The Earth's core, primarily composed of iron, does not have such a high density that it could consist solely of this element. Determining the proportion of lighter elements in the core can provide valuable information about the planet's formation process. However, direct measurement of the core is impossible, and scientists are forced to use computer modeling and laboratory experiments, as noted by Scientific American.
In an experiment conducted by scientists from Peking University, diamond anvils were used. Samples of iron and silicate glass containing hydrogen and simulating the ancient magmatic ocean were subjected to pressures of 111 gigapascals and temperatures of 4827 °C. The researchers transformed the samples into needles about 20 nm thick and then bombarded them with ion beams for atomic-level analysis.
The results showed how silicon, oxygen, and hydrogen combined with iron during the Earth's formation. Based on this data, the researchers calculated that hydrogen constitutes between 0.07% and 0.36% of the core's mass, indicating a significant amount of this element that could only have been present during the Earth's formation from a gas-dust disk.
This discovery suggests that water may have been present on Earth from the very beginning, rather than being delivered later by icy comets and other celestial bodies.
The work of the scientists changes our understanding of the origin of water on our planet, and the presence of hydrogen in the core is linked to the formation of conditions necessary for habitation. About 4.5 billion years ago, when the core began to cool, hydrogen, silicon, and oxygen started to crystallize, creating convective flows. According to the authors of the study, these flows may have initiated an ancient geodynamic mechanism responsible for the formation of the Earth's magnetic field, which helps protect life from cosmic radiation.
