The NII 2143A doublet has been observed in the earth's dayglow with a rocket spectrometer at an altitude of 200 km. The slant column emission rate of this airglow is 333¿67 Rayleighs at a zenith angle of 86.6¿. The likely excitation mechanisms are photoionization of molecular nitrogen by solar extreme ultraviolet radiation and photoelectron impact excitation of molecular nitrogen.