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 ...

This astronaut just successfully reached the lowest point on Earth. Kathy Sullivan soared to new heights when she became the first American woman to walk in space in 1984. On Monday, she broke a new ...

Kathy Sullivan, an American geologist, has made history again. This past week, she became the first woman to reach Challenger Deep - that's the deepest point on the surface of the Earth. It's in 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 ...