In the corner of the social-media universe that calls itself #ufotwitter, there’s always some new piece of visual evidence to discuss. Did a police body cam catch an otherworldly craft crash-landing in Vegas this week? And that kid nearby who called 911 to report an eight-foot-tall alien in his back yard—is he for real? What about this video of a saucer losing its tractor-beam grip on a cow and sending it winging over the treetops? Is this connected to the recent spate of cattle mutilations? What do you make of this blurry splotch? Does this light look weird?

Of course, it’s hard to believe anything we see nowadays, and forecasts of an A.I.-fuelled disinformation apocalypse suggest that’s only going to get worse. But, in the world of U.F.O. hunters, the lack of high-quality photographic proof has always been a vexing problem. “Considering the notorious camera-mindedness of Americans,” Carl Jung wrote presciently in his 1958 book “Flying Saucers,” “it is surprising how few ‘authentic’ photographs of UFOs seem to exist, especially as many of them are said to have been observed for several hours at relatively close quarters.” Now with high-definition photographic tools held perpetually in the palms of billions of people across the globe, this problem should give us even more pause. Does this relative shortage of visuals amount to evidence that the U.F.O. phenomenon is pure bunkum, as many skeptics would have us believe? Or is it, as Jung himself famously supposed, because “UFOs are somehow not photogenic”? Or perhaps the truth is already out there, squirrelled away in some Pentagon vault or floating around the Internet, camouflaged amid the dross?

In any case, laughing off U.F.O.s with cracks about tinfoil hats or “little green men” is not as easy as it used to be. In recent years, there has been a welter of developments in the U.F.O. world that has brought the subject out of the realm of science fiction and supermarket tabloids, and into the halls of Congress and the pages of newspapers of record. In 2017, a watershed piece in the New York Times by Helene Cooper, Ralph Blumenthal, and Leslie Kean exposed a secret Pentagon program created to investigate U.F.O.s, and included a pair of flight recordings taken by naval F/A-18F Super Hornets, showing spectral craft performing seemingly impossible maneuvers. (These videos have been the subject of muscular debunking efforts, most prominently by the professional skeptic and ufology bête noire Mick West. Recently, a pair of researchers put forward a detailed thirty-page analysis that attempts to debunk his debunkings.) The piece piqued the interest of both lawmakers and defense officials, who began to take the U.F.O. issue more seriously, creating an investigative body tasked with looking into “unidentified space, airborne, submerged and transmedium objects.”

The most remarkable—or, depending on your perspective, the most unbelievable—recent development came in June, when Kean and Blumenthal released a report in the Debrief, an online news site. It centered on the claims of David Grusch, a former high-level intelligence official who purports to have both knowledge and evidence of U.S.-government U.F.O.-crash-retrieval programs. Last week, in testimony before the House Oversight Committee’s national-security subcommittee, Grusch alleged that the government, in cahoots with unnamed private contractors, has acquired craft of “nonhuman origin” that it has been attempting to reverse engineer for “decades,” and nonhuman “biologics,” a.k.a. the remains of dead aliens. But Grusch has publicly provided no evidence, visual or otherwise, to back up his claims, and he has admitted that all his knowledge of secret U.F.O. programs has come to him secondhand. The problem, as always, is the gap between what we’re told exists and what we can actually see.

So what kind of visual record does the U.F.O. community point to? I made some calls recently, and I got an earful. I was told that the U.S. has a secret space program. I was told about the C.E.O. of an unnamed corporation who saw a gigantic, shape-shifting, probably interdimensional craft fly over Washington, D.C., and then wink miraculously out of existence. I was told about deep underground bases, where U.F.O. reverse-engineering projects have long been operating. I was told that aliens are already walking among us. I was notably not told much about what I was looking for, namely, photographs of the phenomenon that had a stamp of legitimacy. I was assured that such photos exist—in 4K resolution, no less—but that they remain hidden behind a scrim of secrecy. No one seemed to know when the photos might be released. I got the sinking feeling that the answer will always be “soon.”

Over the phone, Kean took me through the collection of famous photographs that she had included in her 2010 book, “UFOs: Generals, Pilots, and Government Officials Go on the Record.” Among them were two impressive-seeming pictures taken during two separate U.F.O. “waves,” the term used for clusters of U.F.O. sightings that occur over a protracted period. One, taken in Belgium during a wave from 1989 to 1990, shows a prototypical “black triangle” U.F.O., a lesser-known cousin of the flying saucer, with fiery blurs of radiance at its corners and a cyclopean eye of light at its center. “I would have told you that was awesome,” Kean said, “but there’s been some questions about it since my book came out. The shooter came forward in 2011 and said that he had hoaxed it.” Another image, taken during the Hudson Valley wave of the mid-eighties, reportedly by a state trooper, shows an arc of lights in a carnivalesque array of colors, hanging in the night sky. “Nobody’s been able to locate and interview the police officer who actually took it,” she said. A series of pictures of an oddly grainy ship that looks like a cross between the planet Saturn and a macaron—which had been “analyzed by the Brazilian Navy” and deemed “authentic” by the president of Brazil, according to the caption accompanying them in the book—were swiftly dismissed as “controversial.” “I trusted the people who vouched for that photograph. But there are people that say that it isn’t,” Kean said. “I just don’t know who to believe sometimes, you know?”

There were a few other photographs, which Kean deemed more promising. The first was a pair of pictures taken in 1950 in McMinnville, Oregon, by a farmer named Paul Trent. One evening that May, the story goes, Trent’s wife Evelyn was out feeding their rabbits when she saw a slow-moving, disc-shaped craft. She called to her husband, who apparently had the presence of mind to snap two photos before the saucer sped off. The resulting images might be the most extensively analyzed U.F.O. photographs in history, even coming under the scrutiny of the U.S. Air Force, which funded a study, known as the Condon Report. It stated that the witness accounts were credible but that it would be “exaggerating to say that we have positively ruled out a fabrication,” and suggested that the craft could have been a “model” suspended from overhead wires visible at the top of the photos. Debates rage to this day.

Kean suggested that I talk to the filmmaker James Fox, who has made several successful documentaries about U.F.O.s. “The one thing that I’m told from all the analysis—folks on the government inside say that, if you see a photograph of an object with clearly defined edges, it’s probably a fake,” he said. “There’s something to do with the propulsion of these objects that blurs the edges of them.” I pointed out that the object in the Trent photograph had rather sharp edges. “Zoom right in,” he replied “Sharpish. Yes. Sharpish. I think if you zoomed right in, you’d find it a little less so.” I was not encouraged.

Kean also directed me to what she called “the best UFO photo ever,” which was taken during an aerial survey of Costa Rica in 1971 and still resides in archives of the country’s National Geographic Institute. The photo has recently circulated online, thanks to the U.F.O. enthusiast Esteban Carranza, who retrieved a copy of the eight-by-ten-inch negative and was able to make a high-resolution drum scan, which provides a stunning level of detail. In the image, what appears to be a disc-shaped object hovers over northern Costa Rica’s Lake Cote, adjacent to a pastoral landscape so richly articulated that you can see individual houses ten thousand feet below. The image is certainly a doozy: government-produced, highly detailed, strange. But is the disc really a craft from another world?

A photograph taken during an aerial survey of Costa Rica in 1971, showing what appears to be a disc-shaped object hovering over Cote Lake.Photograph courtesy of the National Geography Department (IGN) of the National Registry of Costa Rica

A detail of the Costa Rica aerial photograph.Photograph courtesy of the National Geography Department (IGN) of the National Registry of Costa Rica

According to the U.F.O. researcher Mark Pilkington, the answer is no. Pilkington is the author of an excellent 2010 book about U.S. government disinformation operations inside the U.F.O. community, “Mirage Men,” which should be required reading for anyone interested in U.F.O.s. When I asked him about the Costa Rica photo, he sent me a long message-board thread, in which a group of skeptics engage in a Herculean debunking effort, complete with detailed technical analysis of the original camera equipment, heavily annotated dissections of the image’s light, shadow, and grain structure, various internecine squabbles, and talk of pressure marks and chipped glass. Could the shape have been an artifact produced by the camera equipment? Damage to the negative? Maybe. As should be expected, there is an equally detailed set of documents, produced by the U.F.O. researchers Jacques Vallée and Richard Haines, that suggest the image is of a real craft of unknown origin. Neither side’s argument seemed conclusive, but the back-and-forth was enough to at least temper my enthusiasm. “I love the Costa Rica image,” Pilkington wrote to me, “but I think it’s a classic example of seeing what you want to see—which is the key to the whole U.F.O. story, if you ask me.”

This is reportedly the case with the recently released bombshell U.F.O. photograph, which has been dubbed “the Calvine photo,” after the hamlet in Scotland where it was taken, in 1990. For a long time, the picture was the stuff of mere legend: the U.F.O. researcher Nick Pope, a former British Ministry of Defense employee, claimed to have seen a blown-up copy in government offices, but the image remained unseen by the public. That changed last year when the researcher David Clarke discovered a print in the possession of a retired Royal Air Force press officer and published it in the Daily Mail. In the center of the frame, seemingly hovering, is a massive diamond-shaped object, which is being buzzed by what one analyst suggests is a Harrier jet. But Clarke later claimed that he was told by an anonymous U.K. Defence Intelligence officer that the object in question was not an alien craft at all but a highly classified U.S. aircraft flown out of the nearby Machrihanish airbase. Whether this is true or not—compelling analysis by the U.F.O. researcher Wim van Utrecht suggests that the “craft” is merely a Christmas ornament hung sideways from a tree branch—there is a well-documented history, expounded on in “Mirage Men” and elsewhere, of governments using U.F.O.s as a kind of smoke screen to cover up top-secret projects.

Pilkington told me, “From my long experience, almost all U.F.O. cases crumble to dust under heavy analysis.” (He has doubts, for instance, about Grusch’s account of a U.F.O. that supposedly crashed in Italy during the Second World War; according to Pilkington, within Italian U.F.O. circles that incident is considered a “well-known” hoax.) He added, “Ultimately, it’s a matter of taste—whether you want to let the mystery ring or be absorbed by the dull thud of the mundane.” His comment made me think of arguably the most famous U.F.O. photographer of all, the prolific and eccentric hoaxer Eduard (Billy) Meier. Meier took many pictures that he said were of U.F.O.s—he claimed that he was in frequent, intimate contact with an ancient Pleiadian race—but the one that most people would know was featured on a poster in the basement office of the embattled F.B.I. agent Fox Mulder in the sci-fi TV series “The X-Files.” The photograph features a startlingly clear, archetypical saucer suspended in the air above a stand of trees in a bucolic swath of Swiss countryside. In the poster, a cropped closeup of the saucer is accompanied by a phrase in white block letters—which became a kind of mantra for the viewers of the show, myself among them. It reads: “I want to believe.”