CNN — (CNN) — 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 ...

ANCHORAGE, Alaska — 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 ...

Retired Capt. Don Walsh, Ph.D., who commanded the U.S. Navy’s bathyscaphe Trieste, discusses the dive to the deepest place on Earth, the Challenger Deep located at the southern end of the Mariana ...