Early Earth got much of its water from relentless bombardment by water-rich asteroids and icy comets. Now, scientists say the young planet had a way to hold onto much more of that water than once thought: Rocks deep in Earth’s belly may have contained up to 100 times more water than previously estimated, researchers report December 11 in Science. That adds up to perhaps a whole ocean’s worth of water once stowed away in the ancient mantle rocks.
Using laboratory experiments that re-created the extreme conditions of Earth’s deep mantle, geochemist Wenhua Lu of the Chinese Academy of Sciences in Guangzhou and colleagues investigated how much water bridgmanite, one