Mariana Trench Facts for Kids — The Deepest Place on Earth
By Andrew Signore | Brave Hearts Publishing
If you dropped Mount Everest — the tallest mountain on Earth — into the Mariana Trench, it would disappear completely beneath the surface. And there would still be more than a mile of water above it.
That's how deep the Mariana Trench is.
It's one of the most mysterious and fascinating places on our planet — and it's right here on Earth, hiding beneath the Pacific Ocean. Here are the most amazing Mariana Trench facts for kids, explained in a way that makes the deep sea feel real.
Where Is the Mariana Trench?
The Mariana Trench is located in the western Pacific Ocean, east of the Mariana Islands — a group of islands near Guam. It stretches for about 1,550 miles and is shaped like a long crescent, kind of like a giant curved scar on the ocean floor.
It sits at the boundary of two massive tectonic plates — the Pacific Plate and the Mariana Plate. Over millions of years one plate has slowly pushed beneath the other, creating this extraordinary deep valley.
How Deep Is the Mariana Trench?
This is where the numbers get almost impossible to imagine.
The deepest point is called Challenger Deep.
It measures approximately 36,000 feet deep — that's nearly 7 miles beneath the surface of the ocean.
To put that in perspective:
• Mount Everest is 29,032 feet tall — and would fit inside the trench with room to spare
• If you stacked 25 Empire State Buildings on top of each other they still wouldn't reach the surface
• It would take more than an hour for a rock to fall from the surface to the bottom
• The pressure at the bottom is 1,000 times greater than at sea level — strong enough to crush a soda can flat
What Lives in the Mariana Trench?
Here's the part that surprises most people — things actually live down there.
Even in the crushing darkness of the deep sea, life finds a way. Scientists have discovered some extraordinary creatures in and around the Mariana Trench:
The Anglerfish
One of the most famous deep-sea creatures, the anglerfish has a built-in glowing light on its head that dangles like a fishing rod. It uses this light to attract smaller fish in the complete darkness — like a living flashlight. Despite its terrifying appearance it's only about the size of a football.
The Dumbo Octopus
Named after the Disney elephant, the Dumbo octopus has two ear-like fins that flap as it moves through the water. It's one of the deepest-living octopuses ever discovered and looks almost cartoonishly cute for a deep-sea creature.
Sea Cucumbers
These soft, tube-shaped animals crawl along the ocean floor eating sediment. They make up a surprising portion of the life at extreme depths and play an important role in the deep-sea ecosystem.
Snailfish
The snailfish holds the record for the deepest fish ever recorded. Its body is specially adapted to survive the extreme pressure — its cells are built differently from fish that live near the surface.
Why Is It So Dark Down There?
Sunlight can only penetrate about 650 feet into the ocean — after that the water gets progressively darker. By 3,300 feet there is no sunlight at all. The Mariana Trench goes down to 36,000 feet.
That means the deepest parts of the trench exist in complete and total darkness — not just dim light, but absolute pitch black. The only light down there is the bioluminescence that some creatures make themselves, like the anglerfish's glowing lure.
Has Anyone Been to the Bottom?
Yes — but only a handful of people in all of human history.
In 1960 Jacques Piccard and Don Walsh became the first humans to reach Challenger Deep in a submersible called the Trieste. The journey took nearly five hours just to descend.
In 2012 filmmaker James Cameron made a solo dive to the bottom in a specially designed submersible, spending several hours exploring the seafloor.
The ocean explorer Sylvia Earle — one of the most famous marine biologists in history — spent decades pushing the boundaries of deep-sea exploration, setting records for the deepest solo dives and advocating for ocean conservation.
Quick Mariana Trench Facts for Kids
• The Mariana Trench is located in the Pacific Ocean near Guam
• It's approximately 36,000 feet deep at its lowest point — Challenger Deep
• It's about 1,550 miles long and 43 miles wide
• The water pressure at the bottom is over 16,000 pounds per square inch
• The temperature near the bottom is just above freezing — about 34-39°F
• It was first explored in 1875 by the HMS Challenger — which is how Challenger Deep got its name
• More people have walked on the Moon than have visited the bottom of the Mariana Trench
• Scientists have found plastic pollution even at the deepest parts of the trench
Explore the Mariana Trench Through Story
In our early chapter book Adventures of Charlotte and Henry: The Mariana Trench, Charlotte and her loyal dog Henry discover a glowing magical book that sweeps them away to the deepest place on Earth.
Along the way they meet real ocean explorers — Steve Irwin, Jacques Cousteau, and Sylvia Earle — and learn that bravery isn't about being fearless. It's about choosing to move forward anyway.
Written at a Lexile 580L reading level for grades 1–3, it's the perfect book for curious kids who want to explore one of Earth's greatest mysteries.
Adventures of Charlotte and Henry: The Mariana Trench
Frequently Asked Questions About the Mariana Trench
How deep is the Mariana Trench in miles?
The Mariana Trench is approximately 6.8 miles deep at its lowest point, Challenger Deep.
What lives at the bottom of the Mariana Trench?
Scientists have found various creatures including snailfish, sea cucumbers, tiny shrimp-like amphipods, and microbial life even at the very deepest points.
Can humans go to the bottom of the Mariana Trench?
Yes, but it requires a specially designed submersible. Only a small number of people have ever made the journey due to the extreme pressure and depth.
How long would it take to fall to the bottom of the Mariana Trench?
A dense object dropped from the surface would take more than an hour to reach the bottom due to the increasing water resistance as it descends.
Why is the Mariana Trench important?
It's one of the least explored places on Earth and holds clues about the origins of life, plate tectonics, and how organisms adapt to extreme conditions. It's also an important reminder of how much of our planet remains undiscovered.
The Bottom Line
The Mariana Trench is proof that Earth is still full of wonders waiting to be explored. From glowing fish to crushing pressure to the handful of brave humans who have descended into complete darkness — it's one of the most extraordinary places on our planet.
And the best part? You don't have to be a scientist or an explorer to discover it. All it takes is a brave heart — and maybe a glowing book.
Andrew Signore is a travel ICU nurse, adventurer, and author of the Adventures of Charlotte and Henry series. He has scuba dived in oceans around the world and wrote the series for his niece — to show her that brave hearts can go anywhere.
Big Places. Brave Hearts.
Adventures of Charlotte and Henry: The Mariana Trench
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