Project Blue Book Final Report

January 1970 — US Air Force

Overview

Project Blue Book was the systematic study of unidentified flying objects (UFOs) conducted by the United States Air Force from 1952 to 1969. It was the third and final official USAF study, following Project Sign (1947) and Project Grudge (1949). The project investigated a total of 12,618 UFO reports.

Findings

Of the 12,618 sightings investigated, 701 (approximately 5.5%) remained classified as "unidentified" after analysis. These cases defied explanation by any known natural phenomenon, aircraft, satellite, or other conventional explanation despite thorough investigation.

Conclusions

The official conclusions stated that no UFO reported, investigated, and evaluated by the Air Force was ever an indication of threat to national security, and that there was no evidence indicating that sightings categorized as "unidentified" were extraterrestrial vehicles. Critics have argued these conclusions were politically motivated and did not reflect the actual evidence.

The Condon Report

The project was closed following the Condon Committee report from the University of Colorado, which recommended ending the project. However, the report itself contained contradictions, with individual case analyses sometimes contradicting the summary conclusions, leading many researchers to view the closure as premature.