“I just sat there looking out the window, looking at this barren lunar plain and appreciating it,” he told reporters, following the trip, which was funded by the National Geographic Society, Rolex, and the Alfred P. Sloan Foundation.
More trips are in the offing this year by various groups aiming to take people into the Challenger Deep or other parts of the Mariana Trench. These efforts include Sir Richard Branson's Virgin Oceanic sub, which like Cameron's Deepsea Challenger, is a single-seater. Several of the marine scientists who have worked with Cameron also are working with Mr. Branson's group.
Although deep-sea trenches make up only about 1 percent of the sea floor, they are of keen scientific interest. They form as old, dense oceanic crust, long ago made by lava welling up along mid-ocean volcanic ridges, now is pushed beneath more-buoyant continental crust.
The process creates a long, canyon-like boundary. The Mariana Trench, for instance, has an average width of about 43 miles but narrows to a slot-like valley at the bottom, nearly 7 miles below the ocean surface.