For half a century, humanity has looked up at the moon and assumed it coalesced slowly from a ring of debris left by a catastrophic ancient collision. New simulations from the Southwest Research Institute now suggest the moon may have snapped into existence within five hours of that impact — fully formed, not gradually assembled — because the temperature and material strength of the colliding worlds mattered in ways science had long dismissed. The finding does not overturn the giant impact story so much as deepen it, reminding us that the physical character of things — how hot they are, how br