He did not think much of it until he was airborne, bound for Detroit, and an air traffic controller told him two or three unidentified flying objects were spotted on radar traveling at high speed.

The controller told Captain Pierman to follow them, the pilot told government investigators at the time. Captain Pierman agreed, and headed northwest over West Virginia where he saw as many as seven bluish-white lights that looked “like falling stars without tails,” according to a newspaper report.

The sighting of whatever-they-were garnered headlines around the world. And in the decades since, U.F.O.s have become part of the pop culture zeitgeist, from “Close Encounters of the Third Kind” to “The X-Files.” In September, a star of that long-running series, Gillian Anderson, will appear in “UFO,” a movie about a college student haunted by sightings of flying saucers. A “Men in Black” remake is in the works. And the History Channel plans to air “Project Blue Book,” a scripted series about the government program that studied whether U.F.O.s were a national threat.

And the topic is back in the headlines. Last year, The Times wrote about a little known project founded in 2007, the Advanced Aerospace Threat Identification Program, to investigate U.F.O. sightings. A search of The Times’s historical archives reveals a rich bounty of U.F.O. sightings, lore and explanations since the 1950s. And who can forget in 2016 when Hillary Clinton said she would reopen the real X-files if she were president?

Captain Pierman’s 68-year-old daughter, Faith McClory, said in an interview last month that her father became something of a celebrity as reports like his in the summer of 1952 fueled fear of a space alien invasion.

“My sister has memories of men coming to our home,” said Ms. McClory, who grew up in Belleville, Mich. (She said they were reporters.) “People were enthralled with the flying saucers,” she added.

Researchers say government officials have sought to publicly debunk the existence of alien evidence ever since the Washington sightings.

“Unidentified flying objects exploded into the public consciousness then,” said Mark Rodeghier, the scientific director for the Center for UFO Studies, a group of scientists and researchers who study the U.F.O. phenomenon. “There was concern in a way you hadn’t seen before.”

It should be noted that the term U.F.O., as used by the government, does not mean extraterrestrials from outer space. It means any object in the sky that has not been identified. When asked recently about the 1952 Washington sightings, Ann Stefanek, chief of media operations for the Air Force, wrote in an email that the objects had posed no threat to national security.

In the spring of 1952, though, numerous mysterious sightings had captured the Air Force’s attention. It created “Project Blue Book” that March — the third investigative government project of its kind and the one that lasted the longest, until 1969.

The events in Washington were not the first unexplained encounter report. Debris from what observers called a “flying disc” had been spotted in Roswell, N.M., five years earlier, which Army officials said was from a “weather balloon.” By 1952, though, a number of sightings of U.F.O.s were being reported across the country and the nation was on edge.

Life magazine was one of the first mainstream magazines to suggest the phenomenon was real and revealed in an April story that the Air Force was secretly investigating. That story inspired a sharp increase in reports of sightings that summer.

The Washington sightings centered on events that started around 11:40 p.m. on July 19, as air traffic controllers at Washington National Airport noticed blips speeding near Andrews Air Force Base, according to government accounts. The unidentified aircrafts fanned out, flying over the White House and the U.S. Capitol. Captain Pierman saw them that night. They vanished around 5 a.m.

It was a second sighting a week later, though, that caused the wave of hysteria that forced the government to speak out. Albert Chop, then a spokesman with the Pentagon who was given the job of answering questions about U.F.O.s, said he was awakened by a call on the evening of July 26.

Mr. Chop described the events in a 1999 oral history to the Sign Historical Group, an association of archivists and amateur researchers who held a workshop that year to study U.F.O history. He said the new objects were spotted on radar at Washington National Airport and he was told to get there right away.

The Air Force dispatched jet fighters from New Castle, Del., to intercept the flying objects. But every time one of the jets closed in, they disappeared. When the jets backed off, they reappeared.

“It was frightening,” Mr. Chop said. “I think everybody in the room was very apprehensive.”

At one point, a pilot found himself in the midst of four unidentified aircrafts and asked what to do. “I didn’t say anything,” Mr. Chop told the interviewers. “Nobody said anything. All of a sudden these things began to move away from him and he said, ‘They’re gone!’” The pilot returned to his base.

“These things hung around all night long,” Mr. Chop added.

The next day, almost every major newspaper wrote about the U.F.O.s. “‘Objects’ Outstrip Jets Over Capital,” was the headline in The Times.

“People didn’t know what to think of it,” said Rob Swiatek, a U.F.O. researcher and scientist, in a recent interview.“They were very disturbed.”

Public panic was a problem for the Air Force, which feared a diversion of resources during the Cold War. “The Air Force and the Central Intelligence Agency became worried that the Soviet Union would take advantage of the situation and launch an attack on the United States,” Mr. Rodeghier said. “They were looking at worst-case scenarios.”

Worse, no one could explain the phenomenon to President Harry Truman, according to press reports. One theory promoted by the Air Force was that a layer of hot air in the sky, called a temperature inversion, caused radar to mistake a weather event for flying objects. “Nobody had any answers,” Mr. Chop told the interviewers. “That’s why General Samford had the press conference.”

On July 29, 1952, Maj. Gen. John Samford, the director of Air Force intelligence overseeing the inquiry, held a news conference at the Pentagon to reassure the public. He dismissed the Washington sightings as a temperature anomaly. Still, the general conceded that not all the details could be explained by natural causes. Witness reports “have been made by credible observers of relatively incredible things,” he said at the time. “It is this group of observations that we now are attempting to resolve.”

The news conference was front page news, including in The Times, which ran the headline “Air Force Debunks ‘Saucers’ as Just ‘Natural Phenomena.’”

Case closed? Not quite.

“I don’t think temperature inversion had much to do with it, but the news media accepted that explanation at the time,” said Kevin Randle, a former lieutenant colonel in the Army who has studied the events of July 1952 and is the author of the 2001 book, “Invasion Washington: U.F.O.s Over the Capitol.”

In January 1953, spurred by the Washington sightings, a scientific committee led by Howard Robertson, a well-known mathematician and physicist, was formed by the government to explore the phenomenon. “One of the conclusions was that they needed to debunk U.F.O.s,” Mr. Randle said.

The committee, called the Robertson Panel, suggested in its report that the government conduct a mass media education campaign to “reduce the current gullibility of the public and consequently their susceptibility to clever hostile propaganda.”

The campaign to re-educate Americans did not work — U.F.O.s have persisted as a fixture in pop culture. Besides, the government’s explanation was not that convincing anyway. Ms. McClory, Captain Pierman’s daughter, said her father did not believe that the bluish-white lights he saw were weather-related.

“I don’t want to use the words ‘cover up,’” she said, of her father’s view. “But it was very clear. He saw it. Everything was seen on radar.”

Source: The New York Times