Scientists identify remnants of Theia, the ancient planet that collided with early Earth

Four and a half billion years ago, a planetary body called Theia struck the young Earth with enough force to forge the Moon and reshape the world we would one day inhabit. Scientists have long held this giant impact hypothesis as their best explanation for the Moon's unusual origin, but the case rested more on elegant reasoning than physical proof. Now, researchers have identified chemical anomalies deep within Earth's interior that bear the unmistakable signature of Theia itself — remnants of the impactor absorbed into our planet and preserved across geological time. In finding the fingerprin