The Bathyscaphe Revolution

The breakthrough came from Auguste Piccard, a Swiss physicist who designed the bathyscaphe — a self-propelled deep-sea vessel. His son Jacques Piccard, alongside US Navy Lieutenant Don Walsh, rode the bathyscaphe Trieste to the bottom of the Mariana Trench on January 23, 1960.

They reached 10,916 meters — the deepest point any human had ever been. The descent took nearly five hours. Piccard reported glimpsing a flatfish on the bottom, though stirred-up sediment made the view, in Walsh's words, "like looking in a bowl of milk." Most biologists now doubt the sighting, since fish are not known to survive at such crushing depths, and suspect he saw a sea cucumber. They stayed just 20 minutes before ascending, but those minutes changed ocean science.