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
Astronomy & Astrophysics
K. Altwegg, M. Combi, S. A. Fuselier, N. Haenni, J. De Keyser, A. Mahjoub, D. R. Mueller, B. Pestoni, M. Rubin, S. F. Wampfler
Summary: Ammonium hydrosulphide has been found to exist in certain layers of giant planets and may be the reason for Jupiter's red color. In this study, in situ measurements from the Rosetta mission were analyzed, and it was discovered that NH4+SH- is the most abundant salt, even more than water. The balance between ammonia and acids confirms that ammonia is mainly in the form of salt embedded in dust grains.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Naceur Bouziani, David Jewitt
Summary: Recent observations have shown that the long-period comet C/2017 K2 is active at distances beyond the orbit of Uranus. In order to understand this phenomenon, researchers have developed a simple model to simulate the sublimation process of supervolatile ice in the comet nucleus. The model reveals that there is a localized increase in carbon monoxide sublimation at a distance of 150 astronomical units from the Sun, followed by a plateau and a slow increase in activity towards smaller distances. This finding suggests that future observations may discover comet activity at distances far beyond the planetary region of the solar system.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Yu Skorov, V Reshetnyk, M. Kuppers, M. S. Bentley, S. Besse, P. Hartogh
Summary: Explanation of gas activity based on comet's nucleus parameters is not obvious. In this study, the dependence of gas activity on these parameters is assessed, considering various model porous dust layers and examining solid state and gas thermal conductivities. The results show that uncertainties in the structure of the layer have a small effect when sublimation is the main energy sink, but can lead to significant changes in gas production as the relative contribution of sublimation decreases. The uncertainty in the values of some model parameters, such as thermal conductivity, blurs the theoretical simulation estimates.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
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
Jens Biele, Jean-Baptiste Vincent, Joerg Knollenberg
Summary: This paper provides an overview of the available direct and indirect data on the strength of cometary material, focusing on comet Churyumov-Gerasimenko/67P and including a discussion on the Deep Impact strength results. The paper discusses the definition of strength, soil mechanics, bulk density, porosity, sintering, and the physics of cohesive granular medium strength. It also explores the scaling of strength with size and strain rate, and the correlation between elastic properties, thermal data, and strength. The paper concludes with a review of high and low strength values inferred from Philae’s motion and collisions with the comet's surface.
Article
Astronomy & Astrophysics
Libor Nouzak, David James, Zdenek Nemecek, Jana Safrankova, Jiri Pavlu, Jaroslava Novakova, Jakub Vaverka, Zoltan Sternovsky
Summary: Faraday cups are instruments used to measure velocity distribution functions of space plasmas, frequently utilized in heliophysics missions. A new version of this instrument is being developed for the Luna 26 mission to quickly monitor solar wind plasma parameters. The prototype is tested for dust impacts in a 0.2-60 km/s velocity range, with collected data indicating sufficient sensitivity for detecting interplanetary dust and lunar surface dust lift-off. Simple modifications to the FC electronics could significantly increase detection efficiency.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Prithish Halder, Sujan Sengupta
Summary: By incorporating a mixture of rough fractal aggregates and agglomerated debris, we successfully replicated the unusual polarization-phase curve observed in the interstellar comet 2I/Borisov at multiple wavelengths. Our model suggests that the higher percentage of porous rough fractal aggregates in the comet contributes to the steep polarimetric slope and the high dust-to-gas ratio observed in newer comets.
ASTROPHYSICAL JOURNAL
(2023)
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
Wenbo Zuo, Aigen Li, Gang Zhao
Summary: This study investigates the interstellar dust composition, size, and quantity by examining the extinction and abundances of 10 interstellar sight lines. The findings suggest that solar and protosolar abundances may not be appropriate representations of the interstellar abundances, while the GCE-augmented protosolar abundances are supported as a viable representation.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2021)
Article
Multidisciplinary Sciences
J. Manfroid, D. Hutsemekers, E. Jehin
Summary: Iron and nickel have been found in cometary atmospheres, even at a distance from the Sun, with emission lines of Fe I and Ni I present. These abundances appear to be of similar magnitude, contrasting the typical Solar System abundance ratio.
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
Bin Yang, Aigen Li, Martin A. Cordiner, Chin-Shin Chang, Olivier R. Hainaut, Jonathan P. Williams, Karen J. Meech, Jacqueline V. Keane, Eric Villard
Summary: The interstellar comet 2I/Borisov is the first actively behaving comet detected in our Solar System, with a dense dust coma primarily consisting of 'pebbles' exceeding 1 mm in radius. The comet exhibits a high dust mass-loss rate of approximately 200 kg s(-1) and a dust-to-gas ratio of around 3. Observations suggest a heterogeneous cometary nucleus with components formed at different locations beyond the volatile snow-line, indicating efficient radial mixing processes within the system.
Article
Geochemistry & Geophysics
Kainen L. Utt, Ryan C. Ogliore, Nan Liu, Alexander N. Krot, John P. Bradley, Donald E. Brownlee, David J. Joswiak
Summary: Filamentary enstatite crystals, formed by gas-solid condensation in the solar nebula, are found in chondritic porous interplanetary dust particles of probable cometary origin. Our measurements provide evidence for very early vaporization of dust-poor and dust-rich regions of the solar nebula, followed by condensation and outward transport of crystalline dust to the comet-forming region very far from the Sun. Similar processes are likely responsible for the crystalline silicates observed in the outer regions of protoplanetary disks elsewhere in the Galaxy.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Astronomy & Astrophysics
M. Kim, T. Mannel, P. D. Boakes, M. S. Bentley, A. Longobardo, H. Jeszenszky, R. Moissl, MIDAS Team
Summary: The MIDAS atomic force microscope on board the Rosetta comet orbiter has been used to collect and investigate cometary dust in the nanometer to micrometer range. The aim is to catalog all collected dust particles and present the scientific results obtained from the catalog, such as the size distribution and statistical characteristics of cometary dust particles. The catalog has been improved and updated, resulting in a comprehensive list of detected cometary dust particles.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Engineering, Aerospace
B. Bonvoisin, M. Meisnar, J. Merrifield, J. Beck, T. Lips, A. Guelhan, T. Schleutker, G. Herdrich, A. Pagan, E. Kaschnitz, V Liedtke, B. Helber, S. Lopes, J. B. Gouriet, O. Chazot, T. Ghidini
Summary: In order to reduce the risk of spacecraft re-entry causing casualties on the ground, ESA tested and analyzed material modeling, using the results as inputs for re-entry simulations.
CEAS SPACE JOURNAL
(2023)
Article
Astronomy & Astrophysics
Zach Ulibarri, Tobin Munsat, Michael Voss, John Fontanese, Mihaly Horanyi, Sascha Kempf, Zoltan Sternovsky
Summary: Impact ionization time of flight mass spectrometry (TOF-MS) instruments are used to study the molecular composition of space-borne dust grains by impacting them at high velocities. These instruments are important for assessing the inventory and distribution of organics in the solar system, especially for potentially habitable ocean worlds such as Europa. Experiments using a novel airbrushing technique for ice creation show that water ice layers significantly reduce fragmentation rates of amino acids when impacted by high-speed dust particles. The observed fragmentation species correlate with those produced by electron ionization experiments.
Article
Astronomy & Astrophysics
Oliver Price, Geraint H. Jones, Karl Battams, Mathew Owens
Summary: The process of forming striated features in cometary dust tails is not yet fully understood. This article uses observations of the tail evolution of C/2011 L4 Pan-STARRS and the reorganisation of striae in the tail of C/2006 P1 McNaught to study the influence of Lorentz forces and solar wind on the alignments of the reorganised striae. The discovery of a bright neutral sodium tail in C/2011 L4 is also reported.
Article
Astronomy & Astrophysics
Qasim Afghan, Geraint H. Jones, Oliver Price, Andrew Coates
Summary: Cometary dust tails exhibit various structures, most of which are believed to be caused by factors such as variable dust production and interactions with the solar wind. However, not all of these structures have been fully understood. This study reports the discovery of a peculiar dust tail feature, where a section of the tail is missing. This suggests a temporary decrease in dust production near perihelion.
Article
Geochemistry & Geophysics
Matthew J. Genge, Luke Alesbrook, Natasha V. Almeida, Helena C. Bates, Phil A. Bland, Mark R. Boyd, Mark J. Burchell, Gareth S. Collins, Luke T. Cornwell, Luke Daly, Hadrien A. R. Devillepoix, Matthias van Ginneken, Ansgar Greshake, Daniel Hallatt, Christopher Hamann, Lutz Hecht, Laura E. Jenkins, Diane Johnson, Rosie Jones, Ashley J. King, Haithem Mansour, Sarah McMullan, Jennifer T. Mitchell, Gavyn Rollinson, Sara S. Russell, Christian Schroeder, Natasha R. Stephen, Martin D. Suttle, Jon D. Tandy, Patrick Trimby, Eleanor K. Sansom, Vassilia Spathis, Francesca M. Willcocks, Penelope J. Wozniakiewicz
Summary: Fusion crusts form during meteorite atmospheric entry, providing a record of atmospheric deceleration conditions. The Winchcombe meteorite's fusion crust is similar to other stony meteorites, dominated by olivine phenocrysts embedded in a glassy matrix with magnetite and highly vesicular. Unusually abundant dehydration cracks and weak layer failure contribute to particle formation, supported by plasma pulses observed in the fireball videos. Oscillatory zoning in olivine phenocrysts suggests temperature fluctuations from calving events. Unique features include magnetite monolayers and silicate warts, indicating intense gas loss and inter-shower material transfer.
METEORITICS & PLANETARY SCIENCE
(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)
Article
Geosciences, Multidisciplinary
L. K. Tarnecki, R. A. Marshall, J. Fontanese, Z. Sternovsky, T. Munsat
Summary: Calculating meteoroid masses from photometric observations relies on the uncertain parameter of luminous efficiency. In this study, an experimental campaign was conducted to determine the relationship between luminous efficiency and mass, velocity, and composition. Iron and aluminum microparticles were accelerated and ablated, and their light production was measured. The results show that the luminous efficiency is not consistent between different materials and velocities, emphasizing the need for considering composition and velocity when determining luminous efficiency.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Astronomy & Astrophysics
G. Cruz Mermy, F. Schmidt, F. Andrieu, T. Cornet, I. Belgacem, N. Altobelli
Summary: Europa's surface shows evidence of active resurfacing, potentially from either internal or external processes. Previous spectroscopic studies were limited by the lack of laboratory measurements, but recent access to optical constants and laboratory spectra of chemical compounds allows for testing the relevance of 15 potential endmembers. A fitting procedure using realistic modeling and Bayesian inference identifies sulfuric acid octahydrate and water ice as essential compounds.
Article
Chemistry, Multidisciplinary
Ana de Sousa, Rafael Pinto, Bruno Couto, Beltran Nadal, Hugo Onderwater, Paulo Gordo, Manuel Abreu, Rui Melicio, Patrick Michel
Summary: This paper focuses on the implementation of two important technologies in light detection and ranging for space applications: microchip Q-switched laser and indium gallium arsenide avalanche photodiode. The microchip Q-switched laser generates high-energy short pulses and is implemented using specific materials. The avalanche photodiode uses multiple layer composition to build up high values of photocurrent from small optical signals. These technologies are crucial for mobile light detection and ranging due to their low mass and high efficiencies.
APPLIED SCIENCES-BASEL
(2023)
Article
Astronomy & Astrophysics
Mitchell M. Shen, Zoltan Sternovsky, David M. Malaspina
Summary: Electric field instruments on spacecraft complement dedicated dust detectors by registering impact-generated plasma through transient voltage perturbations. A set of laboratory measurements investigates the variations in antenna signals caused by different SC and impactor parameters. The results show that dipole antenna configurations are sensitive to dust impacts and that the detected signals vary with impact location. The measurements also demonstrate that different impacting materials do not significantly affect the measured waveform or plasma parameters.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Multidisciplinary Sciences
Sascha Kempf, Nicolas Altobelli, Juergen Schmidt, Jeffrey N. Cuzzi, Paul R. Estrada, Ralf Srama
Summary: There is ongoing debate about whether Saturn's main rings are young or ancient. The rings are mostly composed of water-ice but are polluted by non-icy material. Continuous bombardment from micrometeoroids from outside the Saturnian system is the source of this pollution. By measuring the micrometeoroid flux into the Saturnian system, it is possible to estimate the rings' exposure time and infer their age. The final measurements by Cassini's Cosmic Dust Analyzer indicate a ring exposure time of less than or similar to 100 to 400 million years, supporting recent ring formation scenarios.
Article
Physics, Atomic, Molecular & Chemical
Thomas Stephan, Reto Trappitsch
Summary: The paper discusses the problem of correlated errors in experimental data and provides tools for propagating uncertainties in such cases. Techniques applicable to three-isotope plots in geo-and cosmochemistry are specifically discussed, where common denominators in isotope ratios and instrumental effects could lead to significant correlation of errors. The paper also compares various techniques for calculating linear regressions and suggests that the method proposed by Mahon (1996) [1] gives the best results after correcting some typographical errors and eliminating a minor mistake. A method for calculating linear regressions through a fixed point is also provided to avoid previous mistakes.
INTERNATIONAL JOURNAL OF MASS SPECTROMETRY
(2023)
Article
Astronomy & Astrophysics
Alex J. Meyer, Harrison F. Agrusa, Derek C. Richardson, R. Terik Daly, Oscar Fuentes-Munoz, Masatoshi Hirabayashi, Patrick Michel, Colby C. Merrill, Ryota Nakano, Andrew F. Cheng, Brent Barbee, Olivier S. Barnouin, Steven R. Chesley, Carolyn M. Ernst, Ioannis Gkolias, Nicholas A. Moskovitz, Shantanu P. Naidu, Petr Pravec, Petr Scheirich, Cristina A. Thomas, Kleomenis Tsiganis, Daniel J. Scheeres
Summary: With the successful impact of NASA's DART spacecraft on the Didymos-Dimorphos binary asteroid system, an initial analysis of the perturbed dynamics of the binary asteroid is provided. Observable elements calculated based on the physical separation of the binary asteroid, instead of traditional Keplerian elements, are introduced to compare simulation results with observations. Numerical methods that consider the fully spin-orbit-coupled dynamics are used to estimate the system's mass and the impact-induced changes in orbital velocity, semimajor axis, and eccentricity. The findings indicate that the changes in the mutual orbit depend on the separation distance between Didymos and Dimorphos at the time of impact, and potential tumbling state of Dimorphos after the impact may be observed through changes in the system's eccentricity and orbit period. Additionally, any reshaping of Dimorphos caused by DART would reduce the required change in orbital velocity, which will be assessed by the ESA Hera mission in 2027.
PLANETARY SCIENCE JOURNAL
(2023)
