Abstract: | Chemical and physical processes in the outer solar nebula are reviewed. It is argued that the outer nebula was a chemically
active environment with UV photochemistry and ion-molecule chemistry in its low density regions and grain-catalyzed chemistry
in Jovian protoplanetary subnebulae. Presolar material was altered to greater or lesser extent by these spatially and temporally
variable processes, which mimic many features of interstellar chemistry. Experiments, models, and observations are recommended
to address the questions of presolar versus nebular dominance in the outer solar nebula and of how to distinguish interstellar
and nebular sources of cometary volatiles.
This revised version was published online in June 2006 with corrections to the Cover Date. |