Science breakthrough as secrets of Earth's inner core unlocked

The core's inaccessibility has meant that even basic characteristics remain uncertain, with temperature estimates hovering around 4,727C but lacking precision.

New research from explorers focused on the carbon in the core, which showed the temperature needed to begin freezing.

For example, if 2.4 per cent of the core's mass was carbon, around 420C of supercooling would be needed.

This new research is the first time that freezing of the core has been shown to be possible.

Should the carbon content be higher, then supercooling would need a lower temperature.

The planet's central region plays a vital role too in shielding the atmosphere and oceans from harmful solar radiation through its magnetic field generation.

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This protective barrier exists because of processes occurring deep within the iron-rich interior.

Continental drift and the movement of tectonic plates also depend on heat released from the core.

As the centre gradually cools, thermal energy flows into the surrounding mantle, creating currents that reshape Earth's surface.

Today, the strength of the magnetic field is primarily due to the ongoing solidification process, where liquid material transforms into solid matter.

This freezing process releases energy that maintains the protective magnetic shield essential for life on Earth.

Researchers have found that the boundary where solid and liquid regions meet holds the key to understanding core properties.

At this freezing point, temperatures must match the melting point of core materials, providing a crucial reference for calculations.

Earthquake studies have mapped this boundary's location through seismic wave analysis.

Scientists explain that knowing the exact melting temperature would unlock precise data about core conditions and chemical composition.

Previous attempts to determine core properties have relied on examining space rocks believed to be remnants of unformed planets or fragments from destroyed Earth-like worlds.

These meteorites suggest an iron-nickel composition with possible traces of silicon or sulphur, though specifics have remained elusive.

Seismic earthquake waves provide more detailed insights, as their speed variations through different materials reveal interior composition.

Scientists measure how these waves accelerate or decelerate when passing through various substances, comparing field data with laboratory experiments on minerals and metals.

However, even with limited material options, possible melting points differ by hundreds of degrees.

This variation has prevented researchers from pinpointing exact core properties, leaving fundamental questions unanswered.

The recent discovery offers a pathway to overcome these limitations, potentially revealing when the core started solidifying and its precise chemical makeup.