Plot: In this special programme to mark the 25th anniversary of The Sky at Night, Patrick Moore reports on what's happening at great observatories all over the world; he talks to space researchers and 'ground-based' astronomers, and his journey round the world took him from the top of Mauna Kea, at 14,000 feet above sea-level, to one mile down a goldmine in South Dakota. This is a report not only upon what has happened in the past, but also a look ahead to the future, with the Space Telescope and other developments undreamed of when the first Sky at Night was transmitted