Moon may have formed in just 5 hours after giant impact, new simulations suggest

Some 4.5 billion years ago, a Mars-sized world called Theia struck the young Earth, and from that violence our moon was born — or so the broad consensus holds. What has long remained uncertain is the pace of that birth, whether it unfolded over weeks or months of slow gravitational gathering. New computer simulations now propose something far more startling: that the moon may have taken shape in as little as five hours, compressing one of the solar system's most consequential events into a single afternoon's worth of cosmic time. The finding invites us to reconsider not only our own origins, b