Did you know that there a few things known about Earth’s interior?! Some say we know more for the boundaries of the universe than the center of our planet. What we know less comes largely from the transmitted seismic waves through the layers of the planet. The deepest drilling has ever been executed in Earth is what Russia did for 22 years (1970-1992) in Kola Peninsula and barely came to 12.3 km (1/3 of the cortex and less than 0.2% of the terrestrial radio).
Photo 1, 2, 3, 4, 5: officespam.chattablogs