This study investigated high-frequency gravity waves (HFGWs) observed by the Zhurong/Tianwen-1 and Perseverance/Mars 2020 rovers between 09:00 and 11:00 local time, from Ls 140° to 165° in Mars Year 36. By analyzing the eccentricity of hodographs for monochromatic wind perturbations obtained from the horizontal wind perturbation, HFGWs were identified via their predominantly linear characteristics.The propagation directions of these waves were determined using polarization relationships from the linear theory of HFGWs. The stability of the background atmosphere was estimated from the Dynamic Meteorology Laboratory general circulation model simulation. The frequency of HFGWs doubled following the onset of a regional dust storm (RDS) in the Utopia Planitia region, where the Zhurong rover landed. The HFGWs observed by Zhurong predominantly propagated in a north-south direction before the RDS and then in an east-west direction afterward. The changes in propagation direction were likely related to atmospheric instability and the background wind changes before and after the storm.

How to cite: Yang, C., Sun, C., Ban, C., Lai, D., Wu, Z., Fang, X., and Li, T.: Observed Martian High-frequency gravity waves by Zhurong and Perseverance rovers before / after a regional dust storm, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5310, https://doi.org/10.5194/egusphere-egu25-5310, 2025.

The Chang’e-6 (CE-6) mission, part of China's lunar exploration program, marked a significant milestone as the first mission to return samples from the far side of the Moon. One of the highlights of CE-6 mission is that it piggybacked four international payloads, including the INstrument for landing-Roving Laser Retroreflector Investigations (INRRI), developed through a collaboration between the Italian National Institute for Nuclear Physics — Frascati National Labs (INFN-LNF) and the Aerospace Information Research Institute, Chinese Academy of Sciences (AIRCAS).

INRRI is a lightweight, passive optical instrument composed of eight cube corner retroreflectors made from fused silica, offering a wide 120° field of view. This robust and miniaturized design has a high level of maturity and inheritance from previous missions such as NASA’s Mars InSight and Perseverance, where similar retroreflectors had been successfully deployed. For CE-6 mission particularly, INRRI was mounted on a specialized bracket to minimize interference from ascender plume effects during liftoff. CE-6 INRRI underwent rigorous qualification tests, including mechanical (acceleration, shock, sinusoidal and random vibrations) and thermal vacuum tests, to validate its structural integrity. After integrated with the lander, CE-6 INRRI underwent the whole spacecraft random and sinusoidal vibration tests and successfully passed all evaluations.

The CE-6 INRRI serves as a high-precision absolute control point, crucial for improving lunar surface mapping especially for the lunar far side. Initial validation of INRRI’s operational status has been achieved through observations by the Lunar Orbiter Laser Altimeter (LOLA) onboard NASA’s Lunar Reconnaissance Orbiter (LRO). Future observations by laser ranging from lunar orbiters will refine its position, and will contribute to improving the accuracy of orbit determination for lunar orbiters, advancing studies of lunar geodesy, Earth-Moon dynamics and lunar physics.

Building on this success, the Italian-Chinese collaboration team are working on the piggybacking of Chang’e-7 LAser Retroreflector Arrays (CLARA), including MoonLIGHT (Moon Laser Instrumentation for Geodesy, Geophysics and General relativity High accuracy Tests) and INRRI. Currently INRRI for CE-7 has just completed its mechanical tests and is in the process of arranging the subsequent experiments.

How to cite: Wang, Y., Dell'Agnello, S., Di, K., Muccino, M., Cao, H., Porcelli, L., Deng, X., Salvatori, L., Ping, J., Tibuzzi, M., Li, Y., Filomena, L., Kang, Z., Montanari, M., Meng, Z., Mauro, L., Xie, B., and Maiello, M.: The First Lunar Far-Side Laser Retroreflector Deployed on Chang’e-6 Lander and Prospect for Chang’e-7 Mission , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8557, https://doi.org/10.5194/egusphere-egu25-8557, 2025.

With the rapid advancements in computer graphics, rendering technologies, and artificial intelligence, 3D visualization of deep-space environments has become a transformative approach to improving teleoperation systems. Traditional Lunar-to-Earth teleoperation faces challenges such as low bandwidth, high latency, and limited situational awareness, which hinder intuitive and efficient remote operations. To address these issues, we propose a novel framework that integrates AI-driven 3D reconstruction algorithms and cutting-edge rendering techniques to reconstruct and visualize deep-space environments with exceptional precision and clarity. By processing sparse telemetry data into high-fidelity 3D models and leveraging photorealistic rendering, our system enhances spatial awareness, reduces cognitive load, and improves decision-making efficiency for ground-based operators. Furthermore, the framework is designed to overcome deep-space constraints, such as limited computational resources and communication delays, ensuring its robustness in real-world missions. This approach not only advances the efficiency of telemetry and teleoperations but also bridges the gap between remote sensing data and actionable insights, paving the way for more autonomous, immersive, and scientifically impactful deep-space exploration.

How to cite: Li, Y., Yang, S., Lu, J., Chen, J., Xu, T., Xing, Z., Chen, L., and Zhang, Z.: Immersive 3D Visualization for Enhanced Lunar Teleoperation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18510, https://doi.org/10.5194/egusphere-egu25-18510, 2025.

Aromatic compounds, with their stable cyclic structure and [4n+2]π electrons, are resistant to chemical attack and degradation. This stability makes them prevalent in celestial bodies and valuable in designing polymers that withstand harsh space conditions [1-4].
In interstellar space, aromatic molecules make up ~20% of atomic carbon and are key to forming complex organic molecules [1]. Cyanopyrene, cyanonaphthalene, and indene have been identified in the TMC-1 molecular cloud [5]. Aromatic molecules are also found in Solar System objects, including Martian soil from Gale Crater mudstones [7-10].
Thiophene, an aromatic molecule, was detected by NASA’s Curiosity rover in the Glen Torridon clay unit, where high-temperature pyrolysis (~850°C) revealed sulfur-bearing organics, including alkyl derivatives, likely from Martian organic materials [9]. Atomic oxygen (O) in its ground state (³P) is a strong oxidant that degrades aromatic compounds like benzene and pyridine, releasing CO [10-13]. Recent models show O(³P) is present in small amounts on Mars’s surface and abundant in low orbit [13]. This presents a dual challenge: degrading thiophene-based polymers used in spacecraft and explaining Mars's organic scarcity [16].
Using quantum chemistry methods, we examined thiophene fragmentation from O(³P) interactions. Our results matched experimental data from the crossed molecular beam (CMB) scattering technique [10], showing that the reaction forms thioacrolein and CO, attacking the sulfur atom and breaking the aromatic ring. This ISC-enhanced mechanism may destabilize sulfur-containing polymers and contribute to organic compound loss on Mars.

Additionally, the photodissociation of O₃ on Mars generates highly reactive atomic oxygen in the excited ¹D state, which likely accelerates organic degradation [13]. While photodissociation degrades complex organics, residual organic matter remains unless converted to volatile species. These findings are pivotal for developing space-resilient materials and understanding atomic oxygen's role in Mars's chemical evolution. Furthermore, the degradation products, including released carbon, may contribute to forming prebiotic molecules, enriching the diversity of planetary systems and interstellar chemistry.

References
[1] A.G.G.M. Tielens, Rev. Mod. Phys. 85, 1021.


[2] D.A.F.T.W. Strganac, et al., J. Spacecr. Rocket 1995, 32,502–506


[3] K.K. De Groh, et al., High Perform. Polym. 2008, 20, 388–409


[4] T. K. Minton, et al., ACS Appl. Mater. Interfaces 2012, 4, 492−502


[5] G. Wenzel, et al., Science, 2024, 386,810-813.


[6] M.A. Sephton, Nat. Prod. Rep., 2002,19, 292-311


[7] C. Sagan, et al., Astrophys. J., 414, 1, 399-405

[8] J. L. Eigenbrode, et al., Science, 2018, 360, 1096–1101


[9] M. Millan, et al., J. Geophys. Res. Planets, 2022, 127, e2021JE007107


[10] Vanuzzo G., et al., J.  Phys. Chem. A, 2021, 125, 8434–8453


[11] Recio P., et al., Nat. Chem., 2022, 14, 1405–1412


[12] J. Lasne, et al., Astrobiology, 2016, 16, 977


[13] G. M. Paternò, et al., Scientific Reports, 2017, 7, 41013


[14] S. A. Benner, et al., PNAS, 2000, 97, 6, 2425–2430


How to cite: Campisi, D., Parriani, M., Pannacci, G., Vanuzzo, G., Casavecchia, P., Rosi, M., and Balucani, N.: Reaction of Atomic Oxygen with Thiophene: Implications for Satellite Polymers in Low Mars Orbit and Chemistry of Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20186, https://doi.org/10.5194/egusphere-egu25-20186, 2025.

Some problems of gravity assist and terraforming of Mars

Introduction

Here we consider versions of terraforming that would allow colonists to live without pressure suits. The current mass of the Martian atmosphere is 2.5x10¹⁶ kg [1]. We consider 4 variants of terraforming. C indicates how many times we need to increase the mass of the atmosphere. For version v1 we assume a pressure of 10 kPa at the bottom of Hellas Planitia, C= 8.6, for v2 we use 10 kPa at the reference level for Mars and C=16.4, for v3 we use 101.3 kPa at the bottom of Hellas Planitia, C= 87.3, and for v4 we use 101.3 kPa at the reference level for Mars, C= 166.1.

For variant v4, 1 body with a radius of ~100 km (and density of 1000 kg m^-3) would be sufficient.

Possible sources

Celestial bodies orbiting far from the Sun contain large amounts of water, CO₂, nitrogen, etc. There are two places where there are enough bodies useful to our problem: the Kuiper Belt (KB) and the Oort Cloud (OC) [2]. The Kuiper Belt (KB) contains over 70,000 objects with diameters larger than 100 km. The mass of the KB is large enough [2, 3]. The total mass of the OC is ~3×10²⁵ kg [4]. The problem is the large distance from the Sun, so we consider only the KB as the source.

Transporting bodies

Initially ion engines change orbit of the chosen body, in order to later use the effect of gravity assist. This requires precise maneuvering. Since there are many bodies in the KB whose size is sufficient for gravity assist, we assume that a change in velocity of ~50 m/s  (using the engine) is sufficient. However, in our case, gravity assist is fraught with significant danger. KB bodies are unstable when volatiles escape. To calculate possible tidal effects, we use the methods developed in [5].

The gravity assist may be used to reduce the relative velocity of Mars and the impactor. This is important because strong heating of the atmosphere will lead to the escape of gases [6].

[1] Mars Fact Sheet. NASA.

[2] Hargitai, H. and Kereszturi, A., 2015, ISBN 978-1-4614-3133-6.

[3] Lorenzo I. 2007. Monthly Notices RAS. 4 (375), 1311–1314.

[4] Weissman, P. R. 1983. Astronomy and Astrophysics. 118 (1): 90–94.

[5] Czechowski, L., 1991. Earth, Moon and Planets, 52, 2, 113-130 DOI: 10.1007/BF00054178

[6] Czechowski, L., et al., 2023. Icarus, doi.org/10.1016/j.icarus. 2023.115473.

How to cite: Czechowski, L.: Some problems of gravity assist and terraforming of Mars, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16329, https://doi.org/10.5194/egusphere-egu25-16329, 2025.

On 13 June, day 165 of 2024, Juno passed through Io's main Alfvén wing at a distance of some 23 Io radii (R_I) below the moon during perijove (PJ) 62.  Evidence for this passage was clearly seen in the Juno plasma wave, magnetometer, and ion plasma data. The plasma wave signature was an intensification of quasi-electrostatic waves below about 1 kHz with a weaker magnetic component, all lasting for about 90 seconds.  A strong modification of the magnetic field was observed primarily in the co-rotation direction but with a significant component in the direction away from Jupiter. Ions in the range below about 1 keV/q were slowed within the Alfvén wing. The Juno mission has afforded multiple opportunities to examine the Io-Jupiter interaction near the planet and two close flybys through the Alfvén wing during perijoves 57 and 58.  Hence, PJ62 provided observations of the Io-magnetosphere interaction at an intermediate distance.  The broadband electromagnetic emission below 1 kHz was observed during PJs 57 and 58, however, the magnetic component is markedly reduced from those. An estimate of the power in the interaction obtained by scaling the Poynting flux and integrating over the cross section of the flux tube is ~500x10⁹ W.  And modeling of the current suggests filamentation of the Alfvén waves as observed in other Io Alfvén wings.

How to cite: Kurth, W., Sulaiman, A. H., Connerney, J. E. P., Allegrini, F., Valek, P., Ebert, R. W., Paranicas, C., Clark, G., Kruegler, N., Hospodarsky, G. B., Piker, C. W., Kotsiaros, S., Imai, M., and Bolton, S. J.: Juno Observations of Io's Alfvén Wing from 23 Io Radii , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3870, https://doi.org/10.5194/egusphere-egu25-3870, 2025.

Introduction: The Outer Planet Atmospheres Legacy (OPAL) program began in 2014 as part of the Hubble 2020 legacy initiative (Simon et al. 2015; DOI: 10.1088/0004-637X/812/1/55). These observations were meant to cement long-term legacy of the Hubble Space Telescope (HST) by ensuring a regular cadence of giant planet observations to fill temporal gaps between individual programs. The giant planets have highly dynamic atmospheres, so long-term trends tied to seasonal or other evolutionary cycles require regular data collected using the same instruments and filters.

In addition to building up a long data base of consistent observations on an annual cadence, serendipitous discoveries have been made along the way. Filters extend from the near-UV (F225W at 225 nm) to the near-IR (FQ889N at 889 nm), and each planet is imaged to cover all longitudes over a period of two planetary rotations. All raw data are immediately available to the public, and the team also hosts high level science products in the form of global maps at the MAST Archive (Simon 2015; DOI: 10.17909/T9G593).

OPAL at Jupiter: Hubble’s exquisite spatial resolution and OPAL’s global and temporal coverage allow detailed study of Jupiter’s long-lived vortices, high speed narrow wind jets, and alternating, variable, bands of colored clouds. OPAL results have included studies of vortices including the Great Red Spot (GRS), zonal wind speeds, small atmospheric waves, long-term color trends, and UV-dark ovals in the polar hoods.

Space missions: OPAL data have extended the science return of several space missions, with Jupiter observations commencing one year before Juno arrived at Jupiter. OPAL wind and cloud structure measurements have been used in diverse analyses of phenomena from the gravitational anomaly of the GRS, to deep zonal atmospheric structure revealed by microwave emission, to convective cycles in cyclonic vortices. Wave, jet, and vortex features previously observed by Voyager and Cassini have also been studied in greater detail with the long-term OPAL program.

Earth-based observatories: High-resolution visible-wavelength observations from OPAL target the planets near solar opposition to maximize spatial resolution, as do many Earth-based programs. Multi-observatory studies include correlations between cloud color from OPAL and microwave brightness from the VLA, comparisons between Doppler velocimetry from the ground and time-series imaging from OPAL, calibration, validation, and context for spectroscopic measurements, and deep context for stratospheric aerosol anomalies.

Conclusion: The results cited here are a small subset of the Jupiter results achieved with the OPAL monitoring of the outer planets, with additional discoveries at Saturn, Uranus, and Neptune. As of January 2025, 62 papers have cited OPAL data. With more than 10 years of data in hand, and continuing for the life of Hubble, we expect the scientific return to increase exponentially. OPAL serves as a model for future long-term programs at other observatories.

Acknowledgments: This research is based on HST observations (with NASA support; see Simon et al. 2015). GSO was additionally supported by NASA through contract 80NM0018D0004 to JPL.

How to cite: Wong, M. H., Simon, A. A., and Orton, G. S.: The Hubble OPAL Program: 10 years of time-variable phenomena on Jupiter and the other giant planets (invited), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14713, https://doi.org/10.5194/egusphere-egu25-14713, 2025.

After its arrival at Jupiter in July 2016, Juno conducted a global survey of Jupiter's magnetosphere with its highly eccentric polar orbit. Since then, the JADE instrument has accumulated a large amount of plasma measurements. Using a developed forward modeling method and a supercomputer cluster, we fit all ion measurements between 10 and 50 R_J from PJ5 to PJ56, obtaining a dataset with 70,487 good fits that consists of the following set of plasma parameters: abundances of different heavy ions, density, temperature, and 3‐D bulk flow velocity of heavy ions. This dataset has applications in the research on large-scale structures and small-scale dynamics in Jupiter’s magnetosphere, particularly the equatorial plasma disk region. Potential applications of this dataset include, but are not limited to, the following topics: 1) How is plasma distributed radially and vertically within the plasma disk? 2) What drives the local time asymmetry of plasma flow? 3) What are the consequences of centrifugal instabilities? 4) How is mass and energy transported in the magnetosphere? 4) How is force balance achieved and maintained? An overview of the dataset and some example applications will be presented in this talk.

How to cite: Wang, J., Bagenal, F., Wilson, R., Valek, P., Ebert, R., and Allegrini, F.: Ion Parameters Dataset from Juno/JADE Observations and Its Applications, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14033, https://doi.org/10.5194/egusphere-egu25-14033, 2025.

Modeling the formation conditions of the Galilean moons remains a significant challenge. While it is widely assumed that the moons formed within a circumplanetary disk (CPD) that surrounded Jupiter during the final stages of its growth, the physical properties and composition of this disk remain poorly constrained in theoretical models.

One approach to infer the properties and composition of the CPD is to use the bulk composition of the Galilean moons as a reference to extract compositional trends for the disk. A notable example is the gradient in water content with distance from Jupiter: from completely dry Io to a 1:1 water to rock ratio on Ganymede and Callisto. This gradient strongly suggests that the CPD exhibited a corresponding water abundance gradient during its formation.

With the JUICE and Europa Clipper missions currently cruising to the Jovian system, the coming decade will provide an unprecedented opportunity to study Europa, Ganymede, and Callisto. These missions are expected to refine our understanding of the bulk composition of the moons and provide new constraints for CPD models.

In this context, we aim to model the midplane volatile species composition of the CPD using a 2-dimensional proprietary framework. The model assumes a quasi-stationary disk heated by viscous stress, infalling gas, and the young, hot Jupiter. A key feature of the model is the presence of shadow regions that can be up to 100 K cooler than their surroundings and persist for up to 100 kyr.

Our results indicate that the profile of volatile species in the midplane shows enrichment peaks during the early evolution of the disk. However, maintaining these enrichments requires an accretion rate to the CPD of about 10^-7 M_jup/yr for at least 1 Myr. If the accretion rate decreases too rapidly, the ice abundances rapidly decrease.

In addition, we show that shadows within the CPD can significantly influence its volatile composition on short timescales of less than 100 kyr. These shadowed regions may trap ice of volatile species that would otherwise remain in the vapor phase, thereby altering the overall composition of the CPD.

How to cite: Schneeberger, A., Bennacer, Y., and Mousis, O.: Impact of self-shadowing on the Jovian Circumplanetary disk ice composition, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15614, https://doi.org/10.5194/egusphere-egu25-15614, 2025.

The formation of the ice giants Uranus and Neptune remains poorly understood, with several competing hypotheses attempting to explain their observed compositions. In particular, the carbon enrichment and nitrogen depletion observed in these planets challenge traditional models of planet formation. However, the measurement of the deuterium-to-hydrogen (D/H) ratio in Uranus by the Herschel Space Telescope provides a critical constraint on its bulk composition, including the CO/H2O ratio, providing valuable insights into the planet's formation and evolution.

D/H measurements in comets and planets are crucial for understanding their formation history. In the protosolar nebula, water ice is enriched in deuterium in the colder, outer regions and depleted in the warmer, inner regions relative to protosolar hydrogen. For example, D/H measurements from gas giants, which are predominantly composed of hydrogen, typically reflect or closely resemble the protosolar hydrogen D/H ratio. In contrast, D/H measurements from ice giants like Uranus and Neptune show supersolar D/H ratios in their atmospheres. The leading hypothesis to explain this is that their envelopes formed through the mixing of protosolar hydrogen with deuterium--rich primordial ices that they accreted during their formation. 

Under this assumption, the atmospheric D/H ratio of Uranus can be directly linked to the D/H ratio of its building block ices, depending on models of its internal structure. Assuming a cometary D/H ratio for the primordial ices accreted by Uranus enables the estimation of the planet's bulk composition, particularly its CO/H2O ratio. The objective of this study is to compare the inferred CO/H2O ratio of Uranus, derived from D/H remote sensing measurements, with values predicted for the protosolar nebula using a protoplanetary disk model. These findings provide critical constraints on the timing and location of Uranus's formation within the early Solar System and offer valuable insights into the processes that shaped its evolution.

How to cite: Benest Couzinou, T. and Mousis, O.: Constraints on Uranus formation from its D/H ratio, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16970, https://doi.org/10.5194/egusphere-egu25-16970, 2025.

The Comet Interceptor mission will attempt to fly by a yet undetermined target comet. The conditions of this flyby will remain largely unknown up to the selection of target and possibly even the moment of encounter. A detailed trajectory design phase, which includes verification of the technical limitations implied by the flyby geometry, precedes target comet selection, so the flyby velocity and the details of the geometry are known in advance. Solar irradiance and the neutral gas expansion speed can be estimated reasonably well. However, the comet outgassing rate, the dust production rate, and the solar wind conditions are only known within broader uncertainty margins. The present contribution aims to optimally choose the distance of closest approach based on a simplified formalism that expresses, on one hand, the science return to be expected as a function of the closest approach distance, and, on the other hand, the risks implied by a close approach. This is done by performing Monte Carlo simulations over a large sample of possible flyby configurations, based on the expected probability distributions of the gas and dust production rates and the solar wind conditions, and for different closest approach distances. For small flyby distances, a spacecraft can study the nucleus, the neutral gas coma, and the induced magnetosphere from up close, benefiting the science return. There is a trade-off to be made against the cometary dust collision risk, which becomes larger close to the nucleus. The change of the optimal flyby distance with gas and dust production rate, solar EUV flux, and flyby speed is discussed. The conclusion is that the Comet Interceptor main spacecraft and its two daughter probes – within the limitations of the approximations made – would benefit from a target comet with a gas production rate of 10²⁸-10²⁹ molecules·s^-1, a low dust-to-gas ratio, a high solar EUV flux, and a slow flyby speed (De Keyser et al., 2024, https://doi.org/10.1016/j.pss.2024.106032), for which the optimal closest approach distance (somewhere between 300 to 2000 km for the mother spacecraft) would yield a good science return at a limited risk.

How to cite: De Keyser, J., Edberg, N. J. T., Henri, P., Rothkaehl, H., Della Corte, V., Rubin, M., Funase, R., Kasahara, S., and Snodgrass, C.: Finding the optimal flyby distance for the Comet Interceptor comet mission, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6228, https://doi.org/10.5194/egusphere-egu25-6228, 2025.

With the growth of industry, transportation and machinery the issue of studying and damping vibrations and acoustic oscillations has become critical. Up to 4,000 earthquakes occur on Earth each year. Structures such as skyscrapers and bridges must be designed to withstand ground vibrations without damage. Machinery and tools operate with components that torsion and vibrate in the form of structural nodes. These nodes are connected by specific links to form complex multi-mass mechanical systems. Preventing vibration damage to multi-mass structures remains a pressing problem today. Therefore, the development of methods to calculate the amplitude, frequency and phase of the generated vibrations is a relevant task. Currently known methods of dynamic calculations are the use of analytical techniques for determining the intrinsic frequency of transverse and longitudinal oscillations of shells, rods and rotating machine parts (L.D. Landau, E.M. Lifshitz, V.I. Mossakovskiy, K.V. Frolov). Each task solved with these methods must strictly define the initial and boundary conditions of the oscillatory process. The application of these computational methods to multi-mass systems is very labor-intensive because, in addition to the calculation of amplitude, frequency, and phase, it is necessary to take into account the mode of oscillation. The study of free oscillations in multi-mass systems requires the formation of a system of linear differential equations and the use of cyclic frequency equations for multi-mass systems. Currently, simpler engineering methods such as electromechanical analogies were widely adopted in engineering practice. This period also saw the beginning of research into the resonant frequencies of living organisms to ensure the safety of vehicles subjected to vibration loads. This research was particularly important to the aerospace industry. When launching rockets carrying astronauts, spacecraft experience tremendous vibration shocks. In order to avoid harmful resonance effects, the natural frequencies of the astronaut's body and its organs must be determined. We have used a method based on electromechanical analogies to calculate the resonance frequencies. This method is based on the model of the astronaut's body as a vibrating system proposed by Prof. I. K. Kosko. The computational scheme of this model was developed for the first time. The astronaut's body was modeled as a lumped mass system connected by elastic links, the stiffness of which was determined according to the series and parallel rules. The study used data on the elastic modulus and mass of each part of the astronaut's body. The intrinsic frequency of the astronaut's body was calculated to be 1.702 Hz. The results highlight the importance of taking these data into account when designing the damping system for the astronaut's seat in order to prevent the vibration frequency of the rocket from coinciding with the resonance frequency of the astronaut's body. This approach allows the identification of frequencies that must be avoided to minimize the risk of damage caused by vibration loads. This work demonstrates the application of electromechanical analogies as a simplified engineering method for determining the natural frequencies of complex multi-mass systems such as the human body.

How to cite: Sokol, G., Snobko, D., Kadilnikova, T., and Dalik, M.: Method of electromechanical analogies in calculations of natural frequencies of multi-mass mechanical and biological systems, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10294, https://doi.org/10.5194/egusphere-egu25-10294, 2025.

The observing time of the cutting-edge radio interferometers tends to be heavily oversubscribed. This, coupled with the fact that solar activity is inherently unpredictable leads to limited observing time being granted for solar observations. There are, of course, dedicated solar monitoring radio telescopes, but their data quality, and hence the resulting science, pales in comparison with what is possible with the best-in-class instruments. A robust and reliable automated near-real time observing trigger for cutting-edge radio interferometers derived from dedicated solar monitoring telescopes can improve this situation dramatically. By enabling one to use precious observing time only when some solar activity is known to have just taken place, such a system can vastly increase the efficiency of limited available observing time to capture instances of solar activity. With observatories like the Square Kilometre Array Observatory (SKAO) on the horizon, the need for such a system is even more imperative. We present such a system developed by us for the SKAO-low precursor, the Murchison Widefield Array (MWA) based on near-real time data from the Yamagawa spectrograph which observes the Sun daily from rise to set in the band from 70 MHz to 9 GHz and is located at similar longitude as the MWA.  Generating an observing trigger poses an interesting and challenging problem. Not only does one have to reliably detect and reject any radio frequency interference (RFI) which is inevitably present, to be successful, a trigger needs to be raised as early after the start of the event as feasible. We have devised, implemented and tested algorithms to identify and remove the RFI and do an effective ‘de-noising’ of the data to improve the contrast with which features of interest can be detected. We note that much of the event data lost due to the latency from Yamagawa can be recovered using the data buffer available at the MWA, which was designed exactly to meet such needs. These triggers have been tested and tuned using the archival Yamagawa data, end-to-end tests of triggered observations have successfully been carried out at the MWA. Very recently this real time triggering has been operationalized at the MWA, a very timely development in view of the approaching solar maxima.

How to cite: Patra, D., Kansabanik, D., Oberoi, D., Kubo, Y., Williams, A., Meyers, B., and Nishizuka, N.: A Real-time Automated Triggering Framework for Solar Radio Burst Detection using Yamagawa Spectrograph for the Murchison Widefield Array, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18086, https://doi.org/10.5194/egusphere-egu25-18086, 2025.

The Parker Solar Probe (PSP) has provided unprecedented detailed in-situ measurements of proton velocity distributions (VDs) in the young solar wind, unveiling striking hammerhead features. The first interpretations and analyses, including PIC simulations of these unexpected shapes, suggested the involvement of more complex processes, especially kinetic instabilities. Recently, in A&A, 692, L6 (2024), we have identified a self-generated instability triggered by proton beams, whose back-reaction on the proton VDs can form the hammerhead proton population. An effective and numerically less-expensive quasi-linear approach enabled us to explore how this plasma micro-instability reshapes proton distribution, reducing beam drift and inducing a strong perpendicular temperature anisotropy, the main feature of the hammerhead structure. Our results align with PSP's in situ data and provide a fresh perspective on these distributions' dynamic and transient nature. These findings offer new insights into the role of kinetic instabilities in shaping space plasma dynamics.

How to cite: Shaaban, S. M., Lazar, M., López, R. A., Yoon, P. H., and Poedts, S.: Plasma Mechanisms Behind Hammerhead Proton Populations Observed by Parker Solar Probe, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8215, https://doi.org/10.5194/egusphere-egu25-8215, 2025.

Heavy ion composition and charge-state distributions provide valuable information about the source region of the solar wind due to the 'freeze-in' effect, making them valuable diagnostics for understanding the conditions of their source regions. Small-scale flux ropes (SFRs) have been studied for decades, but their source regions and formation mechanisms are still under debate. While heavy ion signatures in relatively large-scale flux rope structures, known as magnetic clouds (MCs), have been well studied, those signatures are still unclear in SFRs that last only couple of minutes. More importantly, heavy ions do not necessarily travel at the same speed as protons in the solar wind. A potential ion-proton differential velocity could cause a temporal lag between the heavy ion signal and the boundaries of SFRs, which introduces deviations when heavy ion signatures in SFRs are investigated.

In this study, we review ten years of in-situ solar wind heavy ion data obtained from the Solar Wind Ion Composition Spectrometer (SWICS) on board the Advanced Composition Explorer (ACE). The data set is derived from the Pulse Height Analysis (PHA) data, at 12-min resolution. By investigating every energy per charge step of each SWICS measurement interval, more SFRs with short duration, even shorter than 12 minutes, are included. We conduct a statistical study on the ion-proton differential streaming in over 6300 SFRs that are heavy ion abundant, as well as in the surrounding solar wind.

Positive ion-proton differential streaming is found common in SFRs but less common in SFRs that are located in recorded Interplanetary Coronal Mass Ejections (ICMEs) . About 50% heavy-ion-dense SFRs show ion-proton differential velocity larger than 0.2 times the local Alfvén speed. Positive ion-proton differential streaming has also been observed in the background solar wind near SFRs. However, some cases show strong positive ion-proton differential streaming exclusively within SFRs. Ion-proton differential streaming is crucial for understanding heavy-ion signatures in small-scale structures, with their acceleration mechanisms being of particular interest. A further study shows that SFRs detected at 1 AU are unlikely to be the interplanetary manifestations of nanoflare- or microflare-associated small CMEs, or at least not solely so.

How to cite: Gu, C., Heidrich-Meisner, V., and Wimmer-Schweingruber, R. F.: The ion-proton differential streaming observed in Small-scale Flux Ropes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6031, https://doi.org/10.5194/egusphere-egu25-6031, 2025.

Space weather causes geomagnetic disturbances that can affect critical infrastructure. Understanding the dynamic response of the coupled solar wind-magnetosphere-ionosphere system to severe space weather is essential for mitigation purposes. This paper reports on a detailed analysis of the most recently observed May 10, 2024, storm. We demonstrate that the global response to the storm dynamics was strikingly different in various sectors and at various latitudes. Results in the American and European sectors show that the most extreme mid-latitude response was associated to substorm related activity. However, no adverse impact of the storm on bulk power systems was report in North America or other parts of the world.

How to cite: Ngwira, C. and Weygand, J.: Global Geomagnetic Response and Impact During the 10 May 2024 Gannon Storm – Observations and Modeling, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12754, https://doi.org/10.5194/egusphere-egu25-12754, 2025.

Motivated by the need for more accurate radiation environment modelling, this study focuses on identifying and analyzing the drivers behind the sub-relativistic electron flux variations in the inner magnetosphere. We utilize electron flux data between 1 and 500 keV from the Hope and MagEIS instruments on board the RBSP satellites, as well as from the FEEPS instruments on board the MMS spacecrafts, along with solar wind parameters and geomagnetic indices obtained from the OmniWeb2 and SuperMag data services. We calculate the correlation coefficients between these parameters and electron flux. Our analysis shows that substorm activity is a crucial driver of the source electron population (10 - 100 keV), while also showing that seed electrons (100 - 400 keV) are not purely driven by substorm events, but also from enhanced convection/inward diffusion. By introducing time lags, we observed a delayed response of electron flux to changes in geospace conditions, and we identified specific time lag periods where the correlation is maximum. This work contributes to our broader understanding of the outer belt sub-relativistic electron dynamics, and forms the basis for future research.

How to cite: Christodoulou, E., Katsavrias, C., Kordakis, P., and Daglis, I.: Influence of solar wind driving and geomagnetic activity on the variability of sub-relativistic electrons in the inner magnetosphere, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4720, https://doi.org/10.5194/egusphere-egu25-4720, 2025.

During the May 2024 space weather event, Kiruna magnetometer (KIR) registered historically large positive deviation of the northward geomagnetic disturbance (dX = +1300 nT) at around 12 UT (14 MLT, i.e., postnoon).  The large dX is observed entire Scandinavia, giving AU = 1431 nT at 12:11 UT, but not in the Atlantic or North American sectors (although we do not know the disturbance at 15-23 ML because no data at > 55° Mlat is available).  

Such large positive dX of dayside stations is not very rare, most of them are observed in the North American continent.  Out of total 21 AU peaks of > +1300 nT separated by more than 1 hour (12 magnetic storms) during 1978-2019, 2 events are peaked at 09-15 UT, 8 events at 15-21 UT, 6 events at 21-03 UT, and 5 events at 03-09 UT.

For the European sector, dX value in the May 2024 event is the second largest after the 24 November 2001 event in both AU statistics (1978-2019) and Kiruna magnetometer (1962-2024).  The same uncommon nature is even seen in Kp=9 that was registered at 09-12 UT.  During 1932-2024, Kp=9 was observed only during 4 events at 09-15 UT, whereas Kp=9 was observed during 10 events at 15-21 UT, 8 events at 21-03 UT, and 5 events at 03-09 UT.

Although these UT anomaly is within the statistical fluctuation, we attribute this to the geomagnetic tilt toward the North American sector.  This makes stations at the same geomagnetic latitudes (e.g., AE stations and Kp stations) located at lower geographic latitudes (i.e., under higher ionospheric conductivity) in the North American sector than the other longitudes when the stations are located near noon (09-15 MLT).  Accordingly, the dayside dX and local K tends to register higher in the North American sector than the other longitudes.  Since extremely large AU (> 1300 nT) tends to occur near noon (this is the case with the 12 storms mentioned above), we expect more frequent large dX when the North America is near noon (15-24 UT).  For Kp, large Kp requires K=9 at Kp station even in the dayside where the disturbance is normally smaller than the nightside.  Then the North America may easier to register large K even during daytime due to higher conductivity.  If the rareness of high AU and Kp during 09-15 UT has such solid reason, the May 2024 space weather event was actually very unusual. 

Finally, there is one more peculiar feature of the large dayside AU for the May 2024 event is that it is preceded only by normal substorm (AL ≈ -600 nT) and followed by a strong negative excursion in the Alaska-Pacific sector instead.  This is quite different from ordinary dayside positive dX that is normally preceded by substorm of large AL (which is the case for the 24 November 2001 event with AL < -1300 nT).

Acknowledgment: We used provisional AE, SuperMAG, INTERMAGNET and Kp.  We thank all contributing observatories and institutions for these datasets.  

How to cite: Yamauchi, M., Nanjo, S., Kotani, T., and Matzka, J.: Unusually large positive geomagnetic variation (AU) near noon on 11 May, 2024, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12948, https://doi.org/10.5194/egusphere-egu25-12948, 2025.

A typical long-duration positive ionospheric storm (LDPS) developed in the midlatitude ionosphere in the European sector in response to a strong geomagnetic storm of February 26-27, 2023 (Kp = 7-, minimum SYM-H = -161 nT). To advance the current understanding of storm-time midlatitude ionosphere, we investigated the drivers of this LDPS using combination of multi-instrument observations and modeling, with focus on magnetically conjugate locations. Simulations with the field line interhemispheric plasma (FLIP) model constrained by the observed F2-layer peak height (h_mF₂) and density (N_mF₂) data at Kharkiv (50^oN, 36^oE) and Grahamstown (33.3^oS, 26.5^oE) were validated with the O/N₂ ratio data from the Global Ultraviolet Imager (GUVI). Our results indicate that neither the F2-layer peak uplift nor the O/N₂ ratio increase can be considered exclusive drivers of an LDPS. Each driver can be dominant depending on conditions. An LDPS can develop even when the h_mF₂ decreases and sometimes, a small h_mF₂ increase of ~10-20 km can cause a strong LDPS. Similarly, an O/N₂ increase is not a primary or necessary condition for an LDPS to develop but a small O/N₂ increase of ~20-30% can cause a prominent LDPS. Finally, the formation of a positive or negative storm can be inhibited if the raising/lowering of h_mF₂ is counterbalanced by a decrease/increase in the O/N₂ ratio.

How to cite: Reznychenko, M., Kotov, D., Richards, P. G., Bogomaz, O., Goncharenko, L., Paxton, L. J., Hernandez-Pajares, M., Reznychenko, A., Shkonda, D., Barabash, V., and Domnin, I.: Investigation of the Drivers of Long-Duration Positive Ionospheric Storms During the Geomagnetic Storm on February 26-27, 2023, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5836, https://doi.org/10.5194/egusphere-egu25-5836, 2025.

Recently, a model of the vertical profiles of shell currents and the magnetic field in the ionosphere has been developed (Romashets and Vandas, 2024). The distribution was determined for polar and equatorial regions. A global three-dimensional pattern of the shell-currents flow and its interconnections with the field aligned current (FAC) can be reconstructed. The magnetic field induced by the shell currents can produce at some locations a geomagnetic effect comparable to that of the ring current. The Biot-Savart integration over the entire ionosphere to derive the shell-currents induced magnetic field could be a challenging task. Here, we present an alternative method which utilizes spherical harmonics of different types for the inner and outer problems. The magnetic field inside the ionosphere is known, and outside of it is current-free and is represented as a gradient of a scalar potential, a sum of spherical harmonic functions with their coefficients. For the inner problem, only terms with (r/r0)^-n-1 are present in the sum, while the outer scalar potential contains only terms with (r/r0)ⁿ. Here 0<n<N, N=13, and r0 is the average distance from the Earth’s center to the ionosphere. Both the inner and outer problems for finding the induced magnetic field have only one condition: the magnetic field calculated with the scalar potential must be equal to the known magnetic field in the ionosphere. This research was supported by the NSF 2230363 and AVCR RVO:67985815 grants.

References.

• Romashets, M, Vandas, Determination of Vertical Profiles of Shell
  Currents in the Ionosphere, Annales Geophysicae, submitted, 2024.

How to cite: Romashets, E. and Vandas, M.: Magnetic field induced by the ionospheric shell currents., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6829, https://doi.org/10.5194/egusphere-egu25-6829, 2025.

The ESA-PROBA3 spacecraft was successfully launched aboard a four-stage PSLV-XL rocket from the Satish Dhawan Space Centre in Sriharikota, India, on Thursday, December 5th, at 11:34 CET (10:34 GMT, 16:04 local time).  Formation flying a pair of spacecraft will form an artificial solar eclipse in space, casting a precisely-controlled shadow from the Occulter platform to the  Coronograph spacecraft to open up sustained views of the Sun's faint surrounding corona. The payload on the ESA-PROBA3 Occulter spacecraft includes the Digital Absolute Radiometer (DARA) from the Physikalisch Meteorologisches Observatorium, Davos and World Radiation Center (PMOD/WRC). It aims at measuring the Total Solar Irradiance (TSI) in orbit. The destination of the spacecraft is a highly elliptical orbit (600 x 60530 km at around 59 degree inclination). We will present the initial results from this new experiment since its launch.

How to cite: Montillet, J.-P., Finsterle, W., Haberreiter, M., Schmutz, W., Pfiffner, D., Koller, S., and Gander, M.: Initial Results of Total Solar Irradiance Measurements by DARA-PROBA3, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18737, https://doi.org/10.5194/egusphere-egu25-18737, 2025.

During the active phase of solar cycle 25, the Parker Solar Probe (PSP) spacecraft frequently observes circularly polarized Type III radio storms. The most intense and longest duration event occurred following a large coronal mass ejection (CME) on 5 September 2022. For several days following the CME, PSP observed a storm of Type III radio bursts. The polarization of the storm started as left hand circularly polarized (LHC) and switched to right hand circularly polarized (RHC) at the crossing of the heliospheric current sheet.

We analyze properties of this Type III storm. The drift rate of the Type IIIs indicates a constant beam speed of ~0.1c, typical for Type III-producing electron beams. The sense of polarization is consistent with fundamental emission generated primarily in the o-mode.

In addition to this prototypical event, we present a survey of radio observations throughout the PSP mission, demonstrating that the majority of encounters contain Type III storms, that the storms are typically strongly (but not completely) circularly polarized, and that the sense of polarization and the sign of the radial magnetic field are consistent with o-mode emission.

How to cite: Pulupa, M., Bale, S., Jebaraj, I., Romeo, O., and Krucker, S.: Circularly Polarized Type III Storms Observed with PSP, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14886, https://doi.org/10.5194/egusphere-egu25-14886, 2025.

Introduction:

The presence of a range of secondary alteration minerals including phyllosilicates, extensive magnetite, and carbonates in CI chondrites have been inferred to represent aqueous alteration of their parent body asteroids¹. Many simultaneous organic synthesis processes have been identified as potentially occurring within parent bodies². Analysing the soluble organic matter (SOM) produced under analogous hydrothermal conditions can elucidate the chemical pathways involved in this alteration within CI chondrite precursor asteroids³, and even asteroids Ryugu and Bennu ^4,5.
Various asteroidal analogue experiments have previously been performed, but these have been non-specific in terms of conditions and minerals utilised^3,6. While other minerals are often added, the influence of carbonates on SOM produced from parent body alteration processes remains to be investigated. This project will therefore examine the effects of carbonate on organic synthesis in an analogue system for hydrothermal alteration in a CI chondrite parent body. 

Samples and methods:

Hexamethylenetetramine (HMT) solutions, and combinations of HMT and carbonate, were heated at 150ᵒC and pH 10 for a 30-day period. The samples were dried down and resuspended in 100μl of Milli-Q water.
Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to investigate the solutions’ elemental composition to determine salt abundances. Dilution of 10μl of the resuspended samples with 3% nitric acid was performed to make 2ml. 
From January 2025 onwards, gas chromatography-mass spectrometry (GC-MS) and ultra-high-throughput liquid chromatography-mass spectrometry (UPLC-MS) will be conducted, as well as more ICP-OES and Fourier-transform infrared (FTIR) spectroscopy. 

Preliminary results:

The six samples yielded a variety of elemental compositions (Fig. 1). Comparison of the concentrations of Al, Ca, Fe, Mg and Na shows that the different samples show significant distinctions in the concentrations of these elements present. The sample with both carbonate and saponite heated for 7 days and the sample with saponite heated for 30 days contain high concentrations of Ca, Mg and Na.

Discussion:

The elevated concentrations of certain elements in these samples suggests the presence of multiple types of salt - potentially even organic salts such as magnesium formate and iron acetate. Despite the insensitivity to salts that has characterised similar experimental procedures⁶, the larger amount of salt associated with certain saponite-containing samples may be significant. These salts have been produced from minerals like peridot and troilite under similar conditions, and interpreted to facilitate specific reaction pathways⁷. In our future investigation, it might be expected that different minerals have affected the organic composition of these solvents.

References: 
[1] Brearley A. J. (2006) Meteorites and the early solar system II, 943, 587-624. 
[2]Kebukawa Y. et al. (2017) Science advances, 3(3). 
[3] Vinogradoff V. et al. (2017) Icarus, 305, 358-370. 
[4] Chan Q. et al. (2023) In Hayabusa2 International Symposium.
[5] Zega T. J. et al. (2024) LPI Contributions, 3036, 6450.
[6] Vinogradoff V. et al. (2020) ACS Earth Space Chem., 4, 1398-1407.
[7] Serra C. et al. (2024) Icarus, 423, 116-273.

Fig. 1: A bar chart showing the concentrations of different elements within the analogue samples containing different mixtures of minerals, as measured through ICP-OES.

How to cite: Coker, S., Chan, Q., Vinogradoff, V., Bays, C., and Brakeley, J.: Salts produced by hydrothermal alteration of soluble organic matter in CI chondrite parent bodies, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12930, https://doi.org/10.5194/egusphere-egu25-12930, 2025.