The Mariana Trench was formed when one tectonic plate was pushed beneath another.
The trench was first discovered in 1875 by the crew of the British ship HMS Challenger.
If Mount Everest was placed at the deepest point, its summit would still be 2km underwater…
…and you'd need to stack 13 Burj Khalifas, the world's tallest building, to reach the bottom.
It's said that we know more about the surface of the Moon than we do Earth's oceans. The deepest parts of our oceans sit