Deepest Dive: Trieste Reaches Ocean's Bottom 1960

# The Bathyscaphe Trieste Touches the Bottom of the World ## January 23, 1960 On this date in 1960, two men did something no human had ever done before: they descended nearly seven miles straight down into the ocean's deepest known point, the Challenger Deep in the Mariana Trench. Swiss oceanographer Jacques Piccard and U.S. Navy Lieutenant Don Walsh squeezed into a specially designed submersible called the *Trieste* and plunged into the abyss. The journey to the bottom took nearly five hours. Imagine sitting in a steel sphere barely large enough for two people, feeling the weight of the entire Pacific Ocean pressing down on you. The pressure at that depth—almost 11,000 meters (about 36,000 feet)—reaches roughly 1,100 times the atmospheric pressure at sea level, or about 8 tons per square inch. Your vessel would need to withstand forces that could instantly crush a submarine like an aluminum can. The *Trieste* was essentially a giant underwater balloon—but instead of being filled with helium to rise through air, its float was filled with gasoline (which is lighter than water and, crucially, incompressible under pressure) to provide buoyancy. Beneath this float hung the pressure sphere, a masterpiece of Italian engineering made of steel walls five inches thick with a tiny window of acrylic cone. As they descended through the darkness, the men passed through distinct ocean layers. First, the sunlit waters teeming with life. Then, the twilight zone where bioluminescent creatures sparkled like underwater fireworks. Finally, the midnight zone—pitch black, cold, and seemingly lifeless. At around 30,000 feet, disaster nearly struck. They heard a loud crack—one of the exterior Plexiglas windows had fractured. The men had to make a split-second decision: abort or continue? They chose to press on, reasoning that the window wasn't part of the critical pressure hull. When they finally touched down on the sea floor at 1:06 PM, they became the first humans to reach the deepest point on Earth. And then came the surprise: through their tiny window, illuminated by their lights, they saw a flatfish swimming along the bottom. Life existed even here, in this crushing darkness where the sun never shines and the pressure would kill a human instantly. They spent just twenty minutes on the bottom before beginning their ascent, but those minutes revolutionized our understanding of Earth's oceans. The discovery of life at such depths proved that no part of the ocean was too extreme for living organisms—a finding that would influence everything from biology to theories about life on other planets. The *Trieste's* dive remained unmatched for over fifty years until filmmaker James Cameron made a solo descent to the same spot in 2012. Even today, fewer people have visited the Challenger Deep than have walked on the Moon. This achievement represented the culmination of decades of underwater exploration technology and human courage. Jacques Piccard's father, Auguste Pi