Scientists Find a New State of Matter at Earth’s Center

Earth’s inner core may not be a conventional solid at all, but a superionic material where light elements drift like liquid through a rigid iron lattice. New experiments show that this unusual state dramatically softens the core, matching seismic clues that have puzzled scientists for decades. Credit: Shutterstock




Chinese researchers have discovered that interstitial carbon in iron-carbon alloys behaves in a superionic, liquid-like state under Earth’s core pressure and temperature conditions.

Beneath Earth’s molten outer core lies a solid central region, the inner core, a compact sphere made of an iron light-element alloy pressed by more than 3.3 million atmospheres and heated to temperatures comparable to the Sun’s surface.

For many years, researchers have struggled to explain its unusual behavior: although it is solid, it behaves like an unexpectedly soft metal, slowing seismic shear waves and displaying a Poisson’s ratio closer to butter than to steel. This has raised a long-standing question about how the planet’s solid center can appear both firm and surprisingly pliable.

READ MORE...

Earth's Inner Core

Deep beneath our feet, at a staggering depth of over 5,100km, lies Earth's inner core — a solid ball of iron and nickel that plays a crucial role in shaping the conditions we experience on the surface. In fact, without it we'd be unlikely to even exist.


But despite its significance, it's a bit of a puzzle how it formed and developed. We don't even know how old it is. Luckily, mineral physics is bringing us closer to solving the mystery.


The inner core is responsible for Earth's magnetic field, which acts like a shield, protecting us from harmful solar radiation. This magnetic field might have been important for creating the conditions that allowed life to thrive billions of years ago. 


The Earth's inner core was once liquid, but has turned solid over time. As the Earth gradually cools, the inner core expands outwards at the surrounding iron-rich liquid "freezes". That said, it is still extremely hot, at least 5,000 Kelvin (K) (4726.85°C).   READ MORE...