Since its founding in 1974, the National UFO Reporting Center (NUFORC) has served as a non-judgmental hub where you can share—via hotline or written report—any potentially otherworldly experience you’ve had. The online archive contains thousands of these stories, which range from UFO and alien sightings to other unexplained phenomena. The NUFORC doesn’t question the veracity of the reports, and it doesn’t always speculate about possible causes, either. In fact, the organization encourages a healthy skepticism about what you read on its site.

Decide for yourself whether each eerie tale below is the result of extraterrestrial intervention, military experimentation, a scientific anomaly, or just a misunderstanding—that is, if you believe them at all.

1. Too Much Hair, Too Little Time // 1969

On a weekend trip to Boulder, Colorado, in 1969, a young member of the Air Force was in bed when his motel room suddenly darkened, “followed by a bright flash of light.” The next day, he realized his half-inch-long hair was now almost two inches long, a mystery that his roommate “totally freaked out” about when he returned to the base in Aurora, Colorado. “He wasn’t sure what to think of my story, but did realize there was glaring physical evidence,” the airman recalled. Though he didn’t remember anything else from that night, he speculated in his report that he had been abducted (and presumably taken to a place where time passes more quickly than it does on Earth). “I still have trouble remembering many things, as it has always been very ‘foggy’ since that time,” he said.

2. The Long-Armed Collector // 1971

At about 10 p.m. one summer night in 1971, two teenage girls crept from their houses in Sunnyvale, California, and met up for a neighborhood stroll. All was still and silent for an hour or so, until they came upon a 20- to 30-foot flying ship hovering as low as the streetlights “probably a full five-minute walk ahead” of them. The friends watched it drift toward some nearby apartment buildings and appear to survey them, bobbing slightly up and down. “It had these great enormous arms on the sides that slowly swiveled around and they had lines on the ends, like ropes, but they weren’t ropes,” one of the friends explained in her report.

It didn’t make noise or light up, and it looked more like wood than metal. She got the impression it was “collecting things,” though she couldn’t see what was inside. The girls fled in terror when the aircraft abruptly turned its attention on them, and they tried in vain to convince the one friend’s father that they had seen something truly extraordinary. “He dismissed it and said it was probably just a weather balloon,” the witness wrote. “If I am sure of anything, it is that that thing was no weather balloon.”

3. Cows Gone Wild // 1975

Scared now, brown cow?kmatija/iStock via Getty Images

Two friends were driving along the quiet country roads of La Fontaine, Indiana, after a fishing trip one evening in 1975. About a quarter mile away, a flying disc “with white lights revolving around it” appeared and lowered itself gradually until it was completely obscured by a nearby house. They followed it behind the house, but found only “cows running all over the road, frightened and mooing.” The cows had apparently torn right through the electric fence, and a neighbor soon showed up to see what all the fuss was about. “He asked if we knew what had happened because cows just don't break down an electric fence for nothing,” the witness said. “We didn’t say anything about what we had just seen.”

4. The Vanishing Silver Ship // 1979

From his front step in Wenatchee, Washington, a man watched a silver triangular aircraft with “no discernible fuselage, no wings or other protruding control devices” coast slowly over the tops of 150-foot-tall poplar trees. “A jet liner could not have stayed airborne at such a sedate rate of speed,” he recalled, and this was significantly larger than a Boeing 747. There wasn’t much time to wonder about the physics that kept the craft in flight, because it was drifting straight toward Burch Mountain. “My immediate thought was that a monstrous crash was imminent,” the witness explained, but it never came to pass. Instead, the UFO just disappeared.

The NUFORC actually vouched for this particular onlooker. “One of two excellent reports from [the] same witness,” they wrote in a note below his report. “We know this witness, and have spoken with him on several occasions. He formerly served in the U.S. military, and held a high security clearance.”

5. The Glowing Gray Nighttime Visitor // 1982

A man in Leicester, England, awoke one night in 1982 to find a soft light illuminating his room. It was coming from the face of a 4-foot-tall gray creature that resembled the classic aliens from 1977’s Close Encounters of the Third Kind. The witness, “overwhelmed with a feeling of calm and peace,” pinched himself several times to make sure he wasn’t simply dreaming and scanned the room in vain for some other explanation. Knowing he’d have a tough time convincing anyone he was telling the truth, he nudged his wife awake so she could bear witness, too. But as soon as she stirred, the room went completely black and the visitor vanished. “Did I imagine or dream the whole thing?” he wrote in his report. “Absolutely one million percent no.”

6. The Disembodied Search Beam // 1988

Three friends were on their way home from an INXS concert in Pittsburgh when they encountered a ball of light sweeping a “very bright beam of light” over the dark road and its surroundings. They promptly pulled over, and two of them exited the car so they could get a better look. (The third friend “remained in the car, screaming.”) Though the light resembled a helicopter’s search beam, “there was no hint of any craft or body emitting the beam, even when it faced away from us.” Furthermore, the whole scene was completely silent. They quickly returned to the car when the beam drew closer, and it suddenly darted away and disappeared into the night. When they resumed their journey, the radio played static before cutting out completely. “We heard a commentator say ‘…further evidence that there is life on Mars…’ and then it went back to static,” the witness reported.

7. A Fiery Hoberman Sphere // 1991

A normal Hoberman sphere.membio/iStock via Getty Images

Late one evening in 1991, a young man and his girlfriend parked the car in a peaceful spot overlooking the port of Olympia, Washington, and passed about half an hour “talking about life and random things.” Suddenly, what they thought was one abnormally bright star split into a sphere comprising roughly 20 points of light—much like a Hoberman sphere expands ("I found out many years later what a Hoberman Sphere is, and just about crapped myself the first time I saw one in motion its movement looked so similar," the witness noted)—and rotated rapidly before contracting back into a single bright light. That light then glowed red and spit out five identical red lights, one by one, which pulsated in a synchronized manner as they flew through the sky in a straight line and eventually vanished. The witness actually managed to capture video footage of the event, but the camera only showed “a blank screen with a few strange flickering whitish dots on it that seem to come and go.”

“I am (after seeing it) hard pressed to believe it to be anything of ‘known’ terrestrial technology,” he wrote. “I have resigned to the likelihood that I will never know what it was at all.”

8. The Ides of March Sightings // 1995

On March 15, 1995, the NUFORC received an influx of calls across several states from witnesses who saw a bright object flying through the night sky. The first of these so-called “Ides of March sightings” was reported by two men in Florida, who described it as “luminous,” “white,” and “disc-shaped,” though subsequent descriptions from others varied. A Tennessee caller thought it was more of a “blue-green 'cloud of light'” that emitted sparks before vanishing, and a Missouri State Highway Patrol sergeant said it was a green light that turned yellow and suddenly snuffed out “like a light being switched off.” He also explained that many people called the patrol’s 911 dispatch line to report their own sightings, and one person claimed his cell phone and car radio both died when the UFO got close. Other reports came from Virginia, West Virginia, and Missouri.

“In summary, it appears that one or more egg-shaped objects, radiating intensely bright green, blue-green, and yellow light, and periodically spewing out a cloud of sparks, streaked over at least seven states, stopping from time to time, and the whole event occurred in a matter of minutes,” the NUFORC summarized in a case brief.

9. The Phoenix Lights // 1997

In March 1997, Arizona played host to what the NUFORC dubbed “perhaps the most dramatic UFO sighting” reported in a few years. Dozens of people from all over the state phoned the hotline to report having seen a group of white or red lights in a V formation flying across the sky. One man with flight experience estimated that the lights were about 1000 feet from the ground, and multiple people claimed the display was totally silent—making it unlikely that airplanes were responsible. When that same observer phoned Luke Air Force Base about the event, the operator told him they had received calls from many other witnesses, too. But according to the NUFORC, the base later claimed that nobody had called them about it.

After these “Phoenix Lights” received national media attention several months later, the military finally offered an explanation: The lights were just leftover flares that the Maryland Air National Guard had dropped at the end of an operation in Arizona. But some people remain unconvinced.

10. Elk, Abducted // 1999

Please do not beam up the elk.ericfoltz/iStock via Getty Images

Three foresters were planting seedlings in Washington’s mountains when a gently wobbly disc-shaped aircraft appeared and drifted toward a herd of elk. Nearly all the animals fled together, but one set off in a different direction. The UFO positioned itself over the lone elk and beamed it right off the ground, though the observers couldn’t discern any “visible means of support,” attached to it. The UFO wobbled more, seemingly struggling with the weight of its prey, and eventually rose so high that the witnesses couldn’t see it anymore. They assumed the elk had somehow ended up inside the aircraft.

When NUFORC director Peter Davenport traveled to Washington to conduct an investigation, he was shown the carcass of a pregnant elk that had been found dead just a few miles from the UFO sighting. As for whether that was the same sorry creature that the UFO had supposedly targeted, we’ll almost definitely never know.

11. High-Flying Real Estate // 2000

Shortly after 4 a.m. one morning in January 2000, Ed Barton, a police officer in Lebanon, Illinois, heard a dispatch about a strange UFO sighting at a neighboring police station. He looked up and saw the object for himself: two extraordinarily bright lights that seemed to merge into one even brighter light. He sped off in the object’s direction until it was almost overhead, and ballparked its altitude somewhere between 1000 and 1500 feet. It was triangular, with a light on each corner and many more along one end. The object abruptly shot through the sky so fast that Barton concluded it couldn’t possibly have been created by humans.

Other Illinois residents witnessed it, too. A Millstadt police officer named Craig Stevens thought it was between one and two stories tall, and “perhaps three stories long.” Highland resident Melvern Noll also likened it to a house. “There were big windows, about two and a half feet wide and five or six feet high, two stories, one on top of each other,” he told the St. Louis Post-Dispatch in 2010. “I still believe it was something from another planet.”

Though a spokesman for the nearby Scott Air Force Base is said to have claimed that the base’s radar had been shut off at the time and nobody had seen the UFO, other reports allege that the government was involved. The NUFORC received one report from “a highly reliable source” who said the Air National Guard jets "may have been 'scrambled" to take a look at the object,'" and several other people even told the NUFORC that federal government employees visited police departments and citizen witnesses to ask that they “curtail all their statements to the press."