Astronomy appears to us as a combination of art, science, and
philosophy. Its study puts the universe into perspective, giving a sense
of pleasure in its beauty, awe at its immensity, and humility at our
trivial place in it. From earliest human history, man has scrutinized
the night sky - and wondered and marveled. With unaided eye but
perceptive mind, he recognized order in the regular appearance and
movements of individual objects, such as the planets and star groups
(constellations), in their rhythmic and majestic progressions across the
bowl of night. Even in the present era of scientific exactitude, there
remains a profound awareness of mysteries beyond our present
interpretations. It is only in comparatively recent years, however, that
man has recognized that it takes more than conventional astronomy to
account for the beauties ofthe night sky. Radiations in the Earth's
upper atmosphere provide a foreground light, the study of which has come
under a new name, aeronomy. The science of aeronomy has rapidly
burgeoned, and the student of the light of the night sky finds that he
is involved in an interdisciplinary domain.