First Earthshine photography from lunar orbit

Abstract

During Apollo 15, fifteen photographs of the moon were taken under Earthshine illumination. These were the first Earthshine photographs taken from lunar orbit. The photographs are of photometric interest, particularly as they involve double reflection of sunlight: by the earth, then the moon, prior to photographic exposure. Certain published data on the mean illumination of the moon by the crescent earth predicted lower exposure values than obtained for each measured area. The apparent albedo values obtained for the floor of the crater Aristarchus were anomalously higher than those obtained for the surrounding maria.