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
H. N. Williamson, H. Nilsson, G. Stenberg Wieser, A. Moeslinger, C. Goetz
Summary: This study investigates the interaction between the solar wind and cometary ions at comet 67P using the Rosetta Ion Composition Analyzer. The results show that the solar wind species are deflected by mass loading, but the velocity distribution function is not significantly changed. H+ ions exhibit a narrow cometosheath distribution compared to He2+ and H2O+ ions. The momentum flux analysis suggests the presence of a non-gyrotropic momentum flux component in all species.
ASTRONOMY & ASTROPHYSICS
(2022)
Review
Astronomy & Astrophysics
Andrea Longobardo, Minjae Kim, Boris Pestoni, Mauro Ciarniello, Giovanna Rinaldi, Stavro Ivanovski, Fabrizio Dirri, Marco Fulle, Vincenzo Della Corte, Alessandra Rotundi, Martin Rubin
Summary: This study summarizes the findings of the ESA/Rosetta mission on the Jupiter Family Comet 67P/Churyumov-Gerasimenko. The data collected from instruments onboard the Rosetta orbiter, along with numerical models and experimental work, have provided important insights into cometary activity mechanisms. The study reveals correlations between dust ejection and solar illumination, as well as the dominance of water sublimation during the perihelion phase. The comparison of dust fluxes and particle sizes also suggests a link between dust morphology and ejection speed.
Correction
Astronomy & Astrophysics
M. Galand, P. D. Feldman, D. Bockelee-Morvan, N. Biver, Y. -C. Cheng, G. Rinaldi, M. Rubin, K. Altwegg, J. Deca, A. Beth, P. Stephenson, K. L. Heritier, P. Henri, J. Wm. Parker, C. Carr, A. I. Eriksson, J. Burch
Summary: The paper has been corrected and the updated version can be found at https://doi.org/10.1038/s41550-021-01373-5.
Article
Astronomy & Astrophysics
Sofia Bergman, Gabriella Stenberg Wieser, Martin Wieser, Hans Nilsson, Erik Vigren, Arnaud Beth, Kei Masunaga, Anders Eriksson
Summary: The study corrected the flow directions of low-energy ions around comet 67P using Particle-In-Cell simulation results, revealing the presence of counter-streaming ions which affect the overall expansion velocity of the ions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Min Chen, Xianfeng Huang, Jianguo Yan, Zhen Lei, Jean Pierre Barriot
Summary: In this article, we used over 5200 Rosetta/OSIRIS-NAC images to create a high-resolution 3D model of the bilobate comet 67P/Churyumov-Gerasimenko, which is visually more impressive than the existing models. We also measured the volume, mean density, and surface area of the comet, and analyzed the differences between the three models.
Article
Astronomy & Astrophysics
Sofia Bergman, Gabriella Stenberg Wieser, Martin Wieser, Fredrik Leffe Johansson, Erik Vigren, Hans Nilsson, Zoltan Nemeth, Anders Eriksson, Hayley Williamson
Summary: This study analyzes low-energy ions in the diamagnetic cavity of comet 67P and finds that their speeds are significantly higher than neutral particles, indicating a weak coupling between ions and neutrals. The temperature is mainly influenced by the acceleration of ions born at different locations in the coma.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
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
John W. Noonan, Giovanna Rinaldi, Paul D. Feldman, S. Alan Stern, Joel Wm. Parker, Brian A. Keeney, Dominique Bockelee-Morvan, Ronald J. Vervack, Andrew J. Steffl, Matthew M. Knight, Rebecca N. Schindhelm, Lori M. Feaga, Jon Pineau, Richard Medina, Harold A. Weaver, Jean-Loup Bertaux, Michael F. A'Hearn
Summary: Cometary outbursts provide valuable insights into the composition of comet nuclei by forcefully ejecting dust and volatiles in explosive events. Understanding the influence of different outburst types on dust properties and volatile abundances is crucial for interpreting the signatures of primordial composition versus processing effects, and a multi-instrument approach is the best way to tackle this task. The analysis of two outbursts observed by instruments on board the Rosetta mission reveals that spectral signatures of mixed gas and dust outbursts may vary depending on their initiating mechanisms, opening up the possibility of remote spectral classification of cometary outbursts in future studies.
ASTRONOMICAL JOURNAL
(2021)
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
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
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
Engineering, Aerospace
A. A. Burov, A. D. Guerman, V. I. Nikonov
Summary: In this study, we investigate the local minima, maxima, and saddle points of the augmented potential applied to comet (67P) Churyumov-Gerasimenko's surface. We specifically determine the isolines of the augmented potential on this surface, including those corresponding to the saddle points. The findings are utilized to uncover the relationship between the structure of potential motion areas on the comet surface and the previously defined geographic objects during the Rosetta mission.
Article
Astronomy & Astrophysics
Bjorn J. R. Davidsson, Samuel Birch, Geoffrey A. Blake, Dennis Bodewits, Jason P. Dworkin, Daniel P. Glavin, Yoshihiro Furukawa, Jonathan Lunine, Julie L. Mitchell, Ann N. Nguyen, Steve Squyres, Aki Takigawa, Jean-Baptiste Vincent, Kris Zacny
Summary: This study focuses on the transfer process of material on an active comet nucleus, specifically 67P/Churyumov-Gerasimenko. The research finds that the thickness of airfall material varies significantly with location, with water ice being able to be preserved for a longer period in relatively small dust aggregates.
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
Younas Khan, Erika L. Gibb, Nathan X. Roth, Michael A. DiSanti, Neil Dello Russo, Boncho P. Bonev, Chemeda T. Ejeta, Mohammad Saki, Ronald J. Vervack Jr, Adam J. McKay, Hideyo Kawakita, Michael R. Combi, Danna Qasim, Yinsi Shou
Summary: In this study, the chemical composition of comet 46P/Wirtanen was analyzed using near-IR observations. The production rates and mixing ratios of H2O and C2H6 were reported. The results showed spatial characteristics of the volatile gases, similar to other hyperactive comets. The molecular abundances in 46P/Wirtanen showed small variations compared to the overall comet population, with CH3OH showing notable differences.
ASTRONOMICAL JOURNAL
(2023)
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)
Review
Astronomy & Astrophysics
Peter Hoppe, Martin Rubin, Kathrin Altwegg
Summary: ESA's Rosetta mission has expanded the data sets on isotopic compositions of comets through its study of comet 67P/CG. By comparing these data with meteorite data, new insights into the formation conditions of small planetary bodies in the early Solar System have been gained.
SPACE SCIENCE REVIEWS
(2023)
Article
Astronomy & Astrophysics
Y. Ma, M. R. Combi, V. Tenishev, Y. Shou, S. Bougher
Summary: Since Venus lacks a substantial planetary magnetic field, the solar wind plasma directly interacts with its ionosphere, upper atmosphere, and corona. The role of the thermal atmosphere and hot oxygen corona in this interaction process is examined using three-dimensional numerical models. The results show that the hot oxygen corona can enhance ion loss rates by up to 25% during high solar activity.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Multidisciplinary Sciences
Ahmed Mahjoub, Kathrin Altwegg, Michael J. Poston, Martin Rubin, Robert Hodyss, Mathieu Choukroun, Bethany L. Ehlmann, Nora Hanni, Michael E. Brown, Jordana Blacksberg, John M. Eiler, Kevin P. Hand
Summary: The ROSINA instrument aboard the Rosetta mission has advanced our understanding of cometary material composition. By analyzing data from a dust event in September 2016, the study reveals the detection of large organo-sulfur species and an increase in the abundance of sulfurous species in the comet's coma. Laboratory simulations further suggest that these materials may have formed from the irradiation of mixed ices containing H2S. This study emphasizes the significance of sulfur chemistry in cometary and precometary materials, and proposes the possibility of characterizing organosulfur materials in other comets and small icy bodies using the James Webb Space Telescope.
Article
Astronomy & Astrophysics
N. Haenni, K. Altwegg, D. Baklouti, M. Combi, S. A. Fuselier, J. De Keyser, D. R. Mueller, M. Rubin, S. F. Wampfler
Summary: The complexity of terrestrial biomolecules has led to a search for complex organic molecules in the interstellar medium. The study focused on the analysis of O-bearing organic volatiles in a comet and compared the results with molecules found in the interstellar medium, other comets, and meteorites. The study discovered abundant O-bearing heterocycles and various other molecule classes in the comet, providing insights into the chemical complexity of space.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
M. R. Combi, T. Makinen, J. -l. Bertaux, E. Quemerais, S. Ferron
Summary: The hydrogen comae of three long period comets, C/2020 S3 (Erasmus), C/2021 A1 (Leonard), and C/2021 O3 (PanSTARRS), were observed using the Solar Wind ANisotropies (SWAN) all-sky hydrogen Lyman-alpha camera on the SOlar and Heliosphere Observer (SOHO) satellite in 2021 and 2022. SWAN captures daily full-sky images of the interstellar hydrogen's Lyman-alpha distribution as it passes through the solar system, providing information about the solar wind and solar ultraviolet fluxes. Water production rates were calculated for each comet over time. The behavior of comet C/2020 S3 (Erasmus) was typical, while comet C/2021 O3 (PanSTARRS) appeared to disintegrate before perihelion and comet C/2021 A1 (Leonard) disintegrated after its perihelion peak.
Article
Astronomy & Astrophysics
Z. M. Lewis, A. Beth, K. Altwegg, M. Galand, C. Goetz, K. Heritier, L. O'Rourke, M. Rubin, P. Stephenson
Summary: The European Space Agency/Rosetta mission analyzed the ion composition in the coma of comet 67P/C-G and found high proton affinity species, particularly NH4+, indicating a high level of ion-neutral chemistry. The increased comet outgassing around perihelion led to more detections of NH4+ and other protonated HPA species, suggesting complex ion-neutral chemistry. The low magnetic field strength associated with the diamagnetic cavity was linked to higher NH4+ counts, indicating different transport dynamics inside and outside the diamagnetic cavity.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
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)
Review
Astronomy & Astrophysics
Andrea Longobardo, Minjae Kim, Boris Pestoni, Mauro Ciarniello, Giovanna Rinaldi, Stavro Ivanovski, Fabrizio Dirri, Marco Fulle, Vincenzo Della Corte, Alessandra Rotundi, Martin Rubin
Summary: This study summarizes the findings of the ESA/Rosetta mission on the Jupiter Family Comet 67P/Churyumov-Gerasimenko. The data collected from instruments onboard the Rosetta orbiter, along with numerical models and experimental work, have provided important insights into cometary activity mechanisms. The study reveals correlations between dust ejection and solar illumination, as well as the dominance of water sublimation during the perihelion phase. The comparison of dust fluxes and particle sizes also suggests a link between dust morphology and ejection speed.
Article
Chemistry, Physical
Murthy S. Gudipati, Benjamin Fleury, Robert Wagner, Bryana L. Henderson, Kathrin Altwegg, Martin Rubin
Summary: Ice is an important component of astrophysical environments and can coexist with complex organic matter. It is believed that primordial ice brought the molecules of life to Earth and kickstarted the origin of life. Laboratory experimental studies combined with telescopic observations can provide deeper insight into the processes occurring in these environments. In this study, simultaneous mass spectrometric and infrared spectroscopic investigations were conducted to understand the behavior of molecular ice mixtures at different temperatures and its implications for interpreting observational data.
FARADAY DISCUSSIONS
(2023)
Article
Astronomy & Astrophysics
Boncho P. Bonev, Neil Dello Russo, Hideyo Kawakita, Ronald J. Vervack Jr., Michael A. Disanti, Yoshiharu Shinnaka, Takafumi Ootsubo, Erika L. Gibb, Michael R. Combi, Kathrin Altwegg, Nicolas Biver, Jacques Crovisier, Gregory Doppmann, Geronimo L. Villanueva, Younas Khan, Chemeda T. Ejeta, Mohammad Saki, Adam J. McKay, Anita L. Cochran, Emmanuel Jehin, Nathan X. Roth, Martin A. Cordiner, Yinsi Shou
Summary: By conducting high-resolution near-infrared ground-based spectroscopic observations of comet 67P/Churyumov-Gerasimenko near its maximum activity in 2021, researchers were able to obtain valuable insights into its composition and compare the results with the findings from the Rosetta mission. These observations provide important data for the study of comets as a whole.
ASTRONOMICAL JOURNAL
(2023)
Article
Engineering, Aerospace
T. M. Ho, E. Kuehrt, X. J. Zhang, U. Auster, J. Biele, M. Grott, J. T. Grundmann, H. Heg, A. Hoerdt, J. C. Huang, T. Mai, S. Mottola, K. Otto, D. Plettemeierj, L. Qin, M. Rubin, N. Schmitz, S. Ulamec, J. B. Vincent
Summary: CALICUT, a nanolander, is proposed for an Asteroid Exploration Mission by a joint European-Chinese team. It is designed to operate on an active asteroid in the main belt, with mobility and autonomy capabilities for at least 6 weeks of data collection. The nanolander carries four scientific instruments to provide unique measurements on the surface.