UFO sighted near Boston in 1957

Summary

A round, metallic object was observed on August 27, 1957, at high altitude northeast of Boston. A fighter pilot attempted to approach it but failed to reach its altitude. The observation lasted 20 minutes, and the object appeared almost stationary. Although no photos or radar were used, it was concluded to be likely a balloon. The available information was limited, but intelligence officers ruled out aircraft or astronomical phenomena.