Groundbreaking Discovery: Massive Helium Reserves Found in Earth’s Core Transform Our Understanding of Planetary Formation

Scientists have long been intrigued by primordial helium, specifically the rare isotope known as ³He. This helium escapes from volcanic rocks in places like Hawaii and Iceland. Unlike the more common ⁴He, which is made through radioactive decay, ³He doesn’t form naturally on Earth. This has led experts to believe it comes from deep inside the planet.

A recent study published in Physical Review Letters offers a fresh perspective: the Earth’s core might hold significant amounts of helium. The research team from the University of Tokyo, led by Professor Kei Hirose, discovered that helium can bond with iron under extreme pressures, challenging the idea that helium is too inert to form stable compounds.

This finding not only changes how we view Earth’s deep interior but also hints that ancient gases from the early solar system might still be trapped beneath us. This could reveal new information about how planets formed, how Earth’s atmosphere originated, and how its core evolved.

The researchers used a laser-heated diamond anvil cell to create conditions similar to those found deep inside the Earth. They applied intense pressure and heat to iron and helium to see what happened.

“For years, I’ve studied geological and chemical processes that occur deep within the Earth. To understand these conditions, we need to replicate the extreme temperatures and pressures. That’s why we use a laser-heated diamond anvil cell,” Professor Hirose explained.

They subjected the samples to pressures ranging from 5 to 55 gigapascals—equivalent to about 50,000 to 550,000 times the pressure of the atmosphere—and heated them to temperatures between 1,000 and nearly 3,000 Kelvin (about 1,340 to 4,900°F).

In earlier studies, tiny amounts of helium bonded with iron were found, about seven parts per million. However, this new experiment revealed an astonishing concentration of up to 3.3% helium—5,000 times more than previously observed. What’s even more significant is that the helium remained stable in the iron structure even when pressure decreased, implying it could be locked in the core for billions of years.

The presence of ³He in volcanic rocks has long suggested that primordial materials from the early solar nebula still exist inside Earth. But the question remained: where is this helium stored, and how does it escape?

This study suggests that the Earth’s core may be a vast reservoir of trapped helium, slowly leaking through the mantle and rising to the surface through volcanic activity. If this is true, it means our core might still be releasing gases from the formation of the solar system, connecting Earth’s interior to its earliest history.

Moreover, this discovery raises even more questions: could other noble gases like neon or hydrogen also be hidden in the core? Understanding this could shed light on how Earth’s atmosphere formed and even how water came to be on our planet.