Ammonia and Nitrogen Abundances in Comets

Comets consist of pristine material preserved from an earlier galactic epoch. Determination of the molecular, elemental, and isotopic abundances in the dust and volatile components of comet nuclei produce vital clues to the chemical evolution of both interstellar and solar nebula matter. Here the abundances of nitrogen-containing molecules in comets are considered. The molecular abundances of NH3 in four comets are summarized (Tegler 1990, Wyckoff, Tegler, and Engel, 1990). From an inventory of nitrogen-containing compounds (Wyckoff, Engel, and Tegler 1990, Wyckoff, Engel, Womack, Ferro, Tegler and Peterson, 1990), an estimate of the elemental N abundance is also presented.