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| The 300-foot Green Bank Telescope before and after the collapse |
In 1958, the Federal Communications Commission and the Interdepartment Radio Advisory Committee established that it is need of an area in which radio transmissions to be strictly restricted by law to facilitate scientific research and military intelligence. This area of approximately 13,000 square miles is located in West Virginia, Virginia, and a small part of Maryland, and is named United States National Radio Quiet Zone. Within it, at Green Bank, in West Virginia, was completed in 1962 a a 91m (300-foot) partially steerable radiotelescope, one of the most powerful in the world.
The huge structure consisted of a pair of steel towers that supported a swiveling parabolic dish, consisting of a mesh of aluminum wires about one-quarter inch apart supported by a steel framework. It focused radio radiation from celestial objects in much the same way that the collecting mirrors in optical telescopes gather and focus light. The instrument, operated by the Government's National Radio Astronomy Observatory, had been responsible for major discoveries, including the finding that pulsating super-dense stars, pulsars, are created in the debris of exploding stars.
This telescope collapsed without warning on 15 November 1988, at about 10 P.M., due to the sudden loss of a gusset plate in the box girder assembly, which was a key component for the structural integrity of the telescope. No one was injured, even if it struck and damaged part of the roof of the nearby building. In to replace him was build the Robert C. Byrd Green Bank Telescope (GBT), the world's largest fully steerable radio telescope, as well as the world's largest moveable land object, completed in 2000.
About the stamp, issued in 2014 with the occasion of Earth Day, I wrote here.
References
Giant Telescope Collapses; Big U.S. Research Setback - The New York Times
Green Bank Telescope - Wikipedia
Sender: Judith Hallowood (direct swap)
Sent from Durham (North Carolina / Canada), on 03.10.2015
Photo: Richard Porcas
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