From stars to planets: chemical pathways to habitable worlds

Planets form and acquire their compositions from the residual dust and gas in protoplanetary disks surrounding young stars. The chemical nature of this material governs nearly every aspect of planetary composition, from bulk chemistry and volatile inventories to atmospheric properties and the conditions required for life. In this talk, I will present recent advances from cosmochemical studies of meteorites, asteroids, and returned planetary samples that provide new constraints on the formation and early evolution of the Solar System. High-precision isotopic measurements reveal that planetary building blocks inherited nucleosynthetic heterogeneity from their natal environment, reflecting both stellar sources and thermal processing within the protoplanetary disk. In particular, emerging evidence shows that supernova-derived material was delivered to the disk in volatile interstellar ices and selectively removed in the inner disk, establishing large-scale chemical gradients that were subsequently recorded by asteroids and planets. These observations support a formation framework in which planetesimals formed rapidly by streaming instability and grew predominantly by pebble accretion, allowing efficient inward transport of volatile-rich material during the main growth phase of rocky planets. Together, these results link disk-scale transport processes, planetary accretion timescales, and the origin of volatile elements, and suggest that the acquisition of life-essential volatiles is a natural outcome of planet formation. As such, the chemical conditions required for habitable worlds may be common in planetary systems beyond our Solar System.