Observations of NH2, OI, CH, CO(+), CO2(+), H2O(+), and N2(+) in optical spectra of comets represent ionization and dissociation product abundances of N2, NH3, H2O, CH4, CO2, and CO. The primary objectives are to determine: (1) accurate production rates for the observed species, and (2) accurate relative abundances of condensates in a sample of comet nuclei. The ultimate goal is to constrain models of comet formation and chemical processing in the outer primordial solar nebula.
