By WILIAM HUNTER, SENIOR SCIENCE & TECHNOLOGY REPORTER
Published: 12:10 BST, 4 August 2026 | Updated: 13:57 BST, 4 August 2026
Earth's inner core is filled with a rare material known as 'extreme hydrogen', a study has claimed.
This bizarre substance, known as super–ionic hydrogen, behaves unlike anything found on the surface.
At the extreme pressures found 3,200 miles (5,100 km) beneath the surface, this otherworldly version of hydrogen flows like a liquid through solid iron and even conducts electricity.
Now, researchers say that this flow of extreme hydrogen could play an important role in shaping the magnetic field that makes life on Earth possible.
Although scientists have long suspected there might be hydrogen in the inner core, it has proven challenging to work out exactly how it is distributed.
In their new paper, published in the journal PNAS, the researchers used quantum–mechanical simulations to model how hydrogen might behave in the extreme conditions of the inner core.
They discovered that super–ionic hydrogen isn't evenly distributed, but is most likely concentrated right on the boundary between the inner and outer core.
At temperatures of 5,226°C (5,500 K), hydrogen makes up 16 per cent of the atoms in the inner–core boundary, dropping to around nine per cent near the centre.
Scientists say that Earth's solid inner core could be hiding a bizarre form of 'extreme hydrogen' that is unlike anything found on the surface
The 102 quintillion–tonne sphere of iron alloy that makes up our planet's innermost core is one of the most extreme environments in the solar system.
More than 3,000 miles beneath the surface, the core is crushed by more than 3.3 million atmospheres of pressure and heated to temperatures close to the surface of the sun.
This unique part of the planet also has a number of strange and contradictory properties that have baffled scientists for decades.
Scientists know that the planet's innermost core is made of superheated iron, kept solid by the extreme pressures 3,200 miles (5,100km) beneath the surface.