Imagine if Earth's history had a mystery novel, and one of its biggest unsolved puzzles was: Where did all the nitrogen go?

As the Aral Sea has been drained by irrigation and dried up, the mass loss on the surface has caused Earth’s upper mantle to ...

deep beneath our feet has yielded precious few details over the past few decades. We all grew up learning that we live on the Earth’s crust, which is just a thin layer above the mantle.

Making the mission a milestone for both China and space exploration as a whole ... And it's a whopping 8 km deep — for comparison, the deepest natural point on Earth, the Challenger Deep ...

Following is a transcript of the video. Narrator: The Mariana Trench is the deepest point on Earth. So deep that if you dropped Mount Everest inside, its peak would still be more than a kilometer ...