Latest research suggests Earth’s core may contain a surprisingly large amount of hydrogen – up to 45 times the amount found in the planet’s oceans. The findings, published Tuesday, February 10, 2026, in Nature Communications, could reshape our understanding of the planet’s formation and the origins of its magnetic field.
The study, led by Assistant Professor Dongyang Huang of Peking University’s School of Earth and Space Sciences, challenges traditional models that propose hydrogen was delivered later through impacts from comets and other icy bodies. Instead, the research indicates the element was likely incorporated during the planet’s initial formation.
“The idea that hydrogen within the Earth, including in the core, was delivered during planetary formation is a well-established hypothesis,” Huang stated in an interview with LiveScience.
While primarily composed of iron, the Earth’s core is slightly less dense than expected if it were solely metallic. This suggests the presence of lighter elements dissolved within the iron’s crystalline structure, according to Galileu. Determining the quantity and proportion of these elements is crucial for understanding the processes that shaped the early Earth.
Direct measurement of the core’s composition is currently impossible due to its location thousands of kilometers beneath the surface. Researchers are therefore relying on computational simulations and laboratory experiments to estimate the extreme pressures and temperatures within the core. Calculating the amount of hydrogen presents a unique challenge, as it is the smallest and lightest element in the universe and highly diffuse, making it difficult to detect in such extreme conditions.
To overcome these hurdles, Huang and his team employed a technique called atomic probe tomography, which can map the composition of all elements in a sample in three dimensions at the nanoscale.
Small samples of metallic iron were coated with hydrated silicate glass, mimicking the magma ocean that covered the early Earth. These samples were then subjected to extreme pressures using a diamond anvil cell – a device that compresses samples between two diamond crystals.
The samples, reduced to needle-like shapes approximately 20 nanometers in diameter, were analyzed atom by atom. The results revealed that hydrogen, oxygen, and silicon dissolve simultaneously into the iron’s crystalline structure under these extreme conditions.
Based on the simultaneous introduction of hydrogen and silicon from the “magma” into the “core,” scientists estimated that hydrogen accounts for between 0.07% and 0.36% of the core’s mass – equivalent to nine to 45 oceans of hydrogen, as reported by Galileu.
If most of the hydrogen had been supplied by comets after the core had solidified, it would be concentrated in the planet’s shallower layers. Although, Scientific American notes that the findings suggest the element was incorporated before the Earth’s internal differentiation was complete.
According to Huang, the crystallization process of the core would have promoted convection within it. This movement could have provided the driving force for a primitive geodynamo, the mechanism responsible for generating Earth’s magnetic field.
- Under supervision of Giovanna Gomes
