PS7.8 | Earth-based remote sensing of the Jupiter System and synergies with current and future planetary probes
Earth-based remote sensing of the Jupiter System and synergies with current and future planetary probes
Co-organized by ST2
Convener: Michel Blanc | Co-conveners: Patrick Gaulme, Rosie JohnsonECSECS, Valéry Lainey, Glenn Orton
Orals
| Mon, 28 Apr, 08:30–10:15 (CEST)
 
Room N2
Posters on site
| Attendance Fri, 02 May, 10:45–12:30 (CEST) | Display Fri, 02 May, 08:30–12:30
 
Hall X4
Posters virtual
| Attendance Thu, 01 May, 14:00–15:45 (CEST) | Display Thu, 01 May, 08:30–18:00
 
vPoster spot 3
Orals |
Mon, 08:30
Posters on site |
Fri, 10:45
Posters virtual
Thu, 14:00
The Jupiter is a complex system composed of a broad diversity of interacting components: regular and irregular moons, rings, magnetosphere, linked together by gravitational, electrodynamic and radiative coupling. At a time when the Juno mission orbits Jupiter and a new wave of space missions to Jupiter is underway with JUICE, Europa Clipper and Tianwen-4, remote sensing of the different components of the system will be critical to provide a comprehensive description of its dynamics and and better understand how it works. This session will review current and planned facilities and programs providing observations of the Jupiter system. It will welcome new ideas of observing techniques, instruments and facilities for Jupiter system observations and encourage international collaborations and citizen science initiatives for observing Jupiter in a new, more integrative perspective over the two coming decades

Orals: Mon, 28 Apr | Room N2

Chairperson: Ricardo Hueso
08:30–08:35
5-minute convener introduction
08:35–08:45
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EGU25-13744
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Virtual presentation
Observations of Io, its neutral clouds and plasma torus reveal processes driving the predominant source to Jupiter’s giant magnetosphere. 
Fran Bagenal

Jupiter’s giant magnetosphere is powered by the combination of a prodigious source of material from Io interacting with the strong planetary magnetic field. To understand the processes that drive this powerful system one needs to take observations of multiple components: Io’s volcanic activity, the spatial and temporal variability of the atmosphere, the structure of the escaping neutral clouds, the ionized products that form the plasma torus and the subsequent radial transport and heating of what becomes Jupiter’s extensive plasma disk. A key factor in this complex system is the coupling of the equatorial plasma to the high latitude ionosphere of Jupiter. To quantify these multiple, coupled processes one needs to observe the system over time with both in situ measurements and with remote sensing. In this talk I will review the different observations made by spacecraft at Jupiter as well as from Earth and outline future observations that would complement measurements by Juno, JUICE and Europa Clipper missions.

How to cite: Bagenal, F.: Observations of Io, its neutral clouds and plasma torus reveal processes driving the predominant source to Jupiter’s giant magnetosphere., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13744, https://doi.org/10.5194/egusphere-egu25-13744, 2025.

08:45–08:55
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EGU25-1961
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Highlight
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On-site presentation
A half century of Io plasma torus science: current mysteries and opportunities 
Jeffrey Morgenthaler

The Io plasma torus was first observed 50 years ago and has been studied by all of the space missions to visit Jupiter, the JAXA Hisaki satellite, HST, and a host of ground-based observatories.  These observations reveal significant structure in the torus: the "ribbon" near Io's orbit; the "warm torus," outside of the ribbon; and the "cold torus" inside of the ribbon.  Individually, the ribbon, cold torus, and warm torus have been the subject of significant study, but to date, no study has focused on combining the observations of these disparate parts of the torus.  I will outline several scientific questions that can be answered by simple analysis of existing and planned long-term observations of the torus.  The answers to these questions are important because they can help focus the efforts of Earth-based remote-sensing observations that would support JUICE, Europa Clipper and Tiawen-4 studies of the Jovian magnetosphere and Galilean satellites.

How to cite: Morgenthaler, J.: A half century of Io plasma torus science: current mysteries and opportunities, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1961, https://doi.org/10.5194/egusphere-egu25-1961, 2025.

08:55–09:05
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EGU25-7558
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Virtual presentation
Variability of Io plasma torus before and during the Juno era 
Masato Kagitani, Mizuki Yoneda, and Fuminori Tsuchiya

Volcanic gases, primarily composed of SO2, SO, and S, originating from Io are ionized through interactions with magnetospheric plasma, forming a dense plasma region known as the Io plasma torus. Ion pickup serves as the most significant energy source for the plasma torus though, the spatial distribution of the pickup region and its temporal variability remain poorly understood. Measuring ion distributions with sufficient spatial resolution enables the derivation of ion temperatures and temperature anisotropy, being closely related to the influx of fresh pickup ions.

Since 2014, we have carried out ground-based observations of sulfur ion emissions ([SII] 671.6 nm and 673.1 nm) from the Io plasma torus at the Haleakal Observatory in Hawaii, utilizing Tohoku 60-cm telescope. The telescope is equipped with a monochromatic imager and a coronagraph, enabling us to observe the distribution of singly charged sulfur ions with a spatial resolution as fine as 0.03 Jovian radii. This unique setup has allowed us to track changes in the torus structure with high spatial and temporal precision.

Over the past six years, our observations revealed five significant peaks in [SII] brightness. For three of these events, we observed that the [SII] ribbon scale height began to increase shortly after the brightness peaks. This phenomenon likely indicates a rise in ion temperature, driven by volcanic outbursts on Io that introduce fresh ions into the torus. Such findings provide critical insights into the dynamic nature of the Io plasma torus and its response to volcanic activity.

In this presentation, we will review past and ongoing remote sensing projects, present the latest observational results from our multi-year campaign, and discuss future plans for supporting upcoming space missions.

How to cite: Kagitani, M., Yoneda, M., and Tsuchiya, F.: Variability of Io plasma torus before and during the Juno era, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7558, https://doi.org/10.5194/egusphere-egu25-7558, 2025.

09:05–09:15
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EGU25-16160
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On-site presentation
Plans for observing Jupiter, Io and its torus at Lenghu Observatory in China 
Fei He, Yiqing Zou, Zhonghua Yao, and Yong Wei

The Jupiter system is the most interesting in the solar system. The Jupiter is the biggest and the most massive and possesses the strongest magnetic field. The first moon of Jupiter, the Io, is the only moon in the solar system that has volcanic eruptions. These characteristics make Jupiter one of the top priorities for deep space exploration in China and other countries. Earth-based remote sensing can provide important information on geological activity of Io, plasma torus evolution, neutral nebula evolution, atmospheric circulation, and internal structure. Recently, a high-quality optical astronomical site was found on the Tibetan Plateau at Lenghu, China. The median of atmospheric seeing is 0.75 arcseconds and the light pollution can be neglected. This site is quite suitable for solar system planet observations. A large aperture optical telescope with diameter of 1.8 meters is currently under construction at Lenghu by the Institute of Geology and Geophysics, Chinese Academy of Sciences. Two important instruments will be mounted to the telescope: a Jovian coronograph and a Jovian seismological imager. These instrument will continuesly observe Jupiter, Io and its torus from 2025 summer on. 

How to cite: He, F., Zou, Y., Yao, Z., and Wei, Y.: Plans for observing Jupiter, Io and its torus at Lenghu Observatory in China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16160, https://doi.org/10.5194/egusphere-egu25-16160, 2025.

09:15–09:25
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EGU25-14954
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Virtual presentation
Multi-wavelength telescopic observations of the Galilean moons from Earth and its orbit 
Katherine de Kleer

The Galilean moons present a diverse and dynamic set of bodies, from the surface volcanism of Io and the subsurface oceans of the icy moons to the rapidly-varying interactions between these objects’ atmospheres and the jovian magnetosphere. Understanding this system as a whole, and the complex interplay between different components, requires a multi-faceted approach. Spacecraft currently at Jupiter or arriving in the coming decade will provide a wealth of new and detailed information. Earth-based observatories (both on the ground and in orbit) provide complementary approaches, including long-term temporal coverage and access to a broad swath of instruments spanning the UV through radio wavelengths. For example, JWST’s high sensitivity in the near-infrared has enabled detection and mapping of new molecules on the Galilean moon surfaces, which can be compared to ALMA maps of thermal emission to draw connections between thermophysical properties and composition. UV/optical (HST/Keck) and millimeter (ALMA) observatories measures atomic and molecular species (respectively) in the atmospheres of these moons, giving insight into ongoing chemistry and the role of endo- and exogeneous processes in sourcing their atmospheres. This talk will highlight some key recent results on the Galilean moon surfaces, atmospheres, and magnetosphere interactions, and will discuss how telescope data can complement and enhance science return from upcoming missions.

How to cite: de Kleer, K.: Multi-wavelength telescopic observations of the Galilean moons from Earth and its orbit, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14954, https://doi.org/10.5194/egusphere-egu25-14954, 2025.

09:25–09:35
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EGU25-8152
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Highlight
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On-site presentation
Amateur Astronomers: Sentinels of Jupiter 
Jean-Luc Dauvergne

Thanks to advancements in processing software, imaging techniques, and cameras, amateur astronomers have been able to regularly produce high-resolution images of the planets in the Solar System for about fifteen years. Their efforts are particularly focused on Mars, Saturn, and Jupiter.

They are most often equipped with telescopes ranging from 250 to 400 mm in diameter and are regularly able to obtain images limited by diffraction in the visible part of the spectrum (0.3 to 0.5 arc seconds). These high-resolution images are captured using the Lucky Imaging technique. For example, on Jupiter, the capture rate is typically 50 to 100 images per second, and during processing, the software Autostakkert! 4 helps to correct some of the distortion effects caused by the atmospheric turbulence. Some of these observers use specific filters to produce scientific data. For instance, a filter at 890 nm is used to capture images of Jupiter in the methane absorption band, a UV filter for Venus, or a filter centered at 425 nm to search for Martian auroras.

The most experienced observers share their data across several databases: Junocam, PVOL from the University of Bilbao, the scientific society ALPO Japan, and the Detect program, which aims to detect impacts on Jupiter. Detect has accumulated 74 continuous observation days with 276 contributors, who are spread across the globe. The largest communities are in Europe, North America, and Japan.

The strength of the amateur community lies in its ability to produce daily data and provide almost continuous monitoring of Jupiter. For example, on ALPO Japan, during Jupiter's opposition, new data are added every single day. The number of observers varies greatly depending on the weather; on some days, there are only three contributions, while on others, there are more than thirty.

For amateur astronomers, knowing that their data can serve scientific purposes is an additional source of motivation. It is often very rewarding for them to see their names associated with scientific publications. Additionally, there is a strong sense of community, which has been significantly enhanced by the Juno mission through workshops held in Nice in 2016 and London in 2018, as well as citizen science sessions at the EPSC, supported by financial aid from Europlanet.

It could be valuable to continue fostering this network of observers during the upcoming missions to explore the Jovian system, whether it be JUICE, Europa Clipper or TianWen-4.

How to cite: Dauvergne, J.-L.: Amateur Astronomers: Sentinels of Jupiter, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8152, https://doi.org/10.5194/egusphere-egu25-8152, 2025.

09:35–09:45
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EGU25-14788
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Virtual presentation
Spin states of Europa and Ganymede 
Jean-Luc Margot

Radar speckle tracking observations of Europa and Ganymede with the Goldstone Solar System Radar and the Green Bank Telescope in 2011-2023 yield estimates of their spin axis orientations to ~0.01 degrees. These measurements conform to the expected 30-year precessional cycle and provide insights into the moons' Cassini States. I will describe the latest results and discuss new scientific prospects associated with these observations. First, the spin state can reveal the presence of a subsurface ocean: a decoupling between the icy shell and the interior results in a different obliquity than that of a solid body. Second, an angular deviation from the strict Cassini state enables estimates of energy dissipation. Third, a measurement of librations, if detectable, would enable a measurement of the shell's moment of inertia and provide bounds on the rheology and thickness of the shell. Fourth, the obliquity may explain remarkable surface features, such as the distribution and orientation of cycloids, strike-slip faults, and lineaments on Europa. Fifth, knowledge of the obliquity is required to enable tidal heating calculations. Finally, these measurements are expected to facilitate Clipper and JUICE operations and prevent initial, large mapping errors in spacecraft data products.

How to cite: Margot, J.-L.: Spin states of Europa and Ganymede, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14788, https://doi.org/10.5194/egusphere-egu25-14788, 2025.

09:45–09:55
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EGU25-20656
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ECS
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On-site presentation
Radio observations of the Jupiter system, present and future, and synergies between space and Earth-based observations 
Corentin Louis

Jupiter's radio emissions were first discovered in the 1950s. Since then, Earth-based radio telescopes have monitored Jupiter's emissions above 10 MHz, while several spacecraft have conducted flybys or have orbited the planet, like Juno. The synergy between space-based and ground-based observations has provided complementary data, including multi-point, in situ, and statistical measurements. In this presentation, we will review recent discoveries about auroral and Galilean moon-induced radio emissions made over the past few years using Juno and Earth-based radio telescopes. We will also look ahead to upcoming missions to Jupiter, such as JUICE, and discuss the crucial role of ground-based support observations.

How to cite: Louis, C.: Radio observations of the Jupiter system, present and future, and synergies between space and Earth-based observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20656, https://doi.org/10.5194/egusphere-egu25-20656, 2025.

09:55–10:05
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EGU25-14477
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On-site presentation
Unveiling Giant Magnetospheres: Research Advances in China and Prospectives for Future Missions 
Binzheng Zhang and Zhonghua Yao

The exploration of the Jupiter system has reached new heights with the ongoing Juno mission and the upcoming JUICE and Europa Clipper missions, making it a focal point in planetary space exploration. Significant breakthroughs have emerged since Juno's arrival in 2016, shedding light on the complex dynamics of the Jovian magnetosphere. Magnetospheric research, focusing on the outermost layer of planetary atmospheres, plays a crucial role in controlling mass and energy circulation, shaping the space environment. In this presentation, I will discuss recent progress in modeling the Jovian magnetosphere using three-dimensional MHD simulations, together with comparative analyses with Saturn. The simulation results reveal the global dynamics of the Jovian magnetosphere, showcasing complex magnetic topologies and large-scale plasma instabilities that govern the mass and energy circulation within the space environment. Validated against Juno measurements, these global simulations may offer new perspectives for future space missions to the Jupiter system, potentially revolutionizing our understanding of outer solar planetary systems.

How to cite: Zhang, B. and Yao, Z.: Unveiling Giant Magnetospheres: Research Advances in China and Prospectives for Future Missions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14477, https://doi.org/10.5194/egusphere-egu25-14477, 2025.

10:05–10:15
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EGU25-14544
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Virtual presentation
Results from Hisaki and prospects for LAPYUTA observations of the Jupiter System 
Fuminori Tsuchiya, Go Murakami, Atsushi Yamazaki, Kazuo Yoshioka, Masato Kagitani, Tomoki Kimura, Chihiro Tao, Ryoichi Koga, Hajime Kita, Jun Kimura, Shuya Tan, Kei Masunaga, Shotaro Sakai, Mizuki Yoneda, Masaki Kuwabara, Shingo Kameda, and Ichiro Yoshikawa

Remote sensing with ultraviolet wavelength (UV) are one of powerful probes to uncover dynamic behaviors of the planetary environment. The Hisaki satellite was an earth orbiting extreme ultraviolet (EUV) spectroscope dedicated for observing solar system planets. Thanks to its long-term monitoring capability, Hisaki had carried out unprecedented continuous observation of Io plasma torus, Jovian aurora, and Mars and Venus upper atmospheres from 2013 to 2023. One of notable phenomena observed by Hisaki is significant enhancements of neutral gas from presumed activation of volcanic activity on Io. Hisaki revealed, for the first time, that not only the plasma source, but transport, heating, and loss processes of magnetospheric plasma were influenced by the variation in the neutral source input.

After the end of the Hisaki mission, we have proposed the next UV space telescope, LAPYUTA (Life-environmentology, Astronomy, and PlanetarY Ultraviolet Telescope Assembly). One of goals of this mission is dynamics of our solar system planets and moons as the most quantifiable archetypes of extraterrestrial habitable environments in the universe. LAPYUTA will not only provide a UV monitoring platform like Hisaki but also have a high spatial resolution and high sensitivity to uncover stability of Io’s atmosphere, water plumes that gushes from the subsurface ocean of icy moons, and spatio-temporal aspects of Jupiter's giant UV aurora. Primary goal of the LAPYUTA mission other than the Jovian system includes atmospheric evolution of Venus and Mars, characterization of exoplanet atmosphere, galaxy formation, and time-domain astronomy.

How to cite: Tsuchiya, F., Murakami, G., Yamazaki, A., Yoshioka, K., Kagitani, M., Kimura, T., Tao, C., Koga, R., Kita, H., Kimura, J., Tan, S., Masunaga, K., Sakai, S., Yoneda, M., Kuwabara, M., Kameda, S., and Yoshikawa, I.: Results from Hisaki and prospects for LAPYUTA observations of the Jupiter System, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14544, https://doi.org/10.5194/egusphere-egu25-14544, 2025.

Posters on site: Fri, 2 May, 10:45–12:30 | Hall X4

Display time: Fri, 2 May, 08:30–12:30
Chairpersons: Valéry Lainey, Michel Blanc
X4.177
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EGU25-7854
The Juno-Supporting Earth-Based Observing Campaign 
Glenn Orton, Thomas Momary, Emma Dahl, Shawn Brueshaber, John Rogers, Scott Bolton, and Steven Levin

To support the Juno mission and provide necessary spatial and spectral context to measurements made by the spacecraft, the science team has established and coordinated an international network of observational astronomers and Earth-based observatories. This network of supporting observations of the Jovian system continues to expand. The measurements cover a broad spectral range with over 60 groups contributing to the campaign. The support provided by these observations constitutes several specific enhancements to Juno’s own data. (1) They provide knowledge about the evolution of features detected by the spacecraft at a single point in time. (2) Contextual information is gathered about the larger spatial environment surrounding the often very limited regions covered by Juno’s own instruments. (3) The spectral range covered by Juno’s suite of instruments is expanded, now including observations that cover X-ray through radio wavelengths. Observations at intermediate wavelengths, such as the mid-infrared, can detect thermal signatures that can measure temperatures in the upper troposphere through stratosphere unambiguously. (4) Supporting measurements also assess the extent to which distant phenomena taking place within the Jovian system may influence atmospheric or auroral properties detected by Juno’s instruments, such as the mass loading from Io by tracking its observed volcanic activity and the opacity of its torus. Observations of Jupiter’s neutral atmosphere included images and spectra of reflected sunlight from the near-ultraviolet through the near-infrared and thermal emission from 5 µm through the radio region.  The ultimate goal of these Earth-based measurements is to relate properties of the deep atmosphere (that are the focus of Juno’s mission) to the state of the “weather layer” at much lower pressures  Of special consideration during Juno’s extended mission are observations of thermal emission that cover narrow regions where temperature profiles are created from the phase change of the high-beam antenna’s radio signal as it is being occulted by Jupiter’s atmosphere. The spectral region and timeline of all of these observations are summarized in the web site: https://www.missionjuno.swri.edu/planned-observations. Besides a global network of professional astronomers, the Juno mission also benefited significantly from a network of dedicated amateur astronomers who provided a quasi-continuous picture of the evolution of features observed by Juno’s instruments. Examples of support will be shown from the primary and extended mission.

How to cite: Orton, G., Momary, T., Dahl, E., Brueshaber, S., Rogers, J., Bolton, S., and Levin, S.: The Juno-Supporting Earth-Based Observing Campaign, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7854, https://doi.org/10.5194/egusphere-egu25-7854, 2025.

X4.178
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EGU25-19473
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ECS
A novel method to remotely analyse Jupiter’s ionospheric flows 
(withdrawn)
Rosie Johnson, Tom Knight, Tom Stallard, and Henrik Melin
X4.179
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EGU25-19678
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Earth-based monitoring of Io torus Proposition for a Community Project 
Michel Blanc, Giuliano Vinci, Nicolas Andre, Vincent Hue, Olivier Mousis, Marie Devinat, Jonas Rabia, Quentin Nenon, and Alessandro Mura

The moon Io, the most active volcanic body in the Solar System,  is the “energy convertor” of the Jupiter system: indeed, Io’s interior is  continuously heated by tidal interactions with Jupiter and the other Galilean moons, while its volcanic activity is the main source of its neutral and plasma torus and generates the Jovian magnetodisk via complex processes likely related to a centrifugal instability.

A number of spacecraft have flown by Jupiter or have been placed into orbit around the planet. Some of them crossed the Io Plasma Torus (IPT), which is the main source of charged particles for the magnetosphere of Jupiter, revealing the complex spatial structure of the IPT. As an important complement, observations of the IPT from the Earth’s surface that are presented at this session, together with observations from Earth orbit (JAXA’s Hisaki) have revealed not only that the spatial structure of the IPT is complex, but also that it displays a large temporal variability over a broad spectrum of timescales, from hours to decades. Achieving a deeper understanding of the sources that drive the complex spatial structure and temporal variability of the IPT remains a very challenging open scientific question. In return, addressing this challenge will provide us with a key piece in the assembly of the puzzle of the Jupiter System.

While a new international flotilla of spacecraft is heading to Jupiter, time is ripe to unite all Io and IPT observers, space-based and Earth-based, to contribute to an around-the-world program of continuous observations. By the addition of observations at different longitudes from America, Hawaii, Japan, China, Europe and Africa, it will be possible to retrieve the complexity of the temporal variability of the IPT, while providing unique support to current Juno observations and upcoming observations by JUICE, Europa Clipper, TianWen-4 and hopefully LAPYUTA.

In this talk, we will review the rich diversity of IPT observations from space and from Earth, propose a modelling tool to assimilate all data into a single model of the Io torus, and propose that the Io and Jupiter science community work together to establish this joint endeavor as a major international scientific program.

How to cite: Blanc, M., Vinci, G., Andre, N., Hue, V., Mousis, O., Devinat, M., Rabia, J., Nenon, Q., and Mura, A.: Earth-based monitoring of Io torus Proposition for a Community Project, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19678, https://doi.org/10.5194/egusphere-egu25-19678, 2025.

Discussion Post a comment
X4.180
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EGU25-2569
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Highlight
Perspectives of Jovian seismology: sounding the interior of the Gas Giants through oscillations 
François-Xavier Schmider, Patrick Gaulme, Tristan Guillot, Jason Jackiewicz, Steve Markham, Hans-Peter Doerr, Raul Morales-Juberías, Lyu Abe, Julien Dejonghe, Amy Simon, and Sean Hsu

Jupiter and Saturn played a major role in the formation and evolution of the Solar System. The internal structure of the gas giants was shaped during their birth process and still contains traces of this formation. A detailed description of the internal structure would be key for understanding physical properties, Equations of State, high-pressure physics, effects of rotation, heat transfer, interaction between interiors and atmospheres, and finally would be a necessary step for the study of extra solar planets.

The measurement of gravitational moments by space missions can give a view of the internal structure. However, it is only sensitive to the external layers. Despite recent progress provided by the spacecrafts Juno and Cassini, our knowledge of the repartition of pressure, temperature and composition inside giant planets remains sparse and would not permit a unique model solution. The situation for Uranus and Neptune is even worse as these planets have not received any visit since Voyager. Among the different methods able to reveal the internal structure of planets, seismology is certainly the most powerful. A complete set of acoustic oscillations could give a profile of the sound speed and the rotation rate along the radius and latitudes. However, it requires long continuous observations, difficult to achieve from the ground.

So far, seismic measurements of Saturn have been obtained thanks to structure in the rings observed by Cassini and attributed to resonances with surface waves (f modes) of the planet. Ring seismology is very powerful as it allows recording of oscillations for many years, giving sensitivity and precision on the frequencies not achievable with other means. The analysis of these frequencies has shown the existence of stable layers inside Saturn. This fantastic result could not be extended further because of the small number of modes able to resonate with the rings. Gravity measurements from Cassini and Juno also proved the existence of acoustic modes on Jupiter and Saturn with detectable amplitudes but could not measure individual frequencies.

Many efforts were made to observe these modes through different techniques. The most promising is the monitoring of Doppler velocity images of the planet with a dedicated instrument. In 2011, a time series recorded with this method permitted the determination of a fundamental frequency present in the structure of the power spectrum and compatible with our knowledge of the Jovian internal structure. With a similar instrument, recent observations of Jupiter provided measurements of the 3 components of the wind at the surface of Jupiter, demonstrating its sensitivity. However, ground-based observations remain limited in resolution and duration. Such an instrument on a dedicated space mission would give unvaluable information.

During this talk we will present previous attempts to measure oscillations on Jupiter and Saturn from Earth and space. We will show the results and the remaining questions, including mode excitation and amplitudes. We will also review the present instrumental development and the most promising projects. Finally, we would derive a possible strategy for future observations in the frame of the international space mission context.

How to cite: Schmider, F.-X., Gaulme, P., Guillot, T., Jackiewicz, J., Markham, S., Doerr, H.-P., Morales-Juberías, R., Abe, L., Dejonghe, J., Simon, A., and Hsu, S.: Perspectives of Jovian seismology: sounding the interior of the Gas Giants through oscillations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2569, https://doi.org/10.5194/egusphere-egu25-2569, 2025.

X4.181
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EGU25-18631
The multiple layers of Jupiter’s troposphere observed by the NIRCAM instrument in the James Webb Space Telescope  
Ricardo Hueso, Arrate Antunano, Agustin Sanchez-Lavega, Mikel Sanchez-Arregui, Imke de Pater, Thierry Fouchet, Leigh Fletcher, Jake Harkett, Glenn Orton, Pablo Rodríguez-Ovalle, John Stansberry, and Mike Wong

The James Webb Space Telescope observed the Jovian System during Cycle 1 through the Early Release Science program 1373 (de Pater et al. 2022). The NIRCAM instrument obtained high-spatial resolution observations of the Jovian atmosphere in July 2022 in 5 different filters in wavelengths from 1.6 to 4.1 microns, with observations in three filters repeated after one planetary rotation to asses winds and atmospheric dynamics. The combination of high sensitivity in the near infrared and spatial resolution provided images that reveal exciting new aspects of the Jovian atmosphere. Early results from those observations include the discovery of a fast and narrow equatorial jet in the upper hazes near the tropopause potentially related with Jupiter’s Equatorial Stratospheric Oscillation (Hueso et al. 2023), the wind field of the upper levels of the Great Red Spot (Harkett et al. 2024), and in exciting views of the polar hazes and auroras that may give us hints of their potential relations (Antuñano et al. 2024). Observations also show new features in the atmosphere, such as a detached limb brightening from fluorescent emissions similar to observations attained by the JIRAM instrument on Juno (Migliorini et al. 2023). The 405N image shows the deep troposphere combined in some areas with thermal emissions from the interior of the planet. We here review those images, discussing atmospheric dynamics retrieved from those observations through the planet at multiple altitudes beyond the equator and the polar areas and we present additional aspects revealed by these observations that, together with a few commissioning observations from program 1022, remain so far the unique NIRCAM observations of the Jupiter atmosphere.

References:

de Pater et al. JWST Observations of the Jovian System from Commissioning and ERS data . AAS Division of Planetary Science meeting #54, 2022. id. 306.07

Hueso et al. An intense narrow equatorial jet in Jupiter’s lower stratosphere observed by JWST, Nature Astronomy, 2023. https://doi.org/10.1038/s41550-023-02099-2

Harkett et al. Thermal Structure and Composition of Jupiter’s Great Red Spot from JWST/MIRI, Journal of Geophysical Research: Planets, 2024. https://doi.org/10.1029/2024JE008415

Antuñano et al. JWST/NIRCAM views of Jupiter's polar regions, EPSC Meeting Europlanet Science Congress 2024, id. EPSC2024-808.

Migliorini et al. First Observations of CH4 and H3+ Spatially Resolved Emission Layers at Jupiter Equator, as Seen by JIRAM/Juno, Journal of Geophysical Research: Planets, 2024. https://doi.org/10.1029/2022JE007509

 

How to cite: Hueso, R., Antunano, A., Sanchez-Lavega, A., Sanchez-Arregui, M., de Pater, I., Fouchet, T., Fletcher, L., Harkett, J., Orton, G., Rodríguez-Ovalle, P., Stansberry, J., and Wong, M.: The multiple layers of Jupiter’s troposphere observed by the NIRCAM instrument in the James Webb Space Telescope , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18631, https://doi.org/10.5194/egusphere-egu25-18631, 2025.

X4.182
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EGU25-11127
JWST Observations of Jupiter's Ionosphere: Great Red Spot and Northern Aurora
(withdrawn)
Henrik Melin, Tom Stallard, Luke Moore, James O'Donoghue, Rosie Johnson, Leigh Fletcher, Imke de Pater, Thierry Fouchet, Oliver King, Paola Tiranti, Emma Thomas, Katie Knowles, and Mike Roman
X4.183
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EGU25-21868
A view from the other side: complementary observations of the Jovian UV aurorae from Hubble and Juno 
Bertrand Bonfond, Alessandro Moirano, Bilal Benmahi, Denis Grodent, Linus Head, Guillaume Sicorello, Jean-Claude Gérard, Thomas Greathouse, Randy Glastone, Rohini Giles, Joshua Kammer, Vincent Hue, Zhonghua Yao, Jonathan Nichols, Sarah Badman, and John Clarke

Starting from the Jupiter approach phase in early 2016, several Hubble Space Telescope observation campaigns dedicated to the UV aurorae have been executed in order to support the Juno mission. For example, these images have been used to study the auroral response to solar wind shocks measured by Juno's in situ instruments, or to identify the specific auroral morphologies associated with a compressed magnetosphere. In this presentation, we will focus on the images acquired simultaneously from Juno's UV spectrograph on one hand and from the Space Telescope Imaging Spectrograph on the other hand, each one looking at a different hemisphere. While the overall morphology is similar, variations of relative brightness between conjugate features, or shifts in the timing of some flares, are observed and are interpreted as signatures of distinct electron acceleration mechanisms or of magnetic field anomalies. Such combined observations thus provide unique insights into the asymmetries of the Jovian magnetosphere and its coupling with the ionosphere and upper atmosphere.

How to cite: Bonfond, B., Moirano, A., Benmahi, B., Grodent, D., Head, L., Sicorello, G., Gérard, J.-C., Greathouse, T., Glastone, R., Giles, R., Kammer, J., Hue, V., Yao, Z., Nichols, J., Badman, S., and Clarke, J.: A view from the other side: complementary observations of the Jovian UV aurorae from Hubble and Juno, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21868, https://doi.org/10.5194/egusphere-egu25-21868, 2025.

X4.184
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EGU25-14285
Variations in Jupiter's extended sodium nebula over two decades 
Mizuki Yoneda, Fuminori Tsuchiya, Carl Schmidt, Jeff Morgenthaler, Masato Kagitani, and Takeshi Sakanoi

We have been performing ground-based observations of Jupiter's sodium nebula longer than two decades. The sodium atoms in the nebula originate in Io's volcanic gas. The nebula distributes over 1,000 Jupiter's radii, and its angular size is approximately 10 degrees. Therefore, ground-based observations of D-line emissions in the sodium nebula can be made with small optics. The observation results indicate that the sodium D-line brightness in the nebula varies with various timescales like day-to-day through year-to-year. While it is naturally expected that variations in the brightness of the nebula reflect that of volcanism on Io, it may be influenced by locations of active volcanic plumes on Io. Sometimes, variations of the nebula differ between the eastern and western sides of Jupiter.  Details on the variations of Jupiter's extended sodium nebula will be shown. Especially, a period in which Juno spacecraft has been orbiting Jupiter will be focused. 

How to cite: Yoneda, M., Tsuchiya, F., Schmidt, C., Morgenthaler, J., Kagitani, M., and Sakanoi, T.: Variations in Jupiter's extended sodium nebula over two decades, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14285, https://doi.org/10.5194/egusphere-egu25-14285, 2025.

X4.185
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EGU25-21864
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ECS
Jupiter's X-ray Aurorae: A high signal spectral analysis of the 0.24 to 7.00 keV energy range
(withdrawn)
Bryn Parry and William Dunn

Posters virtual: Thu, 1 May, 14:00–15:45 | vPoster spot 3

Display time: Thu, 1 May, 08:30–18:00
Chairpersons: Guram Kervalishvili, Emilia Kilpua, Dalia Buresova

EGU25-14713 | Posters virtual | VPS27

The Hubble OPAL Program: 10 years of time-variable phenomena on Jupiter and the other giant planets (invited) 

Michael H. Wong, Amy A. Simon, and Glenn S. Orton
Thu, 01 May, 14:00–15:45 (CEST)   vPoster spot 3 | vP3.8

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.

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