From Science Magazine.

Read the story: https://www.science.org/content/article/scientists-probing-secrets-earths-inner-core-saved-life-planet

About the size of Pluto, Earth’s inner core is made of solid iron and helps power the magnetic field that protects life from harmful space radiation. For more than a century, seismic waves have helped researchers identify and characterize the core’s properties. Science reporter Paul Voosen wrote about the most recent insights into the mysterious center of the planet.