The Scar Season

Every drop of water you have ever tasted carries a scar. Not a metaphor. A physical record, pressed into the molecule itself, of a time when this solar system went briefly, catastrophically insane. You are going to learn what made that scar. It is not a gentle story. For reasons that took astronomers decades to accept, the giant planets — Jupiter, Saturn, the cold slow ones further out — drifted. Just slightly. Just enough. And when a planet the size of Jupiter drifts, the gravity it drags behind it is enough to reach into the asteroid belt and shake it like a bag of stones. What happened next is called the Late Heavy Bombardment, and we know it happened because the Moon still wears the bruises. Every large crater you see in a photograph of the Moon was punched there in a single furious window — not millions of years of random knocking, but one short season of almost total violence. Earth was hit too, harder, because Earth is bigger and closer. The oceans may have been boiled away entirely. More than once. And yet water came back. Some of it had been waiting on the rocks. Some of it arrived again, riding the same rocks that were doing the hitting. The scar in your water is the timestamp of that moment — a ratio of heavy hydrogen to ordinary hydrogen that tells you exactly which part of the chaos your particular molecule survived.