Harrow, Weald, England, April 1957April 1957

On April 23, 1957, someone in Harrow-Weald, England observed an unusual bright object in the night sky. The observer described a red object about three times as bright as Jupiter, which changed color to orange when its direction shifted. Over thirty to sixty seconds, the object made sharp, angular turns. At the start of the observation, it was spotted at forty-five degrees elevation. As the sighting continued, the angle dropped to thirty degrees above the horizon.

The U.S. Air Force officer who reviewed the case noted that the description matched the behavior of aircraft seen at high altitude, despite the witness's claim that no aircraft sound was heard. The officer explained that aircraft flying very high can often travel silently and produce colored light from jet exhaust, which may shift colors depending on atmospheric conditions. He also pointed out that untrained observers frequently struggle to accurately describe moving objects against a night sky. The Air Force suggested checking standard procedures for identifying UFO reports, including whether any military or civil aircraft were in the area at the time.

A follow-up message from the Third Air Force confirmed that no U.S. Air Force aircraft were within the general area during the ten minutes around the sighting time. London air traffic control found no aircraft on the reported course or track within their zone. The Royal Air Force reported no military aircraft were within sight of Harrow-Weald at that time. No radar plots of the object could be identified.

The case file lists the evaluation as "unknown," though the investigating officer characterized the maneuvers as typical of aircraft behavior. The full case file is reproduced below as held by the National Archives across seven pages of microfilm.