Using the results of a recent study of the sources of O(1D) atoms in the aurora we show that the reaction N(2D)+O2→k1NO+O(1D) constitutes the main source of 6300 ¿ surface brightness about 150 km altitude in the daytime thermosphere. In summer the volume emission rate of this source is 2.5 times larger than the sum of all other sources at 180 km, and ~1.5 times as larger in winter. Inclusion of the new source alleviates the need for the large dissociation frequency of O2 by solar UV radiation in the Schumann-Runge wavelength range found in previous work (J02=3¿10-6 s-1), thus bringing the 6300 ¿ airglow measurement into harmony with the measurements of the Schumann-Runge continuum made on the Atmosphere explorer (AE) satellites; i.e., J02 =1.5¿10-6 s-1. Neglect of the N(2D) source of O(1D) in the past has resulted in an overestimation of O2 concentrations in the twilight thermosphere from both ground based and satellite measurements of the 6300 ¿ emission. When the N(2) source of O(1D) is taken into account the rate coefficient for quenching of O(1D) by N2 is estimated to be ~30% higher than that determined in a recent AE study; i.e., the new value is 4¿1¿10-11 cm3 s-1.