Challenger Deep in the Mariana Trench near Guam is the deepest spot on Earth. How do we know? We didn't look for it. We listened.
National Geographic Explorer-in-Residence and Filmmaker James Cameron has announced he will soon operate a one-man submarine 7 miles deep to the Pacific's Mariana Trench, the deepest point on earth. Cameron plans to spend as much as 6 hours on the ocean floor and will film and take specimens for scientific study.