Just as Earth’s land surface has enormous peaks and valleys, the oceanic world has similarly varied topography. Perhaps the most intriguing of these features is the Mariana Trench — a chasm in the ...

Retired Navy Capt. Don Walsh, an explorer who in 1960 was part of a two-man crew that made the first voyage to the deepest part of the ocean — to the “snuff-colored ooze” at the bottom of the ...

What's at the bottom of the Mariana Trench, and how do we know? How deep does the ocean go? We'll answer these questions and ...