Although the Earth's core is primarily composed of iron, its density does not suggest that it is entirely made up of this element. Determining the proportion of lighter elements in the core can provide valuable information about the process of our planet's formation. Due to the impossibility of directly measuring the core, researchers use computer models and laboratory experiments, reports Scientific American.
In their experiments, scientists from Peking University used diamond anvils to create conditions that mimic an ancient magmatic ocean. Samples consisting of iron and hydrogen-containing silicate glass were subjected to pressures of 111 gigapascals and temperatures of 4827 °C. The researchers reduced the samples to needle-like shapes about 20 nm thick and analyzed them using ion beams.
The results showed that during the formation of the Earth, silicon, oxygen, and hydrogen were combining within the iron. Based on this data, the scientists determined that hydrogen makes up between 0.07% and 0.36% of the core's mass, which represents a significant volume likely incorporated during the Earth's formation from the gas-dust disk.
This discovery implies that water may have been present on the planet from the very beginning, rather than being later delivered by comets and other celestial bodies.
The work of the scientists revises scientific views on the source of water on Earth, and the presence of hydrogen in the core is linked to the conditions that made the planet habitable. 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 initiated an ancient geodynamic mechanism that led to the formation of the Earth's magnetic field, protecting all living things from cosmic radiation.
