The 28 Scariest Things in the Universe

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A list of the spookiest ideas, animals, locations, diseases, and unexplainable events
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The “scariest thing in the world” is going to be entirely subjective and personal. Different people are just naturally going to be scared of different things. That said, we’ve compiled what’s probably the scariest list on the internet. If you aren’t terrified of anything we’ve presented here, you’re a special breed of courageous. Check it out and see what you can stomach!

What Is the Scariest Thing to Humans?

  • Theories: The unknown, the Fermi Paradox, the Great Filter, Solipsism
  • Space: Black holes, Tabby’s Star, space junk, Jupiter’s Great Red Spot
  • Ocean: Unidentifiable sounds, the bottom of the Mariana Trench, giant squid
  • Phenomena: The Mantell Incident, the Wow! Signal, number stations
Section 1 of 5:

Scariest Things in Space

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  1. Step 1 Black holes
    A black hole is an object in space with a gravitational pull that is so strong that nothing can possibly escape it—even light. These mysterious objects are created when stars collapse, and they’re potentially the most unstoppable objects anywhere.[1]
    • Black holes aren’t actually holes; they’re super dense in the middle and contain all of the matter they absorb.[2]
  2. 2
    KIC 8462852 Also known as Tabby’s Star, this star was discovered in the Cygnus constellation in 2016. Unlike other stars, though, the light coming from KIC 8462852 seems to randomly turn up and down. It gets light or dark for days at a time. The problem here is that stars just aren’t supposed to do that, which makes this unexplainable phenomenon pretty scary![3]
    • Some people suggest that the star is a Dyson Sphere—a theoretical structure that an alien civilization could build around a star to harvest its power. The best guess right now, though, is that something seems to block the star randomly. We just can’t figure out what it is. Spooky!
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  3. Step 3 Space junk
    Every time we launch a rocket, space shuttle, or satellite, a little bit of debris comes off. Some of it falls back to Earth, while some of it escapes orbit, but a lot of it ends up getting trapped in Earth’s gravitational field. As time goes on, that junk will just keep accumulating and accumulating until eventually our sky is covered in random trash.[4]
  4. 4
    Jupiter’s Great Red Spot Picture a hurricane twice as strong as any hurricane ever seen on Earth. Now, imagine that hurricane is the size of Earth itself and has been raging for over 150 years. That’s Jupiter’s Great Red Spot. Scary, right?! Imagine being in a storm like that![5]
    • We still aren’t totally sure how the Red Spot formed or why it’s so persistent, which only adds to the scary factor.
  5. 5
    HD 189773b Widely accepted by astronomers as the scariest planet ever discovered, HD 189773b is a nightmare world. If you were to travel there, you’d think you’d be looking at an Earth-like planet as you approach, but upon landing, you’d find winds blowing at 5,400 miles per hour (8,700 km/h)—seven times the speed of sound itself. This would create a whipping noise and force so sickening that you can’t even imagine it. The planet also rains a lot, but instead of water, the rain is glass. Picture shards of glass flying around horizontally every time it rains…terrifying![6]
  6. 6
    Supernovae A supernova occurs as a dying star lets out a massive burst of nuclear energy. Blasts this massive and powerful are very hard to imagine, but think of the brightest light you’ve ever seen and the hottest heat you’ve ever experienced, followed by the creation of a black hole. Not a fun time.[7]
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Section 2 of 5:

Scariest Things in the Ocean

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  1. Step 1 Unidentifiable sounds
    We monitor a lot of things going on in the ocean, but there are a few sounds that have been recorded that have basically zero explanation. These mysterious noises could come from animals we’ve never seen, unexplained geological phenomena, or even aliens! (Okay, probably not aliens, but it’s a theory!)
    • “Slow Down” is a sound discovered in 1997. The leading theory is that this bizarre noise is from an iceberg sliding off an ice shelf, but nobody knows for sure.
    • “Bloop” refers to a series of repeated noises (also discovered in 1997) off the coast of South America. It’s thought that it might be an ice quake (an earthquake that occurs in an ice shelf), but this has never been confirmed.
    • “Upsweep” gets our vote for scariest unidentified sound. These noises appear almost every year, in even intervals, and we have zero logical explanations for them. Plus, the sound is just so scary: it sounds like a ghoulish ambulance siren underwater.
  2. 2
    The bottom of the Mariana Trench Roughly 120 miles (190 km) east of the Mariana Islands sits the Mariana Trench—the deepest trench on Earth. This is as close as you can get to the center of the Earth, with a maximum depth of roughly 6.8 miles (10.9 km) below the surface of the ocean. Not only is the trench pitch black, but its incredibly strong pressure makes it one of the least hospitable places imaginable.[8]
    • Animals also live there (very weird-looking animals, like the dumbo octopus and the frilled shark), which just elevates the overall spooky factor.
  3. 3
    Giant squid These rare creatures grow up to 43 feet (13 m) long and weigh up to 2,000 pounds (910 kg), which is undeniably huge. These enormous sea animals are so rare that a living specimen wasn’t even documented until 2012, when the squid was finally caught on video.[9]
  4. 4
    Rogue waves Also known as freak or killer waves, rogue waves refer to extremely massive waves that appear seemingly out of nowhere. These rare waves are formed by far-away storms that combine with currents to generate massive bursts of oceanic energy. Imagine you’re just hanging out on a cruise ship, living your best life, when a mile-high wave appears out of nowhere with no warning. Pretty scary![10]
  5. Step 5 Goblin shark
    The goblin shark is one of the scariest-looking creatures you could possibly imagine. It has a massive spike sticking out of its head and a protruding mouth that sticks out from its jaw. Luckily, the goblin shark lives nowhere near people, and it’s harmless to us, but it’s still incredibly scary.[11]
  6. 6
    Point Nemo Located at 48°52.6′S 123°23.6′W, Point Nemo is the point in the ocean furthest from any land. If you were to be dropped off at Point Nemo, you’d be 1,670 miles (2,690 km) from any land. Just imagine how scary and alone you’d feel if you were to end up there!
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Section 3 of 5:

Scariest Unexplained Phenomena

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  1. Step 1 The Mantell Incident
    In 1948, veteran pilot Captain Thomas Mantell was flying alongside three other pilots in a training exercise when the group received a request from command to investigate an odd sighting in the sky. Mantell immediately climbed 15,000 feet to pursue the object. He reported something that looked “metallic and … tremendous in size,” Mantell was so shocked that he pursued it past 25,000 feet, then he passed out from a lack of oxygen and his plane stalled. He died in the crash, but the question remains: what did he see in the sky that day?[12]
    • To add to the mystery, the other pilots with Mantell also saw something flying through the sky. To this day, what they saw has never been proven, although many believe Mantell was observing a top-secret atmospheric research balloon developed as Project Skyhook.[13]
  2. Step 2 The Wow! Signal
    The Wow! Signal is probably the best evidence we have of aliens. In 1977, a powerful radio signal was picked up in Ohio. It appears to have come from the Sagittarius constellation, and it was extremely loud. Additionally, the frequency of the signal was 1420 MHz, which is the same frequency emitted by hydrogen in spectral readings. In other words, something threw a loud radio signal at the Earth that just said “hydrogen.” Spooky, right?[14]
    • The name comes from a note written by the radio operator who picked it up. He scribbled “Wow!” on the margins of the data printout.
  3. 3
    Number stations Number stations refer to short-wave radio stations that you can find all across the US and Europe. As the name implies, these stations typically only play lists of random numbers alongside weird jingles. You can hear an example here. Nobody knows why these stations exist, what the numbers mean, or who is sending these weird messages.[15]
    • The most popular theory is that these stations are used to communicate secret codes between secret service agencies and/or spies.
  4. Step 4 The Moberly–Jourdain Incident
    A little over 100 years ago, two professors, Charlotte Moberly and Eleanor Jourdain, visited the gardens of Versailles to take a tour of the grounds. While in separate areas of the tour, the two women independently experienced something odd. They met members of the royal family, French guards from the 1700s started walking around, and everyone’s accents slipped into a courtly version of French. When the women reunited, they both reported what they saw. Eventually, they became convinced that they had accidentally traveled through time.[16]
    • As simple as this sounds to make up, both women seemed to be able to recall specific details that matched up perfectly with historical records.
  5. 5
    Fast radio bursts Fast radio bursts refer to tiny bursts of radio signal that come from space. We don’t know where these waves come from or what they mean. Hundreds of these bursts have been documented, but nobody can explain what kind of celestial object could possibly produce that much power in random bursts.[17]
  6. Step 6 The disappearance of Brian Shaffer
    In 2006, medical school student Brian Shaffer joined a few friends to grab drinks after a long night. But as the night came to a close, Brian’s friends realized he was nowhere to be found. The weird part is that every entrance and exit to the bar was under constant surveillance with security cameras. Brian couldn’t have left the bar, yet he was nowhere to be found. He is still missing to this day.[18]
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Section 4 of 5:

Scariest Concepts & Ideas

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  1. Step 1 The unknown
    Think about it…the unknown literally encompasses everything you don’t know. Just pause and meditate on what that means for a moment. Picture a pet dog hanging out around the house. It has zero idea what death means, what ghosts are, how big the void of space is, etc. Picture how terrified it would be if it were capable of learning about all of those things! What if we’re just as unaware of the true nature of things as that dog?[19]
    • This applies to your own future, too. You have no idea what is going to happen—a giant chicken creature could hop out of a time travel portal in your bedroom tomorrow and totally mess up your whole life. You never know!
  2. 2
    The Fermi Paradox Named after physicist Enrico Fermi, the Fermi Paradox goes basically as follows: if space and time are infinite, there have to be other forms of life in the universe. But we see no evidence of this, so where are they? If we really are the only conscious life in the universe, how is that possible?[20]
  3. Step 3 The Great Filter
    The Great Filter is a proposed solution to the Fermi Paradox. The idea is that there is life in other parts of the universe, but every civilization that would become capable of escaping its own solar system would eventually die out before actually achieving intergalactic travel. As a result, nobody ever finds alien life anywhere.[21] The proposed explanations here are:
    • Every civilization eventually nukes itself. If nuclear energy and weapons are discoverable everywhere, civilizations could end themselves with nuclear war before they get the chance to colonize space.
    • Intelligent life capable of travel chooses not to travel. Earth hasn’t progressed far enough to know how to travel intergalactically. What if getting that far also means discovering something horrifying enough to keep us home by choice?
    • Natural disasters are just too likely. This theory suggests that there has never been a planet safe enough for living creatures to achieve the ability to travel in space before being wiped out by a natural disaster.
  4. 4
    Solipsism How do you know that you aren’t just hallucinating everything in your life? Solipsism is the theory that you can’t possibly know anything other than what you perceive, so there’s no way to actually know that other people exist, that your loved ones are real, or that you’re even able to trust your own senses![22]
    • This is also expressed as the “brain in the jar” problem. Basically, you have zero tools at your disposal that could prove you aren’t just a brain floating in a jar that’s hooked up to a bunch of machines feeding you information.
  5. Step 5 Roko’s Basilisk
    Most people have heard the theory that a hyperintelligent artificial intelligence could take over the world (the Terminator movies cover this exact topic!). Roko’s Basilisk is the idea that an AI like that would probably take revenge on anyone who tried to stop it from existing. In other words, if you aren’t actively trying to end the world with robots right now, your butt could be in trouble![23]
    • Now, you know about the Basilisk. So, if you are ever in any position to help an AI like that, you have a bizarre incentive to help it.
  6. 6
    Dead internet theory Does it ever feel like everyone you talk to online is a bot? Dead internet theory suggests that this might actually be true. Since there is a limited number of potential human beings who could be online at any given time, but there is an unlimited number of fake bot accounts, it stands to reason that you may not be running into real humans very often online.[24]
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Section 5 of 5:

Scariest Conditions and Illnesses

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  1. Step 1 Fatal insomnia (FFI)
    This rare genetic condition makes it literally impossible to sleep. It starts off with general irritability, memory loss, and trouble sleeping, but eventually it’s impossible to sleep at all. This quickly leads to memory loss, high blood pressure, hallucinations, and other extremely unpleasant side effects. The brain shuts down at a certain point after being unable to repair itself with sleep.[25]
    • Luckily, this condition seems to only impact 50-70 families in the world, and all of them are aware of the situation. If you’ve never heard of FFI, you don’t have to worry about it!
  2. 2
    Mad cow disease Mad cow only impacts cows, but humans can get a variant known as Creutzfeldt-Jakob disease. You get the disease by eating meat from a cow with mad cow disease, and the symptoms are identical. At first, you slowly start to lose track of reality. You lose your memory, become anxious, and lose control of your body. Within a year of the first symptoms, this condition has a 100% fatality rate.[26]
    • Luckily, mad cow is super rare and has largely been eradicated, so it’s not thought to pose much risk to the public currently![27]
  3. 3
    Rabies What’s so scary about rabies is that you don’t know you have rabies until after the symptoms appear, but once the symptoms appear, the disease has a nearly 100% fatality rate. The symptoms themselves are pretty spooky: fever, anxiety, agitation, trouble controlling your body, and fear of water.[28]
    • This is why it’s so important to get pets vaccinated against rabies, and why you should always see a doctor if you’ve been bitten or scratched by a wild animal.
    • Luckily, rabies vaccinations are nearly 100% effective, as are post-exposure treatment methods if administered right away. So, as long as you follow medical advice, you should be completely fine![29]
  4. 4
    Brain-eating amoeba Officially known as Naegleria fowleri, the brain-eating amoeba does what it sounds like it does—it eats brains. The amoeba can only enter your body if unfiltered water gets into your nose, usually by swimming in a lake or using a neti pot with regular tap water.[30]
    • A brain-eating amoeba infection sounds pretty terrifying, but luckily, it’s also super avoidable. Just don't put your head under the water in warm lakes, ponds, and other fresh water sources (the amoeba thrives in warm water), especially if there are official warnings about the water quality in a specific area.[31]
    • You should also only use boiled, sterile, or distilled water with neti pots (not regular tap water).[32]
    • A Naegleria fowleri infection is also very rare. There are only about 10 or fewer deaths per year in the U.S.[33]
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  • Question
    What is the scariest paranormal event?
    Brittney Crabb
    Brittney Crabb
    Paranormal and Horror Content Creator
    Brittney Crabb is a paranormal and horror content creator based in Toronto, Ontario. With over 17 years of experience creating content, Brittney shares all things paranormal and horror, including haunted places, urban legends, ghost stories, and more. Brittney has over 580k followers with over 149 million views on her YouTube channel @BrittneyCrabb, where her lifelong passion for the paranormal and video creation shines through. She is also a TV host, TV personality, and interviewer with vast experience in the entertainment industry and interviewing celebrities at premieres and other events.
    Brittney Crabb
    Brittney Crabb
    Paranormal and Horror Content Creator
    Expert Answer
    The one that gives me real chills is the idea of a doppelganger. I find the concept of a doppelganger absolutely terrifying. It's said to be a sign of bad luck, or even a premonition. To see a perfect double of yourself just walking around, completely separate from you, that just freaks me out on a whole other level. I can't even imagine what I'd do if I saw my own doppelganger. It's a deeply unsettling thought!
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References

  1. ↑ https://www.nasa.gov/universe/what-are-black-holes/
  2. ↑ https://science.nasa.gov/universe/black-holes/
  3. ↑ https://www.discovermagazine.com/the-sciences/is-tabbys-star-a-swarm-of-extraterrestrial-structures
  4. ↑ https://www.nhm.ac.uk/discover/what-is-space-junk-and-why-is-it-a-problem.html
  5. ↑ https://www.nasa.gov/centers-and-facilities/goddard/jupiters-great-red-spot-a-swirling-mystery/
  6. ↑ https://www.nasa.gov/image-article/rains-of-terror-exoplanet-hd-189733b/
  7. ↑ https://spaceplace.nasa.gov/supernova/en/
  8. ↑ https://www.fws.gov/story/2023-02/mariana-trench-photos-and-videos
  9. ↑ https://ocean.si.edu/ocean-life/invertebrates/giant-squid-caught-live-screen
  1. ↑ https://oceanservice.noaa.gov/facts/roguewaves.html
  2. ↑ https://australian.museum/learn/animals/fishes/goblin-shark-mitsukurina-owstoni/
  3. ↑ https://www.army.mil/article/263119/questions_remain_75_years_after_mysterious_fort_knox_ufo_incident_downed_pilot
  4. ↑ https://www.daviddarling.info/encyclopedia/S/Skyhook.html
  5. ↑ https://www.seti.org/news/the-wow-signal-a-lingering-mystery-or-a-natural-phenomenon/
  6. ↑ https://www.bbc.com/news/magazine-24910397
  7. ↑ https://www.ranker.com/list/moberly-jourdain-incident-and-time-travel/genevieve-carlton
  8. ↑ https://science.nasa.gov/missions/hubble/hubble-finds-weird-home-of-farthest-fast-radio-burst/
  9. ↑ https://people.com/what-happened-to-brian-shaffer-disappearance-11706304
  10. ↑ https://www.psychologytoday.com/us/blog/vitalogy/202302/whats-so-scary-about-the-unknown
  11. ↑ https://www.astronomy.com/science/the-great-filter-a-possible-solution-to-the-fermi-paradox/
  12. ↑ https://earthsky.org/space/avoiding-the-great-filter-earth-alien-civilizations/
  13. ↑ https://iep.utm.edu/solipsis/
  14. ↑ https://slate.com/technology/2014/07/rokos-basilisk-the-most-terrifying-thought-experiment-of-all-time.html
  15. ↑ https://theconversation.com/the-dead-internet-theory-makes-eerie-claims-about-an-ai-run-web-the-truth-is-more-sinister-229609
  16. ↑ https://my.clevelandclinic.org/health/diseases/25001-fatal-familial-insomnia
  17. ↑ https://www.fda.gov/animal-veterinary/animal-health-literacy/all-about-bse-mad-cow-disease
  18. ↑ https://www.cdc.gov/mad-cow/php/animal-health/index.html
  19. ↑ https://www.fda.gov/animal-veterinary/animal-health-literacy/all-about-bse-mad-cow-disease
  20. ↑ https://www.chop.edu/vaccine-education-center/vaccine-details/rabies-vaccine
  21. ↑ https://my.clevelandclinic.org/health/diseases/24485-brain-eating-amoeba
  22. ↑ https://www.cdc.gov/naegleria/prevention/swimming.html
  23. ↑ https://www.pbs.org/newshour/health/what-to-know-about-another-dangerous-amoeba-linked-to-neti-pots-and-nasal-rinsing
  24. ↑ https://www.cdc.gov/naegleria/prevention/swimming.html

About This Article

Brittney Crabb
Co-authored by:
Brittney Crabb
Paranormal and Horror Content Creator
This article was co-authored by Brittney Crabb and by wikiHow staff writer, Eric McClure. Brittney Crabb is a paranormal and horror content creator based in Toronto, Ontario. With over 17 years of experience creating content, Brittney shares all things paranormal and horror, including haunted places, urban legends, ghost stories, and more. Brittney has over 580k followers with over 149 million views on her YouTube channel @BrittneyCrabb, where her lifelong passion for the paranormal and video creation shines through. She is also a TV host, TV personality, and interviewer with vast experience in the entertainment industry and interviewing celebrities at premieres and other events.
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Updated: September 3, 2025
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