3. The far (> 1°) wings of the scattering profile assumed for this study have not been measured well to my knowledge. It is not clear 2 that the 1/r profile is anything more than a best guess at this point. The scattering will be critically sensitive to dust and aerosols in the atmosphere. NEW INSTRUMENTS Astronomy is in the midst of a period of tremendous intellectual growth and excitement. This has been fueled in part by the improvement in instrumentation used to overcome physical limitations. The number of major telescopes at good, dark-sky sites has more than tripled in the last decade. It is no accident that most of these new telescopes, whether U.S. or foreign, were built along the west coasts of North and South America and on Hawaii. These sites are the premier astronomical sites in the world. Unfortunately, they lie directly under the SPS array. Astronomers, always faced with the photon limit, are now considering a new type of telescope which will provide much larger apertures of 10 to 25 meters. The University of California is planning for the construction of a 10-meter instrument which would be located in California and would serve the entire University of California system. The Kitt Peak National Observatory has also started on a program which will lead to the construction of a 25-meter telescope. Both these instruments are being built to observe faint and distant objects, fainter by far than can be reached by the space telescope (which is only a 100-inch telescope). They would operate in the regime where increasing sky brightness would be most detrimental. Unfortunately, new detectors are not the answer. For many applications the technology is already available to record and count all possible photons and to subtract the contribution from the sky as effectively as possible. The next generation of optical telescopes will suffer the full brunt of any increased sky brightness, losing capability linearly with increasing brightness and being effectively blocked from access to an interesting portion of the sky.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==