| AVS 66th International Symposium & Exhibition | |
| Surface Science Division | Friday Sessions |
| Session SS+HC+PS-FrM |
| Session: | Planetary, Ambient, and Operando Environments |
| Presenter: | Edith Fayolle, Jet Propulsion Laboratory, California Institute of Technology |
| Authors: | E. Fayolle, Jet Propulsion Laboratory, California Institute of Technology R. Hodyss, Jet Propulsion Laboratory, California Institute of Technology P. Johnson, Jet Propulsion Laboratory, California Institute of Technology K. Oberg, Harvard University J-H. Fillion, Sorbonne Université M. Bertin, Sorbonne Université |
| Correspondent: | Click to Email |
Molecular ices have been observed in various planetary and astrophysical environments: from patches in permanently shadowed regions on Mercury and the Moon, to the ice crust of outer Solar System bodies, and onto dust grains in prestellar cores, protostellar envelopes, and protoplanetary disks. Interstellar and planetary ices are mostly composed of H2O, and more volatile molecules, e.g. N2, CO, CH4, CO2, H2S, SO2, NH3, held together as a solid through van Der Waals forces and dipole-dipole interactions, such as hydrogen bonding. They are found as mixtures or pure layers and display crystalline or amorphous structures.
Understanding ice formation, sublimation, and composition is crucial to interpret both gas phase and solid state observations, constrain the physical conditions encountered in space, and test for the likely chemical inheritance from star-forming environments to planetary systems. Vacuum and cryogenic techniques are used to reproduce astrophysical conditions and grow ice analogues. Analytical techniques, including IR- UV-spectroscopy, mass spectrometry, and microgravimetry, are employed to measure fundamental parameters such as desorption, diffusion energies, and reactions products & rates in the solid phase.
In this talk, I will show several examples of astrochemical experiments relevant to icy environments. The fundamental parameters derived from these experiments are further used as inputs for astrochemical models simulating the formation and evolution of ices on various bodies. In some cases, these experiments can directly explain recent observations, for e.g., the unexpected variety of molecules detected in lunar cold traps by the Lunar Crater Observation and Sensing Satellite mission or the location of snowlines in protostellar and protoplanetary environments probed by radio-interferometers like the Atacama Large Millimeter Array.