Utilizing the fly-through mode, the open source neutral mass spectrometer on Atmosphere Explorer-D (AE-D) has measured O2 densities, as well as N2 densities and in situ neutral temperatures, at midmorning during winter solstice over the latitude range 90¿ S to 90¿ N. We find the expected seasonal variation in N2 at 200 km but a more complex behavior in molecular oxygen than might be expected from a diffusive equilibrium model with constant lower boundary values. Under geomagnetically quiet conditions the equatorial 200 km value of [02> was about 1.7¿108 cm-3. At 120 km and equatorial latitudes a value of [02> of ~5¿1010 cm-3 is calculated if [N2> there is 3.1¿1011 cm-3. A somewhat higher value would be calculated if 02 is not in diffusive equilibrium above 120 km. A local maximum in the 200 km 02 densities was found near 70¿ N, where an average quiet time value was 2.5¿108 cm-3, implying a 120 km density of 8.3¿1010 cm-3. The in situ temperature measurements confirm the presence of higher temperatures near 70¿ N latitude, even during geomagnetically quiet conditions.