Decoding the Formation and Evolution of Planetary Bodies through Surface and Interior Characterization

Co-organized by G7/GI3

Convener: Antonio Genova | Co-conveners: Salvatore BuoninfanteECSECS, Gene SchmidtECSECS, Maurizio Milano, Laura LarkECSECS

Deciphering the formation and evolution of planetary bodies requires a comprehensive investigation of both their surfaces and internal structures. Seismic data provide the most direct constraints on interiors, but such measurements remain scarce across the Solar System. In their absence, gravity and magnetic field observations have become fundamental for inferring the structure and dynamics of interiors of planetary bodies, spanning the Earth, Moon, and terrestrial planets to giant planets, their moons, and small bodies.
The scientific return of these geophysical datasets is greatly enhanced when combined with complementary surface observations, laboratory experiments, and numerical modeling. Multi-spectral and hyperspectral imaging, together with experimental analyses, link remote sensing data to mineralogical and physical properties, offering insights into the composition of outer and internal layers. Altimetry measurements provide independent constraints on tidal responses and rotational dynamics, complementing gravity and magnetic data and offering key insights into the rheology and differentiation of the deep interior. Joint analyses of gravity and topography provide information regarding the thickness, density, and elastic properties of interior layers, while thermochemical evolution models connect present-day structures through space and time to long-term geophysical and geological processes. Together, these approaches provide a more integrated understanding of how planetary bodies formed, differentiated, and evolved.
This session will focus on the instruments, measurement techniques, modeling approaches, and laboratory studies that enable robust constraints on the evolution of surfaces and interiors of planetary bodies. Contributions are invited that address both achievements and limitations of current methods, as well as innovative strategies to overcome existing challenges or combine disparate methodologies. Results from past, ongoing, and forthcoming missions, integrative analyses across multiple datasets, and forward-looking exploration concepts are all welcome. By bringing together diverse perspectives, the session aims to provide a broad and technically rigorous overview of the methods by which we can infer the processes shaping planetary bodies and to outline pathways for major discoveries in the coming decades.