Terrestrial planets are complex systems and their evolution is dependent on a variety of different mechanisms and their interaction. The aim of this session is to emphasize the importance of coupling and feedback processes between different layers of the terrestrial planets, with a focus on the planetary deep carbon cycle. For example, surface conditions are dependent on atmosphere composition, which results from early and on-going degassing, atmospheric losses and chemistry, chemical reactions with the surface, and in the case of our planet, it is also shaped by the interaction with the biosphere. In turn, surface conditions can affect the habitability of the planet. Changes in surface temperature have consequences on surface alteration processes as well as volatile exchanges and might even affect which tectonic regime is active.

As a volatile, carbon plays a fundamental role on Earth's surface and interior, with wide-ranging influences on physical and chemical processes and its coevolution with the biosphere. A decadal program as part of the Deep Carbon Observatory (DCO) has integrated multidisciplinary approaches to study the cycle of carbon, as well as the consequences for energy resources, the evolution of life, as well as extreme physics and chemistry that enable this complex multi-scale process. Although much of the effort has been focused on observing and modelling the deep carbon cycle at the present-day, new approaches that incorporate the geological record are providing insights into the role of mantle convection, plate tectonics, large-scale volcanism and climate change in modulating carbon exchanges between atmospheric, hydrospheric, lithospheric and mantle reservoirs.

This interdisciplinary session aims to showcase all aspects of terrestrial planet evolution and the planetary carbon cycle, including advances in data collection, experimental techniques, “Big Data” analysis, and modelling of these processes. We welcome contributions focused on individual planets as well as from comparative planetology. Both solar system bodies and exoplanets studies will be covered. Targeted disciplines include planetary structure and composition, mantle dynamics, tectonic regimes, geomagnetism, volcanism, surface interaction/erosion, atmospheric sciences, volatile cycling, climate and habitability. We foster collaborations between geologists, geochemists, petrologists, volcanologists, geophysicists, modellers, planetary scientists, bioengineers, and microbiologists, and we hope all researchers in this area will consider contributing to this session.

Invited speaker: Emily Mason, University of Cambridge