From Astronomy to Chemistry: Towards a Continuous Path for the Origins of Life


The origins of life on Earth have been a longstanding scientific puzzle, prompting scientists from Orgel to Sagan to grapple with the fundamental question of “how did we get here?” While a complete theory of the origin of life on Earth – with experimental support and no unresolved issues – has yet to be elucidated, certain pieces of the puzzle have seen recent progress. We need to have a cohesive model of the origins of life on Earth to better inform which exoplanets should be observational targets for upcoming telescopes and what tools will be necessary in future missions to deduce the presence or absence of life on a potentially habitable world. Fortunately, we have unprecedented access to the one planet where we know circumstances led one way or another to life’s origins: the Earth. While astronomers find and characterize exoplanets and planetary scientists explore the possibility for habitability in our Solar System, chemistry can play an invaluable role in facilitating the search for life beyond Earth. Here, I will discuss results from several recent projects along the pathway from the chemical environment readily available on planets, to understanding prebiotic chemistry reactions in the planetary context, to the emergence of the eventual first life – whatever form it may take. The necessary building blocks of life – whatever they may be – should be available in planetary environments; understanding the chemical feedstocks present on planets is a crucial first piece of the puzzle. Next, productive prebiotic chemistry reactions should be able to occur under planetary conditions and from plausible reagents in the environment. Finally, the interplay between the potentially messy chemical environments on planets must also allow for the development of complexity that could go on to form the first life. If we better understand the chemical reactions and pathways possibly leading to the origins of life on Earth, we can better inform and constrain the search for life in other planetary environments. By working towards a continuous and plausible pathway towards delineating the origins of life on Earth, we can place constraints on the astronomical, planetary, and chemical environments necessary for habitability.