How the Pentagon Started Taking U.F.O.s Seriously
extraterrestrials aliens national press club investigations pentagon u.f.o.s astronomy space
Gideon Lewis-Kraus Jonathan Blitzer E. Tammy Kim Benjamin Wallace-Wells Charles Bethea Condé Nast
For decades, flying saucers were a punch line, Gideon Lewis-Kraus writes. Then the U.S. government got over the taboo.
https://www.newyorker.com/verso/static/the-new-yorker/assets/favicon.ico
The New Yorker
On May 9, 2001, Steven M. Greer took the lectern at the National Press Club, in Washington, D.C., in pursuit of the truth about unidentified flying objects. Greer, an emergency-room physician in Virginia and an outspoken ufologist, believed that the government had long withheld from the American people its familiarity with alien visitations. He had founded the Disclosure Project in 1993 in an attempt to penetrate the sanctums of conspiracy. Greer’s reckoning that day featured some twenty speakers. He provided, in support of his claims, a four-hundred-and-ninety-two-page dossier called the “Disclosure Project Briefing Document.” For public officials too busy to absorb such a vast tract of suppressed knowledge, Greer had prepared a ninety-five-page “Executive Summary of the Disclosure Project Briefing Document.” After some throat-clearing, the “Executive Summary” began with “A Brief Summary,” which included a series of bullet points outlining what amounted to the greatest secret in human history.

Over several decades, according to Greer, untold numbers of alien craft had been observed in our planet’s airspace; they were able to reach extreme velocities with no visible means of lift or propulsion, and to perform stunning maneuvers at g-forces that would turn a human pilot to soup. Some of these extraterrestrial spaceships had been “downed, retrieved and studied since at least the 1940s and possibly as early as the 1930s.” Efforts to reverse engineer such extraordinary machines had led to “significant technological breakthroughs in energy generation.” These operations had mostly been classified as “cosmic top secret,” a tier of clearance “thirty-eight levels” above that typically granted to the Commander-in-Chief. Why, Greer asked, had such transformative technologies been hidden for so long? This was obvious. The “social, economic and geo-political order of the world” was at stake.

The idea that aliens had frequented our planet had been circulating among ufologists since the postwar years, when a Polish émigré, George Adamski, claimed to have rendezvoused with a race of kindly, Nordic-looking Venusians who were disturbed by the domestic and interplanetary effects of nuclear-bomb tests. In the summer of 1947, an alien spaceship was said to have crashed near Roswell, New Mexico. Conspiracy theorists believed that vaguely anthropomorphic bodies had been recovered there, and that the crash debris had been entrusted to private military contractors, who raced to unlock alien hardware before the Russians could. (Documents unearthed after the fall of the Soviet Union suggested that the anxiety about an arms race supercharged by alien technology was mutual.) All of this, ufologists claimed, had been covered up by Majestic 12, a clandestine, para-governmental organization convened under executive order by President Truman. President Kennedy was assassinated because he planned to level with Premier Khrushchev; Kennedy had confided in Marilyn Monroe, thereby sealing her fate. Representative Steven Schiff, of New Mexico, spent years trying to get to the bottom of the Roswell incident, only to die of “cancer.”

Greer’s “Executive Summary” was woolly, but discerning readers could find within it answers to many of the most frequently asked questions about U.F.O.s—assuming, as Greer did, that U.F.O.s are helmed by extraterrestrials. Why are they so elusive? Because the aliens are monitoring us. Why? Because they are discomfited by our aspiration to “weaponize space.” Have we shot at them? Yes. Should we shoot at them? No. Really? Yes. Why not? They’re friendly. How do we know? “Obviously, any civilization capable of routine interstellar travel could terminate our civilization in a nanosecond, if that was their intent. That we are still breathing the free air of Earth is abundant testimony to the non-hostile nature of these ET civilizations.” (One obvious question seems not to have occurred to Greer: Why, if these spacecraft are so advanced, do they allegedly crash all the time?)

At the press conference, Greer appeared in thin-framed glasses, a baggy, funereal suit, and a red tie askew in a starched collar. “I know many in the media would like to talk about ‘little green men,’ ” he said. “But, in reality, the subject is laughed at because it is so serious. I have had grown men weep, who are in the Pentagon, who are members of Congress, and who have said to me, ‘What are we going to do?’ Here is what we will do. We will see that this matter is properly disclosed.”

Among the other speakers was Clifford Stone, a retired Army sergeant, who purported to have visited crash sites and seen aliens, both dead and alive. Stone said that he had catalogued fifty-seven species, many of them humanoid. “You have individuals that look very much like you and myself, that could walk among us and you wouldn’t even notice the difference,” he said.

Leslie Kean, an independent investigative journalist and a novice U.F.O. researcher who had worked with Greer, watched the proceedings with unease. She had recently published an article in the Boston Globe about a new omnibus of compelling evidence concerning U.F.O.s, and she couldn’t understand why a speaker would make an unsupported assertion about alien cadavers when he could be talking about hard data. To Kean, the corpus of genuinely baffling reports deserved scientific scrutiny, regardless of how you felt about aliens. “There were some good people at that conference, but some of them were making outrageous, grandiose claims,” Kean told me. “I knew then that I had to walk away.” Greer had hoped that members of the media would cover the event, and they did, with frolicsome derision. He also hoped that Congress would hold hearings. By all accounts, it did not.

Ufologists have perpetual faith in the imminence of Disclosure, a term of art for the government’s rapturous confession of its profound U.F.O. knowledge. In the years after the press conference, the expected announcement was apparently postponed by the events of September 11th, the War on Terror, and the financial crisis. In 2009, Greer issued a “Special Presidential Briefing for President Barack Obama,” in which he claimed that the inaction of Obama’s predecessors had “led to an unacknowledged crisis that will be the greatest of your Presidency.” Obama’s response remains unknown, but in 2011 ufologists filed two petitions with the White House, to which the Office of Science and Technology Policy responded that it could find no evidence to suggest that any “extraterrestrial presence has contacted or engaged any member of the human race.”

The government may not have been in regular touch with exotic civilizations, but it had been keeping something from its citizens. By 2017, Kean was the author of a best-selling U.F.O. book and was known for what she has termed, borrowing from the political scientist Alexander Wendt, a “militantly agnostic” approach to the phenomenon. On December 16th of that year, in a front-page story in the Times, Kean, together with two Times journalists, revealed that the Pentagon had been running a surreptitious U.F.O. program for ten years. The article included two videos, recorded by the Navy, of what were being described in official channels as “unidentified aerial phenomena,” or U.A.P. In blogs and on podcasts, ufologists began referring to “December, 2017” as shorthand for the moment the taboo began to lift. Joe Rogan, the popular podcast host, has often mentioned the article, praising Kean’s work as having precipitated a cultural shift. “It’s a dangerous subject for someone, because you’re open to ridicule,” he said, in an episode this spring. But now “you could say, ‘Listen, this is not something to be mocked anymore—there’s something to this.’ ”

Since then, high-level officials have publicly conceded their bewilderment about U.A.P. without shame or apology. Last July, Senator Marco Rubio, the former acting chairman of the Select Committee on Intelligence, spoke on CBS News about mysterious flying objects in restricted airspace. “We don’t know what it is,” he said, “and it isn’t ours.” In December, in a video interview with the economist Tyler Cowen, the former C.I.A. director John Brennan admitted, somewhat tortuously, that he didn’t quite know what to think: “Some of the phenomena we’re going to be seeing continues to be unexplained and might, in fact, be some type of phenomenon that is the result of something that we don’t yet understand and that could involve some type of activity that some might say constitutes a different form of life.”

Last summer, David Norquist, the Deputy Secretary of Defense, announced the formal existence of the Unidentified Aerial Phenomena Task Force. The 2021 Intelligence Authorization Act, signed this past December, stipulated that the government had a hundred and eighty days to gather and analyze data from disparate agencies. Its report is expected in June. In a recent interview with Fox News, John Ratcliffe, the former director of National Intelligence, emphasized that the issue was no longer to be taken lightly. “When we talk about sightings,” he said, “we are talking about objects that have been seen by Navy or Air Force pilots, or have been picked up by satellite imagery, that frankly engage in actions that are difficult to explain, movements that are hard to replicate, that we don’t have the technology for, or are travelling at speeds that exceed the sound barrier without a sonic boom.”

Leslie Kean is a self-possessed woman with a sensible demeanor and a nimbus of curly graying hair. She lives alone in a light-filled corner apartment near the northern extreme of Manhattan, where, on the wall behind her desk, there is a framed black-and-white image that looks like a sonogram of a Frisbee. The photograph was given to her, along with chain-of-custody documentation, by contacts in the Costa Rican government; in her estimation, it is the finest image of a U.F.O. ever made public. The first time I visited, she wore a black blazer over a T-shirt advertising “The Phenomenon,” a documentary from 2020 with strikingly high production values in a genre known for grainy footage of dubious provenance. Kean is stubborn but unassuming, and she tends to speak of the impact of “the Times story,” and the new cycle of U.F.O. attention it has inaugurated, as if she had not been its principal instigator. She told me, “When the New York Times story came out, there was this sense of ‘This is what the U.F.O. people have wanted forever.’ ”

Kean is always assiduously polite toward the “U.F.O. people,” although she stands apart from the ufological mainstream. “It’s not necessarily that what Greer was saying was wrong—maybe there have been visits by extraterrestrials since 1947,” she said. “It’s that you have to be strategic about what you say to be taken seriously. You don’t put out someone talking about alien bodies, even if it might be true. Nobody was ready for that; they didn’t even know that U.F.O.s were real.” Kean is certain that U.F.O.s are real. Everything else—what they are, why they’re here, why they never alight on the White House lawn—is speculation.

Kean feels most at home in the borderlands between the paranormal and the scientific; her latest project examines the controversial scholarship on the possibility of consciousness after death. Until recently, she dreaded the inevitable dinner-party moment when other guests asked about her line of work and she had to mumble something about U.F.O.s. “Then they’d sort of giggle,” she said, “and I would have to say, ‘There’s actually a lot of serious information.’ ” Her blunt, understated way of talking about incomprehensible data gives her an air of probity. During my visit, as she peered at her extensive library of canonical ufology texts—with such titles as “Extraterrestrial Contact” and “Above Top Secret”—she sighed and said, “Unfortunately, most of these aren’t very good.”

In her best-selling book, “UFOs: Generals, Pilots, and Government Officials Go on the Record,” published in 2010 by an imprint of Random House, Kean wrote that “the U.S. government routinely ignores UFOs and, when pressed, issues false explanations. Its indifference and/or dismissals are irresponsible, disrespectful to credible, often expert witnesses, and potentially dangerous.” Her book is a sweeping reminder that this was not always the case. In the decades after the Second World War, about half of all Americans, including many in power, accepted U.F.O.s as a matter of course. Kean sees herself as a custodian of this lost history. In her apartment, a tranquil space decorated with a Burmese Buddha and bowls of pearlescent seashells, Kean sat down on the floor, opened her file cabinets, and disappeared into a drift of declassified memos, barely legible teletypes, and yellowing copies of The Saturday Evening Post and the Times Magazine featuring flying-saucer covers and long, serious treatments of the phenomenon.

Kean grew up in New York City, a descendant of one of the nation’s oldest political dynasties. Her grandfather Robert Winthrop Kean served ten terms in Congress; he traced his ancestry, on his father’s side, to John Kean, a South Carolina delegate to the Continental Congress, and, on his mother’s, to John Winthrop, one of the Puritan founders of the Massachusetts Bay Colony. She speaks of her family’s legacy in rather abstract terms, except when discussing the abolitionist William Lloyd Garrison, her grandfather’s great-grandfather, whom she regards as an inspiration. Her uncle is Thomas Kean, who served two terms as New Jersey’s governor and went on to chair the 9/11 Commission.

Kean attended the Spence School and went to college at Bard. She has a modest family income, and spent her early adult years as a “spiritual seeker.” After helping to found a Zen center in upstate New York, she worked as a photographer at the Cornell Lab of Ornithology. In the late nineteen-nineties, after a visit to Burma to interview political prisoners, she stumbled into a career in investigative journalism. She took a job at KPFA, a radio station in Berkeley, as a producer and on-air host for “Flashpoints,” a left-wing drive-time news program, where she covered wrongful convictions, the death penalty, and other criminal-justice issues.

In 1999, a journalist friend in Paris sent her a ninety-page report by a dozen retired French generals, scientists, and space experts, titled “Les OVNI et la Défense: À Quoi Doit-On Se Préparer?”—“U.F.O.s and Defense: For What Must We Prepare Ourselves?” The authors, a group known as COMETA, had analyzed numerous U.F.O. reports, along with the associated radar and photographic evidence. Objects observed at close range by military and commercial pilots seemed to defy the laws of physics; the authors noted their “easily supersonic speed with no sonic boom” and “electromagnetic effects that interfere with the operation of nearby radio or electrical apparatus.” The vast majority of the sightings could be traced to meteorological or earthly origins, or could not be studied, owing to paltry evidence, but a small percentage of them appeared to involve, as the report put it, “completely unknown flying machines with exceptional performances that are guided by a natural or artificial intelligence.” COMETA had resolved, through the process of elimination, that “the extraterrestrial hypothesis” was the most logical explanation.

Kean had read Whitley Strieber’s “Communion,” the 1987 cult best-seller about alien abduction, but until receiving the French findings she had never had more than a mild interest in U.F.O.s. “I had spent years at KPFA reporting on the horrors of the world, injustice and oppression, and giving voice to the voiceless,” she recalled. As she acquainted herself with the plenitude of odd episodes, it was as if she’d seen beyond our own dismal reality and the limitations of conventional thinking, and caught a glimpse of an enchanted cosmos. “To me, this just transcended the endless struggle of human beings,” she told me, during a long walk around her neighborhood. “It was a planetary concern.” She stopped in the middle of the street. Gesturing toward a heavily overcast sky, she said, “Why should we assume we already understand everything there is to know, in our infancy here on this planet?”

An editor of the Boston Globe’s Focus section, who had admired Kean’s writing on Burma, tentatively agreed to work with her on a story about U.F.O.s. Kean chose not to discuss it with her KPFA colleagues, apprehensive that they would consider the topic, at best, frivolous. She was certain, though, that anyone given access to the French report’s data and conclusions would understand why she had dropped everything else. She refused to include any ironizing asides in the article, which was published on May 21, 2000, as a straightforward summary of the COMETA investigations. “But then, of course, nothing happened,” she said. “And that was the beginning of my education in the power of the stigma.”

Some aficionados believe that U.F.O.s have been documented since Biblical times; in “The Spaceships of Ezekiel,” published in 1974, Josef F. Blumrich, a NASA engineer, argued that the prophet’s heavenly vision of wheels within wheels was an encounter not with God but with an alien spaceship. In “The UFO Controversy in America” (1975), David Jacobs wrote about a series of “airship” sightings across the country in 1896 and 1897. Spaceships, in our descriptions, have always displayed capabilities just beyond our technological horizon, and with our own wartime advances they grew staggeringly impressive. It’s generally agreed that the modern U.F.O. era began on June 24, 1947, when a private aviator named Kenneth Arnold, while flying a CallAir A-2, saw a loose formation of nine undulating objects near Mt. Rainier. They had the shape of boomerangs or tailless manta rays, and in his estimation they moved at two to three times the speed of sound. He described their motion as that of a “saucer skipped over water.” A newspaper headline conjured “flying saucers.” By the end of the year, at least eight hundred and fifty similar domestic sightings had been reported, according to one independent U.F.O. investigator. Meanwhile, scientists asserted that flying saucers didn’t exist because they couldn’t exist. The Times quoted Gordon Atwater, an astronomer at the Hayden Planetarium, who attributed the flurry of reports to a combination of a “mild case of meteorological jitters” and “mass hypnosis.”

Within government circles, the issue of how seriously to take what they renamed “unidentified flying objects” provoked a deep conflict. By September of 1947, incoming reports of sightings had become too profuse for the Air Force to ignore. That month, in a classified communiqué, Lieutenant General Nathan F. Twining advised the commanding general of the armed forces that “the phenomenon reported is something real and not visionary or fictitious.” The “Twining memo,” which has since gained ecclesiastical stature among ufologists, articulated concerns that some foreign rival—say, the Soviet Union—had made an unimaginable technological breakthrough, and it initiated a classified study, Project Sign, to investigate. Its officials were evenly split between those who thought that the “flying discs” were of plausibly “interplanetary” origin and those who chalked up the sightings to rampant misperception. On the one hand, according to a memo, a full twenty per cent of U.F.O. reports lacked ordinary explanations. On the other hand, there was no dispositive evidence—the wreckage of a crashed saucer, perhaps—and, as a scientist at the RAND Corporation reasoned, interstellar travel was simply infeasible.

But unaccountable things kept happening. In 1948, about a year after the Arnold sighting, two pilots in an Eastern Airlines DC-3 saw a large, cigar-shaped light speed toward them at a tremendous velocity before making an impossibly abrupt turn and vanishing into a clear sky. A pilot in a second plane, and a few witnesses on the ground, gave compatible accounts. It was the first time that a U.F.O. had been observed at close range: the two pilots described seeing a row of windows as it streaked past. Project Sign investigators filed a top-secret “Estimate of the Situation” memorandum, which leaned in favor of the extraterrestrial hypothesis. But, opponents argued, if they were here, wouldn’t they have notified us?

In July, 1952, such a formal notification seemed to nearly occur, when an armada of U.F.O.s reportedly violated restricted airspace over the White House. The Times headline resembled something out of a Philip K. Dick novel: “Flying Objects Near Washington Spotted by Both Pilots and Radar: Air Force Reveals Reports of Something, Perhaps ‘Saucers,’ Traveling Slowly But Jumping Up and Down.” The Air Force, playing down the incident, told the newspaper that no defensive measures had been taken, although it subsequently emerged that the military had scrambled jets to intercept the trespassers. Major General John Samford, the Air Force’s director of intelligence, held the largest press conference since the end of the Second World War. Samford, who had the grave mien of a lawman in a John Ford movie, squinted as he referred to “a certain percentage of this volume of reports that have been made by credible observers of relatively incredible things.”

The following January, the C.I.A. secretly convened an advisory group of experts, led by Howard P. Robertson, a mathematical physicist from Caltech. The “Robertson panel” determined not that we were being visited by U.F.O.s but that we were being inundated with too many U.F.O. reports. This was a real problem: if notices of genuine incursions over U.S. territory could be lost in a maelstrom of kooky hallucination, there could be grave consequences for national security—for instance, Soviet spy planes could operate with impunity. The Cold War made it crucial that the U.S. government be perceived to have full control over its airspace.

To stem the flood of reports, the panel recommended that “the national security agencies take immediate steps to strip the Unidentified Flying Objects of the special status they have been given and the aura of mystery they have unfortunately acquired.” It also suggested that civilian U.F.O. groups be infiltrated and monitored, and enlisted the media in the debunking effort. The campaign culminated in a 1966 TV special, “UFO: Friend, Foe or Fantasy?,” in which the CBS anchorman Walter Cronkite patiently consigned U.F.O.s to the oblivion of the third category.

Not all members of the military were content with this stance. Vice Admiral Roscoe Hillenkoetter, the first director of the C.I.A., told a Times reporter, “Behind the scenes, high-ranking Air Force officers are soberly concerned about the UFOs. But through official secrecy and ridicule, many citizens are led to believe the unknown flying objects are nonsense.”

The government maintained one public repository for U.F.O. reports: Project Blue Book, a continuation of Project Sign, which operated out of Wright-Patterson Air Force Base, near Dayton, Ohio. Blue Book was a meagrely funded division run by a series of low-ranking officers who would have preferred any other billet. The program’s only continuous presence, and its only in-house scientist, was an Ohio State astronomer named J. Allen Hynek, a U.F.O. skeptic and a former member of the Robertson panel. Initially, Hynek assumed a “commonsense” approach; as he later wrote, “I felt the lack of ‘hard’ evidence justified the practical ‘it just can’t be’ attitude.” Ninety-five per cent of supposed U.F.O.s really did have a garden-variety derivation: uncommon clouds, weather balloons, atmospheric temperature inversions. Luminous orbs were attributable to Venus; silent triangles could be connected to classified military technology. (The U-2 spy plane and the SR-71 Blackbird were often reported as U.F.O.s, a confusion embraced by the counterintelligence community, which was eager to keep these projects secret.) But the remaining five per cent, despite the government’s best efforts, could not be neatly resolved. Hynek, to his surprise, developed sympathy for the people who saw U.F.O.s; they were much more likely to be respectable, embarrassed citizens than cranks, hoaxsters, and “U.F.O. buffs.”

Still, he was expected to do his job. Beginning on March 14, 1966, more than a hundred witnesses in and around Dexter, Michigan, reported seeing glowing lights and large football shapes at low altitudes. Hynek arrived to discover a community in a state of “near hysteria.” At a press conference on March 25th, under pressure to avert panic, Hynek attributed some of the sights to the moon and the stars and others to the spontaneous combustion of decomposing vegetation, or “swamp gas.” The people of Michigan took this as an affront. (“Swamp gas” became a common ufological metonym for the government’s patronizing obfuscation.) Gerald Ford, a native of Grand Rapids and at the time the House Minority Leader, called for congressional hearings, “in the firm belief that the American public deserves a better explanation than thus far given by the Air Force.” In testimony before the House Armed Services Committee, Hynek recommended that an independent body be set up to evaluate the merits of Project Blue Book and finally settle the question of U.F.O. legitimacy. In seventeen years, Blue Book had reviewed approximately twelve thousand cases; seven hundred and one of them remained unexplained.

In late 1966, Edward U. Condon, a physicist at the University of Colorado, was given three hundred thousand dollars to conduct such a study. The project was plagued by infighting, especially after the discovery of a memo written by a coördinator noting that a truly disinterested approach would have to allow for the fact that U.F.O.s might exist. That was out of the question—their behavior was not commensurable with our understanding of universal laws. The associated scientists, the coördinator proposed, should stress to their colleagues that they were primarily interested in the psychological and social circumstances of U.F.O. believers. In other words, sightings should be understood as metaphors—for Cold War anxiety or ambivalence about technology.

The thousand-page “Scientific Study of Unidentified Flying Objects,” or the Condon Report, as it became known, was completed in the late fall of 1968. Of the ninety-one Blue Book cases selected for examination, thirty of them remained official mysteries. In a “puzzling and unusual” incident in 1956, a preternaturally fast object was recorded on multiple radars near a U.S. Air Force base in England. One of Condon’s researchers wrote that “the apparently rational, intelligent behavior of the UFO suggests a mechanical device of unknown origin as the most probable explanation of this sighting.” As Tim McMillan, a retired police lieutenant who writes about U.F.O.s and national defense, put it to me, “You didn’t even need the other seven hundred cases. You only needed one like that to say, ‘Hey, we should look into this.’ ”

Condon, who announced long before the study was complete that U.F.O.s were unmitigated bunk, wrote the report’s summary and its “Conclusions and Recommendations” section. He seemed to have only a glancing familiarity with the other nine hundred pages of the report. As he put it, “Careful consideration of the record as it is available to us leads us to conclude that further extensive studies of UFOs probably cannot be justified in the expectation that science will be advanced thereby.” Schoolchildren, he advised, should not be given credit for work involving U.F.O.s. Scientists should take their talents and their money elsewhere. Project Blue Book was shut down in January, 1970.

In 1972, Hynek published “The UFO Experience: A Scientific Enquiry,” a scathing postmortem on Blue Book and the Condon Report, and a blueprint for systematic research. Blue Book’s remit had not been to try to explain U.F.O.s, he wrote; rather, it had been to explain them away. The Condon Report, which focussed on disproving any conjecture about alien spaceships, was even worse. What was instead required was an agnostic approach, one biased in favor neither of extraterrestrial craft nor of the weather or Venus. U.F.O.s were unidentified by definition. But, as Kean writes in her book, the Condon Report licensed scientists and officials to look the other way; meanwhile, “the media could enjoy the ride while making fun of UFOs or relegating them to science fiction.” The Robertson panel had finally succeeded in its mission: “The ‘golden age’ of official investigations, congressional hearings, press conferences, independent scientific study, powerful citizen groups, best-selling books, and magazine cover stories had come to an end.” Hynek founded an independent organization to continue his research, but he died, at age seventy-five, in 1986, without having altered the course of public opinion.

Once it was clear that U.F.O.s were going to be her life’s work, Kean resolved to ally herself with the research tradition that Hynek had pioneered. Ufologists liked to dwell on certain historic encounters, like Roswell, where any solid evidence that might once have existed had become hopelessly entangled with mythology. Kean chose to focus on “the really good cases” that had been reported since the close of Blue Book, including those that involved professional observers, such as pilots, and ideally multiple witnesses; those that had been substantiated with photos or radar tracks; and especially those in which experts had eliminated other interpretations. One case she studied involved a spooky incident in England in 1980, known as “Britain’s Roswell,” in which several U.S. Air Force officers claimed to have observed a U.F.O. at close range just outside R.A.F. Bentwaters, in Rendlesham Forest. The deputy base commander made a contemporaneous audio recording. The details of the incident as it is described in Kean’s book are sensational, to say the least. Another witness, Sergeant James Penniston, said that he got close enough to a silent triangular craft to feel its electric charge and to note the hieroglyphic-like designs etched into its surface.

Kean has always avoided the word “disclosure,” but it was clear to her that, notwithstanding the Condon Report, the government had concealed a persistent interest in U.F.O.s. In 1976, Major Parviz Jafari, a squadron commander in the Iranian Air Force, was dispatched in an F-4 jet to intercept a glowing diamond outside Tehran, near the Soviet border. In a contribution to Kean’s book, Jafari wrote that, as he approached the object, it was “flashing with intense red, green, orange and blue lights so bright that I was not able to see its body.” He found his weapons and radio communications jammed. American intelligence sources in Iran described the incident in a classified, four-page memo to Washington. Kean read to me an assessment attached to the document, written by Colonel Roland Evans: “An outstanding report. This case is a classic, which meets all the criteria necessary for a valid study of the UFO phenomenon.” She arched her brow and said, “I mean, you don’t see that written very often in a government document, especially when they’re telling you they’re not interested.”

In 2002, Larry Landsman, the director of projects for the Sci Fi Channel (now Syfy), invited Kean to lead a broad public “effort seeking new government records on a well-documented UFO case,” one that might provide fodder for a television special. Sci Fi’s producers hired lawyers, researchers, and a P.R. group—the Washington-based firm PodestaMattoon. Edwin S. Rothschild, the head of PodestaMattoon’s energy and environment sector at the time, remembered telling Kean, “Most people may have this idea that there’s something out there, but there are also people who think that, if you start talking about it, you could be a kook.” He went on, “We had to draw a firm line between the people who would not have credibility and those who would.”

Kean selected an incident that occurred in Kecksburg, Pennsylvania, a rural hamlet southeast of Pittsburgh, on December 9, 1965, in which an object the size of a Volkswagen Beetle allegedly hurtled from the sky. According to multiple witnesses, the acorn-shaped bulk had been removed from the woods on a flatbed truck as service members guarded the area with guns. Kean filed Freedom of Information Act requests for NASA files, including some that she believed contained information about debris that was retrieved from the scene. NASA claimed that the relevant records had gone missing in 1987. After a fruitless appeal, Kean filed a lawsuit against NASA to force its compliance. Rothschild introduced Kean to John Podesta, President Clinton’s former chief of staff, who had a well-known interest in both government transparency and U.F.O.s. Podesta agreed to publicly support the suit. The case dragged on for four years, until Kean won a settlement. She received hundreds of largely irrelevant documents. Podesta told me, “There was a real story there, and you know that when the boxes are missing in the basement and the dog ate my homework. They just refused to own up to what had actually happened. I was perfectly willing to believe that it was the debris of a Soviet satellite that we didn’t want to return, but there was nothing that provided any clarity—and after forty years there was no plausible reason for them not to come clean and just say what they thought it was.”

As Kean discovered, a legacy of Cold War paranoia and obstructionism continued to bedevil the U.F.O. issue. On November 7, 2006, at about 4 p.m., a revolving, metallic-looking disk was seen suspended approximately nineteen hundred feet above Gate C17 at Chicago’s O’Hare Airport. The object hovered for several minutes before accelerating at a severe incline and leaving “an almost perfect circle in the cloud layer where the craft had been,” as one anonymous witness subsequently put it. When the Chicago Tribune published an account of the sighting—not a single witness was willing to go on the record—it became the most-read article on the newspaper’s Web site up to that time. Initially, the Federal Aviation Administration denied that it had any information about the incident, but media pressure brought to light a taped phone conversation between a United Airlines supervisor and an air-traffic controller. In the recording, the supervisor, named Sue, asks, “Hey, did you see a flying disk out by C17?” She is met with audible laughter. “A flying . . . you’re seeing flying disks?” the controller asks. Sue replies, “Well, that’s what a pilot in the ramp area at C17 told us.” There is a pause. “You’re celebrating Christmas today?” the controller asks, then continues, “I haven’t seen anything, Sue, and if I did I wouldn’t admit to it.”

The F.A.A. claimed that it must have been a “hole-punch cloud”—a cirrocumulus or altocumulus cloud crisply perforated with a circular gap, which occasionally appears in below-freezing temperatures. According to meteorologists whom Kean interviewed, it was much too warm that day for hole-punch clouds to occur. The episode sparked Kean’s indignation. As she put it in her book, “Those who do know the facts about the O’Hare incident continue to mistrust our government, which has demonstrated, once again, that it will avoid dealing with UFO incidents at all costs.”

Kean looked abroad for cases that were treated with greater open-mindedness, and did not have to wait long. On Monday, April 23, 2007, an eighteen-passenger plane operated by Aurigny Air Services departed from Southampton, England, for a routine flight to Alderney, one of the Channel Islands. The captain, Ray Bowyer, had been a professional pilot for eighteen years. In the previous decade, he had flown the forty-minute Channel crossing more than a thousand times. That particular day, the plane took off as scheduled, and climbed through a layer of shallow haze before reaching cruising altitude. Bowyer engaged the autopilot and turned his attention to some paperwork.

At 2:06 P.M., Bowyer looked up to discover a gleaming yellow light directly ahead. He first thought that it was sunlight reflecting off the glass vineries of Guernsey’s tomato industry below, but the light did not flicker. Bowyer reached for his binoculars. At a magnification of ten times, the yellow glow took on the contour of a corporeal object. It had a long, thin, cigarlike shape, with sharp edges and pointed ends, like a wheel viewed in profile. It was stationary, and radiated a brilliance that was “difficult to describe,” Bowyer later wrote, but he “was able to look at this fantastic light without discomfort.” Moments later, he saw a second object, which appeared to move in formation with the first. The passenger seated behind Bowyer, whose name was not made public, reached forward to borrow the binoculars. Three rows back, Kate Russell, an Alderney resident, looked up from her book, and she and her husband both saw the “sunlight-colored” objects. When the flight landed in Alderney, Bowyer filed the details with Britain’s Civil Aviation Authority—which has a Mandatory Occurrence Report system—including a sketch of what he’d seen. In his professional opinion, the objects were each about the size of a “reasonably large town.” He had time for a quick cup of tea before his return to Southampton.

Local papers made reference to “The X-Files,” and the C.A.A. refused to provide further information. A number of Freedom of Information Act requests were filed by the sorts of people who regularly FOIA U.F.O.s. A week after the sighting, the U.K.’s Ministry of Defence concluded that, because the flight position reported was in French airspace, a definitive identification was not the British government’s problem. Nevertheless, three weeks later, the British ministry released the available documentation, a packet that included corroborating radar data from an air-traffic controller on the nearby island of Jersey and a statement from a second commercial pilot in the vicinity, who had seen the objects from a different direction.

Ten months later, David Clarke, a known U.F.O. skeptic, along with three collaborators, published an audit. The “Report on Aerial Phenomena Observed Near the Channel Islands, UK, April 23 2007” was drafted with the coöperation of dozens of domain experts—meteorologists, oceanographers, harbormasters—and various French institutes and British ministries, and it culminated with sixteen prevailing hypotheses, ranked by plausibility. Largely ruled out were such atmospheric aberrations as sun dogs and lenticular clouds, and an exceedingly rare and poorly understood seismological phenomenon known as “earthquake lights,” in which tectonic distress expresses itself in bluish auroras or orbs. The report concluded, “In summary, we are unable to explain the UAP sightings satisfactorily.”

Soon after the Alderney encounter, Kean began working with James Fox, the director of the documentary “The Phenomenon,” to organize an event at the National Press Club. She and Fox chose a date that roughly coincided with the first anniversary of the O’Hare sighting. Among the fourteen speakers were Major Jafari, of the “dogfight over Tehran,” and Captain Bowyer, whom Kean encouraged to expound on the differences that he had observed between the official treatment of U.F.O. encounters in the U.K. and the U.S. “I would have been shocked if I was told that the C.A.A. would obstruct an investigation, or if the C.A.A. told me that what I had seen was something entirely different,” Bowyer said at the lectern, contrasting his experience with the episode at O’Hare. “But it seems that pilots in America are used to this kind of thing, as far as I can tell.”

None of the speakers made mention of Roswell, alien bodies, reverse-engineered craft, or government coverups. Over the next two years, Kean collected their accounts, and other reports, for her book. In it, she argued that, for reasons of safety and security, and to encourage people who saw peculiar stuff in the sky to speak out, the government needed some sort of centralized U.F.O. agency. Many other countries had followed the lead set by France, and had either declassified and published U.F.O. files (the U.K., Denmark, Brazil, Russia, Sweden) or formed their own official organizations dedicated to the issue (Peru, Chile). The problem in the U.S., as Kean saw it, was that discrete initiatives had been driven by interested individuals; there was no single clearing house for salient data. She met with her uncle Thomas Kean to discuss the U.F.O. issue and her proposal for a dedicated agency, in the context of his experience as chair of the 9/11 Commission. He told me, “Like a lot of Americans, I had an immense curiosity about U.F.O.s. The government hasn’t come clean about what they have.”

Kean’s book, which was praised by the theoretical physicist Michio Kaku as “the gold standard for U.F.O. research,” and to which John Podesta had contributed a foreword, enhanced and expanded her influence. In June of 2011, Podesta invited Kean to make a confidential presentation at a think tank he founded, the Center for American Progress. Standing alongside a physicist from Johns Hopkins University and foreign military figures, Kean advised the audience—officials from NASA, the Pentagon, and the Department of Transportation, along with congressional staff and retired intelligence officials—that the challenge was “to undo fifty years of reinforcement of U.A.P. as folklore and pseudoscience.”

Podesta told me, “It wasn’t a bunch of people coming in looking like they were going to a ‘Star Wars’-memorabilia convention—it was serious people from the national-security arena who wanted answers to these unexplained phenomena.” Soon after the event, he said, a Democratic senator invited him for a meeting. “I thought it was going to be on food stamps and tax cuts or whatever, and the door closed and they said, ‘I don’t want anybody to know this, but I’m really interested in U.F.O.s, and I know you are, too. So what do you know?’ ”

In August, 2014, Kean visited the West Wing to meet again with Podesta, who was by then an adviser to President Obama. She had scaled down her request, proposing that a single individual in the Office of Science and Technology Policy be assigned to handle the issue. Nothing came of it. She was, however, a well-known figure on the international U.F.O. circuit and had a cordial relationship with the Chilean government’s Comité de Estudios de Fenómenos Aéreos Anómalos (CEFAA). She had begun breaking stories from its case files with an atypical recklessness. Kean’s work from this period, mostly published on the Huffington Post, shows signs of agitation and evangelism. In March of 2012, she wrote an article called “UFO Caught on Tape Over Santiago Air Base,” which referred to a video provided by CEFAA. Kean described the video as showing “a dome-shaped, flat-bottomed object with no visible means of propulsion . . . flying at velocities too high to be man-made.” She asked, “Is this the case UFO skeptics have been dreading?”

For the most part, people who do not feel that U.F.O.s represent a meaningful category of study regard the opposing view as a harmless curiosity. The world is full of weird, unaccountable convictions: some people believe that leaving your neck exposed in winter makes you ill, and others believe in U.F.O.s. But a small fraction of nonbelievers, known as “debunkers,” mirror ardent belief with equally ardent doubt. When Kean wrote about the CEFAA video, debunkers leaped at the chance to point out that the object in the case they had been dreading was in all probability a housefly or a beetle buzzing around the camera lens. Robert Sheaffer, the proprietor of a blog called Bad UFOs, wrote in his column in the Skeptical Inquirer, “Indeed, the very fact that a video of a fly doing loops is being cited by some of the world’s top UFOlogists as among the best UFO images of all time reveals how utterly lightweight even the best UFO photos and videos are.” Kean consulted with four entomologists, who mostly declined to issue a categorical judgment on the matter, and urged patience with CEFAA’s ongoing investigation.

“An informed skeptic is a very different thing from a debunker on a mission,” she wrote to me. “There are many out there who are on a mission to debunk UFOs at all costs. They’re not rational and they’re not informed.” Kean thought that they were blinded by zealotry. The skeptic Michael Shermer, for example, in a review of Kean’s book, had idly adduced that a wave of silent black triangles seen over Belgium in 1989 and 1990 were probably experimental, classified stealth bombers—despite official attestations to the fact that any government would be crazy to trot out its latest devices over heavily populated areas of Western Europe.

A tendency to discount or overlook inconvenient facts is a thing debunkers and believers have in common. One dogged British researcher has convincingly shown that the Rendlesham case, or Britain’s Roswell, probably consisted of a concatenation of a meteor, a lighthouse perceived through woods and fog, and the uncanny sounds made by a muntjac deer. Eyewitness reports are subject to considerable embroidery over time, and strings of improbable coincidences can easily be rendered into an occult pattern by a human mind prone to misapprehension and eager for meaning. The researcher had exhaustively demystified the case, and I was perturbed to learn that Kean seemed unfazed by his verdict. When I asked her about it, she did little more than shrug, as though to suggest that such fluky accounts violated Occam’s razor. Even if Rendlesham was “complex,” she said, it was still “one of the top ten U.F.O. encounters of all time.” And, besides, there were always other cases. Hynek, in “The UFO Experience,” had contended that U.F.O. sightings represented a phenomenon that had to be taken in aggregate—hundreds upon hundreds of incredible stories told by credible people.

Many U.F.O. debunkers are overtly hostile, but Mick West has a mild, disarming manner, one that only occasionally recalls the performative deference with which an orderly might cajole a patient back into his straitjacket. He grew up in a small mill town in northern England. His family did not have a television or a phone, and he learned to read with his father’s collection of Marvel comics. He was very good at math, and, after buying an early home computer with his earnings from a newspaper route, he became obsessed with primitive video games. As an adolescent, in the early nineteen-eighties, he loved science fiction, and was bewitched by a magazine called The Unexplained: Mysteries of Mind, Space and Time. The periodical was full of “true” stories about U.F.O.s and the paranormal—ghosts and the menacing creatures of cryptozoology. He used to lie in bed at night, as he wrote in his book, “Escaping the Rabbit Hole,” “literally trembling with the thought that some alien could enter my room and spirit me away to perform experiments on me.” Of particular cause for terror was the “Kelly-Hopkinsville encounter,” a 1955 case in which a Kentucky farmhouse was said to have come under attack by little green men.

As West became scientifically literate, he came to trust that the Kelly-Hopkinsville “aliens” were probably owls. Rather than cure his interest in the paranormal, however, this understanding refined it, and he began to take pleasure in the patient dismantling of unsound logic. This practice had, for West, therapeutic value, and as an adult his childhood anxieties are manifested only in a vestigial discomfort with the dark. In the nineties, West moved to California, where he co-founded a video-game studio; he is best known as one of the programmers behind the hugely popular Tony Hawk franchise. In 1999, the company he worked for was acquired by Activision, and, before the age of forty, he more or less retired. He found himself involved in Wikipedia edit wars concerning such contentious topics as homeopathy, scientific foreknowledge in sacred texts, and vegetarian lions. He eventually established his own Web site to combat the widespread misinformation surrounding Morgellons disease, an affliction with no established medical basis, which is characterized by the worry that strange fibres are emerging from one’s skin. Then he took on the chemtrails theory, and engaged with 9/11 truthers. As he put it in his book, “A small part of the reason why I debunk now (and still occasionally address ghost stories) is anger at the fear this nonsense instilled in me as a young child.”

West is a thoughtful, intelligent man. His e-mails feature numbered and lettered lists and light math. Everything he told me was perfectly persuasive, but even an hour on the phone with him left me feeling vaguely demoralized. Morgellons sufferers and chemtrail hysterics, he supposed, would be grateful to be relieved of their baseless fears, just as he had been disburdened of the psychic hazard posed by farmhouse aliens—and he didn’t see why U.F.O. advocates should be any different. He seemed unable to envisage that someone might find solace in the decentering prospect that we are not alone in a universe we ultimately know very little about.

In 2013, West founded Metabunk, an online forum where like-minded contributors examine anomalous phenomena. On January 6, 2017, another skeptic brought to his attention a Huffington Post piece by Kean. In the article, “Groundbreaking UFO Video Just Released by Chilean Navy,” Kean wrote in detail about an “exceptional nine-minute” film, shot on infrared cameras from a helicopter, that cefaa had been studying for two years. West watched the clip with an immediate sense of recognition. He posted the link to Skydentify, a Metabunk subforum, positing his theory that the video’s odd formations were “aerodynamic contrails,” which he was used to seeing as planes flew over his home in Sacramento. By January 11th, the community had ascertained that the purported U.F.O. was IB6830, a regularly scheduled passenger flight from Santiago to Madrid.

U.F.O. inquiries can proceed only through the process of elimination, a style of argument that is highly vulnerable to erroneous assumptions. In this case, as the Metabunk participants extrapolated, the helicopter pilots had inaccurately gauged the distance and altitude of the U.F.O., and viable possibilities—such as its being a commercial airliner in a takeoff climb—had been prematurely ruled out. West was not surprised. Although Kean regards pilots as “the world’s best-trained observers of everything that flies,” even Hynek determined, in 1977, that pilots are particularly prone to error. (He asserted, however, that “they do slightly better in groups.”) As West has written, “You can’t be an expert in the unknown.”

During one of my phone calls with Kean—greatly pleasurable distractions that tended to absorb entire afternoons—I mentioned to her that I had been in touch with Mick West. It was the only time I had known her to grow peevish. “If Mick were really interested in this stuff, he wouldn’t debunk every single video,” she said, almost pityingly. “He would admit that at least some of them are genuinely weird.”

Robert Bigelow was three years old in the spring of 1947, when his grandparents were almost run off the road by a glowing object in the mountains northwest of Las Vegas. The Nevada desert of the early atomic age was one of the few places a child could see nuclear tests or rocket launches from his back yard, and Bigelow’s dreams of space exploration commingled with his curiosity about U.F.O.s. In the late nineteen-sixties, when he was in his early twenties, he began to invest in real estate—first in Las Vegas, then across the Southwest—and eventually he made a fortune with Budget Suites of America, a chain of extended-stay motels. Later, he founded a private company, Bigelow Aerospace, to build inflatable astronaut habitats. In 1995, he established the National Institute for Discovery Science, which described itself as “a privately funded science institute engaged in research of aerial phenomena, animal mutilations, and other related anomalous phenomena.” Among the consultants he hired was Hal Puthoff, whose work in paranormal studies dated back decades, to Project Stargate, a C.I.A. program to investigate how “remote viewing,” a form of long-distance E.S.P., might be useful in Cold War espionage. The next year, Bigelow purchased Skinwalker Ranch, a four-hundred-and-eighty-acre parcel a few hours southeast of Salt Lake City, named for a shape-shifting Navajo witch. Its previous owners had described being driven away by coruscating spheres, exsanguinated cattle, and wolflike creatures impervious to gunshots. In 2004, in the wake of a purported decrease in domestic paranormal activity, Bigelow shut down his institute, but he kept the ranch.

In 2007, Bigelow received a letter from a senior official at the Defense Intelligence Agency who was curious about Skinwalker. Bigelow connected him to an old friend from the Nevada desert, Senator Harry Reid, who was then the Senate Majority Leader, and the two men met to discuss their common interest in U.F.O.s. The D.I.A. official later visited Skinwalker, where, from a double-wide observation trailer on site, he is said to have had a spectral encounter; as one Bigelow affiliate described it, he saw a “topological figure” that “appeared in mid-air” and “went from pretzel-shaped to Möbius-strip-shaped.”

Reid reached out to Senator Ted Stevens, of Alaska, who believed he’d seen a U.F.O. as a pilot in the Second World War, and Senator Daniel Inouye, of Hawaii. In the 2008 Supplemental Appropriations Bill, twenty-two million dollars of so-called black money was set aside for a new program. The Pentagon was not enthusiastic. As one former intelligence official put it, “There were some government officials who said, ‘We shouldn’t be doing this, this is really ridiculous, this is a waste of money.’ ” He went on, “And then Reid would call them out of a meeting and say, ‘I want you to be doing this. This was appropriated.’ It was sort of like a joke that bordered on an annoyance and people worried that if this all came out, that the government was spending money on this, this will be a bad story.” The Advanced Aerospace Weapon System Applications Program was announced in a public solicitation for bids to examine the future of warfare. U.F.O.s were not mentioned, but according to Reid the subtext was clear. Bigelow Aerospace Advanced Space Studies, or BAASS, a Bigelow Aerospace subsidiary, was the only bidder. When Bigelow won the government contract, he contacted the same cohort of paranormal investigators he’d worked with at his institute. Other participants were recruited from within the Pentagon’s ranks. In 2008, Luis Elizondo, a longtime counterintelligence officer working in the Office of the Undersecretary of Defense for Intelligence and Security, was visited by two people who asked him what he thought about U.F.O.s. He replied that he didn’t think about them, which was apparently the correct answer, and he was asked to join.

Bigelow believes, as one source put it to me, that “there are aliens walking around at the supermarket.” According to an article by MJ Banias, on the Web site the Debrief, Bigelow hired investigators to look into reports at Skinwalker of doglike creatures who smelled of sulfur and goblins with long, pendulous arms, as well as U.F.O. activity near Mt. Shasta. The program appears to have produced little more than a series of thirty-eight papers, all unclassified except one, about the kind of technology a U.F.O. might exploit—including work on the theoretical viability of warp drives and “spacetime metric engineering.” Bigelow’s researchers, convinced that crash debris was being hidden in some remote hangar, wanted access to the government’s classified data on U.F.O.s. In June, 2009, Senator Reid filed a request that the program be awarded “restricted special access program,” or SAP, status. The following month, BAASS issued a four-hundred-and-ninety-four-page “Ten Month Report.” The portions of the report that were leaked to Tim McMillan, along with additional sections that I was able to review, were almost exclusively about U.F.O.s, and the information provided was not limited to mere sightings; it included a photo of a supposed tracking device that supposed aliens had supposedly implanted in a supposed abductee. As one former government official told me, “The report arrived here and I read the whole thing and immediately concluded that releasing it would be a disaster.” In November, 2009, the Defense Department peremptorily denied the request for SAP status. (A representative of BAASS declined to comment for this article.)

Soon afterward, Elizondo, the counterintelligence officer, was asked to take over the program. Beginning in 2010, he turned an outsourced study of Utah cryptids into the Advanced Aerospace Threat Identification Program, or AATIP, an in-house effort that focussed on the national-security implications of military U.A.P. encounters. According to Elizondo, the program studied a number of incidents in depth, including what later became known as the “Nimitz encounter.”

The Nimitz Carrier Strike Group was conducting training operations in restricted waters off the coast of San Diego and Baja California in November of 2004, when the advanced SPY-1 radar on one of the ships, the U.S.S. Princeton, began to register some strange presences. They were logged as high as eighty thousand feet, and as low as the ocean’s surface. After about a week of radar observations, Commander David Fravor, a graduate of the élite Topgun fighter-pilot school and the commanding officer of the Black Aces squadron, was sent on an intercept mission. As he approached the location, he looked down and saw a roiling shoal in the water and, hovering above it, a white oval object that resembled a large Tic Tac. He estimated it to be about forty feet long, with no wings or other obvious flight surfaces and no visible means of propulsion. It appeared to bounce around like a Ping-Pong ball. Two other pilots, one seated behind him and one in a nearby plane, gave similar accounts. Fravor descended to chase the object, which reacted to his maneuvers before departing abruptly at high speed. Upon Fravor’s return to the Nimitz, another pilot, Chad Underwood, was dispatched to follow up with more advanced sensory equipment. His aircraft’s targeting pod recorded a video of the object. The clip, known as “FLIR1”—for “forward-looking infrared,” the technology used to capture the incident—features one minute and sixteen seconds of a blurry ashen dot against a gunmetal background; in the final few seconds, the dot appears to outwit the FLIR track and make a rapid getaway.

Elizondo’s exposure to cases like the Nimitz encounter convinced him that U.A.P.s were real, but the government’s willingness to invest resources in the issue remained uncertain. Elizondo tried repeatedly to brief General James Mattis, the Secretary of Defense, about AATIP’s research, and was blocked by underlings. (General Mattis’s personal assistant at the time does not recall being approached by Elizondo.)

On October 4, 2017, at the behest of Christopher K. Mellon, a former Deputy Assistant Secretary of Defense for Intelligence, Leslie Kean was called to a confidential meeting in the bar of an upscale hotel near the Pentagon. She was greeted by Hal Puthoff, the longtime paranormal investigator, and Jim Semivan, a retired C.I.A. officer, who introduced her to a sturdy, thick-necked, tattooed man with a clipped goatee named Luis Elizondo. The previous day had been his last day of work at the Pentagon. Over the next three hours, Kean was taken through documents that proved the existence of what was, as far as anyone knew, the first government inquiry into U.F.O.s since the close of Project Blue Book, in 1970. The program that Kean had spent years lobbying for had existed the whole time.

After Elizondo resigned, he and other key AATIP participants—including Mellon, Puthoff, and Semivan—almost immediately joined To the Stars Academy of Arts & Science, an operation dedicated to U.F.O.-related education, entertainment, and research, and organized by Tom DeLonge, a former front man of the pop-punk outfit Blink-182. Later that month, DeLonge invited Elizondo onstage at a launch event. Elizondo announced that they were “planning to provide never-before-released footage from real U.S. government systems—not blurry amateur photos but real data and real videos.”

Kean was told that she could have the videos, along with chain-of-custody documentation, if she could place a story in the Times. Kean soon developed doubts about DeLonge, after he appeared on Joe Rogan’s podcast to discuss his belief that what crashed at Roswell was a reverse-engineered U.F.O. built in Argentina by fugitive Nazi scientists, but she had full confidence in Elizondo. “He had incredible gravitas,” Kean told me. She called Ralph Blumenthal, an old friend and a former Times staffer at work on a biography of the Harvard psychiatrist and alien-abduction researcher John Mack; Blumenthal e-mailed Dean Baquet, the paper’s executive editor, to say that they wanted to pitch “a sensational and highly confidential time-sensitive story” in which a “senior U.S. intelligence official who abruptly quit last month” had decided to expose “a deeply secret program, long mythologized but now confirmed.” After a meeting with representatives from the Washington, D.C., bureau, the Times agreed. The paper assigned a veteran Pentagon correspondent, Helene Cooper, to work with Kean and Blumenthal.

On Saturday, December 16, 2017, their story—“Glowing Auras and ‘Black Money’: The Pentagon’s Mysterious U.F.O. Program”—appeared online; it was printed on the front page the next day. Accompanying the piece were two videos, including “FLIR1.” Senator Reid was quoted as saying, “I’m not embarrassed or ashamed or sorry I got this going.” The Pentagon confirmed that the program had existed, but said that it had been closed down in 2012, in favor of other funding priorities. Elizondo claimed that the program had continued in the absence of dedicated funding. The article dwelled not on the reality of the U.F.O. phenomenon—the only actual case discussed at any length was the Nimitz encounter—but on the existence of the covert initiative. The Times article drew millions of readers. Kean noticed a change almost immediately. When people asked her at dinner parties what she did for a living, they no longer giggled at her response but fell rapt. Kean gave all the credit to Elizondo and Mellon for coming forward, but she told me, “I never would have ever imagined I could have ended up writing for the Times. It’s the pinnacle of everything I’ve ever wanted to do—just this miracle that it happened on this great road, great journey.”

It was hard to tell, however, what exactly AATIP had accomplished. Elizondo went on to host the History Channel docuseries “Unidentified,” in which he solemnly invokes his security oath like a catchphrase. He insisted to me that AATIP had made important strides in understanding the “five observables” of U.A.P. behavior—including “gravity-defying capabilities,” “low observability,” and “transmedium travel.” When I pressed for details, he reminded me of his security oath.

Perhaps unsurprisingly for a Pentagon project that had begun as a contractor’s investigation into goblins and werewolves, and had been reincarnated under the aegis of a musician best known for an album called “Enema of the State,” AATIP was subject to intense scrutiny. Kean is unwavering in her belief that she and an insider exposed something formidable, but a former Pentagon official recently suggested that the story was more complicated: the program she disclosed was of little consequence compared with the one she set in motion. Widespread fascination with the idea that the government cared about U.F.O.s had inspired the government at last to care about U.F.O.s.

Within a month of the Times article’s publication, the Pentagon’s U.A.P. portfolio was reassigned to a civilian intelligence official with a rank equivalent to that of a two-star general. This successor—who did not want to be named, lest U.F.O. nuts swarm his doorstep—had read Kean’s book. He channelled the cascade of media interest to argue that, without a process to handle uncategorizable observations, rigid bureaucracies would overlook anything that didn’t follow a standard pattern. At the height of the Cold War, the government had worried that the noise of lurid phantasmagoria might drown out signals relevant to national security, or even provide cover for adversarial incursions; now, it seemed, the concern was that valuable intelligence wasn’t being reported. (The Nimitz encounter didn’t become subject to official investigation until years after the incident, when an errant file landed on the desk of someone who decided that it merited pursuit.) “What we needed,” the former Pentagon official said, “was something like the post-9/11 fusion centers, where a D.O.D. guy can talk to an F.B.I. guy and an N.R.O. guy—everything we learned from the 9/11 Commission.”

In the summer of 2018, Elizondo’s successor brandished Kean’s article to make this case to members of Congress. According to the former Pentagon official, a member of the Senate Armed Services Committee inserted language into the classified annex of the 2019 National Defense Authorization Act, passed in August of 2018, that obligated the Pentagon to continue the investigations. “The U.A.P. issue is being taken very seriously now even compared to where it was two or three years ago,” the former Pentagon official said.

The activity intensified. In April of 2019, the Navy revised its official guidelines for pilots, encouraging them to report U.A.P.s without fear of scorn or censure. In June, Senator Mark Warner, of Virginia, admitted that he had been briefed on the U.A.P. matter. In September, a spokesperson for the Navy announced that the “FLIR1” video, along with two videos associated with sightings off the East Coast in 2015, showed “incursions into our military training ranges by unidentified aerial phenomena.” The “unidentified” label had been given an institutional imprimatur.

The debunkers were unimpressed by the designation, and their work continued apace. Mick West devoted multiple YouTube videos to his contention that “FLIR1” shows, in all likelihood, a distant plane. He maintained that the remainder of the available evidence from the Nimitz encounter was even shakier: he suspects that the presences picked up by the U.S.S. Princeton were probably birds or clouds, registered by a brand-new and likely miscalibrated radar system—the U.S.S. Roosevelt, off the East Coast, had also received a technological upgrade before a similar raft of sightings in 2014 and 2015—and that the Tic Tac-shaped object Commander Fravor saw was something like a target balloon. He has no explanation for what the other pilots saw, but points out that perceptions are subject to illusion, and memory is malleable.

Were our finest pilots and radar operators so inept that they were unable to recognize an airplane in restricted airspace? Or was the government using the word “unidentified” to conceal some deeply classified program that a branch of the service was testing without bothering to notify the Nimitz pilots? The former Pentagon official assured me that West “doesn’t have the whole story. There’s data he will never see—there’s much more that I would include in a classified environment.” He went on, “If Mick West feeds the stigma that allows a potential adversary to fly all over your back yard, then, cool—just because it looks weird, I guess we’ll ignore it.”

The point of using the term “unidentified,” he said, was “to help remove the stigma.” He told me, “At some point, we needed to just admit that there are things in the sky we can’t identify.” Despite the fact that most adults carry around exceptionally good camera technology in their pockets, most U.F.O. photos and videos remain maddeningly indistinct, but the former Pentagon official implied that the government possesses stark visual documentation; Elizondo and Mellon have said the same thing. According to Tim McMillan, in the past two years, the Pentagon’s U.A.P. investigators have distributed two classified intelligence papers, on secure networks, that allegedly contain images and videos of bizarre spectacles, including a cube-shaped object and a large equilateral triangle emerging from the ocean. One report brooked the subject of “alien” or “non-human” technology, but also provided a litany of prosaic possibilities. The former Pentagon official cautioned, “ ‘Unidentified’ doesn’t mean little green men—it just means there’s something there.” He continued, “If it turns out that everything we’ve seen is weather balloons, or a quadcopter designed to look like something else, nobody is going to lose sleep over it.”

Elizondo never got to Mattis, but his successor managed to get briefings in front of Mark Esper, the Secretary of Defense, as well as the director of National Intelligence, the Senate Select Committee on Intelligence, the Senate Armed Services Committee, and several members of the Joint Chiefs of Staff. Government officials in Japan later divulged to the media that they had discussed the topic in a meeting with Esper in Guam. When I asked the former Pentagon official about other foreign governments, he hesitated, then said, “We would not have moved forward without briefing close allies. This was bigger than the U.S. government.”

In June of 2020, Senator Marco Rubio added text into the 2021 Intelligence Authorization Act requesting—though not requiring—that the director of National Intelligence, along with the Secretary of Defense, produce “a detailed analysis of unidentified aerial phenomena data and intelligence reporting.” This language, which allowed them a hundred and eighty days to produce the report, drew heavily from proposals by Mellon, and it was clear that this concerted effort, at least in theory, was a more productive and more cost-effective iteration of the original vision for AATIP. Mellon told me, “This creates an opening and an opportunity, and now the name of the game is to make sure we don’t miss that open window.”

Still, the former Pentagon official told me, “it wasn’t until August of 2020 that the effort was really real.” That month, the Deputy Secretary of Defense, David Norquist, publicly announced the existence of the Unidentified Aerial Phenomena Task Force, whose report is anticipated in June. The Intelligence Authorization Act finally passed in December. The former Pentagon official worries that an appetite for disclosure has been heedlessly stoked. “The public, I would hope, doesn’t expect to see the crown jewels,” he said.

West was nonchalant. “They’re just U.F.O. fans,” he said of Reid and Rubio. “They’ve been convinced there’s something to it and so are trying to push for disclosure.” The former Pentagon official conceded that there were “a lot of government people who are enthusiasts on the subject who watch the History Channel and eat this stuff up 24/7.” But, he said, the current mood was by no means set by “a small cadre of true believers.”

Virtually all astrobiologists suspect that we are not alone. Seth Shostak, the senior astronomer at the SETI Institute, has wagered that we will find incontrovertible proof of intelligent life by 2036. Astronomers have determined that there may be hundreds of millions of potentially habitable exoplanets in just our galaxy. Interstellar travel by living beings still seems like a wildly remote possibility, but physicists have known since the early nineteen-nineties that faster-than-light travel is possible in theory, and new research has brought this marginally closer to being achievable in practice. These advances—along with the further inference that ours is a mediocre or even inferior civilization, one that could well be millions or billions of years behind our distant neighbors—have lent a bare-bones plausibility to the idea that U.F.O.s have extraterrestrial origins.

Such a prospect, as Hynek wrote in the mid-nineteen-eighties, “overheats the human mental circuits and blows the fuses in a protective mechanism for the mind.” Its destabilizing influence was clear. I would begin interviews with sources who seemed lucid and prudent and who insisted, like Kean, that they were interested only in vetted data, and that they used the term “U.F.O.” in the strictly literal sense—whether the objects were spaceships or drones or clouds, we just didn’t know. An hour later, they would reveal to me that the aliens had been living in secret bases under the ocean for millions of years, had genetically altered primates to become our ancestors, and had taught accounting to the Sumerians.

Since 2017, Kean has covered the U.F.O. beat for the Times, sharing a byline with Ralph Blumenthal on a handful of stories. These have steered clear of such genre mainstays as crop circles and Nazca Lines, but their most recent article, published last July, veered into fringe territory. In it, they referred to “a series of unclassified slides,” of somewhat uncertain lineage but apparently shown at congressional briefings, that mentioned “off-world” vehicles and “crash retrievals.” Kean told me in an uncharacteristically hesitant but nonetheless matter-of-fact way that she had begun to come around to the idea that U.F.O. fragments had been hoarded somewhere. In 2019, Luis Elizondo had suggested to Tucker Carlson that such detritus existed. (He then quickly invoked his security oath.) Kean cited Jacques Vallée, perhaps the most famous living ufologist, and the basis for François Truffaut’s character in “Close Encounters of the Third Kind,” who has been working with Garry Nolan, a Stanford immunologist, to analyze purported crash material for scientific publication. (Vallée declined to speak about it on the record, concerned that it might undermine the peer-review process, but told me, “We hope it will be the first U.F.O. case published in a refereed scientific journal.”)

In the story, Kean and Blumenthal wrote that Harry Reid “believed that crashes of vehicles from other worlds had occurred and that retrieved materials had been studied secretly for decades, often by aerospace companies under government contracts.” The day after its publication, the Times had to append a correction: Senator Reid did not believe that crash debris had been allocated to private military contractors for study; he believed that U.F.O.s may have crashed, and that, if so, we should be studying the fallout. When I asked Reid about the confusion, he told me that he admired Kean but that he had never seen proof of any remnants—something Kean had never actually claimed. He left no doubt in our conversation as to his personal assessment. “I was told for decades that Lockheed had some of these retrieved materials,” he said. “And I tried to get, as I recall, a classified approval by the Pentagon to have me go look at the stuff. They would not approve that. I don’t know what all the numbers were, what kind of classification it was, but they would not give that to me.” He told me that the Pentagon had not provided a reason. I asked if that was why he’d requested SAP status for AATIP. He said, “Yeah, that’s why I wanted them to take a look at it. But they wouldn’t give me the clearance.” (A representative of Lockheed Martin declined to comment for this article.)

The former Pentagon official told me that he found Kean’s evidence wanting. “There are terms in Leslie’s slides that we don’t use—stuff we would never say,” he said. “It doesn’t pass the smell test.” But, when I asked him whether he thought that there might be recovered debris somewhere, he paused for a surprisingly long time. He finally said, “I couldn’t say yes, like Lue”—Luis Elizondo—“did. I honestly don’t know.” He continued, “There are guys who spent their lives studying stuff like Roswell and died with no answers. Are we all going to die with no answers?”

Not everyone needs answers, or expects the government to provide them. In February, I spoke to Vincent Aiello, a podcaster and former fighter pilot, who served on the Nimitz at the time of the encounter. He told me that the widespread impression of Commander Fravor’s story back then, thirteen years before it became a news sensation, was that it sounded pretty far out, but that the gossip and laughter on the ship petered out after a day or two. “Most military aviators have a job to do and they do it well,” he said. “Why pursue life’s great mysteries when that’s what Geraldo Rivera is for?”

The mysteries have shown no signs of abatement. In early April, the eminent U.F.O. journalist George Knapp, along with the documentary filmmaker Jeremy Kenyon Lockyer Corbell, best known for his participation in an ill-begotten crusade to “storm” Nevada’s Area 51, released a video and a series of photos that had apparently been leaked from the U.A.P. Task Force’s classified intelligence reports. The video, taken with night-vision goggles, shows three airborne triangles, intermittently flashing with eerie incandescence as they rotate against a starry sky. Kean texted me, “Breaking huge story.” She was trying to get to the bottom of the video, but doubted that any of her sources would be willing to authenticate something so hot. The next day, the Department of Defense confirmed that the video was real and said that it had been taken by Navy personnel. Mick West argued, persuasively, that the pyramids were an airplane and two stars, distorted by a lens artifact. Kean, for her part, told me that she was “only just starting to look into the situation,” but volunteered that West was “being reasonable.” The Pentagon refused further comment.