The ocean covers over 70% of our planet’s surface, and yet much of it remains unexplored. It’s a realm of mystery, pressure, and darkness — especially when we venture into its deepest parts. So, what exactly is the deepest part of the ocean? And what have we discovered down there?
The Challenger Deep: Earth’s Deepest Known Point
The deepest part of the ocean is called the Challenger Deep, located in the Mariana Trench — a crescent-shaped trench in the western Pacific Ocean. It sits roughly 200 miles (320 km) southwest of Guam and plunges down approximately 36,070 feet (10,994 meters) — that’s nearly 7 miles deep.
To put that into perspective: If Mount Everest were placed into the Challenger Deep, its peak would still be more than a mile underwater.
How Do We Know How Deep It Is?
Despite its inaccessibility, several expeditions have ventured into the Challenger Deep:
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In 1960, U.S. Navy Lieutenant Don Walsh and Swiss engineer Jacques Piccard made the first manned descent in a vessel called the Trieste.
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In 2012, filmmaker James Cameron (yes, the Titanic director) made a solo dive in the Deepsea Challenger, bringing back high-resolution images and samples.
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Since then, a number of robotic and crewed missions have followed, refining our measurements and expanding our knowledge of this alien-like environment.
What’s Down There?
At these extreme depths, sunlight can’t reach, and the pressure is over 1,000 times what we experience at sea level. Yet, life exists. Scientists have discovered strange and resilient organisms:
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Amphipods (shrimp-like creatures)
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Microbes that can survive on chemicals instead of sunlight
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Possibly even new species yet to be classified
The environment down there is cold, dark, and hostile — but life finds a way.
Why Does It Matter?
Exploring the deepest parts of the ocean isn’t just about bragging rights or curiosity. It helps us understand:
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The limits of life on Earth (and possibly other planets)
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Plate tectonics and seismic activity (as trenches mark subduction zones)
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The potential impact of human pollution — microplastics and chemical traces have been found even in the deepest ocean layers
Final Thoughts
The Challenger Deep is a reminder of how much remains unknown about our own planet. While space often gets the spotlight, the ocean — particularly its hidden depths — is arguably the final frontier here on Earth. As technology improves and curiosity persists, we can expect more discoveries to come from the silent, crushing blackness of the ocean’s deepest places.
