Scientists have found the oldest known rocks on Earth. They are 4.28 billion years old, making them 250 million years more ancient than any previously discovered rocks.

Earth formed about 4.6 billion years ago from a disk of gas and dust circling the sun. Remnants of crust from Earth's infancy are hard to come by because most of that material has been recycled into Earth's interior several times by the plate tectonics that continue to shape our planet's surface.