Carbamic acid produced by the UV/EUV irradiation of interstellar ice analogs

Abstract

Context.Carbamic acid (NH2COOH) is the smallest amino acid, smaller than the smallest proteinaceous amino acid glycine. This compound has never been observed in the interstellar medium (ISM). Previous experiments where ice mixtures containing H2O, CO2 and NH3 were subjected to 1-MeV proton bombardment showed that carbamic acid is formed in a stable zwitterionic (NHCOO-) form.