Context: Recently, Researchers have revised estimate of the age of Earth’s solid inner core to 1-1.3 billion years from 565 million years old.
Key findings

• The estimates for core age have fluctuated between very young and relatively high.
• A new research has reported that the inner core is about 1-1.3 billion years old.
• It is young compared to the age of Earth i.e. 4.5-billion years old.

Earth’s inner core

• Earth’s inner core is the innermost geologic layer of the Earth.
• It is mostly made of iron and is in the solid state due to extreme pressure.
• The temperature is very hot about 6,000 degrees Celsius.
• The outer core is also iron, but is liquid due to relatively lower pressure.

Geodynamo

• As lighter elements rise through the liquid iron of the outer core at different temperatures, they cause convection currents.
• The circulation of liquid metal creates electric currents (kinetic energy is converted into magnetic energy) and turns Earth into a giant electromagnet.
• This is how Earth’s magnetic field is generated and the process is called geodynamo which is fed by convection.
• The age of the inner core, has been essentially calculated by the effectiveness of iron to transfer heat, known as thermal conductivity.