Dust traps in protoplanetary disks efficiently form organic macromolecular matter

Abstract

The chondritic building blocks from which Earth formed contain most of their elemental carbon and other volatiles in organic macromolecular matter. This substance is essential to set the chemical composition of terrestrial planets and start the emergence of life, but how it formed is unknown. We demonstrate that this organic macromolecular matter can efficiently form in dust traps – a prominent planet formation mechanism – in the solar nebula. By combining a protoplanetary disk dust evolution model with radiative transfer, we confirm that dust traps host regimes where ice-coated grains receive exceptionally large doses of radiation of several 10’s of eV molecule-1 year-1. This allows for the processing of approximately 4% of the total disk ice reservoir from simple molecules into complex macromolecular matter in a matter of decades. This finding shows that planet formation and the emergence of organic macromolecular matter that sets habitable conditions, are intimately linked.