Matter at Extreme Conditions from the Deep Earth to Giant Planets

Understanding the behaviour of materials under extreme pressures and temperatures is fundamental to constraining the structure, composition and evolution of planetary interiors. These environments span a wide range of thermodynamic conditions and timescales, from processes occurring deep inside the Earth to the highly compressed states found in giant planets and during planetary impacts. Their experimental investigation requires combining different compression methods with structural and spectroscopic probes capable of following both equilibrium and transient transformations. This presentation will focus on recent and future developments in this direction, combining static compression in diamond anvil cells with laser-driven dynamic compression at synchrotron and X-ray free-electron laser facilities. Within this broader framework, the S-CAPE project, my recently awarded ERC Consolidator, will represent a major part of the next phase of my research activities, investigating the Earth’s deep sulphur cycle from planetary accretion to present-day mantle environments through the structural, electronic and chemical behaviour of sulphur-bearing materials. The talk will also place S-CAPE within a wider research programme, including the development of state-of-the-art techniques to perform shock-compression experiment of liquids and gases, studies of water and iron-bearing compounds, and ongoing work on hydrogen-helium demixing relevant to the interiors of giant planets. Together, these directions aim to connect static and dynamic compression across different timescales and thermodynamic paths, providing a broader view of matter under planetary extreme conditions.