The mysteries of space have long fascinated us, conjuring a sense of wonder in everyone from Carl Sagan to common stoners (like Carl Sagan).
Our focus on the final frontier, though, shouldn't distract us from the fact that we barely know a thing about the ocean. While you might assume that we've got a strong grasp on our underwater backyard, the truth is, we've only just begun to figure out just what's going on down there. We should look a little closer, because what we have discovered is equal parts interesting, awe-inspiring, and batshit insane.
And just to give you a sense of scale...
2. The deepest point could keep Mount Everest underwater
The bottom of Challenger Deep is seven miles from the surface of the ocean. In other words, if Mount Everest were dropped to the bottom of it, there'd still be more than a mile of water between the peak the surface of the ocean. That's right, the ocean just gave the highest mountain in the world an inferiority complex.
3. Most marine life is still unidentified
Recent estimates show that there could be 700,000 species living in the ocean, and possibly more. And as of now, we've only identified about a third of them. One of which is utterly terrifying...
4. There are immortal jellyfish down there
If you didn't think jellyfish could get any worse, prepare to be very disappointed. The Turritopsis dohrnii is a species that has Benjamin Buttoned its way to scientifically-verified immortality. When these swimming terrors reach adulthood, if they find themselves sick, aging, attacked, or in any other situation that should, you know, kill them, they can physically revert back to an earlier stage of development, beginning their lives anew. Scientists have admitted that, unless they fall victim to a predator, this process ensures that they'll never die.
5. We know more about the surface of Mars and the moon than the bottom of the ocean
Thanks to historic space expeditions, we're learning enough about the Red Planet to at least double the length of its Wikipedia page (probably). So far, no aliens (allegedly), but that doesn't mean that we've got nothing to worry about, considering we actually have more thorough surface maps of Mars and the moon than we have of the ocean floor. Hell, while we're on the topic...
6. It's home to beings that practically are aliens
The water-dwelling Tardigrade, for instance. It's less than half an inch long, it's not dangerous to humans, and its nickname is the "water bear." Oh yeah, it can also survive in near absolute zero temperatures. And in water that's far beyond the boiling point. And environments so radioactive they kill humans and birth Godzillas. Aaand pressure six times stronger than the deepest ocean trenches? And freakin' outer space!
Yeah, they're basically tiny versions of the Xenomorph from Alien.
7. We've explored less than 5% of it
We've been poking around our oceans for centuries. Despite this, we've only managed to explore less than 5% of it. When we're honest with ourselves, we have to face the fact that there could be so much down there that we don't yet know about, a realization that becomes more alarming when you take into account the fact that...
8. About 80% of all life on Earth is found in the oceans
Up to 80% of living beings are at home under the sea. And if you think that watching The Little Mermaid as a kid gave you a decent idea of what kinds of creatures lurk in those depths, you may be surprised to learn that our knowledge of marine life is hilariously limited.
9. The ocean itself might actually be alive
Environments are essentially giant recycling plants, in which all the nutrients in the system get reused. That's unlike an animal metabolism, which uses some nutrients and gets rid of the waste. It's why we need to keep eating to take in new fuel. But some who study the ocean have noticed that it doesn't perfectly reuse nutrients the way it should. Like us, it needs additional outside sources of nutrients. In other words, it basically is one giant superorganism.
And it is hungry.
10. It makes weird sounds we can't really explain
In case that fact doesn't induce any nightmares, here's some more terrifying info about the ocean: it makes sounds that are stranger and more baffling than a dubstep album. Take, for example, the "Bloop," a massively loud noise that, after analysis, was believed to be animal in nature. Which is fine, until you learn that there is no known animal on Earth big enough to create a sound that loud.
There have been several other intensely loud recordings collected from the ocean. In recent years, attempts to reexamine them have led some researchers to believe that original analysis was wrong, and the Bloop can be explained away as iceberg activity. Hopefully that's true, since the source of the sound is also the home of Cthulhu.
11. The ocean is the world's best museum
Shipwrecks. Ancient cities. Lost planes. Beneath the ocean surface, there are countless artifacts of human civilization, many thousands of years old, many as of yet undiscovered. Museums display what we've recovered from a certain chunk of history. The ocean is a museum of all human history, including the parts we don't even know about yet.
12. It's also the world's biggest human cemetery
The space program has certainly had its fair share of disasters, but in terms of taking human life, the cosmos have been shockingly kind to us over the course of our existence. The ocean, on the other hand, has claimed more lives than we'll be able to count, from lost individuals to—if artifacts are any indication—entire cities. Obviously, we should watch out for extraterrestrial threats like asteroids, but we shouldn't forget that, throughout our history, it's been the ocean that truly wanted to murder us.
13. Humans might have been born from the ocean
The search for the origin of life on Earth is ongoing, but there's good scientific reason to believe that it may have begun in the ocean. While it may be a less entertaining scenario than the "giant space skinheads" hypothesis that Prometheus posited, it would mean that, while the ocean is full of mysteries that baffle, intrigue, and terrify us, it's also, potentially, our home.