Horizon Deep, Tonga Trench
The deepest point of the Tonga Trench, about 10,800 m down: the deepest place in the Southern Hemisphere and the second deepest on Earth after the Challenger Deep. The crew of the Scripps ship Horizon found it in 1952; the first crewed submersible reached its floor in 2019.
Dated events and their evidence
- 1952 CE mainstream
December 1952: the crew of the Scripps research vessel Horizon finds the deep that now bears the ship's name source - 1970 CE mainstream
the heat source of Apollo 13's lunar module generator plunges into the Pacific in or near the Tonga Trench; monitoring detects no release of its plutonium-238 source - 2016 CE mainstream
a study of the sediment finds the roundworms on the floor of Horizon Deep six times more abundant than at a site on the trench edge at about 6,250 m source - 2019 CE mainstream
10 June 2019: Victor Vescovo makes the first crewed descent to the bottom in the submersible Limiting Factor and measures 10,823 m by direct pressure readings source
Where
23.2583° S, 174.7267° W
The point is the position Wikipedia gives for Horizon Deep itself; the page's own coordinate for the Tonga Trench (22 S, 174 W) is a point on the trench, not the deep.
Sources
Each event carries Aion's own evidence grade (mainstream, disputed or speculative). This page repeats what the globe shows for this place.