The deepest part of the ocean is the Challenger Deep, a valley within the Mariana Trench in the Pacific Ocean. At 10,994m (6.8 miles) the Challenger Deep is the deepest known point on Earth.
The water here exerts a pressure of 1,086 bar (15,750 psi), more than 1,071 times the pressure at sea level.
Humans have explored the Challenger Deep, a cleft in the ocean floor formed by the boundary of two tectonic plates.
As well as two uncrewed descents by remotely operated vehicles (ROVs), there have been several manned descents. The first person to go down alone was film director James Cameron in his submersible.
Do any animals live in the Challenger Deep?
There are some species that can survive the harsh conditions of the Challenger Deep. Amphipods that are nearly a foot long have been found there along with and strange saucer-sized single-celled organisms, called Xenophyophores.
Mariana hadal snailfish (Pseudoliparis swirei) have been spotted in the in the Mariana Trench at more than 5 miles below the surface.
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Main image: concept image of the deep sea/Getty
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