Humans first descended into Challenger Deep in 1960 in a U.S. Navy submersible.
Notes on verification
Confirmed by multiple independent, high-quality sources including USNI Proceedings and Wikipedia, consistent on date, vessel, and crew details.
Sources
- The Pacific Ocean—facts and information (nationalgeographic.com)
- https://www.usni.org/magazines/proceedings/2020/january/first-deepest-dive (usni.org)
- https://geology.com/records/bathyscaphe-trieste.shtml (geology.com)