We present limb spectral measurements of the Martian atmosphere for four seasonal periods produced from data acquired by the Mars Global Surveyor/Thermal Emission Spectrometer. Between the altitudes of approximately 50 and 90 km, nonlocal thermodynamic equilibrium (non-LTE) emission from CO2 hot bands is observed at 10 ¿m. The centroids of these emissions vary in latitude and height with season, and their emission regions extend approximately 120¿ in latitude. The emission is considerably stronger in the southern summer/northern winter season than in the corresponding northern summer/southern winter season due to large solar flux variations resulting from the eccentricity of the Martian orbit. Modeling of this emission explains its observed altitude, solar zenith angle, and seasonal dependence.