The Challenger Deep, near Guam - named for the vessel that discovered it - is the deepest point known in the world's oceans at over 35,000 feet below the surface. On January 23, 1960 Jacques Piccard and U.S. Navy Lt. Don Walsh descended to its floor in the bathyscaphe Trieste, simultaneously disproving the azoic theory of the ocean depths (which said no life could exist at such pressures; upon landing, Piccard immediately saw a fish outside his view port) and making the most audacious journey below the waves attempted at the time. As of July 2022, 25 more people have made the descent: the solo vessel Deepsea Challenger in 2012; the Chinese submersible Fendouzhe in 2020, and four expeditions in DSV Limiting Factor between 2019 and 2022.