EXOA13

The origin of the molecular universe, comprising hundreds of species detected by astronomical observations and space missions, is a central question linking astrochemistry with (exo)planetary science and astrobiology. James Webb Space Telescope (JWST) now directly probes interstellar and disk ices at unprecedented sensitivity, revealing that interstellar icy mantles are already rich in H₂O, CO₂, CO, CH₄, NH₃, and even complex organic molecules (COMs). Strikingly, many of these species share chemical similarities with volatiles observed in cometary bodies, suggesting chemical continuity from molecular clouds to planet-forming environments.

Interstellar ices are not merely passive reservoirs; they act as molecular factories where simple species are transformed into increasing chemical complexity through surface reactions, UV-driven photochemistry, and thermal processing. These icy mantles store and transport volatile material that ultimately becomes incorporated into protoplanetary disks and nascent planets. Understanding how molecules form, evolve, and survive in the solid state is therefore essential for tracing the chemical inheritance of icy bodies in planetary systems.

This session places solid-state chemistry at the center of the molecular inheritance problem, examining how icy grain mantles regulate the chemical inventory ultimately incorporated into forming planetary systems. Key topics include gas–grain chemistry, reaction networks and rates, energetic and thermal processing of ices, volatile transport and reprocessing in disks, and the spectroscopic characterization of molecular solids at high resolution. We invite contributions spanning laboratory astrochemistry of ices and organics, chemical modeling, and JWST ice observations in molecular clouds, (proto)planetary systems, and comets to develop physico-chemical frameworks that unify chemical networks and constrain the volatile inventories inherited by forming planets.

Given its emphasis on laboratory astrochemistry, spectroscopic database development, and chemical modeling, the session is highly relevant not only to EXOA but also to MITM – Missions, Instrumentation, Techniques, and Modelling, and aims to foster dialogue across these program groups.