This ancient shark fossil is exquisite. But some researchers wonder if they’ll be able to study it

5 Undersung Signposts Of Earth’s Evolution

Remnants of an ancient planet buried inside the Earth may be the cause of a weak spot in the magnetic field

The remnants of an ancient planet might be buried inside Earth. New research suggests the Moon-forming Theia impactor (a Mars-size body that struck Earth 4.5 billion years ago) might have merged with our planet, forming two dense clumps in Earth's mantel that still exist to this day.