Project Blue Book Case #4847. On July 29, 1957, witnesses in Cleveland, Ohio, reported a bright object in the sky over the city. Cleveland was home to the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory (now NASA Glenn Research Center), one of the nation's premier aerospace research facilities, as well as Cleveland Hopkins Airport and multiple industrial operations.
The NACA Lewis laboratory was at the forefront of jet propulsion and rocket engine research in 1957, conducting work that would contribute to America's space program after NACA was absorbed into NASA the following year. The facility's researchers were among the most knowledgeable aerospace experts in the country, and any unexplained aerial phenomena near the laboratory drew attention from both the scientific and military communities.
July 1957 preceded the dramatic November wave by just a few months. The period was marked by steady but not exceptional UFO activity, with the upcoming Soviet launch of Sputnik in October about to transform both the space race and the UFO phenomenon. The pre-Sputnik reports from mid-1957 are of particular interest to researchers, as they occurred before the satellite age added a new category of conventional aerial objects to the sky.
Cleveland's busy airspace — with commercial traffic, general aviation, and NACA test flights — was well-monitored. The bright object could not be matched to any known aircraft or test vehicle. Weather conditions were reviewed with negative results.
The case was classified "Unknown."