Scientists have discovered that Earth's core may contain as much as 45 oceans' worth of hydrogen, a revelation that could reshape our understanding of planetary formation and the origins of life on our planet. This groundbreaking finding, published in the journal Nature Communications, suggests that Earth's water, a primary source of hydrogen, was acquired during the planet's formation rather than through later comet impacts. The study's lead author, Dongyang Huang, an assistant professor at Peking University, explains that the core would have stored most of the water in the first million years of Earth's history, with the mantle and crust following in water abundance. This discovery has significant implications for understanding the early stages of Earth's development and the role of hydrogen in the planet's evolution.
The research, conducted by Rajdeep Dasgupta from Rice University in Texas, involved studying the origin and distribution of hydrogen in Earth's core. Hydrogen, being the lightest and smallest element, is challenging to quantify using routine analytical methods. Previous studies hinted at hydrogen abundance in the core but struggled to determine its exact amount compared to other core elements like silicon and oxygen. The new technique, developed by Huang's team, involves sharpening iron samples into needle-like shapes and ionizing their atoms for precise counting, providing a more accurate measurement of hydrogen in the core.
The study's findings suggest that hydrogen may make up 0.36% to 0.7% of Earth's core weight, a significant amount that could have been delivered during the planet's growth. This discovery raises questions about the sources of Earth's hydrogen, with gas from nebulas and water from comets and asteroids being potential contributors. Kei Hirose, a professor at the University of Tokyo, notes that the amount of core hydrogen could be higher than the new estimate, emphasizing the need for further research to confirm and refine these findings. The study's implications for understanding Earth's magnetic field and the release of heat from the core into the mantle are also significant, offering insights into the planet's habitability.
