How the Earth Was Born: Next NASA Mars Mission Could Deliver New Clues. Published Aug 29, 2017 at 4:29 PM EDT Updated Aug 29, 2017 at 5:11 PM EDT. By .

Plate tectonics describes how Earth’s entire, 100-kilometer-thick outermost layer, called the lithosphere, is broken into a jigsaw puzzle of plates — slabs of rock bearing both continents and ...