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
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
N. Biver, D. Bockelee-Morvan, J. Crovisier, Aa. Sandqvist, J. Boissier, D. C. Lis, M. Cordiner, B. P. Bonev, N. Dello Russo, R. Moreno, S. Milam, N. X. Roth, R. Vervack, M. A. DiSanti
Summary: We conducted a molecular survey of comet 67P/Churyumov-Gerasimenko using the IRAM 30-m radio telescope in November-December 2021. The observations confirmed that the gas outflow velocity, outgassing pattern, and temperature of the comet were consistent with previous in situ measurements. We determined the abundances relative to water for seven molecules and obtained significant upper limits for approximately five others.
ASTRONOMY & ASTROPHYSICS
(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)
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
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
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
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
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
Alissa M. Earle, R. P. Binzel, J. T. Keane, W. M. Grundy, C. J. A. Howett, C. B. Olkin, A. H. Parker, F. Scipioni, K. Ennico, S. A. Stern, H. A. Weaver, L. A. Young
Summary: The New Horizons spacecraft's exploration of the Pluto system in July 2015 has provided unprecedented detailed information about Pluto's origin, surface processes, volatile transport cycles, and atmosphere. This study focuses on the volatile distribution in and around craters, using data from the Ralph/MVIC instrument, and reveals differences in compositional characteristics in different latitudinal bands. The findings highlight the importance of understanding the effects of small scale topography on volatile transport.
Review
Astronomy & Astrophysics
Derek S. Nelson, Frederic J. Pelletier, Marc W. Buie, Jeremy A. Bauman, Joel T. Fischetti, Yanping Guo, Stephen D. J. Gwyn, Mark E. Holdridge, J. J. Kavelaars, Erik J. Lessac-Chenen, Catherine B. Olkin, John Y. Pelgrift, Simon B. Porter, Gabe D. Rogers, Michael J. Salinas, John R. Spencer, Dale R. Stanbridge, S. Alan Stern, Harold A. Weaver, Bobby G. Williams, Kenneth E. Williams
Summary: The New Horizons mission successfully flew by the distant Kuiper-Belt Object Arrokoth, achieving the farthest planetary encounter to date. The navigation strategy involved close collaboration between the science and navigation teams to estimate the target's orbit and reduce uncertainties through various measurements and methods.
SPACE SCIENCE REVIEWS
(2022)
Article
Multidisciplinary Sciences
Kelsi N. Singer, Oliver L. White, Bernard Schmitt, Erika L. Rader, Silvia Protopapa, William M. Grundy, Dale P. Cruikshank, Tanguy Bertrand, Paul M. Schenk, William B. McKinnon, S. Alan Stern, Rajani D. Dhingra, Kirby D. Runyon, Ross A. Beyer, Veronica J. Bray, Cristina Dalle Ore, John R. Spencer, Jeffrey M. Moore, Francis Nimmo, James T. Keane, Leslie A. Young, Catherine B. Olkin, Tod R. Lauer, Harold A. Weaver, Kimberly Ennico-Smith
Summary: The New Horizons spacecraft returned images and data showing that Pluto's terrains have diverse ages, ranging from ancient to very young. One region stands out with very few impact craters and is dominated by huge rises with hummocky flanks. It is believed that this terrain was resurfaced by cryovolcanic processes, which are unique to Pluto and suggest unexpected, active geology in Pluto's history.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
James T. Keane, Simon B. Porter, Ross A. Beyer, Orkan M. Umurhan, William B. McKinnon, Jeffrey M. Moore, John R. Spencer, S. Alan Stern, Carver J. Bierson, Richard P. Binzel, Douglas P. Hamilton, Carey M. Lisse, Xiaochen Mao, Silvia Protopapa, Paul M. Schenk, Mark R. Showalter, John A. Stansberry, Oliver L. White, Anne J. Verbiscer, Joel W. Parker, Catherine B. Olkin, Harold A. Weaver, Kelsi N. Singer
Summary: NASA's New Horizons mission flew by a small Kuiper Belt Object (KBO), (486958) Arrokoth, revealing its interesting geological features and geophysical environment. Arrokoth's surface features have a complex relationship with its geophysical environment, with bright material concentrated in low gravity areas. By inferring density, it was found that Arrokoth has a low bulk density, which is crucial for understanding the formation of planetesimals in the early Solar System.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2022)
Article
Astronomy & Astrophysics
D. J. McComas, B. L. Shrestha, P. Swaczyna, J. S. Rankin, S. E. Weidner, E. J. Zirnstein, H. A. Elliott, K. N. Singer, J. Spencer, S. A. Stern, H. A. Weaver
Summary: This study presents the first high-time-resolution observations of interstellar pickup ions (PUIs) in the outer heliosphere, shedding light on their compression and heating during shock processes. The study also finds that core solar wind properties do not show consistent changes across shocks. These new high-resolution observations have significant implications for understanding shocks in the outer heliosphere and PUI-mediated shocks in other astrophysical systems.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Yoonyoung Kim, David Jewitt, Jessica Agarwal, Max Mutchler, Jing Li, Harold Weaver
Summary: This study presents observations of the active asteroid P/2020 O1 taken by the Hubble Space Telescope, providing insights into its development for a year after perihelion. The research finds that the mass loss of the asteroid peaked in August 2020 and then declined to near zero over a four-month period. The long-duration mass loss is believed to be due to sublimation of ice, suggesting that the asteroid may be an ice-bearing main-belt comet. The study also reveals evidence of rapid rotation and varying ejection speeds of different particle sizes.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
Jason C. Cook, Silvia Protopapa, Cristina M. Dalle Ore, Dale P. Cruikshank, William M. Grundy, Carey M. Lisse, Bernard Schmitt, Anne Verbiscer, Kelsi N. Singer, John Spencer, S. Alan Stern, Harold A. Weaver
Summary: In this study, we examined the 2.21-mu m band of Charon using data obtained by New Horizons/LEISA. We found no significant variation in this band as Charon rotates. The 2.21-mu m band on Charon is several times weaker than on other moons, and we attribute it to NH4Cl based on the appearance of a weaker band at 2.24-mu m. Additionally, we observed two never-before-reported absorption features in Charon's spectrum at 1.60 and 1.63-mu m, which may also be explained by the presence of NH4Cl. If NH3-H2O ice mixtures are present on Charon, they must be a small fraction of the overall composition.
Article
Astronomy & Astrophysics
Eric Quirico, Aurore Bacmann, Cedric Wolters, Basile Auge, Laurene Flandinet, Thibault Launois, John F. Cooper, Veronique Vuitton, Thomas Gautier, Lora Jovanovic, Philippe Boduch, Hermann Rothard, Leopold Desage, Alexandre Faure, Bernard Schmitt, Olivier Poch, William M. Grundy, Silvia Protopapa, Sonia Fornasier, Dale P. Cruikshank, S. Alan Stern
Summary: The New Horizons spacecraft conducted a survey on the classical Kuiper Belt Object (KBO) Arrokoth and discovered a small bilobed object with a red surface. This red color is attributed to reddish organic materials, possibly inherited from the protosolar disk or formed through radiolytic processes. Numerical calculations and experimental simulations were carried out to study the radiolytic scenario. It was found that sputtering is mainly controlled by Solar Wind, and the sputtering rate varies depending on the nature of the material.
Article
Astronomy & Astrophysics
John W. Noonan, Joel Wm. Parker, Walter M. Harris, Steven Bromley, Mohammad Saki, Youssef Moulane, Davide Farnocchia, Marco Micheli, Jian-Yang Li, Kathleen E. Mandt, Kumar Venkataramani, Dennis Bodewits
Summary: Researchers used the Hubble Space Telescope to observe two comets and found that their volatile materials were more abundant than previously thought. The study of sulfur-bearing molecules in comets is important for understanding planetesimal formation environments. Several hypotheses were proposed to explain the discrepancy, and future studies were outlined to address these issues.
PLANETARY SCIENCE JOURNAL
(2023)
Review
Astronomy & Astrophysics
Keith S. Noll, Michael E. Brown, Marc W. Buie, William M. Grundy, Harold F. Levison, Simone Marchi, Catherine B. Olkin, S. Alan Stern, Harold A. Weaver
Summary: This chapter reviews the current state of knowledge of Trojan asteroid satellites and discusses their scientific utility and potential observations.
SPACE SCIENCE REVIEWS
(2023)
Article
Astronomy & Astrophysics
G. Randall Gladstone, Carey M. Lisse, Leslie A. Young, Joel Wm. Parker, Kelsi N. Singer, John R. Spencer, Harold A. Weaver, S. Alan Stern
Summary: In this study, observations were made during the New Horizons flyby of Kuiper Belt object (486958) Arrokoth to search for escaping volatiles. Upper limits to the escape rates for several species were presented using a Haser model. These results are significant for models of the formation and evolution of Kuiper Belt objects.
PLANETARY SCIENCE JOURNAL
(2022)
Article
Astronomy & Astrophysics
C. M. Lisse, G. R. Gladstone, L. A. Young, D. P. Cruikshank, S. A. Sandford, B. Schmitt, S. A. Stern, H. A. Weaver, O. Umurhan, Y. J. Pendleton, J. T. Keane, J. M. Parker, R. P. Binzel, A. M. Earle, M. Horanyi, M. El-Maarry, A. F. Cheng, J. M. Moore, W. B. McKinnon, W. M. Grundy, J. J. Kavelaars, I. R. Linscott, W. Lyra, B. L. Lewis, D. T. Britt, J. R. Spencer, C. B. Olkin, R. L. McNutt, H. A. Elliott, N. Dello-Russo, J. K. Steckloff, M. Neveu, O. Mousis
Summary: This study presents predictions about the rarity of majority hypervolatile ices in Kuiper Belt objects and Oort Cloud comets, based on new ice species-specific data. These predictions have important implications for the study of the Oort Cloud, including the determination of first objects emplaced into the Oort Cloud, the measurement of gas abundance ratios in the protoplanetary disk, and statistical constraints on the emplacement of objects into the Oort Cloud.
PLANETARY SCIENCE JOURNAL
(2022)
Article
Astronomy & Astrophysics
M. K. Bird, I. R. Linscott, G. L. Tyler, O. M. Umurhan, R. A. Beyer, W. M. Grundy, C. M. Lisse, D. P. Hinson, M. Paetzold, S. A. Stern, H. A. Weaver, C. B. Olkin, L. A. Young, J. R. Spencer, K. N. Singer, J. M. Moore, G. R. Gladstone, C. C. DeBoy, M. Vincent, S. B. Porter
Summary: The New Horizons spacecraft conducted a reconnaissance mission of the Kuiper Belt object Arrokoth, obtaining thermal emission measurements and deriving important parameters like global emissivity and thermal inertia. The results provide insights into the nature of this distant solar system body.
PLANETARY SCIENCE JOURNAL
(2022)