HUDSON.

Over the following three years, the J. Allen Hynek Center for UFO Studies (CUFOS) and local investigators collected more than 7,000 reports. Witnesses included police officers across multiple jurisdictions, IBM scientists at Yorktown Heights, a Westchester County district attorney, and an engineer at the Indian Point nuclear power plant who reported the craft hovering above the reactors on July 24, 1984.

The craft was typically described as one to two football fields in span, with red, white and blue or green lights arrayed along its leading edge or perimeter, completely silent, and capable of hovering and slow horizontal flight at very low altitude. Many witnesses reported it appeared to be a single solid object that blocked stars as it passed overhead. The Federal Aviation Administration acknowledged receiving reports, eventually attributing the sightings to a group of small private aircraft from the Stormville Airport flying in tight formation as a hoax.

Investigators including Dr. Hynek, Dr. Bruce Maccabee (an optical physicist with the US Navy), and CUFOS investigator Philip Imbrogno disputed the formation-of-aircraft explanation. Their core objections were the silence (six small piston aircraft would not be silent), the apparent solid mass, and the duration and consistency of the wave across years. Hynek and Imbrogno's 1987 book Night Siege documented hundreds of cases in detail.

The Indian Point nuclear plant incident is the most documented single event of the wave. Plant security and operations personnel reported a large craft hovering directly above Reactor 3 for several minutes. Internal incident reports from Con Edison were obtained via FOIA requests. The Hudson Valley wave remains one of the most thoroughly documented mass sighting events in US history, distinguished by its long duration, large geographic spread, and multi-tiered witness pool.