COMMENTS ON THE EFFECTS OF INCREASED DIFFUSE SKY BRIGHTNESS ON FAINT OBJECT ASTRONOMICAL OBSERVATIONS J. S. Gallagher and S. M. Faber Progress in astronomy for the last century has been strongly dependent on the development of large telescopes and improved auxiliary instrumentation which have allowed the collection of more information for increasingly fainter objects. For example, the known scale of the universe has increased from that of a single galaxy at the turn of the century to a region of billions of light years containing millions of individual galaxies, primarily through the use of very large telescopes. Based on this history, the astronomical community is committed to building the largest feasible telescopes and equipping them with the best detectors. Even with the advent of space telescopes, large, ground- based telescopes will continue to play a major role in astronomical research during the next 20 years (e.g., the New Generation Telescope program is pursuing studies of a telescope having an aperture 5 times larger than existing telescopes.) The sensitivity of even these large instruments is primarily limited by the sky's brightness for observations of faint objects, and any degradation of sky quality is therefore a matter of serious concern. At present, city lights provide the major source of light pollution; astronomers have therefore sought to develop remote sites, such as Mauna Kea in Hawaii, and have encouraged astronomically-oriented cities such as Tucson, Arizona, to pass ordinances designed to curb light pollution. Large artificial satellites, such as the SPS, pose a new and more ubiquitous problem. When such satellites are illuminated by the sun, they become bright sources whose light will be scattered in the Earth’s atmosphere, thereby increasing the diffuse brightness of the night sky. In addition, direct and scattered light from specularly reflected sunlight could cause a loss of observing time during certain seasons. For the purposes of a preliminary assessment of the effects of the SPS on faint-object, ground-based astronomy, we will consider how measurements of the
RkJQdWJsaXNoZXIy MTU5NjU0Mg==