The fourth tranche of the Trump administration's PURSUE program: 40 files — 14 documents, 3 images, 19 videos, 4 audio files — bringing the public corpus to 334 files. Where Release 03 was the FBI's tranche, Release 04 is the historical one: a 1955 CIA debrief of four observers (one a sitting U.S. Senator) watching an object over the Soviet Union, the 1949 Los Alamos conference on 'green fireballs' attended by Manhattan Project physicists, Project Sign's founding 1948 progress report, and three NASA photographs of an unidentified object shot from Space Shuttle Columbia in 1996. Nineteen AARO sensor videos and four Apollo-era 'light flash' audio segments round out the release.
Eighteen sections and serials of the FBI Headquarters master investigative case file on 'flying discs,' covering the Roswell era through the late 1960s. Includes Oak Ridge nuclear-facility overflight reports. The largest single PDF in PURSUE is 101 megabytes.
U.S. Air Force security personnel stationed at the twin Royal Air Force bases of Bentwaters and Woodbridge report a triangular, metallic craft on the ground in adjacent Rendlesham Forest, followed by aerial light phenomena two nights later. The deputy base commander signs a memorandum to the U.K. Ministry of Defence summarizing the events.
Two Imperial Iranian Air Force F-4 Phantoms intercept an unidentified object over Tehran. Both pilots report electronic-system failures, and one reports temporary loss of weapons control. A four-page Defense Intelligence Agency report on the case is later released under FOIA.
A previously-classified CIA intelligence report from 1973 documenting a Soviet citizen's observation of a luminous, bright-green airborne object in the summer of 1973. One of the few PURSUE entries with an explicitly Cold-War-era USSR provenance; reproduced in full as part of Release 02.
A November 9, 1963 Rio de Janeiro radio broadcast claimed a 'large metal sphere' carrying a dead occupant had crashed near Conde, Bahia, Brazil. The CIA's wire service flagged the report the same day; by November 20, the U.S. consulate's scientific attaché in Salvador had traced it to a fabrication with no basis in local reporting. The paper trail — a CIA wire summary preserved in the files of the White House's space council, plus two State Department cables — marks the first appearance of the Executive Office of the President and the Department of State in the PURSUE corpus.
In October 1955, four Americans travelling by train through the Soviet Union — among them U.S. Senator Richard Russell of Georgia, then chairman-in-waiting of the Senate Armed Services Committee — watched a luminescent, greenish-yellow object climb and pass above their train between Baku and Tiflis, now Tbilisi. PURSUE Release 04 declassifies the CIA's debriefing memo and its companion analysis, which concluded the sighting could 'probably be explained as steep climbing aircraft or missiles.' The analysis also weighs the 1953 Robertson Panel's findings and Project 'Y,' the real U.S.-Canadian program then trying to build a saucer-shaped aircraft.
PURSUE Release 03 publishes the CIA's 1952-1953 Scientific Advisory Panel on Unidentified Flying Objects — the Robertson Panel — in less-redacted form, with the Department of War's own transmission copy to the Secretary of Defense. The panel found no direct physical threat but warned that public fascination could clog intelligence channels and that a 'morbid national psychology' could be exploited by adversaries — and recommended an official policy of 'debunking' to 'strip the UFO subject of its mystery.'
Across two consecutive weekends, multiple radar installations and visual observers track unidentified objects above the restricted airspace surrounding the U.S. Capitol and White House. The Air Force convenes its largest press conference since World War II to address the events.
On July 2, 1952, Navy Chief Warrant Officer Delbert C. Newhouse — a Photographer's Mate with more than 1,000 hours of aerial-photography experience — filmed 12 to 14 bright, reflective objects near Tremonton, Utah, on 16mm Kodachrome. The Air Force assessed him as honest, reliable and expert, and never conclusively identified the objects: birds, balloons and mirage early on; 'pillow balloons' after a December 1952 review with General Mills; seabirds reflecting sunlight in later assessments. PURSUE Release 06 publishes the National Archives digitization of the film, the Blue Book case file, the balloon photo file, Newhouse's personnel record, and the Air Force's late-1952 'Flying Discs' compilation.
Three months before the Washington, D.C. flap, the head of the Air Force's reorganised UFO investigation told a Boston audience that roughly 20 percent of about 800 historical cases remained unexplained after technical analysis, that reports concentrated around Los Alamos, Albuquerque and Oak Ridge, and that radar had logged unconfirmed speeds between 1,000 and 3,500 miles per hour. PURSUE Release 06 publishes the transcript and a 65-minute audio recording of the presentation.
PURSUE Release 04 publishes the verbatim transcript of a March 22, 1949 conference at Los Alamos, called after months of unexplained 'green fireball' sightings over the laboratory that built the first atomic bombs. Manhattan Project physicists — Edward Teller among them — argued over explanations ranging from shallow-angle meteors to an 'electron phenomenon'; meteoriticist Lincoln LaPaz told the room nothing like it had ever been seen in a meteorite fall. The conference adjourned without a consensus.
A 116-page joint file from the U.S. Air Force and the Armed Forces Special Weapons Program — the Manhattan Project's nuclear-weapons custodial successor — documenting 209 sightings of 'green orbs,' discs, and fireballs maneuvering near the Sandia, New Mexico custodial nuclear-weapons installation between 1948 and 1950. Released in full as part of PURSUE Release 02; some sighting locations contained recovered copper powder.
Kentucky Air National Guard pilot Capt. Thomas Mantell is killed when his P-51 Mustang crashes during the pursuit of a large, slow-moving object reported above Godman Field. The Air Force eventually attributes the object to a Skyhook research balloon.
PURSUE Release 04 publishes six U.S. Air Force files tracing the government's institutional handling of UFO reports from 1948 to 1967. The centerpiece is Project Sign's first progress report on 100 sightings from 1947-48, alongside both surviving drafts of Air Intelligence Division Study No. 203. Rounding out the file: records of the Avro 'Project Y2' saucer-shaped-aircraft assessments, 1955 correspondence relating to Project Blue Book, and the 1966-67 Scientific Advisory Board review that led directly to the Condon Committee and, eventually, Blue Book's closure.
The Roswell Army Air Field public information officer issues a press release stating that the 509th Bomb Group has come into possession of a 'flying disc' recovered from a nearby ranch. Within twenty-four hours the Army retracts the statement and identifies the debris as a weather balloon.
A U.S. Army General Staff intelligence review, dated January 9, 1947, assesses the wave of 'ghost rocket' sightings reported across Sweden and its neighbors beginning in May 1946. Drawing on Swedish government statements and reporting from the U.S. military attaché in Stockholm, the review reaches no conclusion either way — the earliest document in PURSUE Release 05, and a companion piece to the Swedish military's own Lake Kölmjärv investigation from the same wave.
PURSUE's earliest entry — wartime Department of War records from 1944-1945 documenting the 'foo fighter' encounters reported by U.S. Army Air Forces pilots over the European theater, with corroborating Air Ministry analysis.