A groundbreaking study published in Nature Communications in February 2026 reveals a surprising discovery: the Earth’s core may hold the planet’s largest reservoir of hydrogen, potentially containing nine to 45 times more than all the world’s oceans combined.
Led by geologist Dongyang Huang of Peking University, the research challenges existing understandings of Earth’s composition and the origins of water on the planet. The study estimates the core’s hydrogen content to be between 0.07% and 0.36% of its total mass, equating to approximately 1.35 to 6.75 sextillion kilograms.
Due to the inaccessibility of the Earth’s core, located thousands of kilometers beneath the surface, researchers employed advanced laboratory simulations. Using a diamond anvil cell, they replicated the extreme pressures – up to 111 gigapascals – and temperatures – reaching 5,100 Kelvin – found at the planet’s center. These conditions allowed them to observe how elements like hydrogen, oxygen, and silicon interact within molten iron.
The experiments demonstrated that hydrogen readily dissolves into molten iron, a process believed to have occurred during the Earth’s formation approximately 4.5 billion years ago. This finding similarly offers a potential explanation for the “density deficit” observed in the Earth’s core, where the core’s density is lower than expected for pure iron.
The research suggests a re-evaluation of the prevailing theory that comets were the primary source of Earth’s water. Instead, the study proposes that hydrogen was present during the planet’s initial accretion and became trapped within the growing iron core. If hydrogen and oxygen can migrate between the core and the mantle over geological timescales, the Earth’s water cycle may be far more complex and deeply rooted than previously understood.
According to a September 20, 2025, report by Detik Finance, PT Pertamina (Persero) Tbk, through PT Pertamina Geothermal Energy Tbk (PGEO), is integrating Anion Exchange Membrane (AEM) Electrolyzer technology with geothermal energy to produce green hydrogen in Indonesia. This initiative, marked by a groundbreaking ceremony for a pilot plant in Ulubelu, Lampung on September 9, 2025, as reported by Katadata, demonstrates a practical application of hydrogen technology, though distinct from the core’s vast reserves.
Even as the hydrogen locked within the Earth’s core is currently inaccessible for energy purposes, understanding its presence is crucial. The hydrogen is believed to influence heat flow from the core to the mantle and contribute to the generation of the Earth’s magnetic field, which shields the planet from harmful space radiation.
Researchers acknowledge that extracting this hydrogen is currently technologically impossible, given its depth of nearly 3,000 kilometers and the immense pressures involved. However, the discovery has implications for the search for life on other planets. If hydrogen storage within planetary cores is a common phenomenon, seemingly barren rocky planets like Mars or distant exoplanets may harbor substantial subsurface water reserves.
On September 9, 2025, Vice Minister of Investment and Maritime Affairs/Head of the Investment Coordinating Board (BKPM), Todotua Pasaribu, attended the groundbreaking of the Green Hydrogen Pilot Plant Ulubelu in Lampung, as reported by Media Indonesia. He stated the project represents a significant step towards achieving Net Zero Emission by 2060, aligning with President Prabowo’s vision for energy independence and a green economy. The pilot plant aims to produce approximately 100 kg of hydrogen per day by November 2026, with potential partnerships including Toyota for the development of hydrogen-fueled vehicles.