Guess what Earth's been hiding from us, way down in its belly? Water! Lots and lots of water.
New study challenges the idea that the rate of plate movement remains stable.
Deep within the Earth's rocky mantle lies oceans' worth of water locked up in a type of mineral called ringwoodite.
A dense crystalline 'rain' falling into Earth's mantle could explain how a mysterious seismic boundary forms beneath the crust.
Diamond inclusions indicate that Earth's carbon cycle extends from the surface to the deep lower mantle.
NASA geophysicists find natural cycles to Earth's warming that correlate to movement of liquid iron in Earth's outer core -- up until 1930.