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The Journey to the Deepest Part of the Ocean with Gaelin Rosenwaks


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Where is the deepest part of the ocean, and have we been there in person? Ocean explorer Gaelin Rosenwaks answers with an amazing story of the first explorers to dive to a mysterious place called Challenger Deep. What does it take to get to the bottom of the ocean, and what will they find there? We tell the story of incredible risk and reward that changed the way we understand the ocean environment.

Photo of Gaelin

In this post, we'll tell you more about Gaelin, the Trieste, and deep sea fish!

Gaelin was excited to answer seven year old Nayli's question, out of the many great questions submitted from George Long Elementary in Grass Lake, Michigan. The story behind the answer was a huge inspiration in her life. "It made me want to be an explorer," she told us. Gaelin spent her childhood around the ocean. "I grew up in New York City, but spent time on the ocean and in the ocean. My parents love the ocean. We'd be on the beach, fishing, all our activities were focused around the water."

It's no surprise that Gaelin has dedicated her life to ocean conservation. She went to school to become a marine scientist, but saw that no one was telling the stories of the amazing science being done. That's why she started Global Ocean Exploration, a company that documents research expeditions with video, photography, and writing.

You can come along with Gaelin on one of her expeditions to the Bering Sea in the Arctic in an eight-part web series! Start with this one:

Gaelin now counts Don Walsh, the surviving member of the Challenger Deep expedition team, as one of her friends. Talk about meeting your heroes! The first Navy submersible captain, Don Walsh is now 84. His partner in the dive, Jacques Piccard, passed away in 2008, at the age of 86.

You can read Jacques Piccard's first-hand account of the dive here. This is the article we used to tell the story on Tumble! It has a dramatic beginning...

“Do you think we shall be able to make the dive?”

The voice of our faithful engineer, Giuseppe Buono, was taut with anxiety. A 37-year-old Italian, he had already prepared the Trieste for diving 64 times, first in the Mediterranean and this year in the western Pacific off Guam. Now he was wondering whether it was not sheer madness for the bathyscaph to attempt to descend 36,000 feet—nearly seven miles—under existing conditions. In fact, I was wondering the same thing myself.

Don Walsh and Jacques Piccard sitting in the "ball" of the bathyscaphe Trieste. By Archival Photography by Steve Nicklas, NOS, NGS - NOAA Ship Collection, Public Domain,

This is Don Walsh and Jacques Piccard sitting in the "ball" of the bathyscaphe Trieste. You can see how cramped it is! Imagine sitting there for close to 10 hours. The bathyscaphe was a submersible developed before what we think of as modern submarines. Previous to the bathyscaphe was a bathysphere, a pressure sphere attached to a boat by a tether. (You might want to check out this episode of 99% Invisible for more on the bathysphere.)

Black and White photo of the Trieste. Public Domain,

You can see the tiny "ball" or pressure sphere hanging off the bottom of the Trieste. The body of the "submarine" contained the fancy engineering, groundbreaking at that time.

Cross section chart of the Trieste. By RalphSutherland - Own work, Public Domain,

The Trieste was built by Auguste Piccard, Jacques Piccard's father. Fun fact: The character of Star Trek's Jean-Luc Picard was named for Auguste Piccard and his brother Jean. The Piccard family is famous for their engineering and exploration exploits. Jacques Piccard's son, Bertrand, is attempting the first around-the-world flight on a solar-powered plane.

Photo of Jacques Piccard

Walsh and Piccard have only been followed by James Cameron, a Hollywood filmmaker who produced a documentary with National Geographic about his 2012 dive. It's called DeepSea Challenger, and you can see it in select theaters. Here's the trailer.

Gaelin told us that more robots - remotely operated submersibles - have been to Challenger Deep than people. "It's a lot cheaper and if you don’t need to send a person down, why would you? The reality is that going to a place like the Marianas Trench is not safe," she said. "But being on the ship and putting down a smaller vehicle doesn’t put people in danger. Just the vehicle is in danger. It makes exploring deep far off places safer. You can learn just as much."

We have learned a lot about deep sea life since Don Walsh and Jacques Piccard saw that first fish!

Very few fish live in the deep sea, compared to fish that live near the surface of the ocean or off the coasts. But those who do, have very interesting adaptations for living in a low-energy environment.

Deep Sea Fish. Theodore W. Pietsch, University of Washington, CC BY 3.0,

Check out this photo gallery of deep-sea fish from National Geographic, or this documentary.

Maybe don't watch it before you go to bed, because those fish are scary-looking!

Got more questions? Tell us what you want to know!

Oh, and you want to hear more of that amazing song that we play at the end of the episode? Listen!

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