Explorers Jacques Piccard and Don Walsh wave victoriously from their submersible after descending to the world's deepest point, the Challenger Deep, in 1960.

Photograph by Thomas J. Abercrombie, National Geographic
  • On January 23, 1960, Jacques Piccard and Don Walsh descended 10,915 meters (35,810 feet) into the Pacific Ocean in the bathyscaphe Trieste. The Trieste took four hours and 48 minutes to descend into the portion of the Mariana Trench known as the Challenger Deep. The bathyscaphe—a special submarine with very thick outer plating—spent 30 minutes at the bottom. That far down, the temperature was just above freezing and pressure on the hull was more than 111 megapascals (16,000 pounds per square inch).

    Piccard and Walsh observed flatfish and worms on the seabed, revealing that life could indeed survive in the hostile environment of the deep ocean. Samples of sediment from the ocean floor revealed more 400 species of microorganisms. In 2012, National Geographic Explorer-in-Residence James Cameron became the first person to follow Piccard and Walsh to the Challenger Deep, and the first do to it alone. Walsh, a member of Cameron’s team, was waiting on deck.

  • Term Part of Speech Definition Encyclopedic Entry
    bathyscaphe Noun

    vehicle used to explore the deep ocean. Developed after the bathysphere.

    Encyclopedic Entry: bathyscaphe
    Challenger Deep Noun

    deepest measured point in the ocean (part of the Mariana Trench), about 11,000 meters (36,198 feet), located in the South Pacific Ocean.

    environment Noun

    conditions that surround and influence an organism or community.

    Explorer-in-Residence Noun

    pre-eminent explorers and scientists collaborating with the National Geographic Society to make groundbreaking discoveries that generate critical scientific information, conservation-related initiatives and compelling stories.

    hostile Adjective

    confrontational or unfriendly.

    hull Noun

    main body of a ship.

    microorganism Noun

    very tiny living thing.

    seabed Noun

    the floor of the ocean.

    sediment Noun

    underwater soil.

    submarine Noun

    vehicle that can travel underwater.