Keep Watching the Skies! : The Story of Operation Moonwatch & the Dawn of the Space Age, Hardcover by McCray, W. Patrick, ISBN 0691128545, ISBN-13 9780691128542, Brand New, Free shipping in the US

After the launch of Sputnik, thousands of ordinary Americans became "Moonwatchers," a network of citizen-scientists who helped professional astronomers by providing critical and otherwise unavailable information about the first satellites.