Trieste Reaches the Challenger Deep: The Deepest Place on Earth
1960 · event
On 23 January 1960 two men climbed into a steel sphere hung beneath a float of petrol and began to sink into the Mariana Trench in the western Pacific. The bathyscaphe Trieste took almost five hours to fall through the darkness. Jacques Piccard, the Swiss engineer whose father Auguste had designed the vessel, and Don Walsh, a lieutenant in the United States Navy, settled on the bottom of the Challenger Deep at close to eleven thousand metres. It is the deepest known point on the surface of the planet.
The Trieste had been built in Italy and took its name from the city where it was completed, on the northern Adriatic near the Slovenian border. It worked on the principle of a balloon in reverse. The float was filled with petrol, which is lighter than water and does not compress, and iron shot was released to rise. The crew sphere had walls twelve centimetres thick and a single small window.
During the descent an outer window cracked with a loud report and the pair chose to continue. On the bottom they stayed about twenty minutes, watched sediment swirl up and reported seeing a flat creature that looked like a fish, an observation still discussed by biologists. Their instruments confirmed that life existed in a place where the pressure is more than a thousand times that at the surface.
No one returned to the Challenger Deep for fifty two years, until the filmmaker James Cameron dived alone in 2012, and later expeditions have now made repeat descents. The dive of 1960 answered a question that mattered beyond exploration, because it showed the deepest ocean was not empty and therefore not a suitable dumping ground, an argument that shaped the treatment of the sea for decades afterwards.