Earth's Core May Harbor Massive Hydrogen Reserves, Redrawing Water's Origin
A Nature Communications study estimates Earth’s molten iron core could host a vast hydrogen reservoir—potentially the planet’s largest—amounting to about 0.07% to 0.36% of the core’s weight, equivalent to roughly nine to 45 hydrogen oceans. Using atom probe tomography and high-pressure iron experiments to mimic core formation, researchers examined how hydrogen interacts with silicon and oxygen under extreme conditions. If confirmed, this suggests Earth acquired most of its water during its early growth rather than via late comet deliveries and may relate to heat flow that helps power the magnetic field; however, the estimate relies on indirect methods with uncertainties, and further work is needed to refine the numbers.