Mars’s core continues to be measured — and it’s amazingly big ‘Marsquakes’ expose pink Earth’s hidden geology Earth’s magnetic subject is performing up and geologists don’t know why Earth's core lightens up Topics Even though we haven’t been there, there’s quite a bit we know about Earth’s core. From the https://econopass.com/news/science-technology/earths-inner-core-rotation-slows-down-what-does-it-mean/