Three new progressions consisting of broad bands were obsd. in the absorption spectrum of NO in solid Ar. They are identified as the mol. Rydberg A 2.sum.+,C 2P and D 2.sum.+-X 2P (v', 0) transitions, blue shifted with respect to the gas phase by .apprx.0.85 eV. Excitation of the mol. yields emission from A 2.sum.+ (v = 0) with large absorption-emission Stokes shifts, and from the valence B 2P(v = 0) and a 4P(v = 0) states. Intensity ratios between these states in Ar, Kr, and Xe matrixes are given and discussed. [on SciFinder (R)]