astronomy & astrophysics, Geomorphology, 0105 earth and related environmental sciences, Remote sensing, Comets: individual: 67P/Churyumov, Gerasimenko, Physics, Ecological niche, Comets: general, geography, geography.geographical_feature_category, biology, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, Astronomy and Astrophysics, Landslide, biology.organism_classification, 620 Engineering, 13. Climate action, Space and Planetary Science, Water ice, Osiris
Abstract: International audience; We provide a detailed geomorphological and spectrophotometric analysis of the circular niches located on the Seth region of 67P using OSIRIS images. The features can be related to landslide events that occurred on 67P and shaped its surface, as the recent Aswan cliff collapse detected in the same region. We therefore provide an analysis of the area pre- and post-perihelion suggesting that no specific changes have been observed. To assess this, after performing a geomorphological map of the area that allows us to identify different terrain units, we computed the boulders cumulative size frequency distribution (SFD) of the niches, before and after the perihelion passage. The niches SFDs are characterized by a similar trend with two different power-law indices within the same deposit: lower power-law value (between −2.3 and −2.7) for boulders smaller than 5 m and steeper power-law value (between −4.7 and −5.0) for boulders larger than 5 m. These trends suggest that smaller boulders have evolved and progressively have been depleted (lower power-law index), while bigger boulders are more representative of the event that generated the deposit and are less degraded. Then, we perform the spectrophotometric analysis of this region comparing pre- and post-perihelion results. We found colour changes within the area, in particular brighter patches related to the presence of exposed water ice mixed to the refractory materials have been detected in the post-perihelion images.
Published: 2017

46. The highly active Anhur–Bes regions in the 67P/Churyumov–Gerasimenko comet: results from OSIRIS/ROSETTA observations

Author: Pedro Hasselmann, Philippe Lamy, Clement Feller, J. L. Bertaux, Xian Shi, M. F. A'Hearn, Olivier Groussin, M. De Cecco, Maurizio Pajola, M. L. Lara, J.-C. Lee, J.-B. Vincent, Holger Sierks, Stefano Mottola, Nilda Oklay, Marco Fulle, Wing-Huen Ip, Laurent Jorda, Cesare Barbieri, Imre Toth, Lorenza Giacomini, M. A. Barucci, Carsten Güttler, Jakob Deller, Sabrina Ferrari, V. Da Deppo, J. J. Lopez Moreno, Zhong-Yi Lin, Marc Hofmann, Sonia Fornasier, Detlef Koschny, Ivano Bertini, H. U. Keller, Nicolas Thomas, Michael Küppers, Jörg Knollenberg, Jessica Agarwal, Rafael Rodrigo, Giampiero Naletto, J. D. P. Deshapriya, Stefano Debei, Ekkehard Kührt, Géza Kovács, Gabriele Cremonese, Monica Lazzarin, Francesco Marzari, P. J. Gutiérrez, R. Kramm, Björn Davidsson, Matteo Massironi, Cecilia Tubiana, Stubbe F. Hviid, Mohamed Ramy El-Maarry, Hans Rickman, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric Sciences [Taoyuan City], National Central University [Taiwan] (NCU), Dipartimento di Geoscienze [Padova], Università degli Studi di Padova = University of Padua (Unipd), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Institute of Astronomy [Taiwan] (IANCU), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Department of Physics and Astronomy [Uppsala], Uppsala University, Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Universita degli Studi di Padova, Max-Planck-Institut für Sonnensystemforschung (MPS), European Space Agency (ESA), Consiglio Nazionale delle Ricerche [Roma] (CNR), California Institute of Technology (CALTECH)-NASA, Universität Bern [Bern], Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA)
Subjects: comets: individual: 67P/Churyumov-Gerasimenko, Methods: data analysis, Methods: observational, Techniques: photometric, 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, Outcrop, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Astrophysics, Fault scarp, 01 natural sciences, Mantle (geology), 0103 physical sciences, Spectral slope, OSIRIS, 010303 astronomy & astrophysics, Southern Hemisphere, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], biology, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, Astronomy, Astronomy and Astrophysics, biology.organism_classification, 620 Engineering, Plume, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 13. Climate action, Space and Planetary Science, Layering, Osiris, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: The Southern hemisphere of the 67P/Churyumov-Gerasimenko comet has become visible from Rosetta only since March 2015. It was illuminated during the perihelion passage and therefore it contains the regions that experienced the strongest heating and erosion rate, thus exposing the subsurface most pristine material. In this work we investigate, thanks to the OSIRIS images, the geomorphology, the spectrophotometry and some transient events of two Southern hemisphere regions: Anhur and part of Bes. Bes is dominated by outcropping consolidated terrain covered with fine particle deposits, while Anhur appears strongly eroded with elongated canyon-like structures, scarp retreats, different kinds of deposits, and degraded sequences of strata indicating a pervasive layering. We discovered a new 140 m long and 10 m high scarp formed in the Anhur/Bes boundary during/after the perihelion passage, close to the area where exposed CO$_2$ and H$_2$O ices were previously detected. Several jets have been observed originating from these regions, including the strong perihelion outburst, an active pit, and a faint optically thick dust plume. We identify several areas with a relatively bluer slope (i.e. a lower spectral slope value) than their surroundings, indicating a surface composition enriched with some water ice. These spectrally bluer areas are observed especially in talus and gravitational accumulation deposits where freshly exposed material had fallen from nearby scarps and cliffs. The investigated regions become spectrally redder beyond 2 au outbound when the dust mantle became thicker, masking the underlying ice-rich layers., 16 pages, 15 figures, published online on 24 May 2017 on Mon. Not. R. Astron. Soc. stx1275, https://doi.org/10.1093/mnras/stx1275
Published: 2017

47. EMISSIVITY MEASUREMENTS FOR HOT PLANETARY SURFACES

Author: Jörn Helbert, M. Darby Dyar, Suzanne E. Smrekar, Alessandro Maturilli, Nils Müller, and Sabrina Ferrari
Subjects: Optics, Materials science, business.industry, Emissivity, business
Published: 2017

48. Age relationships of the Rembrandt basin and Enterprise Rupes, Mercury

Author: Matteo Massironi, Christian Klimczak, Gabriele Cremonese, Elena Martellato, Paul K. Byrne, Sabrina Ferrari, and Simone Marchi
Subjects: Oceanography, chemistry, chemistry.chemical_element, Geology, Ocean Engineering, Structural basin, Water Science and Technology, Mercury (element)
Published: 2014

49. Lateral ramps and strike-slip kinematics on Mercury

Author: Pasquale Palumbo, Matteo Massironi, Sabrina Ferrari, Michele Zusi, Lorenza Giacomini, David A. Rothery, G. Cremonese, Valentina Galluzzi, and G. Di Achille
Subjects: chemistry, chemistry.chemical_element, Geology, Ocean Engineering, Kinematics, Strike-slip tectonics, Seismology, Water Science and Technology, Mercury (element)
Published: 2014

50. Surface evolution of the Anhur region on comet 67P/Churyumov-Gerasimenko from high-resolution OSIRIS images

Author: R. Rodrigo, M. De Cecco, Stefano Debei, P. J. Gutierrez, Ivano Bertini, J. M. Sunshine, P. L. Lamy, Detlef Koschny, S. Fornasier, Xian Shi, Laurent Jorda, G. Cremonese, J. B. Vincent, Marco Fulle, Imre Tóth, Maurizio Pajola, M. L. Lara, J. L. Bertaux, Sabrina Ferrari, C. Güttler, V. Da Deppo, Dennis Bodewits, M. A. Barucci, W-H. Ip, Jakob Deller, Holger Sierks, Clement Feller, Stefano Mottola, Monica Lazzarin, Alice Lucchetti, Cecilia Tubiana, J. J. Lopez Moreno, B. J. R. Davidsson, Horst Uwe Keller, Giampiero Naletto, Francesco Marzari, Pedro Hasselmann, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Dipartimento di Fisica e Astronomia 'Galileo Galilei', CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Department of Physics [Auburn], Auburn University (AU), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Department of Mechanical Engineering [Padova], Department of Industrial Engineering [Padova], Universita degli Studi di Padova-Universita degli Studi di Padova, University of Trento [Trento], Dipartimento di Geoscienze [Padova], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig [Braunschweig], European Space Astronomy Centre (ESAC), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), California Institute of Technology (CALTECH)-NASA, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], German Centre for Air and Space Travel, Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Agencia Estatal de Investigación (España), European Space Agency, Swedish National Space Agency, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Padova = University of Padua (Unipd), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA), Università degli Studi di Padova = University of Padua (Unipd)-Università degli Studi di Padova = University of Padua (Unipd), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), ANR-17-CE31-0004,CLASSY,Composition des surfaces du Système Solaire de bas albédo(2017), ITA, USA, GBR, FRA, and DEU
Subjects: 67P/Churyumov-Gerasimenko, Asteroiden und Kometen, photometry, 010504 meteorology & atmospheric sciences, Comet, observational [methods], Data analysis, Narrow angle, High resolution, Individual, rosetta mission, Equinox, Photometric, imaging spectroscopy, Fault scarp, 01 natural sciences, photometric [techniques], techniques: photometric, individual: 67P/Churyumov-Gerasimenko [Comets], 0103 physical sciences, data analysis [methods], Methods, comets, Observational, 010303 astronomy & astrophysics, Southern Hemisphere, 0105 earth and related environmental sciences, [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], biology, comets: individual: 67P/Churyumov-Gerasimenko, Astronomy, Astronomy and Astrophysics, imaging spectroscopy [techniques], biology.organism_classification, methods: data analysis, Techniques, techniques: imaging spectroscopy, 13. Climate action, Space and Planetary Science, Radiance, Comets, Imaging spectroscopy, methods: observational, Osiris, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology
Abstract: Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., The southern hemisphere of comet 67P/Churyumov-Gerasimenko (67P) became observable by the Rosetta mission in March 2015, a few months before cometary southern vernal equinox. The Anhur region in the southern part of the comet's larger lobe was found to be highly eroded, enriched in volatiles, and highly active. Aims. We analyze high-resolution images of the Anhur region pre- and post-perihelion acquired by the OSIRIS imaging system on board the Rosetta mission. The Narrow Angle Camera is particularly useful for studying the evolution in Anhur in terms of morphological changes and color variations. Methods. Radiance factor images processed by the OSIRIS pipeline were coregistered, reprojected onto the 3D shape model of the comet, and corrected for the illumination conditions. Results. We find a number of morphological changes in the Anhur region that are related to formation of new scarps; removal of dust coatings; localized resurfacing in some areas, including boulders displacements; and vanishing structures, which implies localized mass loss that we estimate to be higher than 50 million kg. The strongest changes took place in and nearby the Anhur canyon-like structure, where significant dust cover was removed, an entire structure vanished, and many boulders were rearranged. All such changes are potentially associated with one of the most intense outbursts registered by Rosetta during its observations, which occurred one day before perihelion passage. Moreover, in the niche at the foot of a new observed scarp, we also see evidence of water ice exposure that persisted for at least six months. The abundance of water ice, evaluated from a linear mixing model, is relatively high (>20%). Our results confirm that the Anhur region is volatile-rich and probably is the area on 67P with the most pristine exposures near perihelion.© S. Fornasier et al. 2019, OSIRIS was built by a consortium led by the Max-Planck-Institut fur Sonnensystemforschung, Goettingen, Germany, in collaboration with CISAS, University of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, the Scientific Support Office of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut fur Datentechnik und Kommunikationsnetze der Technischen Universitat Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. We thank the Rosetta Science Ground Segment at ESAC, the Rosetta Mission Operations Centre at ESOC and the Rosetta Project at ESTEC for their outstanding work enabling the science return of the Rosetta Mission. SF acknowledges the financial support from the France Agence Nationale de la Recherche (programme Classy, ANR-17-CE31-0004). The authors thank Dr. E. Howell for her comments and suggestions which helped us to improve this article.
Published: 2019

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