Studies of airglow, zodiacal light, and galactic light in this triennium were almost as active as in the last. Results of observations obtained during and after the IQSY were the major contributions in this term. Night Airglow studies during the IQSY were widely reviewed in the Annals of the IQSY, vol. 4, in which the following articles are included:

“Night Airglow Observations during the IQSY” (F. E. Roach, L. L. Smith and J. R. McKennan);

“Airglow Research during and since the IQSY” (G. Weill);

“Hydrogen and Hydroxyl Emissions in the Nightglow” (N. N. Shefov and Yu. L. Truttse).

Proceedings of the NATO Advanced Study Institute, July 29-August 9,1968, entitled Atmospheric Emissions, contains some ten significant papers on airglow both in observations and interpretations. Many of them are referred to in the following sections.

Many stations have been engaged in airglow observations since the beginning of the IASY in 1969, although the number of stations seems to be a little less than during the IGY. Stations near the equator and in the southern hemisphere, however, are more numerous and active than during the IGY in response to the strong wishes of many airglow researchers. These efforts are being made especially by G. Weill’s group of France, V. J. Dachs’ and Lange-Hesse’s groups of Germany.