Most people don’t typically associate the Central Intelligence Agency with historical UFO investigations but the agency did have a big role in such investigations many years ago.

That’s why I thought it was unusual and kind of interesting that the agency this week issued a release called “How to investigate a flying saucer.” [The release is also a nod to the fact that the science fiction TV series X-Files returns to the screen this weekend]

In the article the CIA talks about the Air Force’s Project Blue Book which investigated public reports of UFOs and operated between 1952-1969. Project Blue Book was based at Wright-Patterson Air Force Base near Dayton, Ohio. Between 1947 and 1969, the Air Force recorded 12,618 sightings of strange phenomena — 701 of which remain "unidentified.”

+More on Network World: 26 of the craziest and scariest things the TSA has found on travelers

“Although the CIA was not directly affiliated with Project Blue Book, the Agency did play a large role in investigating UFOs in the late 1940s and early 1950s, which led to the creation of several studies, panels, and programs. Former CIA Chief Historian, Gerald K. Haines, wrote an in-depth article looking at the Agency’s role in studying the UFO phenomenon for Studies in Intelligence. In his article, “CIA’s Role in the Study of UFOs, 1947-90,” Haines says that ‘while the Agency’s concern over UFOs was substantial until the early 1950s, CIA has since paid only limited and peripheral attention to the phenomena,’” the CIA wrote.

The CIA went on to say: While most government officials and scientists now dismiss flying saucer reports as a quaint relic of the 1950s and 1960s, there’s still a lot that can be learned from the history and methodology of “flying saucer intelligence.”

From there it issued a list: 10 Tips When Investigating a Flying Saucer. Here’s a summary of that list directly from the CIA:

1. Establish a Group To Investigate and Evaluate Sightings: Before December 1947, there was no specific organization tasked with the responsibility for investigating and evaluating UFO sightings. There were no standards on how to evaluate reports coming in, nor were there any measurable data points or results from controlled experiment for comparison against reported sightings. To end the confusion, head of the Air Force Technical Service Command, General Nathan Twining, established Project Sign (initially named Project Saucer) in 1948 to collect, collate, evaluate, and distribute within the government all information relating to such sightings, on the premise that UFOs might be real (although not necessarily extraterrestrial) and of national security concern.

+More on Network World: The coolest Air Force UFO videos+

2. Determine the Objectives of Your Investigation: The CIA’s concern over UFOs was substantial until the early 1950s because of the potential threat to national security from these unidentified flying objects. Most officials did not believe the sightings were extraterrestrial in origin; they were instead concerned the UFOs might be new Soviet weapons. Although Blue Book, like previous investigative projects on the topic, did not rule out the possibility of extraterrestrial phenomena, their research and investigations focused primarily on national security implications, especially possible Soviet technological advancements.

3. Consult With Experts: Throughout the 1950s and 1960s, various projects, panels, and other studies were led or sponsored by the US government to research the UFO phenomenon. This includes the CIA-sponsored 1953 Scientific Advisory Panel on Unidentified Flying Objects, also known as the “Robertson Panel.” It was named after the noted physicist H.P. Robertson from the California Institute of Technology, who helped put together the distinguished panel of nonmilitary scientists to study the UFO issue. Project Blue Book also frequently consulted with outside experts, including: astrophysicists, Federal Aviation officials, pilots, the US Weather Bureau, local weather stations, academics, the National Center for Atmospheric Research, NASA, Kodak (for photo analysis), and various laboratories (for physical specimens). Even the famous astronomer Carl Sagan took part in a panel to review Project Blue Book’s findings in the mid-1960s. The report from that panel concluded that “no UFO case which represented technological or scientific advances outside of a terrestrial framework” had been found, but the committee did recommend that UFOs be studied intensively to settle the issue once and for all.

Photos from US Air Force investigations

4. Create a Reporting System To Organize Incoming Cases: The US Air Force’s Air Technical Intelligence Center (ATIC) developed questionnaires to be used when taking reports of possible UFO sightings, which were used throughout the duration of Project Blue Book. The forms were used to provide the investigators enough information to determine what the unknown phenomenon most likely was. The duration of the sighting, the date, time, location, or position in the sky, weather conditions, and the manner of appearance or disappearance are essential clues for investigators evaluating reported UFO sightings. Project Blue Book categorized sightings according to what the team suspected they were attributable to: Astronomical (including bright stars, planets, comets, fireballs, meteors, and auroral streamers); Aircraft (propeller aircraft, jet aircraft, refueling missions, photo aircraft, advertising aircraft, helicopters); Balloons; Satellites; Other (including missiles, reflections, mirages, searchlights, birds, kites, spurious radar indications, hoaxes, fireworks, and flares); Insufficient Data; and finally, Unidentified.

5. Eliminate False Positives: Eliminate each of the known and probable causes of UFO sightings, leaving a small portion of “unexplained” cases to focus on. By ruling out common explanations, investigators can focus on the truly mysterious cases. Some common explanations for UFO sightings discovered by early investigations included: misidentified aircrafts (the U-2, A-12, and SR-71 flights accounted for more than half of all UFO reports from the late 1950s and most of the 1960s); celestial events; mass hysteria and hallucination; “war hysteria;” “midsummer madness;” hoaxes; publicity stunts; and the misinterpretation of known objects.

6. Develop Methodology To Identify Common Aircraft and Other Aerial Phenomena Often Mistaken for UFOs: Because of the significant likelihood a common (or secret military) aircraft could be mistaken for a UFO, it’s important to know the characteristics of different types of aircraft and aerial phenomenon to evaluate against each sighting. To help investigators go through the troves of reports coming in, Project Blue Book developed a methodology to determine if the UFO sighting could likely be attributable to a known aircraft or aerial phenomenon. They wrote up detailed descriptions characterizing each type of aircraft or astronomical phenomenon, including how it might be mistaken for a UFO, to help investigators evaluate the incoming reports.

7. Examine Witness Documentation: Any photographs, videos, or audio recordings can be immensely helpful in evaluating a reported UFO sighting.

8. Conduct Controlled Experiments: Controlled experiments might be required to try and replicate the unknown phenomena.

9. Gather and Test Physical and Forensic Evidence: In the Zamora case [a famous case of a police officer, Lonnie Zamora, detailed an incredible experience with a UFO in New Mexico]. [the last chief officer of the US Air Force’s Blue Book UFO investigation Hector] Quintanilla contends that during the course of the investigation and immediately thereafter, “everything that was humanly possible to verify was checked.” This included bringing in Geiger counters from Kirtland Air Force Base to test for radiation in the landing area and sending soil samples to the Air Force Materials Laboratory. “The soil analysis disclosed no foreign material. Radiation was normal for the ‘tracks’ and surrounding area. Laboratory analysis of the burned brush showed no chemicals that could have been propellant residue,” according to Quintanilla. “The findings were all together negative.” No known explanation could be found for the mysterious event.

10. Discourage False Reporting: The Robertson Panel found that the Air Force had “instituted a fine channel for receiving reports of nearly anything anyone sees in the sky and fails to understand.” This is a classic example of needing to separate the “signal from the noise.” If you have too many false or junk reports, it becomes increasingly difficult to find the few good ones worthy of investigation or attention. The CIA in the early 1950s was concerned that because of the tense Cold War situation and increased Soviet capabilities, the Soviets could use UFO reports to ignite mass panic and hysteria. Even worse, the Soviets could use UFO sightings to overload the US air warning system so that it could not distinguish real targets from supposed UFOs. By knowing how to correctly recognize objects that were commonly mistaken for UFOs, investigators could quickly eliminate false reports and focus on identifying those sightings that remained unexplained.

The CIA declassified hundreds of documents in 1978 detailing the Agency’s investigations into UFOs. Take a look here.

Check out these other hot stories:

TSA: Gun discoveries up 20% between 2015 and 2014

The Big Hang-up: IRS customer call center service stinks

High-tech plays big role in transportation safety wish list

Will your car become a mini-data center? IBM thinks that’s just the beginning

Should the US change metal coins?

Intelligence agency wants computer scientists to develop brain-like computers

Not in my airspace: Airbus rolls out anti-drone system

DARPA targets tiny, battery-powered atomic clocks that could shield

GPS outages