Formation and Survival of Complex Organic Matter in a Warm Jovian Circumplanetary Disk

This study investigates the formation of complex organic molecules (COMs) in Jupiter’s circumplanetary disk (CPD) during its early, warm phases. This disk served as the formation environment for its major moons—Europa, Ganymede, and Callisto—which are believed to harbor subsurface oceans beneath their icy crusts. Understanding the chemical evolution of these moons is essential for assessing their potential habitability. While several studies have explored the role of COMs in the context of the protoplanetary disk (PPD), direct evidence of their presence on the Galilean moons remains elusive, with detections to date limited to other icy bodies such as Enceladus. COMs, composed of carbon, hydrogen, oxygen, and potentially nitrogen, are fundamental constituents of planetary chemistry and have been observed in comets and star-forming regions. Laboratory experiments have shown that these molecules can form in icy environments through processes such as UV irradiation and thermal processing.

This study shifts the focus to COM formation in a hot CPD, where elevated temperatures influence chemical pathways, providing a dynamic environment for molecular evolution. The work employs simulations of particle trajectories within the CPD, accounting for various particle sizes and release epochs throughout the disk’s evolution. These simulations track the transport of particles released from different regions and examine how thermal processing in specific zones of the CPD transforms simple ices—particularly NH₃:CO₂ mixtures—into complex organic molecules. A key result is that thermal processing, rather than photochemical reactions, is the dominant mechanism driving COM formation in this environment. This transformation occurs before significant irradiation takes place, suggesting that thermally driven processes prevail in the early stages of CPD evolution.

In summary, this study offers new insights into the thermal and dynamical conditions within Jupiter’s CPD and their impact on the chemical development of its forming moons. By demonstrating that thermal processing is the principal pathway for COM formation, the research contributes to our understanding of how the Galilean moons—and potentially other icy satellites—may have acquired their complex chemical inventories. These findings have broader implications for evaluating the origins of life and the habitability of similar bodies in other planetary systems.