Session programme

OPS – Outer Planet Systems

Programme group coordinators: Alice Lucchetti, Vladimir Zakharov, Gianluca Chiarolanza, Luca Morf

OPS2

Atmospheric aerosols and cloud particles are found in every atmosphere of the solar system, as well as, in exoplanets. Depending on their size, shape, chemical composition, latent heat, and distribution, their effect on the radiation budget varies drastically and is difficult to predict. When organic, aerosols also carry a strong prebiotic interest reinforced by the presence of heavy atoms such as nitrogen, oxygen or sulfur.

The aim of the session is to gather presentations on these complex objects for both terrestrial and giant planet atmospheres, including the special cases of Titan’s, Pluto's and Triton's hazy atmospheres. All research aspects from their production and evolution processes, their observation/detection, to their fate and atmospheric impact are welcomed, including observational & laboratory investigations and theoretical modelling.

Co-organized by TP/EXOA
Convener: Panayotis Lavvas | Co-conveners: Anni Määttänen, Audrey Chatain, Ella Sciamma-O'Brien, Sarah M. Hörst, Thomas Drant, Bruno de Batz de Trenquelléon
OPS3

This session will cover all aspects of ice giant (IG) systems including (but not limited to) the atmospheric structure and composition, magnetospheres, interiors, satellites, and rings of the IGs. Interdisciplinary, crosscutting themes of ice giant planet exploration, such as the relationship to exoplanetary science and connections with heliophysics will also be considered in the session. The session will consist of a combination of solicited and contributed oral and poster presentations on new, continuing, and future studies of the ice giant systems and the importance of the ice giants to models of the formation and evolution of the giant planets and the Solar System.

We welcome abstracts that:

Address the current understanding of ice giant systems, including atmospheres, interiors, magnetospheres, rings, and satellites including Triton.
Advance our understanding of the ice giant systems in preparation for future exploration, both by remote sensing and in situ.
Discuss what the ice giants can tell us about solar system formation and evolution leading to a better understanding of the current structure of the solar system and its habitable zone as well as extrasolar systems.
Address outstanding science questions requiring future investigations including from spacecraft, remote sensing, theoretical, and laboratory work necessary to improve our knowledge of the ice giants and their relationship to the gas giants and the solar system.
Present concepts of missions, instruments, and investigations relevant to future exploration of the ice giant planetary systems.
Due to the prioritization of the Uranus Orbiter and Probe (UOP) mission theme by the 2023 National Academy of Sciences "Origins, Worlds, and Life" planetary science decadal survey, we encourage the submission of abstracts that discuss broad science goals as they relate to the proposed objectives of the UOP mission. We welcome abstracts discussing measurements that could be made of the planet, satellites, and rings via remote sensing and/or in situ observations.

Convener: Vincent Hue | Co-conveners: Leigh Fletcher, Thibault Cavalié, Mark Hofstadter, Kurt D. Retherford, Michael T. Roman, Lorenz Roth, Krista Soderlund
OPS4

Dwarf planets and outer Solar System moons display a wide range of geological and geophysical characteristics, reflecting the interaction between internal evolution and surface processes over geological timescales. Their present-day properties are shaped by coupled mechanisms including tectonics, resurfacing, impact cratering, cryovolcanism, volatile processing, and the long-term evolution of their crusts and possible subsurface oceans.

This session focuses on the structure, dynamics, and evolution of these bodies, from surface to deep interior. We welcome contributions based on remote sensing, geological and geomorphological mapping, structural and tectonic analyses, stratigraphy, gravity and geophysical investigations, numerical and theoretical modelling, laboratory experiments, and comparative planetology. Studies addressing links between surface expression and internal processes, as well as long-term evolutionary pathways, are particularly encouraged.

Relevant targets include Io, Europa, Ganymede, Callisto, Enceladus, Titan, Triton, Pluto, and other outer Solar System moons and dwarf planets. Contributions based on data from past and ongoing missions, as well as studies supporting future exploration by Europa Clipper, JUICE, Dragonfly, and other upcoming missions, are strongly encouraged.

Conveners: Hamish Hay, Gianluca Chiarolanza | Co-conveners: Anastasia Consorzi, Davide Sulcanese, Camilla Cioria, Allard Veenstra, Conor Nixon, Tina Rückriemen-Bez, Marc Rovira-Navarro
OPS5

Saturn's moon Titan, despite its satellite status, has nothing to envy the planets: it has planetary dimensions, a substantial and dynamic atmosphere, a carbon cycle, a variety of geological features (dunes, lakes, rivers, mountains and more), seasons, and a potential hidden ocean. It even now has its own mission: Dragonfly, selected by NASA in the frame of the New Frontiers program. In this session, scientific presentations are solicited to cover all aspects of current research on Titan: from its interior to its upper atmosphere, using data collected from the Cassini-Huygens mission (2004-2017) and/or from telescopes (e.g., ALMA, JWST) and/or based on modelling and experimental efforts to support the interpretation of past and future observations of this unique world.

Co-organized by MITM
Conveners: Audrey Chatain, Thomas Gautier | Co-conveners: Sandrine Vinatier, Nicholas Teanby, Bruno de Batz de Trenquelléon, Robin Sultana, Lucy Wright
OPS6

Jupiter’s icy moons - Europa, Ganymede, and Callisto - are at the center of planetary science curiosity, particularly in the search for habitability in the solar system. In this context, ESA’s Jupiter Icy moons Explorer (Juice) is on its way to the Jovian system after its successful Venus gravity assist in August 2025 and is joined by NASA’s Europa Clipper following its launch in October 2024 and its Mars flyby in March 2025.

This session invites contributions from the science community related to these two missions’ objectives. This includes, but is not limited to, better understanding of Jupiter icy moons’ surface properties, internal structures and dynamics, as well as implications for habitability. The session will also cover the moons’ complex interactions with the space environment and their dynamical evolution within the Jovian system. Finally, abstracts related to observations and future science opportunities during cruise are also welcome.

As we reflect on this unique opportunity of having two spacecrafts in the Jovian system at the same time, the session will highlight the scientific opportunities offered by each mission as well as by the dual-spacecraft configuration, emphasizing the synergistic potential of Europa Clipper and Juice.

Conveners: Sam Fayolle, Audrey Vorburger, Corey Cochrane, Hao Cao, Lorenz Roth
OPS7

The gas giants Jupiter and Saturn have complex atmospheres where jet streams, convective storms and variable weather patterns interact at multiple spatial and temporal scales, and where solar radiation, magnetosphere interaction and particle precipitation drive energetic auroras and vigorous dynamics, leading to changes in composition and temperature. Their ring systems also provide important insights into planetary evolution and dynamical processes.

At the same time, understanding the internal structure and evolution of these planets is essential to place atmospheric processes into a broader physical context. Recent results from missions such as Juno and Cassini have provided new constraints on the deep interiors of Jupiter and Saturn, highlighting the strong coupling between interior structure, atmospheric dynamics, and magnetic field generation.

Analysing these atmospheric variations, as well as the properties of the clouds and hazes that cover both planets, allow the exploration of the fundamental mechanisms governing gas giant atmospheres. Key questions focus on the structure of the overall atmospheric circulation, distribution and transport of energy, vertical structure of the clouds, role of convection, and how the upper atmosphere and ionosphere affect the chemistry and dynamics of the lower atmosphere and troposphere, among others. In addition, comparative studies of these planets contribute to advancing our knowledge of the behaviour of exoplanetary atmospheres and serve to establish links with scenarios of formation and evolution of gas giant atmospheres.

This session welcomes contributions addressing both atmospheric, interior, and ring-system processes in Jupiter and Saturn, with particular emphasis on observations (from recent and ongoing planetary missions and from the ground), dynamics, chemistry, vertical structure, clouds and hazes, auroras, interior structure and composition, ring dynamics, and modelling. Studies exploring interior–atmosphere interactions, dynamo processes, and planetary evolution are especially encouraged.

Comparative studies and connections with exoplanetary science are also welcome, in order to place Jupiter and Saturn in a broader planetary context. Abstracts discussing new research on past missions such as Cassini, ongoing missions like Juno, future observations from missions such as JUICE, and ground-based and space-based facilities are also encouraged.

Conveners: Tristan Guillot, Peio Iñurrigarro | Co-conveners: Arrate Antunano, Deborah Bardet, Thibault Cavalié, Sandrine Guerlet, Ingo Müller-Wodarg, Ramanakumar Sankar
OPS8

Since the Galileo mission found evidence for global subsurface oceans at Jupiter’s icy moons over 30 years ago, the icy moons of the giant planets have become central targets of planetary science and astrobiology. The Cassini discovery in 2005 of plumes sourced from Enceladus’ global ocean further raised the interest. Now, with the highly anticipated arrival of NASA’s Europa Clipper & ESA’s Juice spacecraft in the Jovian system in the early 2030s, and NASA’s Dragonfly planned for launch in 2028, there is a growing buzz of excitement about what these missions could uncover.

At the same time, the selection of Enceladus as the primary target of ESA’s L4 mission highlights the importance of preparing for the long-term future of ocean world exploration today. With a landing tentatively on the timeline for the 2050s, this mission has the potential to revolutionise our understanding of the ocean chemistry, habitability, and astrobiology of these worlds.

This session will explore the common physical and chemical processes within the diverse population of the ocean worlds of our solar system. We welcome a broad range of abstracts covering:

Transport of material from ocean to surface and how this may lead to mission observables
Geophysics comparisons between bodies
Aqueous and prebiotic geochemistry
Lab experiments aimed at characterising their interiors or surfaces.
Surface phenomena including geophysics, impacts and space weathering
Constraints on conductive heat flow, ocean composition, and other global properties utilising existing observations and/or modelling

With the advent of Juice, Europa Clipper, Dragonfly, and the progressing planning for ESA L4, we particularly look forward to accepting abstracts relating to to these mission targets, as well as studies of other candidate ocean worlds such as Callisto & Triton, and current efforts aimed at maximising the scientific return of these missions.

Co-organized by EXOA
Convener: Axel Hagermann | Co-conveners: Lorenz Roth, Duncan Lyster, Jessica Hogan
MITM4

Electromagnetic scattering phenomena play a key role in determining the properties of Solar System surfaces based on observations using different techniques and in a variety of wavelengths ranging from the ultraviolet to the radio. This session will promote a general advancement in the exploitation of observational and experimental techniques to characterize radiative transfer in complex particulate media. Abstracts are solicited on advances in numerical methods to extract relevant information from imagery, photometry, and spectroscopy in solid phase, reference laboratory databases, photometric modeling, interpreting features on planetary surfaces, mixing/unmixing methods, AI and machine learning, software and web service applications.

Co-organized by TP/OPS/MITM/SB
Convener: Frédéric Schmidt | Co-conveners: Stéphane Erard, Antti Penttilä
TP2

Space environments, including magnetospheres, ionospheres, atmospheres, and associated auroral regions, are fundamental components of planetary and cometary systems. They are shaped by solar radiation and influenced by a wide range of processes such as space‑weather variability, solar wind dynamics, and changes in the neutral atmosphere. Within these systems, ionospheres play a central role in governing overall dynamics: they form the critical interface linking the neutral atmosphere, exosphere, and surrounding plasma environments (e.g., the solar wind at Mars, Venus, Pluto, and comets, or the Kronian magnetosphere at Titan). Understanding how each unmagnetized body responds to these external and internal drivers is essential for comparative aeronomy. While these bodies may share broadly similar behaviours, their distinct physical characteristics lead to scientifically significant differences, including in their auroral emissions and ionospheric responses.
This session focuses on the space environments, including auroral phenomena of Mars, Venus, Pluto, Titan, Jovian moons, comets, and related comparative studies, including analogies with the ionospheres of magnetized bodies. We invite abstracts addressing remote‑sensing and in‑situ observations, modelling efforts, instrumentation, and mission concepts.
Topics may include, but are not limited to: day‑ and night‑side ionospheric variability; sources and drivers of ionization; ion‑neutral interactions; current systems; comparative ionospheric and auroral studies across bodies; and solar‑wind–ionosphere coupling, including the response of neutral and ionized regimes to transient space‑weather events. Abstracts addressing general plasma processes and atmospheric escape are also welcome.

Co-organized by OPS
Convener: Beatriz Sanchez-Cano | Co-conveners: Christopher Fowler, Catherine Regan, Jacob Parrott, Olivier Witasse
TP10

Planetary cryospheres encompass environments enriched of volatile ices, in the form of frost deposits, polar caps, glaciers, and permafrost. Cryospheres are found across the entire Solar System at very different heliocentric distances: on Earth, ice plays a crucial role in landscape evolution, is a key hydrological resource, and acts as a valuable paleoclimatic indicator.
The Martian polar caps exhibit analogous features to those on Earth, including surface modification and associated landforms, but they also contain CO₂ ice. At mid-latitudes, periglacial landforms, such as polygonal terrains indicate the presence of subsurface ice, while glacier-like features contain relict ice and provide evidence of past glacial activity. Moreover, airless bodies such as Mercury and the Moon host icy deposits within the permanently shadowed regions of their polar craters. Similarly, dwarf planet Ceres presents surface and near-subsurface water ice, along with geomorphological and compositional evidence for volatile-driven activity. Further away, beyond the Solar System’s frost line, water ice becomes the dominant compositional endmember. All satellites of Jupiter and Saturn have icy crusts. For some of them (Europa and Enceladus) we have clues which imply the presence of internal oceans. In addition to water ice, CO₂ and CH₄ also condense into cryospheres at extremely low temperatures.
Therefore, studying ice on various planetary bodies is crucial for understanding their composition, geological history, climate evolution, and the processes which distributed water and other ices around the solar system.
This session welcomes a broad range of contributions, including remote sensing (e.g., geomorphic, geophysical and compositional analyses), numerical modelling, and laboratory experiments, as well as research incorporating terrestrial analogues.

Co-organized by OPS
Conveners: Giovanni Munaretto, Silvia Bertoli, Nicole Costa, Matteo Teodori, Alice Lucchetti, Luca Maggioni, Ariel Deutsch, Frances E. G. Butcher, Costanza Rossi