You would think that by time we had the technology to send people to the moon, we’d be experts on our own planet; but the truth is, more than 95 percent of our underwater world remains unexplored, leaving us nearly clueless as to what lies far below the water’s surface.
In space travel’s short history, we’ve sent 536 humans into the cosmos. Yet only three explorers have braved the depths of the Mariana Trench, the deepest part of the world’s oceans. Its lowest point rests 36,070 feet (nearly 7 miles) below the water’s surface. To give you some context: If you dropped Mount Everest into the Mariana Trench, its peak would still be more than a mile underwater.
U.S. Navy Lieutenant Don Walsh and Jacques Piccard made the first descent to the bottom of the trench, called the Challenger Deep, in 1960. Two descents were later made by unmanned vehicles, and most recently in 2012, an expedition was made by James Cameron—yes, that James Cameron, as in the filmmaker behind movies like “Titanic” and “Avatar.”
With only four descents made to this day to that part of the ocean, it’s no surprise the ocean remains a mystery to us. We do know that some basic life forms somehow exist down there, despite the freezing temperatures and intense pressure (8 tons per square inch, the equivalent of being crushed by 50 jumbo jets). Mud samples and observations by the explorers have discovered more than 200 different microorganisms, plus everything from giant crustaceans and sea cucumbers to enormous amoebas (4-inch, single-celled organisms) and jellyfish.
Some truly bizarre-looking creatures are also able to thrive in the midnight zone, the deepest, darkest ocean light zone (in which the Mariana Trench resides). Among them is the anglerfish, a bony fish that appears to have a built-in fishing rod attached to its head that pulses with glowing bacteria. This serves as a lure to attract prey and mates.
Joining this curious creature in the midnight zone is the vampire squid, which also uses bioluminescence to survive in this dark abyss. When threatened, it flails around frantically and ejects bioluminescent mucus containing orbs of blue light to confuse its predators. Check out our infographic on bioluminescence to learn more about this fascinating phenomenon.
The possibilities of what else exists at these depths are endless, but until we dedicate more resources to exploring our deep seas, we’ll never know the secrets hidden within our own planet.