These attitudes seem to be reflected in the results of the first U.S. poll of public UFO perceptions released by Gallup on August 14, 1947. The term "flying saucer" was familiar to 90% of the respondents. As to what people thought explained them, the poll further showed, that most people either held no opinion or refused to answer the question (33%), or generally believed that there was a mundane explanation. 29% thought they were optical illusions, mirages, or imagination; 15% a U.S. secret weapon; 10% a hoax; 3% a "weather forecasting device"; 1% of Soviet origin, and 9% had "other explanations," including fulfillment of Biblical prophecy, secret commercial aircraft, or phenomena related to atomic testing.