Biomolecule formation by oceanic impacts on early Earth

Intense impacts of extraterrestrial objects melted the embryonic Earth, forming an inorganic body with a carbon-dioxide- and nitrogen-rich atmosphere. Certain simple organic molecules have been shown to form under conditions resembling meteorite impacts, although the link between these events and the development of more complex molecules remains unclear. Ordinary chondrites, the most common type of meteorite, contain solid carbon, iron and nickel-elements essential to the formation of organic chemicals. Here we use shock experiments to recreate the conditions surrounding the impact of chondritic meteorites into an early ocean. We used a propellant gun to create a high-velocity impact into a mixture of solid carbon, iron, nickel, water and nitrogen. After the impact, we recovered numerous organic molecules, including fatty acids, amines and an amino acid. We suggest that organic molecules on the early Earth may have arisen from such impact syntheses. As the natural impacts that were frequent on the early Earth are more sustained and reach higher pressures than our experiments, they may have resulted in the synthesis of a greater abundance, variety and complexity of organic compounds.