Using seismic waves, researchers from the University of Illinois and Nanjing University in China have discovered that the inner core of the Earth has an inner core of its own. It is previously known that the inner core of the Earth contains iron crystals that are aligned in a north to south direction. The newly discovered core has crystals aligned in a east to west direction.
The core was discovered using seismic waves are energy waves generated from an earthquake or loud explosions that passes through the Earth . Using principles similar to ultrasound, the team used seismic sensors to collect data from a seismic wave produced during an earthquake's aftermath.
The discovered core is smaller than the moon and may give information on how the Earth was formed, its history and an understanding what is happening deep inside the planet.