Conservationists say retrieving mineral-rich rocks will destroy sea life. Environmental studies show conflicting results.

To give you an idea, the water pressure at Challenger Deep is about 1,000 times the standard atmospheric pressure at sea level, and the temperatures are just a few degrees above freezing.

Wagner, K. D. (2021). Revised depth of the Challenger Deep from submersible transects; including a general method for precise, pressure-derived depths in the Ocean. Deep Sea Research Part I ...

The film director James Cameron has just completed a dive to Challenger Deep, the deepest point on Earth at nearly 36,000 feet under the sea. His manned descent is the first in 52 years ...