A NExSS/NAI/NSF Joint Workshop

The chemistry and physics of planetary interiors shapes conditions at their surfaces in ways that profoundly affect habitability and our ability to detect life. The nature and extent of these interactions are not well understood even on Earth. For example, we debate the ways in which internal processes affected the emergence of an O2-rich surface environment on Earth, paving the way for complex life. As a result, we lack a guiding theory from which we can infer the likelihood that O2 will accumulate in the atmospheres of exoplanets with slightly different mass or composition from Earth. The implications for exoplanet habitability and life detection strategies have barely been considered.

This workshop will bring together astrobiologists, astronomers, planetary scientists, geochemists, geophysicists, and others needed to develop a working theory about the complex relationships between the surface habitability and internal evolution of Earth and Earth-like worlds.

The goal is a community research roadmap and whitepaper aimed at developing a theory of planetary evolution, from solar nebula to evolving world, that will guide the search for inhabited worlds into the next generation. To this end, the workshop will be open to community participation via face-to-face attendance at ASU, and virtual participation as a NASA Workshop Without Walls.

Key themes include:

Exoplanetary Observations
What can we observe now and in the near future that has bearing on facets of exoplanet geophysics and geochemistry that shape habitability and detectability?

Physics and Chemistry in Planetary Formation
How does our understanding of planetary formation inform our ability to predict planetary compositions and hence important geophysical and geochemical parameters?

Atmospheres and Biosignatures
What are our longer-term observational aims and how are they affected by surface-interior interactions?

Physical Behavior of Planetary Materials and Planetary Structure
What are our limits of understanding of planetary material behaviors and surface tectonics, and how must this understanding extend and evolve to guide the search?

Thermal and Chemical Evolution of Planets
What are our limits of understanding of solid planet evolution and how must this understanding extend and evolve to guide the search?