Based on a lecture given at the USP, on 11 March 2000. Originally published in ABC Color, on 8 October 2006. Photograph: The Arecibo radio telescope, with its 305 meters in diameter, is the world's largest. The University of California at Berkeley collects the signals coming from the sky in this antenna and distributes them to over a hundred thousand computers of volunteers around the world, for analysis in search for extraterrestrial intelligence. Credit: Photo courtesy of the National Astronomy and Ionosphere Center - Arecibo Observatory, Puerto Rico, a facility of the National Science Foundation of the United States of America, designed and formerly operated by Cornell University, currently by SRI International (ex - Stanford Research Institute), Universities Space Research Association and the Metropolitan University, Puerto Rico, under a cooperative agreement with the National Science Foundation of the USA. Photo courtesy of NAIC - Arecibo Observatory, a facility of the NSF. With permission of U.S. National Astronomy and Ionosphere Center - Arecibo Observatory, an entity of the U.S. National Science Foundation.
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