Martha's Vineyard, MassachusettsOctober 1957

On October 12, 1957, five men on a fishing boat near Martha's Vineyard, Massachusetts, saw an unusual object that would puzzle the Air Force for months. The men, including the vessel's captain and several trained military observers, watched the object for about two minutes through binoculars. They described it as spherical or cylindrical, with spike-like or antenna-like protrusions sticking out from it. The object appeared roughly five feet across, though the observers noted their estimate could be way off since they had no way to judge distance.

The object first descended rapidly toward their boat at 1535 local time, then slowed and hovered. After about 90 seconds, it reversed direction and sped away, disappearing within 20 seconds. Throughout the display, the object gave off no vapor, exhaust, or trail. The observers, impressed and somewhat unsettled, reported the sighting to authorities at Otis Air Force Base that same day.

The Air Force received three separate official reports of the incident and ordered what was called a "Blitz Evaluation" by the Air Technical Intelligence Center. However, the three reports disagreed on key details. Some witnesses described the object as spherical, others as cylindrical. The protrusions were variously called antennae, prongs, or trihedral reflectors. Most significantly, the accounts differed on which direction the object was heading and how fast it seemed to move.

The investigation checked everything in the area. No unusual aircraft were reported by any of the 34 Navy jets operating nearby. Radar units that scanned the sector 24 hours a day saw nothing. Weather was clear with visibility of at least 15 miles. Wind data showed a pattern consistent with winds blowing from the northwest. The Air Force learned that a Massachusetts research facility in the area was testing aerially launched radar reflectors (corner reflectors), which are special devices suspended beneath balloons that bounce radio waves back to radar sets to make the balloons easier to track. Given the lack of corroboration from aircraft and radar, the clear weather, the pattern of winds, the object's hovering and slow movement, and the complete absence of any engine noise or exhaust, the Air Force concluded that the object was very likely a balloon carrying radar reflectors. The witnesses, the analysis noted, were competent observers, but under certain lighting conditions with the afternoon sun at a low angle, a balloon with reflectors could produce unusual and puzzling appearances due to reflections and refractions of sunlight. The Air Force concluded there was no compelling reason to think the object was anything other than a balloon or balloon-supported device.

The full case file, consisting of 40 pages as held by the National Archives, is reproduced below.