Article
Astronomy & Astrophysics
Bjorn J. R. Davidsson, Bonnie J. Buratti, Michael D. Hicks
Summary: In this study, we investigate the level of albedo variegation on the nucleus of Comet 67P/Churyumov-Gerasimenko. The observed albedo variegation is strongly related to the nucleus morphology, with smooth terrain being brighter and consolidated terrain being darker. We find that smooth terrain darkens before morphological changes and that stratigraphically low terrain is brighter than stratigraphically high terrain. The observed albedo variegation is attributed to differences in porosity and the coherent effect, where compaction causes brighter small particles to act collectively as darker larger particles.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Martin Rubin, Kathrin Altwegg, Jean-Jacques Berthelier, Michael R. Combi, Johan De Keyser, Stephen A. Fuselier, Tamas Gombosi, Murthy S. Gudipati, Nora Hanni, Kristina A. Kipfer, Niels F. W. Ligterink, Daniel R. Muller, Yinsi Shou, Susanne F. Wampfler
Summary: This study analyzes experimental data from the Rosetta mission at comet 67P and reveals that highly volatile species are trapped in H2O and CO2 ices. The study also suggests that CO2 is seasonal frost and finds an elevation in CO abundance during a certain period, which requires further investigation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Marcin Wesolowski
Summary: The paper discusses several mechanisms that play a significant role in the formation of dune structures on comet surfaces. These mechanisms include dust migration, local avalanches resulting from landslides, and fluidization of unstable dust, all of which are initiated by ice sublimation. Due to the complex nature of cometary nuclei, the movement of dust may abruptly cease, leading to the formation of dune structures by particle piling. The maximum angular width, particle mobility coefficient, and static fluidization pressure were determined for each mechanism.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Daniel Gardener, Colin Snodgrass, Nicolas Ligier
Summary: This article introduces a pipeline that calibrates and measures the photometry of comet 67P during its 2016 perihelion passage. The results show that the activity levels of the comet do not change significantly from orbit to orbit, and the colors of the coma remain constant throughout the apparition. An outburst was also detected, which is consistent with the outbursts observed on the nucleus by Rosetta.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
B. Pestoni, K. Altwegg, V. Della Corte, N. Hanni, A. Longobardo, D. R. Mueller, A. Rotundi, M. Rubin, S. F. Wampfler
Summary: The Rosetta mission has enabled scientists to study a comet in unprecedented detail. Four instruments on the Rosetta orbiter have provided information on cometary dust particles. By comparing the data from two of these instruments, COSIMA and GIADA, it has been found that the particles detected by COSIMA are significantly correlated with the fluffy agglomerates detected by GIADA.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Frederik Dhooghe, Johan De Keyser, Nora Haenni, Kathrin Altwegg, Gael Cessateur, Emmanuel Jehin, Romain Maggiolo, Martin Rubin, Peter Wurz
Summary: A full-mission analysis of Cl-bearing species in the coma of comet 67P/Churyumov-Gerasimenko detected by the Double Focusing Mass Spectrometer (DFMS) of Rosetta's ROSINA instrument revealed a stable chlorine isotopes ratio of 0.336, slightly higher than the standard mean ocean chloride value. The DFMS also indicated the presence of at least one additional chlorine-bearing species besides HCl, CH3Cl, and NH4Cl.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Bjorn J. R. Davidsson, Nalin H. Samarasinha, Davide Farnocchia, Pedro J. Gutierrez
Summary: The study investigates the European Space Agency's Rosetta/Philae mission to Comet 67P/Churyumov-Gerasimenko, aiming to understand the composition and evolution of the comet's nucleus materials.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Maria N. Drozdovskaya, Isaac R. H. G. I. Schroeder, Martin Rubin, Kathrin Altwegg, Ewine F. van Dishoeck, Beatrice M. Kulterer, Johan De Keyser, Stephen A. Fuselier, Michael Combi
Summary: Deuterated methanol provides insight into the chemical reactions forming deuterium-bearing molecules and the physicochemical history of celestial regions. The detection of mono- and di-deuterated methanol in a comet suggests formation through hydrogenation and substitution reactions, with a close relationship to D2O formation. The ratio of D-methanol/methanol in comets aligns with the composition in prestellar cores and low-mass protostellar regions, indicating a connection to the evolutionary phases of star formation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
M. Sachse, D. Kappel, D. Tirsch, K. A. Otto
Summary: By using the discrete element method, this study simulated the formation of aeolian-like surface features on comet 67P/Churyumov-Gerasimenko and found that it involves both deposition of ejected material and surface erosion. The study also determined a set of parameters that produce reasonably realistic simulations.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Selma Benseguane, Aurelie Guilbert-Lepoutre, Jeremie Lasue, Sebastien Besse, Cedric Leyrat, Arnaud Beth, Marc Costa Sitja, Bjorn Grieger, Maria Teresa Capria
Summary: This study aims to understand how cometary activity has affected the characteristics of pits and alcoves on the surface of 67P. The research findings suggest that progressive erosion cannot form pits and alcoves, and deep circular pits are potentially the least processed morphological features at the surface of 67P.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
O. Pinzon-Rodriguez, R. Marschall, S. -B. Gerig, C. Herny, J. S. Wu, N. Thomas
Summary: This study aims to investigate the factors influencing the generation of a comet's inner comae and model the gas activity distribution around its nuclei, with a focus on the effects of thermal conductivity and sub-surface ice sources on insolation-driven sublimation. The research found that thermal inertia and the depth of the sublimation front have a significant impact on the emission distribution of the gas flow field, with potential shifts in activity distribution and composition due to the presence of CO2.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
A. Longobardo, T. Mannel, M. Kim, M. Fulle, A. Rotundi, V Della Corte, G. Rinaldi, J. Lasue, S. Merouane, H. Cottin, M. Ciarniello, F. Dirri, E. Palomba
Summary: This study combined data from two instruments onboard the European Space Agency's Rosetta mission to investigate the morphological and dynamical properties of dust ejected from the 67P/Churyumov-Gerasimenko comet. The results suggest that the compact dust particles detected by the MIDAS atomic force microscope are fragments of larger particles detected by the GIADA dust detector.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Marius Pfeifer, Jessica Agarwal, Matthias Schroeter
Summary: This study used data from the European Space Agency's Rosetta mission to track the motion of particles in image sequences and derive their velocities and accelerations. An algorithm was developed to locate the particles and reconstruct their tracks using the image sequences' pair-nature. The study found significant information about potential genuine particle tracks and obtained preliminary results on velocity, acceleration, and radius distributions.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Y. -C. Cheng, D. Bockelee-Morvan, M. Roos-Serote, J. Crovisier, V. Debout, S. Erard, P. Drossart, C. Leyrat, F. Capaccioni, G. Filacchione, M. -L. Dubernet, T. Encrenaz
Summary: This study analyzed the spectra data of comet 67P and determined an ortho-to-para ratio (OPR) of water in the coma of the comet to be 2.94. The study also found that the OPR is strongly affected by opacity effects and shows an inverse correlation with the column density. The measured water rotational temperatures varied with altitude and heliocentric distance, indicating the influence of adiabatic cooling.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
N. Haenni, K. Altwegg, H. Balsiger, M. Combi, S. A. Fuselier, J. De Keyser, B. Pestoni, M. Rubin, S. F. Wampfler
Summary: By using DFMS data to derive the abundances of three cometary nitriles, the study conducted the first measurements of NCCN in a comet and found that neither NCCN nor the other two nitriles is sufficiently abundant to be a relevant alternative parent to CN.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
D. Telloni, E. Antonucci, L. Adhikari, G. P. Zank, S. Giordano, M. Vai, L. -l. Zhao, V. Andretta, A. Burtovoi, G. E. Capuano, V. Da Deppo, Y. De Leo, S. Fineschi, C. Grimani, P. Heinzel, G. Jerse, F. Landini, A. Liberatore, J. D. Moses, G. Naletto, G. Nicolini, M. Pancrazzi, M. Romoli, G. Russano, C. Sasso, A. Slemer, D. Spadaro, M. Stangalini, R. Susino, L. Teriaca, M. Uslenghi, L. Sorriso-Valvo, R. Marino, D. Perrone, R. D'Amicis, R. Bruno
Summary: This article reports the first estimate of the expansion rate of polar coronal flows performed by the Metis coronagraph on board Solar Orbiter. By extending observations of the outflow velocity of the main component of the solar wind from polar coronal holes, the results suggest that a magnetohydrodynamic turbulence model can satisfactorily reproduce the observations.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Geochemistry & Geophysics
Joel M. Davis, Matthew R. Balme, Peter Fawdon, Peter M. Grindrod, Elena A. Favaro, Steven G. Banham, Nicolas Thomas
Summary: Based on the investigation and analysis of the Oxia Planum region on Mars, fluvial sinuous ridges (FSRs) have been discovered, which are deposits of ancient, episodically active alluvial river systems. Some of these deposits are embedded within the phyllosilicate-bearing bedrock, indicating ancient aqueous processes. These findings increase the chances of detecting signs of ancient life on Mars.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Miguel Angel Lopez-Valverde, Bernd Funke, Adrian Brines, Aurelien Stolzenbach, Ashimananda Modak, Brittany Hill, Francisco Gonzalez-Galindo, Ian Thomas, Loic Trompet, Shohei Aoki, Geronimo Villanueva, Giuliano Liuzzi, Justin Erwin, Udo Grabowski, Francois Forget, Jose Juan Lopez-Moreno, Julio Rodriguez-Gomez, Bojan Ristic, Frank Daerden, Giancarlo Bellucci, Manish Patel, Ann-Carine Vandaele
Summary: We present vertical profiles of temperature and density on Mars using solar occultation observations by the NOMAD spectrometer. We obtained temperature and CO2 profiles up to about 90 km, with consistent hydrostatic adjustment, after adapting a retrieval scheme to Mars conditions. Our results reveal the impact of a global dust storm on the atmosphere, which warmed the atmosphere at all altitudes and limited the sounding of tropospheric layers. The retrieved temperatures agree well with global climate models at tropospheric altitudes, but show differences in the mesosphere, particularly during the dust storm.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Geochemistry & Geophysics
Daniel Mege, Joanna Gurgurewicz, Matteo Massironi, Riccardo Pozzobon, Gloria Tognon, Maurizio Pajola, Livio L. Tornabene, Alice Lucchetti, Beatrice Baschetti, Joel M. Davis, Ernst Hauber, Barbara De Toffoli, Sylvain Doute, Laszlo Keszthelyi, Lucia Marinangeli, Jason Perry, Antoine Pommerol, Loredana Pompilio, Angelo Pio Rossi, Frank Seelos, Francesco Sauro, Ruth Ziethe, Gabriele Cremonese, Nicolas Thomas
Summary: We study the geological activity and water discharge in the Ladon basin on Mars using the data from ExoMars Trace Gas Orbiter/Color and Stereo Surface Imaging System. The combination of this data set with other data sets allows for effective geological mapping. We observe dark lobate flows and altered levels, indicating ultramafic rocks and potential hydrothermal activity. Additionally, kaolin minerals are detected, suggesting groundwater alteration. These findings suggest a coeval relationship between volcanism, tectonics, hydrothermal activity, and kaolinization in the Ladon basin on Mars.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Astronomy & Astrophysics
Daniele Telloni, Gary P. P. Zank, Laxman Adhikari, Lingling Zhao, Roberto Susino, Ester Antonucci, Silvano Fineschi, Marco Stangalini, Catia Grimani, Luca Sorriso-Valvo, Daniel Verscharen, Raffaele Marino, Silvio Giordano, Raffaella D'Amicis, Denise Perrone, Francesco Carbone, Alessandro Liberatore, Roberto Bruno, Gaetano Zimbardo, Marco Romoli, Vincenzo Andretta, Vania Da Deppo, Petr Heinzel, John D. D. Moses, Giampiero Naletto, Gianalfredo Nicolini, Daniele Spadaro, Luca Teriaca, Aleksandr Burtovoi, Yara De Leo, Giovanna Jerse, Federico Landini, Maurizio Pancrazzi, Clementina Sasso, Alessandra Slemer
Summary: This paper reports evidence for the presence of ion cyclotron waves (ICWs) at the boundaries of the current sheet, driven by turbulence. Joint observations by Parker Solar Probe and the Metis coronagraph on board Solar Orbiter allow for the linking of local solar wind measurements with large-scale solar corona structures. The study reveals the dynamics of the current sheet layers generate turbulence, which in turn leads to temperature anisotropy and various instabilities. The presence of ICWs along the current sheet is confirmed, providing insights into the processes involved in coronal heating.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Vidhya Ganesh Rangarajan, Livio L. Tornabene, Gordon R. Osinski, Susan J. Conway, Frank P. Seelos, Simone Silvestro, Francesco Salese, Maurizio Pajola, Alice Lucchetti, Giovanni Munaretto, Valentin T. Bickel, Nicolas Thomas, Gabriele Cremonese
Summary: Mars has a variety of active surface processes related to ice/frost, slope activity, wind, and potential liquid water. Monitoring and detecting changes in these processes are crucial for understanding present and past Martian surface conditions. High-resolution remote sensing images from MRO and the CaSSIS instrument on the ExoMars Trace Gas Orbiter allow detailed tracking and monitoring of these changes. This study provides techniques for conducting change detection campaigns with CaSSIS, including qualitative and semi-quantitative methods for reliable change identification and tracking.
Article
Multidisciplinary Sciences
Andrew F. Cheng, Harrison F. Agrusa, Brent W. Barbee, Alex J. Meyer, Tony L. Farnham, Sabina D. Raducan, Derek C. Richardson, Elisabetta Dotto, Angelo Zinzi, Vincenzo Della Corte, Thomas S. Statler, Steven Chesley, Shantanu P. Naidu, Masatoshi Hirabayashi, Jian-Yang Li, Siegfried Eggl, Olivier S. Barnouin, Nancy L. Chabot, Sidney Chocron, Gareth S. Collins, R. Terik Daly, Thomas M. Davison, Mallory E. DeCoster, Carolyn M. Ernst, Fabio Ferrari, Dawn M. Graninger, Seth A. Jacobson, Martin Jutzi, Kathryn M. Kumamoto, Robert Luther, Joshua R. Lyzhoft, Patrick Michel, Naomi Murdoch, Ryota Nakano, Eric Palmer, Andrew S. Rivkin, Daniel J. Scheeres, Angela M. Stickle, Jessica M. Sunshine, Josep M. Trigo-Rodriguez, Jean-Baptiste Vincent, James D. Walker, Kai Wuennemann, Yun Zhang, Marilena Amoroso, Ivano Bertini, John R. Brucato, Andrea Capannolo, Gabriele Cremonese, Massimo Dall'Ora, Prasanna J. D. Deshapriya, Igor Gai, Pedro H. Hasselmann, Simone Ieva, Gabriele Impresario, Stavro L. Ivanovski, Michele Lavagna, Alice Lucchetti, Elena M. Epifani, Dario Modenini, Maurizio Pajola, Pasquale Palumbo, Davide Perna, Simone Pirrotta, Giovanni Poggiali, Alessandro Rossi, Paolo Tortora, Marco Zannoni, Giovanni Zanotti
Summary: The NASA DART mission successfully conducted a kinetic impact on the asteroid Dimorphos, resulting in a significant reduction in its orbital velocity. This experiment validated kinetic impact as an effective method for asteroid deflection, as it demonstrated enhanced momentum transfer due to the recoil from impact ejecta streams. The findings suggest that the DART mission was highly effective in deflecting the asteroid Dimorphos.
Article
Environmental Sciences
Riccardo La Grassa, Gabriele Cremonese, Ignazio Gallo, Cristina Re, Elena Martellato
Summary: Impact crater detection is of great importance in analyzing the geological processes, morphologies, and physical properties of celestial bodies and potential landing sites. Although automated detection algorithms are needed due to the large amount of craters, the current methods are hindered by the low spatial resolution and varying solar illuminance/incidence. We propose a deep learning architecture called YOLOLens5x, which uses super-resolution for impact crater detection and achieves improved precision and recall compared to other state-of-the-art models.
Article
Environmental Sciences
Alexander Pletl, Michael Fernandes, Nicolas Thomas, Angelo Pio Rossi, Benedikt Elser
Summary: In this paper, we expand upon our previous research on unsupervised learning algorithms to map the spectral parameters of the Martian surface. We apply the UMAP method in combination with k-Means to generate spectral cluster maps in the NIR range, which outperform comparable methods in efficiency and speed.
Article
Geochemistry & Geophysics
L. Trompet, A. C. Vandaele, I. Thomas, S. Aoki, F. Daerden, J. Erwin, Z. Flimon, A. Mahieux, L. Neary, S. Robert, G. Villanueva, G. Liuzzi, M. A. Lopez-Valverde, A. Brines, G. Bellucci, J. J. Lopez-Moreno, M. R. Patel
Summary: The Martian atmosphere was investigated using the Solar Occultation (SO) channel of the NOMAD instrument. Vertical profiles of carbon dioxide density and temperature were analyzed, revealing the presence of warm layers at dawn and dusk in the Northern hemisphere and dawn in the Southern hemisphere. Strong warm layers were observed in more than 13.5% of the profiles, while no warm layers were found in the Southern hemisphere at dusk.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Geochemistry & Geophysics
L. Trompet, A. C. Vandaele, I. Thomas, S. Aoki, F. Daerden, J. Erwin, Z. Flimon, A. Mahieux, L. Neary, S. Robert, G. Villanueva, G. Liuzzi, M. A. Lopez-Valverde, A. Brines, G. Bellucci, J. J. Lopez-Moreno, M. R. Patel
Summary: This study focused on the Solar Occultation (SO) channel of the NOMAD instrument, analyzing vertical profiles of carbon dioxide density and temperature in the Martian atmosphere. The profiles were compared with data from the Mars Climate Sounder instrument and simulations from the Global Environmental Multiscale-Mars model, revealing some biases and features.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Review
Astronomy & Astrophysics
B. E. Clark, A. Sen, X. -D. Zou, D. N. DellaGiustina, S. Sugita, N. Sakatani, M. Thompson, D. Trang, E. Tatsumi, M. A. Barucci, M. Barker, H. Campins, T. Morota, C. Lantz, A. R. Hendrix, F. Vilas, L. Keller, V. E. Hamilton, K. Kitazato, S. Sasaki, M. Matsuoka, T. Nakamura, A. Praet, S. M. Ferrone, T. Hiroi, H. H. Kaplan, W. F. Bottke, J. -Y. Li, L. Le Corre, J. L. Molaro, R. -L. Ballouz, C. W. Hergenrother, B. Rizk, K. N. Burke, C. A. Bennett, D. R. Golish, E. S. Howell, K. Becker, A. J. Ryan, J. P. Emery, S. Fornasier, A. A. Simon, D. C. Reuter, L. F. Lim, G. Poggiali, P. Michel, M. Delbo, O. S. Barnouin, E. R. Jawin, M. Pajola, L. Riu, T. Okada, J. D. P. Deshapriya, J. R. Brucato, R. P. Binzel, D. S. Lauretta
Summary: This paper summarizes the evidence for the optical effects of space weathering and the properties of the surface on asteroid (101955) Bennu. The nature of space weathering on Bennu is explored through recent spacecraft imaging and spectroscopy observations. The working hypothesis suggests that optical effects depend on the hydration level of the substrate and subsequent variations in color depend on surface processes and exposure age.
Article
Astronomy & Astrophysics
Alice Lucchetti, Cristina Dalle Ore, Maurizio Pajola, Riccardo Pozzobon, Costanza Rossi, Valentina Galluzzi, Luca Penasa, Katrin Stephan, Giovanni Munaretto, Gabriele Cremonese, Matteo Massironi, Pasquale Palumbo
Summary: In this study, we analyzed the Melkart impact crater on Ganymede, which is a 103 km crater located at the boundary between the light and dark terrains. Our analysis involved creating a geological map, investigating the deformation, and studying the composition of the crater. We found that the dome of Melkart experienced strike-slip deformation with subtle strain, suggesting a gradual transition between the geological units.
Article
Geochemistry & Geophysics
A. S. Zaki, K. S. Edgett, M. Pajola, E. Kite, J. M. Davis, N. Mangold, A. S. Madof, A. Lucchetti, P. Grindrod, C. M. Hughes, K. Sangwan, N. Thomas, M. Schuster, S. Gupta, G. Cremonese, S. Castelltort
Summary: This study reconstructs the history of fluvial systems in the Antoniadi crater on Mars, revealing that there were four intermittent active periods during the Late Noachian to Early Amazonian, resulting in at least two major lakes. The morphologies of interconnected fluvial systems and lake variations suggest episodic precipitation-induced surface runoff, along with intermittent catastrophic floods that breached crater-lake rims. These findings provide important insights into the frequency, duration, and hydro-climatic context of early Mars.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Geochemistry & Geophysics
Federico Tosi, Valentina Galluzzi, Alice Lucchetti, Roberto Orosei, Gianrico Filacchione, Francesca Zambon, Gabriele Cremonese, Pasquale Palumbo, Giuseppe Piccioni
Summary: This study focuses on the southern region of Ganymede, the largest moon of Jupiter, and provides a detailed geological analysis using high-resolution optical imagery and hyperspectral data. Two theoretical models are applied to infer the thickness of the ice shell and estimate radar clutter noise. The findings contribute to understanding the evolution history of the region and will be crucial for future exploration missions.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)