By creating conditions akin to the center of the Earth inside a laboratory chamber, researchers have improved the estimate of the age of the Earth’s solid inner core, putting it at 1 billion to 1.3 billion years old.
The results place the core at the younger end of an age spectrum that usually runs from about 1.3 billion to 4.5 billion years, but they also make it a good bit older than a recent estimate of only 565 million years.
What’s more, the experiments and accompanying theories help pin down how the core conducts heat, and the energy sources that power the planet’s geodynamo — the mechanism that sustains the Earth’s magnetic field. The geodynamo keeps compasses pointing north and helps protect life from harmful cosmic rays.
“People are really curious and excited about knowing about the origin of the geodynamo, the strength of the magnetic field, because they all contribute to a planet’s habitability,” said Jung-Fu Lin, a professor at The University of Texas at Austin’s Jackson School of Geosciences who led the research.