
A car drives along an empty stretch of highway late one night in the mountains of New Hampshire, USA. Out of nowhere, a bright light appears. Could it be a falling star? It is September 19, 1961, and Betty and Barney Hill are on their way home from vacation in Montréal, Canada. Strangely, the bright light seems to follow them. Then the car starts to vibrate and the Hills hear strange buzzing and beeping sounds. A feeling of drowsiness washes over them.
Suddenly, they find themselves 35 miles further south. They have vague memories of taking a sudden turn and encountering a roadblock. But several hours have passed that they cannot explain. They arrive home around dawn. When they get there, they discover that Barney’s binocular strap is broken and his shoes are scuffed. Betty later notices that her dress is torn and stained.
Ten days later, Betty starts having vivid dreams about going through an alien abduction. A few years later, under hypnosis, the Hills recall a horrifying ordeal. In this memory, the light drops rapidly and a large, disc-shaped ship hovers overhead. Barney gets out and peers through his binoculars at an astonishing sight. Almost a dozen figures in black uniforms stare out from inside the craft. The figures, who look like humans, take Barney and Betty inside. They bring them to different rooms and put each of them through a series of medical tests and procedures. Betty cries out when her examiner pierces her belly button with a sharp needle. But then she talks to her captors. They show her a book full of strange symbols and a map of stars.
After one of the hypnosis sessions, Betty draws the star map her captors showed her . The map seems to represent the Zeta Reticuli system, a pair of dim stars located around 230 trillion miles from Earth. Could the Hills have been the victims of an alien abduction?
The First Flying Saucers
The Hills’ experience became famous . But it wasn’t the first—or last—alien encounter to capture the public’s imagination. Many people have seen lights or flying objects that they can’t explain. In June 1947, pilot Kenneth Arnold was flying near Mount Rainier in Washington state when he saw nine objects flying in formation along the ridgeline of the mountains. He described them as looking like saucers skipping across water. The name “flying saucer” stuck, and the news of this sighting spread around the world.

A few weeks later, a rancher named Mack Braze l brought some unusual debris to the sheriff of Roswell, New Mexico: tinfoil, rubber, and pieces of a strangely lightweight— yet strong—reflective material. Brazel had found the stuff scattered on his property, and wondered if it could be the wreckage of a flying saucer . The nearby Roswell Army Air Force Base had no idea what to make of the debris, either. They told the media that they had recovered a flying disc . Shortly afterwards, higher up government officials claimed it was just a crashed weather balloon . But those who had seen weather balloons before didn’t believe it. Was this a government conspiracy to cover up a real alien landing?
Soon after these two incidents, sightings of flying saucers began flooding in from all over the United States. In 1952, the Air Force launched Project Blue Book to investigate what they dubbed UFOs, short for “unidentified flying objects. ” Though this investigation ended, sightings have continued.
Today, the Mutual UFO Network (MUFON) logs over 500 reports every month of sightings from around the world. Could all of these people, including the Hills, be wrong?
Problems with Perception

In many cases, people really do see strange lights or shapes in the sky. But that doesn’t mean extraterrestrials have visited Earth. The re a re other, more rational explanations. For example, the crashed craft at Roswell was actually a top- secret US government attempt to spy on the Soviet Union during the Cold War. It was a balloon carrying a sensing device complete with microphones and a disc-shaped antenna. Most of the officials who looked at the debris knew nothing about the new technology, so wrongly assumed that it wasn’t human.
Human technology and natural events get mistaken for UFOs all the time. Common false alarms include unusual clouds, mirages, flares, balloons, rocket launches, drones, and more . How do people mistake these things for alien spacecraft? It’s important to understand that what you see is not always actually what’s out there in the world. “It’s a recreation in your brain of what you think you’re seeing,” explains James McGaha, a retired US Air Force major and an astronomer.
The brain is a machine that works to keep you safe. When early humans had to watch out for dangerous animals, it was safer to believe that a rustling sound or shadow was a beast than to assume it was the wind or a trick of the light. The brain seeks edges, shapes, patterns, and connections. It often finds things that could be considered a threat—like alien aircraft—even when they aren’t really there. For example, the objects that Arnold saw were probably a mirage, says McGaha . Mirages are illusions that happen when light bends as it passes through layers of cold and warm air.
In March 1997, many people living in and around Phoenix, Arizona saw a triangular pattern of lights in the sky. An amateur astronomer watching the sky that night through a telescope identified the lights as airplanes. However, some witnesses were adamant that the lights were all part of one huge spacecraft. Perhaps their brains filled in the space between the lights to make a larger shape . Videos showed the lights changing position from a V-shape to a straight line, something that lights on a single craft would not do.
So what about the Hills? They most likely really did see a strange light in the sky, too. Jim Macdonald, a resident of the area in which the Hills claimed to be abducted, thinks the light was actually an ordinary light on top of Cannon Mountain. He’s seen it many times driving that same route. Perhaps he is right. However, if the ‘spaceship’ Betty and Barney saw was really just a light, how is it possible that they remember going on board?
Dreams vs Reality

The Hills aren’t alone in believing that they’ve had contact with aliens. Today, people who have seen or encountered extraterrestrials call themselves Experiencers. Some report scary or terrifying abductions. But many others feel special or lucky to have come into contact with otherworldly beings. They often believe that extraterrestrials are here to help humanity. They are likely not lying about what they saw, heard, or felt. But that doesn’t mean alien encounters actually happened.
Personal experiences aren’t always accurate. For example, in a hallucination, a fully awake person experiences sights, sounds, tastes, or textures that aren’t really there. They might feel real, but they aren’t. This is very rare, and usually indicates a mental illness or other health disorder. However, at night, in dreams, we all experience vivid events that are completely imaginary. When we wake up, if we even remember any dreams, we realize that they were not real. But right at the edge between wakefulness and sleep, reality blurs. This is called the hypnagogic state. While just falling asleep or just waking up, or in a dreamy state such as hypnosis or meditation, a completely healthy person may experience some truly bizarre things.
One of those strange experiences is called sleep paralysis. During sleep, the brain prevents the rest of the body from moving . This keeps you from thrashing around and hurting yourself while dreaming. But sometimes, a person starts to wake up while still in this paralyzed state. The person usually sees his or her real surroundings, but sights, sounds, and other sensations leak in from the dream state. Often, it seems as if someone else is in the room. At the same time, it’s impossible to move, speak, or breathe deeply.
Psychologist Susan Clancy spent several years interviewing people who say they’ve encountered aliens. Some of their stories sounded exactly like sleep paralysis. A computer programmer she calls Mike said, “I woke up around 3 AM and couldn’t move. I managed to open my eyes and there were creatures in the room with me. I saw shadowy figures around my bed … ” And another man, a dermatologist she calls James, said, “I found myself waking up in the middle of the night, seized with fear. There were beings standing around my bed, but I was totally paralyzed, incapable of moving. ”
False Memories

Sleep paralysis helps explain some instances of encounters with aliens. But not all. Betty and Barney Hill weren’t in bed or paralyzed when they saw a strange light. In their case and in many other cases of alien encounters, the complete story of what happened only emerged after hypnosis. During the 1980s and 1990s, many professional psychotherapists believed that hypnosis was a good tool to bring back lost or forgotten memories. But since then, experts have come to realize that hypnosis can actually create false memories. How is this possible?
Many people think that memory is like a video recording of an event. But unlike a video, a memory does not remain the same every time you think about it. Every time you remember something, the brain rebuilds the memory, often with new details. If someone suggests that something happened to you, even if it didn’t, you may begin to remember it happening. When this suggestion happens before or during hypnosis, the mind may create a fantasy that feels like a vivid, real memory.
A person won’t create a memory about an alien abduction out of nowhere. Clancy found that the people she interviewed all believed in aliens before remembering an encounter with them. Betty was interested in UFOs long before the sighting. Also, it’s important to remember that she dreamt about an alien abduction shortly after the event. Her dreams, which she almost definitely shared with her husband, included all the main events which she later ‘remembered’through hypnosis. Could Betty and Barney have just been remembering Betty’s dreams, rather than the reality of what happened that night?
Television may have also played a part. At first, Betty described the aliens as short men with black hair and big noses. But she changed her story after hearing one of Barney’s hypnosis sessions. He remembered the aliens with gray skin, huge eyes, and large, bald heads. This matched the alien character in an episode of the TV show Outer Limits that had aired less than two weeks earlier. Many years later, Barney claimed never to have seen the show . However, it’s an uncanny coincidence. Perhaps he forgot about watching it, or saw advertisements for it.

But what about the map Betty drew? An amateur astronomer named Marjorie Fish painstakingly searched until she found that it matched the Zeta Reticuli system. But she based her search on information from 1969. A later survey of the sky revealed the map didn’t match after all.
Unexplained … but not Unexplainable
So what really happened to the Hills that night? Something certainly made their journey take longer than expected. It was late at night and they’d been driving for a very long time . They remembered feeling drowsy, a common sign of a state of reduced awareness called “highway hypnosis. ”
Perhaps they drifted off the road or took a wrong turn, and got out of the car while trying to figure out what happened. This could help explain the reported damage to the shoes, binocular strap, and dress. A disturbing event like this, coupled with Betty’s interest in UFOs, may have inspired her to dream about an alien abduction . She shared her dreams with her husband and later these were recalled and new details added under hypnosis, which made the dreams feel like real memories. We’ll never know for sure, but perhaps this is the most likely explanation.
The truth is that there are many UFO and alien encounter stories which aren’t easily explained away. Believers like to offer unexplained sightings as evidence that something otherworldly must be happening. But“unexplained” does not imply “unexplainable . ” A lack of information may make it impossible to identify the real cause of a strange light. Casual observers often don’t note the time, date, location, distance, speed, duration, or other facts which could solve the mystery.
And in very rare cases, a strange light remains mysterious even after some serious analysis. In the remote valley of Hessdalen in Norway, balls of lights have been appearing, hovering, and flashing regularly since the 1980s. Some UFO enthusiasts have claimed the valley is a portal to other worlds. And some skeptics say it’s all a hoax.
Meanwhile, a small group of scientists has been methodically measuring the lights and collecting data since 1983. One of their theories suggests that the valley may act as a giant natural battery. The rocks on one side of the river contain copper and those on the other side contain iron and zinc. And sulfur from an abandoned mine flows through a river at the bottom of the valley. This unique arrangement may produce an electric field. But the field on its own wouldn’t make visible light. It needs another energy source. This may come from the sun. When its activity increases, it pelts Earth with bursts of radiation. Sometimes, the scientists suspect,this may spark lights in the valley.

The source of the Hessdalen lights remains a mystery. But that might not imply extraterrestrial visitors. It simply means that the natural world is an amazing place that we still don’t fully understand.
Real Aliens
Someday, people may encounter alien life. It’s not impossible. “We are beginning our own exploration of space, so it’s entirely reasonable there would be others who have done so,” says James Oberg, a retired NASA engineer. Since life evolved on Earth, the same process could certainly take place elsewhere in the universe. It’s a huge place. “There are approximately 100 billion galaxies, each one with about 200 billion stars like our Sun,”says Eddie Irizarry, a solar system ambassador for NASA. Planets circle some of those stars. And some of those planets may have the right conditions for life.
However, to arrive at Earth, an alien species would need to develop enough intelligence to build technology more advanced than our own. Plus, they would then need to explore far beyond their home planet and discover Earth. So most astrophysicists are not expecting to encounter intelligent life any time soon. Rather, they focus on looking for planets with the conditions to support any kind of life.
One of the most important ingredients for life as we know it is liquid water. In our own solar system, liquid water lurks beneath ice caps on moons of Jupiter and Saturn as well as on Mars. If life does thrive in these hidden waters, it is most likely microscopic. Bacteria and other microbes can survive in extreme conditions on Earth. So it’s reasonable to expect that they are much more common in the universe than more complex life forms like us.
Perhaps one day, we will be the aliens who visit another planet and abduct its microbial life.
This is an excerpt from the book, Strange But True: 10 of the world’s greatest mysteries explained. (Quarto, October 1, 2019, 128 pages).