Ultraviolet measurements of the (1.0) gamma band of nitric oxide in fluorescence by a satellite at high latitudes show nitric oxide concentrations which are highly variable in both time and space. The average nitric oxide concentration is 3--4 times higher at high latitudes than at mid-latitudes. If auroral activity is responsible for the larger nitric oxide densities and if the reaction N(2D)+O2 is the source of NO, then auroral processes must be more efficient in the production of N(2D) atoms than dayglow processes.