7K views · 152 reactions | One of the more bizarre features of our planet is that within its molten iron core there is an enormous rotating crystal ball the size of the moon. Not weird enough for you? Consider this: that crystallized iron ball is hotter than the surface of the sun, yet it resists melting. A new study from KTH may finally settle a longstanding debate over how that's possible. | KTH Royal Institute of Technology | Facebook