This conference deals with fundamental issues of planetary habitability, i.e. the environmental conditions capable of sustaining life, and how interactions between the interior of a planet or a moon and its atmosphere and surface (including hydrosphere and biosphere) affect the habitability of the celestial body. The evolution of planets (including the Earth) is driven by its internal energy sources (radiogenic sources and energy stored during accretion) and depends on the composition, structure, and thermal state of their core, mantle, lithosphere, crust, and on interactions with a possible ocean and atmosphere and – in case of the Earth – with a biosphere. Convection of the rocky mantle is the key process that drives the evolution of the interior: it causes plate tectonics, controls heat loss from the metallic core (which generates the magnetic field) and drives long-term volatile cycling between the atmosphere/ocean and interior. Cycling of water and carbon dioxide between the atmosphere/ocean and interior is also a key process that is thought to regulate habitability because the more carbon dioxide we have in the atmosphere, the higher is the temperature, and the more weathering we have. Plate tectonic induces larger outgassing and is therefore a key factor for atmosphere generation. At the same time, the volatile content of the surface environment, particularly the presence or not of liquid water, is thought to have a large feedback on the interior, for example by influencing of the existence or not of plate tectonics. Partial melting and mantle depletion extract water from the interior to the surface. Outgassing and volcanism are also related to that. It is necessary to consider a coupled atmosphere-interior evolution for the understanding of habitability.
Thanks to our sponsors and our networks, we could build up a programme as proposed previously and aggregate excellent speakers and participants. We could also invite young career scientists, which provided very interesting fresh mind views. This workshop gathered 68 participants and was organized in terms of review talks, key notes, oral and poster presentations, and discussions, for a total of 38 oral presentations and 10 posters. It addresses the fundamental understanding of habitability in terms of geophysics of planets. We have reached the critical mass for excellent fruitful discussions and could reach our aims of better understanding the habitability of planets in terms of geoscience inputs.