Tim Lichtenberg, Ph.D.

Education: ETH Zurich, Ph.D., Planetary Physics
Institution: University of Oxford (laboratory of Raymond Pierrehumbert and Richard Katz)

SCOL Project: Geodynamic Regimes During Planetogenesis

On what kind of world(s) did life emerge? Humanity does not know. Earth was once perceived as a typical planet in a typical planetary system, but the exoplanet revolution renders it an oddball among the rich diversity out there. While the origins of biological evolution for long seemed to be inaccessible to quantitative assessments, recent work has elucidated the first steps from inanimate matter to the emergence of life. These steps can occur in UV-stimulated reservoirs of surface water in a relatively stable atmospheric setting, with access to crucial carbon-, sulfur- and nitrogen-based chemical compounds. This represents a set of criteria for seeking potential environments in which these steps can operate. However, from the perspective of planetary physics, our ability to predict conditions at the planetary surface have been insufficient for this task. This is a proposal to extend planetary physics to identify the planet-forming pathways required for the onset of prebiotic chemistry.

From the perspective of our best data point, Earth, we return to the fundamental questions: Are we a cosmic fluke? Or do physics and chemistry act in concert to converge to Earth-like surface environments? With the recent advances in prebiotic chemistry and the rapid detection and characterization of ever more planets beyond the solar system, we are in a prime position to advance our understanding of how rocky worlds like (and unlike) ours form and evolve. When do formation and evolution create the conditions for abiogenesis?

I propose a study of the early dynamical evolution of rocky planets in order to derive the range of possible planetary environments and to set the solar system terrestrial planets in the context of the exoplanetary census. Using recent theoretical tools from the fields of astronomy, geodynamics and atmospheric physics, I will study the coupled interaction and dynamics of the interior and atmosphere of young rocky planets. I will derive the primary evolutionary archetypes of rocky worlds and the supply and availability of critical volatile molecules for the origins of life in surficial aquatic settings.

Assessing the plausibility of origin-of-life theories in the range of possible planetary surface environments will inform prebiotic chemists on the robustness, dynamics and potential chemistry of varying planetary settings, and the physical regimes in which these can operate. These investigations synergize strongly with existing research initiatives within the Simons Collaboration on the Origins of Life and at my proposed host institution. My work will establish crucial links between planetary and atmospheric sciences, astronomy and prebiotic chemistry and will help us to better understand the origin and place of our own world in the galaxy.