Classical trajectory calculations have been performed to determine the reaction rate constants and NO final vibrational-rotational distributions of the N(4S)+O2 reaction at hyperthermal translational energies. The reaction occurs on two electronic potential energy surfaces, both of which must be considered for a realistic description of the N(4S)+O2 dynamics. The calculations, which are in good agreement with the available experimental data, show that the reaction has a very strong translational energy dependence and produces NO with extensive vibrational and rotational excitation. The present study provides the N(4S)+O2 reaction attributes necessary to predict NO formation and emission from translationally hot N(4S) in the thermosphere. ¿ American Geophysical Union 1994