Session PS5.1

[Programme]

PS5.1 | Small Bodies and Dust — Open Session

Small Bodies and Dust — Open Session

Convener: Jiri Pavlu | Co-conveners: Maria Gritsevich, Patrick Shober

Orals

| Wed, 26 Apr, 10:45–12:30 (CEST)

Room L1

Posters on site

| Attendance Wed, 26 Apr, 16:15–18:00 (CEST)

Hall X4

Posters virtual

| Attendance Wed, 26 Apr, 16:15–18:00 (CEST)

vHall ST/PS

The session accepts contributions on dwarf planets and small solar system objects, including comets, asteroids, meteoroids, and dust. Topics also cover dynamics, evolution, physical properties, and interactions in both space and atmospheres. We invite presenters to highlight recent space missions (SolO, PSP ...) results, laboratory studies, meteor observations, and theoretical and numerical simulations. This session also provides a forum for presenting future space instrumentation. We welcome young minds and encourage the presentation of multi-disciplinary research.

Orals: Wed, 26 Apr | Room L1

Chairpersons: Jiri Pavlu, Maria Gritsevich

10:45–11:05

EGU23-6180

ECS

solicited

On-site presentation

Machine learning detection of dust impact signals observed by the Solar Orbiter

Andreas Kvammen, Kristoffer Wickstrøm, Samuel Kociscak, Jakub Vaverka, Libor Nouzak, Arnaud Zaslavsky, Kristina Rackovic Babic, Amalie Gjelsvik, David Pisa, Jan Soucek, and Ingrid Mann

At present, ongoing space missions (PSP, SolO) provide the opportunity to closely observe the dust distribution in the inner solar system. It is however challenging to automatically detect and separate dust impact signals from other observed features for two main reasons. Firstly, since the spacecraft charging causes variable shapes of the dust signals, and secondly because electromagnetic waves (such as solitary waves) may induce resembling electric field signals.

In this presentation, we propose a novel method, based on artificial intelligence, for detecting dust impacts in Solar Orbiter observations with high accuracy. Two supervised machine learning approaches are considered: the support vector machine (SVM) classifier and the convolutional neural network (CNN) classifier. Furthermore, we compare the performance of the machine learning classifiers to the currently used on-board classification algorithm and analyze 2 years of Solar Orbiter data.

Overall, we conclude that detection of dust signals is a suitable task for machine learning techniques. The convolutional neural network achieves the highest performance with 96% ± 1% overall classification accuracy and 94% ± 2% dust detection precision, a significant improvement to the currently used on-board classifier with 85% overall classification accuracy and 75% dust detection precision. In addition, both the support vector machine and the convolutional neural network detect more dust particles (on average) than the on-board classification algorithm, with 16% ± 1% and 18% ± 8% detection enhancement respectively.

How to cite: Kvammen, A., Wickstrøm, K., Kociscak, S., Vaverka, J., Nouzak, L., Zaslavsky, A., Rackovic Babic, K., Gjelsvik, A., Pisa, D., Soucek, J., and Mann, I.: Machine learning detection of dust impact signals observed by the Solar Orbiter, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6180, https://doi.org/10.5194/egusphere-egu23-6180, 2023.

11:05–11:15

EGU23-8649

On-site presentation

Inventory of Interstellar (ISD) and Interplanetary Dust (IDP) at 1 AU

Mihaly Horanyi, Zoltan Sternovsky, Jamey Szalay, Ethan Ayari, and Rebecca Mikula

The Interstellar Mapping and Acceleration Probe (IMAP) is scheduled to launch in 2025, to be stationed at the Sun-Earth L1 Lagrange point with a combination of 10 in-situ and remote sensing instruments. A primary science goal of IMAP is to improve our understanding of the composition and properties of the local interstellar medium. The local interstellar medium contains plasma, magnetic fields, neutral atoms, cosmic rays, and dust which all influence the heliosphere through interconnected time-dependent and multi-scale processes. The Interstellar Dust Experiment (IDEX) instrument onboard IMAP will measure the flux, size distribution, and composition of interstellar dust particles (ISD), characterizing the inflowing solid matter from the local interstellar medium reaching the inner heliosphere. IDEX will determine whether the composition of the contemporary local interstellar cloud's dust population is consistent with being the feedstock for the formation of the Solar System. In addition to heliospheric science goals, IDEX will also detect the shared pool of interplanetary dust particles (IDP) of cometary and asteroidal origin and determine whether some IDPs preserve unprocessed pre-solar molecular cloud particles or show signatures of processing in the solar system. IDEX will identify primary organic material from asteroids and various cometary families to determine if they share a common source or are formed from distinct reservoirs. IDEX dust detection is based on impact ionization, where elemental and molecular ions are generated in a high-velocity dust impact and analyzed in a time-of-flight (TOF) setup. This talk will discuss the expected scientific results of IDEX that are of primary importance to heliospheric, astrophysical, and planetary sciences. This talk will summarize our current understanding of the ISD and IDP inventory and the expected improvements by the IMAP mission.

How to cite: Horanyi, M., Sternovsky, Z., Szalay, J., Ayari, E., and Mikula, R.: Inventory of Interstellar (ISD) and Interplanetary Dust (IDP) at 1 AU, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8649, https://doi.org/10.5194/egusphere-egu23-8649, 2023.

11:15–11:25

EGU23-2452

On-site presentation

The Color Diversity of Kuiper Belt Objects

Ralf Kaiser

Objects in the Kuiper Belt exhibit the reddest known surfaces and reveal a wider range of colors than any other Solar System population. The origin of this extraordinary color diversity is unknown, but likely the result of the prolonged irradiation of organic materials by Galactic Cosmic Rays (GCRs). However, laboratory experiments simulating irradiation processes have provided conflicting results and are highly dependent on the assumed initial composition, GCR flux, and exposure time. Here, we combine ultrahigh vacuum irradiation experiments with comprehensive spectroscopic analyses to examine the GCR processing of simple hydrocarbon surfaces of methane and acetylene under Kuiper Belt conditions. This study efficiently replicates the color diversity shown by Kuiper Belt Objects located at distances from 39 to 44 AU from the Sun such as Makemake, Orcus, and Salacia, and indicates effective exposure ages of at least 1,100 million years. Aromatic structural units carrying up to three rings as in phenanthrene (C₁₄H₁₀), phenalene (C₉H₁₀), and acenaphthylene (C₁₂H₈), of which some carry structural motives of nitrogen bases of DNA and RNA connected via unsaturated linkers, play a key role in producing the reddish colors. These studies demonstrate the level of molecular complexity synthesized by GCR processing and hint at the role played by irradiated ice in the early production of biological precursor molecules. Extrasolar counterparts to the Kuiper belt are known in the population of debris disks such as those around Fomalhaut and Vega, where these processes must also be relevant.

How to cite: Kaiser, R.: The Color Diversity of Kuiper Belt Objects, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2452, https://doi.org/10.5194/egusphere-egu23-2452, 2023.

11:25–11:35

EGU23-9801

ECS

On-site presentation

Contribution of multiple scattering to the distribution of Lyman alpha emission in comet comae

Yudai Suzuki, Kazuo Yoshioka, Kei Masunaga, Hideyo Kawakita, Yoshiharu Shinnaka, Go Murakami, Tomoki Kimura, Fuminori Tsuchiya, Atsushi Yamazaki, and Ichiro Yoshikawa

Comets are important in understanding the material balance of current and past planets. Water production rates from comet nuclei have been evaluated using various instruments including a Japanese satellite, Hisaki. In case of UV observations, water production rates are generally evaluated through the comparison of the observations of the Lyman alpha radiance distribution and kinetic model of hydrogen atoms generated by photodissociation of water molecules. However, dynamics of hydrogen atoms in comae in the vicinity of nuclei has not been well understood especially for long period comets with large water production rates.

In this study, we obtained the spatial distributions of Lyman alpha radiance through the analysis of spectroscopic data of long period comets such as C/2013 US_{10} (Catalina) observed by Hisaki. As a results, inclination of the Lyman alpha radiance was found to become flatter below the impact parameter of 5 × 10^{4} km. We attributed this variation of inclination to multiple scattering, and established a radiative transfer model considering multiple scattering of photons. Then we successfully reproduced the Lyman alpha radiance distributions in comae observed by Hisaki.

According to calculations using this model, multiple scattering becomes effective in comae when the hydrogen column density exceeds approximately 5 × 10^{22} /km^{2}. Additionally, multiple scattering was found to cause the sunward/anti-sunward radiance asymmetry less than 3 %, and the apparent increase of D/H ratio around the nuclei by a factor of more than 10.

Using these results, the feasibility of detecting deuterium and evaluating the D/H ratio via Hydrogen Imager (HI) onboard the Comet Interceptor spacecraft was discussed. It was found that deuterium could be detected with a sufficient S/N ratio and that the D/H ratio could be evaluated with relative error less than 60 % using the model. The largest error factor in D/H ratio calculation is the dependence of the results of radiative transfer model on hydrogen temperature. Constraint on observations by HI or calculation by models such as DSMC will enable the calculation of the D/H ratio with higher accuracy.

How to cite: Suzuki, Y., Yoshioka, K., Masunaga, K., Kawakita, H., Shinnaka, Y., Murakami, G., Kimura, T., Tsuchiya, F., Yamazaki, A., and Yoshikawa, I.: Contribution of multiple scattering to the distribution of Lyman alpha emission in comet comae, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9801, https://doi.org/10.5194/egusphere-egu23-9801, 2023.

11:35–11:45

EGU23-17231

On-site presentation

Sub-surface dust thickness and ice content in the nucleus of comet 67P/Churyumov-Gerasimenko constrained with Rosetta observations

Paul von Allmen, Vatsal Jhalani, and Seungwon Lee

11:45–11:55

EGU23-11092

ECS

On-site presentation

O-bearing molecules in comet 67P revisited: evidence for abundant heterocycles

Nora Hänni, Kathrin Altwegg, Michael Combi, Stephen Fuselier, Johan De Keyser, Daniel Müller, Martin Rubin, and Susanne Wampfler

Alongside meteorites, impacting comets are considered a major source of pristine organic matter delivered to the early Earth, see, e.g., Rubin et al. (2019). Their chemical inventory, hence, is a key towards understanding prebiotic chemistry and the processes that led to the evolution of carbon-based life on Earth. For comet 67P/Churyumov-Gerasimenko (hereafter 67P), especially the high-resolution Double Focusing Mass Spectrometer (DFMS) – part of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA; Balsiger et al. 2007) onboard the European Space Agency’s Rosetta spacecraft – obtained data that allows the study of this comet’s chemical composition in unprecedented detail (LeRoy et al. 2015, Schuhmann et al. 2019). For the time period around its perihelion in early August 2015, the comet was very active and extensive dust ejection was observed (Vincent et al. 2016). Decoupled from the cometary surface, the dust particles heat up and sublimation of also larger molecules is enhanced. Relying on reference spectra – either calibrated or from the database of the National Institute of Standards and Technology –, Hänni et al. (2022) showed how the mass spectrum of pure hydrocarbon species could be fully deconvolved, which led to the identification of new cometary organic species. Following the same approach, also heteroatom-bearing species can be investigated. After the pure hydrocarbon species, O-bearing organic molecules of the general formula C_nH_mO_x (where n = 1-8, m = 0-14, and x = 1-2) depict the second-most abundant group of cometary volatile organics. This group of species is in the focus of our ongoing work, not only for their comparably high abundance in comets but also for their prebiotic relevance. The heteroelement O is common in biomolecules such as fatty acids, amino acids, and sugars. For the first time and with great certainty, we confirm abundant heterocycles like furan and pyran (including several derivatives), which have been long sought but not yet detected in the Interstellar Medium (ISM; Barnum et al. 2022). The presence especially of furan is of great interest because of the furanose moiety in the sugar/phosphate backbone of (deoxy)ribonucleic acid. Eventually, we compare and contrast 67P’s updated and extended inventory of O-bearing organic molecules to other comets (Biver and Bockelée-Morvan 2019) and the ISM (McGuire 2022), showing that our data delivers evidence for many new species.

Rubin et al. ACS Earth Space Chem. 2019, 3, 1792−1811.

Balsiger et al. Space Sci. Rev. 2007, 128, 745-801.

Le Roy et al. Astron. Astrophys. 2015, 583, A1.

Schuhmann et al. ACS Earth Space Chem. 2019, 3, 1854–1861.

Vincent et al. MNRAS 2016, 462 (Suppl_1), 184-194.

Hänni et al. Nat. Commun. 2022 13:3639.

Barnum et al. J. Phys. Chem. A 2022, 126, 2716−2728.

Biver and Bockelée-Morvan ACS Earth Space Chem. 2019, 3, 1550−1555.

McGuire The Astrophysical Journal Supplement Series 2022, 259:30, 51.

How to cite: Hänni, N., Altwegg, K., Combi, M., Fuselier, S., De Keyser, J., Müller, D., Rubin, M., and Wampfler, S.: O-bearing molecules in comet 67P revisited: evidence for abundant heterocycles, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11092, https://doi.org/10.5194/egusphere-egu23-11092, 2023.

11:55–12:05

EGU23-9586

ECS

On-site presentation

Covariance Analysis of Hera Radio Science Experiment including LIDAR Altimetric Crossovers

Edoardo Gramigna, Riccardo Lasagni Manghi, Marco Zannoni, Paolo Tortora, Ryan S. Park, Nicole Dias, Paulo Gordo, Rui Melicio, Michael Kueppers, and Patrick Michel

Hera is a European Space Agency (ESA) space mission, part of the Asteroid Impact and Deflection Assessment (AIDA) international collaboration with NASA, with a targeted launch to the Didymos system next October 2024. Following last 26 September 2022 extremely successful NASA’s DART impact on Dimorphos, the secondary body of the Didymos binary system, all the attention is now focused on the Hera mission. The main goals of Hera are the detailed study and characterization of DART’s crater, analysis of the impact in terms of momentum transfer efficiency, and accurate estimation of the physical properties of Didymos and Dimorphos, in order to validate and demonstrate the kinetic impactor technique to deflect potentially hazardous asteroids in the future.

In this context, one of the main goals is to accurately estimate the mass and mass distribution of Didymos and Dimorphos, by means of radio science investigations. In particular, one of the very few direct measurements of the internal mass distribution of planetary bodies is the determination of their gravity field. The gravity of Didymos and Dimorphos will be estimated by precisely reconstructing the trajectory of Hera and the two companion CubeSats (Juventas and Milani) during a selected number of close encounters, by performing an orbit determination process. In particular, Hera will make use of an Inter-Satellite Link system (ISL) to track Juventas and Milani, measurements which will further improve Didymos’ system extended gravity field estimation.

Furthermore, the Hera spacecraft is equipped with a Light Detection and Ranging instrument (LIDAR), a time-of-flight Planetary ALTimeter (PALT) that will measure the distances from the Hera spacecraft to the target body surfaces. The PALT altimetric measurements can be combined with Earth-based radiometric, ISL radiometric, and Hera optical observables to enhance the gravity science scientific parameters.

This work discusses a covariance study of the Hera radio science experiment including crossovers estimation to the PALT LIDAR altimetry data. The trajectory constraints obtained from the radiometric tracking and optical data can be supplemented by altimetric crossovers, to further improve the reconstruction of the spacecraft trajectory with respect to the case without crossovers (i.e. PALT LIDAR altimetry data considered as single measurements, without estimating the surface landmarks probed multiple times by the LIDAR swaths). As a consequence of a better knowledge of Hera’s trajectory, the formal uncertainties of the scientific parameters of interest decrease, too. In particular, there is a potential further improvement of Dimorphos’ relative orbit estimation, as well as Didymos and Dimorphos gravity field, and their rotational state, with respect to the case without altimetric crossovers.

© 2023 EG, RLM, MZ, and PT wish to acknowledge Caltech and the NASA Jet Propulsion Laboratory for granting the University of Bologna a license to an executable version of MONTE Project Edition S/W. Italian Space Agency (ASI) sponshorship acknowledged, Agreement No. 2022-8-HH.0 in the context of ESA’s Hera mission. EG is grateful to Fondazione Cassa dei Risparmi di Forlì for financial support of his PhD fellowship. This project has received funding from the NEO-MAPP project (European Union’s Horizon 2020 programme, agreement No 870377).

How to cite: Gramigna, E., Lasagni Manghi, R., Zannoni, M., Tortora, P., Park, R. S., Dias, N., Gordo, P., Melicio, R., Kueppers, M., and Michel, P.: Covariance Analysis of Hera Radio Science Experiment including LIDAR Altimetric Crossovers, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9586, https://doi.org/10.5194/egusphere-egu23-9586, 2023.

12:05–12:15

EGU23-16700

ECS

On-site presentation

Linking enstatite meteorites to a unique source.

Chrysa Avdellidou, Marco Delbo, Alessandro Morbidelli, Kevin Walsh, Edhah Munaibari, Jules Bourdelle de Micas, Maxime Devogele, Sonia Fornasier, Matthieu Gounelle, and Gerard van Belle

12:15–12:25

EGU23-16988

solicited

Virtual presentation

The upcoming seismo-acoustic observational campaign of an artificial meteor: The OSIRIS-Rex Sample Return Capsule re-entry

Elizabeth Silber, Sarah Albert, Elizabeth Berg, Daniel Bowman, and Fransiska Dannemann Dugick

Meteoroids and asteroids are of broad scientific interest, from planetary sciences to hypersonic physics. However, impacts into the Earth’s atmosphere, especially by asteroids in a meter-size range, are sporadic and unannounced, making it impractical to plan a dedicated multi-instrument observation campaign aimed at studying and characterizing these objects. Thus, well-documented scientific observations of asteroids are rare and generally happen by chance. In these cases, many parameters of interest (e.g., composition, size, porosity, rotation, ablation rate, shock characteristics, hyperthermal chemical processes) remain poorly defined, and scientific analyses largely rely on assumptions and predictions derived from the theoretical domain. Since the end of the Apollo era, only four instances of a hypersonic re-entry of an artificial body from interplanetary space with an incident speed of 11-12 km/s have been observed and studied. These were the Sample Return Capsules (SRCs) that brought physical samples of extraterrestrial material back to Earth. Arriving from interplanetary space at hypervelocity, SRCs are considered analogues for low velocity meteoroids and asteroids impacting the Earth’s atmosphere, and as such provide unprecedented and unique opportunities to perform detailed studies of meteor phenomena, test and calibrate sensors, and validate and improve models. The next opportunity will present itself on 24 September 2023 with the re-entry of OSIRIX-REx SRC that will bring samples of the carbonaceous near-Earth asteroid Bennu. The OSIRIX-REx asteroid sample return mission was launched in 2016 with the aim to collect samples from the near-Earth asteroid Bennu and bring those samples back to Earth in pristine condition. Bennu was chosen because it is a readily accessible, primitive, carbonaceous asteroid, and it is also one of the most potentially hazardous known near-Earth objects. OSIRIX-REx SRC is identical to that of the Stardust SRC; that includes the mechanical design, and all aspects of re-entry. Landing is planned for 24 September 2023.The OSIRIX-REx re-entry presents a unique and exceptional opportunity to observe a well-defined artificial meteor, to perform detailed studies of hypersonic entry and event characterization, to test sensors, and validate and improve models. We will organize and lead multi-instrument observations of the OSIRIX-REx SRC re-entry. The instruments will include infrasound and seismic sensors strategically positioned in the immediate and extended region around the projected re-entry trajectory to maximize the scientific output. Data collected during this observational campaign will be made freely available to the broad scientific community following publication.

SNL is managed and operated by NTESS under DOE NNSA contract DE-NA000352.

How to cite: Silber, E., Albert, S., Berg, E., Bowman, D., and Dannemann Dugick, F.: The upcoming seismo-acoustic observational campaign of an artificial meteor: The OSIRIS-Rex Sample Return Capsule re-entry, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16988, https://doi.org/10.5194/egusphere-egu23-16988, 2023.

12:25–12:30

closing remarks

Posters on site: Wed, 26 Apr, 16:15–18:00 | Hall X4

Chairpersons: Jiri Pavlu, Maria Gritsevich

down in the terrestrial atmosphere

X4.336

EGU23-8154

ECS

Physical parameters of meteoroids

Ioana Lucia Boaca, Maria Gritsevich, Alin Nedelcu, Tudor Boaca, François Colas, Adrien Malgoyre, Brigitte Zanda, and Pierre Vernazza

In this work we present the main characteristics that derive from the analysis of the luminous part of the trajectory of a meteoroid. Our study is based on applying the α-β algorithm (Gritsevich 2008, Gritsevich 2009, Gritsevich et al. 2012, Lyytinen and Gritsevich 2016, Sansom et al. 2019, Boaca et al. 2022) to the latest detections recorded by the MOROI (Nedelcu et al. 2018) component of the FRIPON network (Colas et al. 2020). Our input parameter are the height and velocity of the meteoroid and the way they change with time. Based on this we determine the ballistic coefficient α and the mass loss parameter β for each analysed meteor event. The α-β algorithm is used in order to decide which of the fireball events produce meteorites and which are fully ablating in the atmosphere. Furthermore, the α and β parameters allow us to determine the mass of the studied meteoroids e.g. at the beginning and at the end of the luminous trajectory.

Boaca I., et al. (2022), ApJ, 936, 150.

Colas, F., et al. (2020), A&A, 644, A53.

Gritsevich, M. I. (2008), DokPh, 53, 97.

Gritsevich, M. I. (2009), AdSpR, 44, 323.

Gritsevich, M. I., et al., (2012), CosRe, 50, 56.

Lyytinen, E., & Gritsevich, M. (2016), P&SS, 120, 35.

Nedelcu, D. A., et al. (2018), RoAJ, 28, 57.

Sansom, E. K., et al. (2019), ApJ, 885, 115.

Acknowledgement.

The work of IB and AN was partially supported by a grant of the Ministry of National Education and Scientific Research, PNIII-P2-1214/25.10.2021, program no. 36SOL/2021. MG acknowledges the Academy of Finland project no. 325806 (PlanetS).

How to cite: Boaca, I. L., Gritsevich, M., Nedelcu, A., Boaca, T., Colas, F., Malgoyre, A., Zanda, B., and Vernazza, P.: Physical parameters of meteoroids, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8154, https://doi.org/10.5194/egusphere-egu23-8154, 2023.

X4.337

EGU23-17435

A discourse on the temperature measurement problem using meteor wind radar

Emranul Sarkar and Thomas Ulich

Sodankylä's high latitude location serves an ideal ground for testing more comprehensive physics theory related to radio meteor data. The atmospheric scale height shows significant variation at this latitude. Also, the observational geometry towards the plane of ecliptic plane changes drastically with seasons. On theory, the reflected radio signal from the ablating meteor train can be used to continuously monitor atmospheric temperature at the 90 km altitudes. In practice, complication arises due to the selection effects in the system as well as the persistent effect of natural variability (size, mass, velocity, entry angle) in meteoroids property. The long-standing hypothesis that needs to be debated: Is the assumed equality between atmospheric scale height (H_KT) and the effective diffusion scale height (H_D) of meteor trails valid for these data? In this study, we argue that such an hypotheis can not be experimentally validated, and hence the need for subsequent calibration. Furthermore, long-term trend analysis showed that the discrepancy between H_KT and H_D has non-linear seasonal trends. Alternatively, we demonstrate an alternative method of scale-height measurement based on meteor height distribution. The technical and theoretical limits of this methodology are discussed and validated using 10 years of observational data.

How to cite: Sarkar, E. and Ulich, T.: A discourse on the temperature measurement problem using meteor wind radar, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17435, https://doi.org/10.5194/egusphere-egu23-17435, 2023.

X4.338

EGU23-4306

Meteor phenomena in the atmosphere of Venus

Apostolos Christou and Maria Gritsevich

Meteor astronomy employs the atmosphere of the Earth as a large area detector for 0.01-1000 mm meteoroids [1]. Monitoring the atmospheres of other planets for meteor activity offers the opportunity to study the parent bodies of as-yet-undetected meteor showers, test ablation models under non-terrestrial conditions and allow spacecraft operators to mitigate the risk of meteoroid impact damage [2]. By adjusting existing techniques to simulate meteoroid ablation in a Venus-like atmosphere [3-8], we show that Venusian meteors are generally brighter but shorter-lived than terrestrial meteors and ablate at a higher altitude, in a predominantly clear region of the atmosphere. These simulations are complemented with a list of cometary bodies and known meteoroid streams that we consider to be prime candidates for producing significant meteor activity at Venus [9,10]. Such predictions may be used in developing future observational campaigns to be carried out from Earth or from Venus orbit.

References: [1] Jenniskens, P. (2006) Meteor Showers and their Parent Comets, Cambridge University Press, Cambridge. [2] Christou A. A. et al (2019) In: Meteoroids: Sources of Meteors on Earth and Beyond, Cambridge University Press, p.119-135. [3] Christou A. A. (2004) Icarus 168, 23-33 [4] McAuliffe, J. P., Christou, A. A. (2006) Icarus 180, 8-22 [5] Gritsevich M., Koschny D. (2011) Icarus 212, 877-884 [6] Bouquet A. et al (2012) Planet. Space Sci. 103, 238-249 [7] Gritsevich, M. I. (2009) Adv. Space Res. 44, 323–334 [8] Lyytinen, E., Gritsevich, M. (2016) Planet. Space Sci. 120, 35-42 [9] Christou A. A. (2010) MNRAS 402, 2759-2770 [10] Christou, A. A., Vaubaillon, J. (2011) In: Proc. Meteoroids Conf, NASA/CP-2011-216469, p.26

How to cite: Christou, A. and Gritsevich, M.: Meteor phenomena in the atmosphere of Venus, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4306, https://doi.org/10.5194/egusphere-egu23-4306, 2023.

close to the comets and asteroids

X4.339

EGU23-17070

Wherever You Go, There You Are — Evolution of Cometary Dust Trails Produced by Outbursts

Maria Gritsevich, Markku Nissinen, Jorma Ryske, Jari Suomela, Arto Oksanen, Veikko Mäkelä, Elizabeth Silber, and Josep Maria Trigo-Rodríguez

In the recent paper [1] we introduced the Dust Trail kit model capable of describing the evolution of a cometary dust trail. The model accounts for solar radiation pressure effects, gravitational disturbance caused by Venus, Earth and Moon, Mars, Jupiter and Saturn, and gravitational interaction of the particles in the trail with the parent comet itself. Excellent accuracy of computations is due to their implementation in Orekit Open Source Library for Operational Flight Dynamics, which executes Dormad-Prince numerical integration methods with higher precision. We demonstrate performance of the model by studying the comet 17P/Holmes, which underwent through a massive outburst in October 2007 — the largest documented outburst by a comet thus far. We simulate several particle populations with sizes ranging from 0.001 to 1 mm and by varying assumptions about ejection speed distribution of the particles at the start of the outburst. The model is validated against our earlier observations of the trail obtained in common nodes for 0.5 and 1 revolutions. Using these data, we made predictions for the two-revolution dust trail behavior near the outburst point and the observability from Earth of the cometary material released in the event [1]. We have further developed a set of Python scripts to calculate position of the dust trail for observatory topographical location coordinates [2]. Using these predictions, a set of new observations of the 2007 outburst dust trail was obtained in February, March, October, and December 2022. The trail is still observable by using even moderate ground-based telescopes. The existence of an observable dust trail requires sunlight scattered by a significant number of micron-sized particles produced in the phenomena. Both the surface brightness and the position of the dust trail are within the limits of the published predictions provided by the Dust Trail kit model [1, 2].

References

1. Gritsevich M., Nissinen M., Oksanen A., Suomela J., Silber E.A. (2022). Evolution of the dust trail of comet 17P/Holmes, Monthly Notices of the Royal Astronomical Society, 513(2), 2201–2214, https://doi.org/10.1093/mnras/stac822

2. Nissinen M., Gritsevich M. (2022). Instructions on where and how to observe the comet 17P/Holmes dust trail. Zenodo. https://doi.org/10.5281/zenodo.6977358

How to cite: Gritsevich, M., Nissinen, M., Ryske, J., Suomela, J., Oksanen, A., Mäkelä, V., Silber, E., and Trigo-Rodríguez, J. M.: Wherever You Go, There You Are — Evolution of Cometary Dust Trails Produced by Outbursts, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17070, https://doi.org/10.5194/egusphere-egu23-17070, 2023.

X4.340

EGU23-4008

Measured mechanical, optical and electrical properties of dust partciles collected in the coma of comet 67/P

Martin Hilchenbach, Oliver Stenzel, and Klaus Hornung

X4.341

EGU23-9261

Spectral Variation on the Trojan Asteroid 4709 Ennomos

Joshua Emery

The Trojan asteroids are hypothesized to have been emplaced from the Kuiper Belt into Jupiter’s stable Lagrange regions early in Solar System history. They therefore contain information about the materials present in the outer Solar System during planet formation and how those materials are affected by inward migration. A bimodal distribution of visible to near-infrared (VNIR; 0.4 to 2.5 μm) spectral slopes suggest two distinct composition groups, but the actual compositions of those groups remain elusive due to a lack of absorption features at these wavelengths. Evolutionary models of Trojans generally predict the sublimation loss of volatiles from surface layers, creating a refractory mantle. Irradiation of surface layers may induce physical and/or chemical changes that further alter the surface relative to the interior. Impacts could break through surface layers and reveal subsurface materials. The absence of spectral variations on Trojans reported in the literature have suggested either that no exposures of sub-surface materials have been detected or that the sub-surface is spectrally identical to the surface layers. An early report of a possible high albedo of the Trojan asteroid 4709 Ennomos was attributed to possible exposure of ice. Follow-up spectra revealed no signatures of ice, but the asymmetric lightcurve is consistent with a bright spot on the surface. In order to further investigate possible exposure of sub-surface materials on Ennomos, we have measured multiple NIR (0.7 to 2.5 μm) spectra at the NASA IRTF, including two sets that continuously cover half a rotation each. The spectral slopes vary with rotation, from spectra consistent with the less-red Trojan spectral group (analogous to P-type asteroids) to slightly blue-sloped spectra (analogous to C- or B-type asteroids). Nevertheless, all spectra remain featureless, including no indication of the presence of water ice. Analyses of these spectra along with other published data of Ennomos place constraints on compositions responsible for the varying spectra. We will discuss these results in the context of the Trojan population, including predictions for surface variability that the Lucy mission may see on the Trojans it visits.

How to cite: Emery, J.: Spectral Variation on the Trojan Asteroid 4709 Ennomos, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9261, https://doi.org/10.5194/egusphere-egu23-9261, 2023.

X4.342

EGU23-6355

ECS

Correlated Multi-Technique Characterisation of Sulfur-Bearing Serpentine in Carbonaceous Chondrites

Niamh Topping, John C. Bridges, Leon J. Hicks, and Takaaki Noguchi

Phyllosilicate minerals in the carbonaceous chondrites provide insights into processes in primitive parent bodies of the early Solar System. It is widely agreed that the CM- and CI-type carbonaceous chondrites underwent aqueous alteration on their parent bodies, resulting in phyllosilicate-rich matrices, where the dominant mineral phase is serpentine. There are many previous studies investigating phyllosilicate structure in carbonaceous chondrites, however, the presence of sulfur in these minerals and its effect on crystal lattice structure has not been studied in detail. We are investigating how the presence of sulfur (up to ≃9-10 wt% SO₃) in serpentine phyllosilicate regions effects basal lattice spacing measurements of serpentine-like minerals in CM- and CI-type chondritic and related asteroidal material.

Four specimens are being studied for this work: Winchcombe and Aguas Zarcas (CM-type), and Ryugu samples (A0058-C2001-08, A0104-00200502 and A0104-01700602) from Hayabusa2 and Ivuna (CI-type). All samples are TEM wafers. We have used a multi-technique approach to study the samples, with the E01 JEOL ARM200CF and E02 JEOL ARM300CF electron microscopes at the ePSIC facility at Diamond Light Source in Harwell, UK. EDS compositional data has been collected using the E01 microscope, whilst HRTEM and HAADF imaging data has been collected at E02. At E02 we are also applying a new 4D-STEM nano-diffraction technique in order to collect lattice spacing data to correlate with our other HRTEM results. Fe-K XANES analyses on Winchcombe and Ryugu have been carried out using the I18 microprobe and I14 hard x-ray nanoprobe respectively, also at Diamond Light Source, to constrain Fe³⁺/ΣFe. By combining these techniques we aim to better understand the physical and chemical structure of serpentine-like minerals in carbonaceous chondrites.

Initial analyses have shown that sulfur presence in carbonaceous chondrite phyllosilicates reduces the basal lattice spacings of serpentine-like minerals. In these sulfur-bearing regions, we have been finding lattice spacings in the range ~0.60-0.74nm for the CM-type chondrites. For the CI-type, these range between ~0.65-0.76nm. Differences in the reduced lattice spacing ranges are likely related to the redox state of the sulfur. In Ryugu and other carbonaceous chondrites the sulfur appears reduced; its content in serpentine is low and we see FeS grains. Comparatively, in Winchcombe (and others) more of the sulfur seems to be in the serpentine structure.

We can conclude that in serpentine-like minerals, the presence of sulfur appears to reduce basal lattice spacing values compared to the expected d-spacing value of 0.70nm for serpentine. Possible reasons for this include further investigations into the valency of the sulfur ions, the bonding environment within serpentine layers, and the location of sulfur in either the octa- or tetrahedral lattice sites.

How to cite: Topping, N., Bridges, J. C., Hicks, L. J., and Noguchi, T.: Correlated Multi-Technique Characterisation of Sulfur-Bearing Serpentine in Carbonaceous Chondrites, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6355, https://doi.org/10.5194/egusphere-egu23-6355, 2023.

X4.343

EGU23-14828

ECS

A Comparative Carbon XANES and EELS Study of Organic Matter in the Ivuna CI Chondrite

Lukas Petera, Hitesh, G. Changela, John, C. Bridges, Yoko Kebukawa, Leon, J. Hicks, Niamh Topping, and Martin Ferus

An understanding the organic matter (OM) in primitive interplanetary materials can provide us with important constraints on both the early solar system carbon cycle and incipient prebiotic synthesis before the origin of life. As a window to the past, primitive chondrites preserve the most pristine record of parent body, nebular and interstellar components and the occurrence of OM in them has been shown in both soluble (SOM) (1) and insoluble (IOM) (2) form. Total organic carbon (TOC) abundance reaches ~3-4 wt% in the most primitive carbonaceous chondrite (CCs) (3), such as Ivuna-type chondrites (CIs) – thus making them highly desirable for the OM studies, and relevant to the study of Asteroid 162173 Ryugu samples from the Hayabusa-2 mission.

A combination of both SOM and IOM analysis of organic bulk meteorite separates together with in-situ analysis of OM have provided a comprehensive account of chondritic OM (4). In the case of in-situ analysis, the combination of both scanning (SEM) and transmission electron microscopy (TEM) together with soft X-Ray scanning transmission microscopy (STXM) have shown the presence of micron to submicron distinctive organic particles (OPs) (5). Carbon K-edge X-ray absorption near edge structure (XANES) has shown the aromatic-carbonyl-carboxyl chemical nature of these organic particles (5). In addition, aromatic-poorer and carboxylic-richer diffuse OM (6) within both amorphous and phyllosilicate occurs as well.

As observation techniques are getting better, aberration corrected TEM coupled with electron energy loss spectroscopy (EELS) might provide the same results as carbon XANES, but with higher image magnification, rapid data acquisition and better accessibility. In this context, we present the results of a comparative carbon K-edge XANES and EELS study of CI meteorite Ivuna. An approximately 100 nm lamella of the Ivuna meteorite was prepared using focused ion beam (FIB)-SEM with the Helios 5 Hydra DualBeam (CEITEC, Masaryk University, Czechia) and analysed by TEM-EELS with the JEOL ARM200CF (ePSIC, Diamond Light Source, UK) and STXM-XANES at Beamline BL19A of the KEK Photon Factory, Japan. We observed that (I) XANES on samples that did not experience TEM-EELS are in agreement with the previous studies of aromatic-carbonyl-carboxylic macromolecular OPs and IOM, while (II) the TEM-EELS of OPs show aromatic-carbonyl functional chemistry but with amorphous carbon convoluting the carboxylic peak, and aromatic-poor spectra with a sharp carbonate peak in diffuse OM. The difference between XANES and EELS particularly in the diffuse OM can be interpreted by electron-beam damage. Thickness and e-beam damage leads to amorphous C formation in the OPs. In the case of more labile OM in the phyllosilicate, its change by heating and oxidation is expected.

References:

1. M. A. Sephton, Nat. Prod. Rep., 19, 292–311 (2022).
2. C. M. O. Alexander et al., Geochim. Cosmochim. Acta, 71, 4380–4403 (2007).
3. S. Pizzarello et al., Meteorites early Sol. Syst. II, 1, 625–651 (2006).
4. D. P. Glavin et al., in Primitive meteorites and asteroids, pp. 205–271 (Elsevier, 2018).
5. H. G. Changela et al, Meteorit. Planet. Sci., 53, 1006–1029 (2018).
6. Le Guillou C., et al, Geochim. Cosmochim. Acta, 131, 368–392 (2014).

How to cite: Petera, L., Changela, H. G., Bridges, J. C., Kebukawa, Y., Hicks, L. J., Topping, N., and Ferus, M.: A Comparative Carbon XANES and EELS Study of Organic Matter in the Ivuna CI Chondrite, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14828, https://doi.org/10.5194/egusphere-egu23-14828, 2023.

farther in the Solar System

X4.345

EGU23-9570

How Predator-Prey Dynamics Creates ‘Straw’ in the Strongest Density Waves

(withdrawn)

Larry W. Esposito, Miodrag Sremcevic, Joshua E. Colwell, Stephanie Eckert, and Melody Green

X4.346

EGU23-16469

Dynamical analysis of mineral dust in the Saturnian system

Mario Trieloff, Christian Fischer, Frank Postberg, and Jürgen Schmidt

Dust in the Saturnian system is dominated by ice grains stemming from the active moon Enceladus [1,2]. Moreover, a significant population of 1859 sub-micron sized mineral dust grains were detected by the Cosmic Dust Analyser (CDA) aboard the Cassini spacecraft. CDA inferred the composition of dust particles with an impact ionisation mass spectrometer via time of flight mass spectroscopy. The successful compositional characterization of 36 interstellar dust particles recorded by CDA showed the potential of this approach [3].

Our previous dynamic analysis [4] conservatively estimated orbital parameters of this non-icy particle population of which many dust particles occurred in confined time intervals (swarms). Two main dynamic populations were identified: retrograde potentially endogenous and polar potentially exogenous swarms. Compositional analysis revealed two main types: iron-rich sulfide and oxide particles (58%) and Mg-rich silicates (34%) while a small share (8%) consisted of mixed type particles [4]. Retrograde swarms contained a significantly higher fraction of iron rich grains compared to exogenous swarms.

Here we present a refined approach to reconstruct orbital parameters. Considering the occurrence of certain element mass lines [5] within the mass spectra, we derive a minimum impact velocity. Assuming that the grains are bound to the Sun, we obtain as an upper bound for the impact speed onto CDA the escape velocity from the solar system at Saturn distance. Due to CDA's large field of view the impact direction is constrained within a range of 56°. We take into account the angular dependence of the sensitive area of the impact Target of CDA to derive the probability distribution of impact directions for a given detection. Combining both constraints we can determine a probability distribution density for the orbital elements which we use to evaluate the mean eccentricity and inclination for each swarm as well as for single detections.

Again, two disjoint dynamic populations are identified: almost certainly endogenous swarms with retrograde inclinations of about 170° and high-eccentricity exogenous swarms with nearly polar inclinations. The inclination of the retrograde endogenous particles is consistent with the previously suggested origin [4] from impact ejecta of Saturn's retrograde outer moons released by micro-meteoroid bombardment. In order to trace the origin of the exogenous particles their hyperbolic orbits in the Saturnian system are projected onto Saturn’s Hill sphere.

In this ongoing work we aim to identify potential sources like the Kuiper Belt and Oort Cloud or Centaur comets and present an updated compositional analysis with the potential to constrain the composition of the sources of the grains detected by CDA.

References

[1] Postberg F. et al (2008) Icarus 193, 438-454.

[2] Postberg F. et al. (2009) Nature 459, 1098-1101.

[3] Altobelli N. et al. Science 352, 312-318 (2016)

[4] Fischer C. et al. Poster EPSC 2018

[5] Fiege K. et al. Icarus 241, 336-345 (2014)

How to cite: Trieloff, M., Fischer, C., Postberg, F., and Schmidt, J.: Dynamical analysis of mineral dust in the Saturnian system, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16469, https://doi.org/10.5194/egusphere-egu23-16469, 2023.

X4.347

EGU23-3325

ECS

Bayesian inference of β-meteoroid parameters with Solar Orbiter

Samuel Kočiščák, Sigrunn Holbek Sørbye, Andreas Kvammen, Ingrid Mann, Arnaud Zaslavsky, and Audun Theodorsen

Solar Orbiter’s Radio and Plasma Waves instrument (SolO/RPW) is capable of detecting hypervelocity dust impacts onto the spacecraft through the fast electrical phenomena that accompany the process. SolO operates within 1AU, in the environment with high density of β-meteoroids – dust grains escaping from the proximity of the Sun due to radiation pressure force counteracting gravity. Recently, Convolutional Neural Network (CNN) classified data were made available^[1], analyzing all the recorded waveforms and providing us with the highest quality dataset of the impact events to date.

We present a model for the in-situ impact rate on SolO/RPW assuming β-meteoroids are the main component of the detections. We fit the model to the highest quality available CNN data assisted by Integrated Nested Laplace Approximation (INLA) for Bayesian inference with informative priors^[2].

Taking into account spacecraft’s position and its velocity vector, we are able to infer mean radial velocity of the detected dust grains to be 63 ± 7 km/s. We are also able to constrain β-meteoroid predominance and dust’s mean acceleration and by extension constrain its mean β-parameter. The procedure is general enough to be used in a different setting for SolO, or by a different spacecraft in the future.

References:

[1] Kvammen, Andreas, et al. "Machine Learning Detection of Dust Impact Signals Observed by The Solar Orbiter." (2022). https://doi.org/10.5194/egusphere-2022-725

[2] Kočiščák, Samuel, et al. "Modelling Solar Orbiter Dust Detection Rates in Inner Heliosphere as a Poisson Process." arXiv preprint arXiv:2210.03562 (2022). https://doi.org/10.48550/arXiv.2210.03562

How to cite: Kočiščák, S., Holbek Sørbye, S., Kvammen, A., Mann, I., Zaslavsky, A., and Theodorsen, A.: Bayesian inference of β-meteoroid parameters with Solar Orbiter, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3325, https://doi.org/10.5194/egusphere-egu23-3325, 2023.

X4.348

EGU23-8212

Generation and Expansion of the Impact Plasma Cloud after Dust Impacts on Solar Orbiter

Jakub Vaverka, Jiří Pavlů, Jana Šafránková, Zdeněk Němeček, Samia Ijaz, Samuel Kočiščák, David Píša, Jan Souček, Arnaud Zaslavsky, Christopher J. Owen, and Daniel Verscharen

Dust grain impacting the spacecraft body can be either partly or totally evaporated and ionized as well as a small part of spacecraft material. A cloud of charged particles (impact cloud) generated by such impact can consequently influence the spacecraft potential and/or measurements of on-board scientific instruments. Electric field antennas are sensitive to these disturbances and typically register signals generated by dust impacts as short transient pulses. This method is commonly used for the detection of dust grains even without dedicated dust detectors. Expanding impact clouds can also influence measurements of other scientific instruments such as magnetometers and particle detectors.

The presented study is focused on the understanding of the generation and consequent expansion of impact cloud after dust impacts on Solar Orbiter. The Time Domain Sampler (TDS), a subsystem of the Radio and Plasma Wave (RPW) instrument, is used for the detection of individual dust impacts. Three channels of short electric field waveforms (typically 62.5 ms) provide us with information about the influence of expanding particles on three electric antennas. We have analyzed more than 2000 waveform snapshots with dust impacts in various operation modes (monopole and dipole antenna configurations) of RPW/TDS. Additional information about particles generated by dust impact is provided by the Electron Analyser System (EAS), one of the Solar Wind Analyser (SWA) suite instrument.

How to cite: Vaverka, J., Pavlů, J., Šafránková, J., Němeček, Z., Ijaz, S., Kočiščák, S., Píša, D., Souček, J., Zaslavsky, A., Owen, C. J., and Verscharen, D.: Generation and Expansion of the Impact Plasma Cloud after Dust Impacts on Solar Orbiter, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8212, https://doi.org/10.5194/egusphere-egu23-8212, 2023.

X4.349

EGU23-7896

ECS

Comparison of Solitary waves and Dust Impact Signals Detected by Electric Field Instruments onboard MAVEN

Samia Ijaz, Jakub Vaverka, Jana Šafránková, and Zdeněk Němeček

Dust impact on the spacecraft body can result in short pulses in the measured electric field. Our study is focused on these pulses detected by the Langmuir Probe and Waves (LPW) instrument onboard the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft. LPW detects electric field signals in dipole and monopole configurations using two long identical stacer booms. Out of all the modes, we use the medium frequency burst mode, the data covers 62.5 milliseconds using 4096 measured points which gives us a sampling frequency of 66.67 kHz. We present a preliminary statistical analysis over the year 2015 (360000 waveforms) and the analysis is focused on distinguishing dust impact signatures from solitary structures. To reliably distinguish solitary waves from dust impact signals by an automatic code is a challenging task as the solitary wave signatures in the electric field data can be similar to the transient pulses generated by dust impacts. Therefore, we choose two different parameters to classify two groups of events: the ratio of rising and decay times and the ratio of positive and negative peaks of the pulse. In total, we find approximately 10000 events which compose both solitary waves and the most probable dust impacts. We discuss signals generated by dust impacts and solitary waves for different operation modes of electric field probes, spacecraft potentials, and distance of probes to the spacecraft surface.

How to cite: Ijaz, S., Vaverka, J., Šafránková, J., and Němeček, Z.: Comparison of Solitary waves and Dust Impact Signals Detected by Electric Field Instruments onboard MAVEN, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7896, https://doi.org/10.5194/egusphere-egu23-7896, 2023.

in the lab

X4.350

EGU23-3179

ECS

Laboratory investigation of ion expansion produced by hypervelocity dust impacts

Libor Nouzak, Kate Edwards, Alessandro Garzelli, Tobin Munsat, and Zoltan Sternovsky

In this laboratory study we present investigation of the angular distribution of expanding ions produced by hypervelocity dust impacts. Spacecraft operated by electric field antennas can characterize interplanetary and interstellar dust populations within our solar system from dust impacts. The recorded dust impact waveforms are diverse and their shape depends on the antenna mode of operation (dipole vs. monopole), impact location with respect to the antennas, spacecraft potential or dust particles properties. A unique experimental setup with delay line detector (DLD) is developed for measuring characteristics of the ion cloud expanding from the impact generated plasma. Dust particles of micron and sub-micron size are accelerated to velocities 1—80 km/s using the electrostatic dust accelerator operated at the University of Colorado. The ions produced after impact of accelerated particles on tungsten target plate are detected using the DLD that provides the position of their detection and time-of-flight. The angular distribution of ions with respect to target normal is calculated from these positions. The preliminary results indicate that the impact-generated ions expand in the form of a narrow cone and the cone angle increases with increasing dust speed.

How to cite: Nouzak, L., Edwards, K., Garzelli, A., Munsat, T., and Sternovsky, Z.: Laboratory investigation of ion expansion produced by hypervelocity dust impacts, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3179, https://doi.org/10.5194/egusphere-egu23-3179, 2023.

X4.351

EGU23-14032

Dust Interaction with Charged Particles in Laboratory

Jiří Pavlů, Libor Nouzák, Jan Wild, Jana Šafránková, and Zdeněk Němeček

Posters virtual: Wed, 26 Apr, 16:15–18:00 | vHall ST/PS

Chairpersons: Jakub Vaverka, Patrick Shober

vSP.12

EGU23-7739

Fe in the inner coma of comet 67P/Churyumov-Gerasimenko: a complete mission overview from Rosetta DFMS mass spectra

(withdrawn)

Frederik Dhooghe, Johan De Keyser, Nora Hänni, Kathrin Altwegg, Gaël Cessateur, Emmanuel Jehin, Romain Maggiolo, Martin Rubin, and Peter Wurz

vSP.13

EGU23-11341

About the possibility of using AMATERAS data to check the detection of dangerous asteroids

Beibit Zhumabayev and Ivan Vassilyev

Asteroids approaching the Earth from the direction of the Sun and may pose a danger to the Earth are detected either too late or are not detected at all by optical observations. They can be detected using passive radar, using the radio emission of the Sun as a probing signal [2,3]. It is most convenient to use Venus, Mercury and the Moon as calibration objects when working out the method of detecting small celestial bodies, since their position relative to the Sun is easy to calculate, and their sizes are well known. If the control bodies deviate from the direction of the Sun by 2 degrees, the delay of the signals reflected from Mercury, Venus and the Moon will be 484, 118 and 0.2 ms, respectively. Due to the relatively small delay values of the reflected signals, it is impossible to use most of the available solar radio telescopes with an integration time of 1 to 10 seconds to implement this method. The radio telescope of the AMATERAS project [1], capable of receiving signals of less than 0.7 SFU with an integration time of 10 ms, is suitable for receiving and isolating reflected signals. The beam width of the radiation pattern of the AMATERAS radio spectropolarimeter is about 4 degrees at a frequency of 150 MHz, which allows receiving signals simultaneously directly from the Sun and reflected from the Moon during periods of solar eclipses. With the passive location of Mercury and Venus, it is most expedient to use type I radio flashes with a duration of less than 1 second as a probing signal. When locating the Moon, it is more convenient to use type III radio flashes, during which the radiation frequency changes at a speed of up to 20 MHz/ s (2 kHz in 10 ms). For ten years of observations of the Sun, a large amount of data has been accumulated on the AMATERAS system, including during solar eclipses, which allows us to work out algorithms for direction finding of small celestial bodies approaching the Earth from the Sun in the post-processing mode.

References

[1] Iwai K., Tsuchiya F., Morioka A., Misawa H. IPRT/AMATERAS: A new metric spectrum observation system for solar radio bursts // Solar Phys. 2012. V. 277. P. 447–457. DOI: 10.1007/s11207-011-9919-y.

[2] Vassilyev I., Zhumabayev B. On the possibility of using the Orbita radio polygon for radar detection of asteroids // Satellite monitoring of geodynamic processes and space weather. – Almaty, 2020 – pp. 133-138.

[3] Pavelyev A., Gubenko V., Matyugov S., Zakharov A., Yakovlev O. Perspectives of the bistatic radar and occultation studying of the Venus and planetary atmospheres and surfaces EGU General Assembly 2013 EGU2013-10289, 07-10 April 2013.

How to cite: Zhumabayev, B. and Vassilyev, I.: About the possibility of using AMATERAS data to check the detection of dangerous asteroids, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11341, https://doi.org/10.5194/egusphere-egu23-11341, 2023.