Challenger Deep
Challenger Deep
Challenger Deep is the deepest point on Earth’s oceans. It sits in the western Pacific Ocean at the southern end of the Mariana Trench, about 300 kilometers (roughly 190 miles) from Guam and Fais Island.
How deep is it? Most measurements put it at about 10,900 meters (roughly 6.8 miles) below the surface. Over the years, depths reported for the Deep have ranged from about 10,800 to 10,990 meters, depending on the method and exactly which part of the trench is measured. In recent years, scientists have often cited depths around 10,925 to 10,935 meters, with small differences due to measurement methods.
The trench isn’t flat. The Challenger Deep actually contains three basins (east, central, and west) that are offset from one another. Each basin is deeply filled with sediment and rocks, and the deepest point can shift slightly depending on how it’s measured.
A brief history of exploration: The Deep gets its name from the HMS Challenger expedition (1872–1876), the first major ocean science voyage. The deepest spot was first probed in the 20th century, and the famous 1960 dive of the bathyscaphe Trieste reached about 10,911 meters, the first time humans touched the very bottom. Since then, many ships, submarines, and robots from different countries have mapped and sampled the Deep, improving our understanding of its depths and life there.
Notable expeditions: In the late 1990s, the Japanese submersible Kaikō made deep dives into the trench. In 2012, filmmaker James Cameron descended to the bottom. Beginning in 2019, the Five Deeps Expedition with the Deep-Submergence Vehicle Limiting Factor completed several dives to the bottom. Other recent missions used landers and remotely operated vehicles to collect samples and record data.
Life at the bottom: The hadal zone hosts simple, but resilient life, including amphipods, sea cucumbers, and tiny worms. In 2017, a snailfish species was identified in the trench area, showing that even the darkest depths can harbor life.
Why it matters: Studying Challenger Deep helps scientists learn how life endures under extreme pressure, what the trench reveals about Earth’s geology, and how the ocean’s deepest zones fit into the planet’s overall systems.
This page was last edited on 3 February 2026, at 17:21 (CET).