The Deepest Place On Earth

The Mariana Trench in the Pacific Ocean is the deepest place on earth at it's very deepest over 11 Kilometres down. In this documentary they look at how the Mariana Trench was found and theories used to explain how such a trench could exist.What it can tell about the history of the earth and the movements of continents over millions of years. Could we travel to the bottom of the trench, is there life over 5 miles down and could it be used for example to dispose of nuclear waste. What is the deepest place on the earth, how was it found and can we go there ?