Webb found the crime scenes where worlds smashed apart — including the kind of crash that made our Moon

Point the James Webb telescope at 21 young stars, and you can read the dust left by planet-shattering collisions — the fossil record of how worlds are built. Astronomer Kate Su's team, publishing in The Astrophysical Journal, found the debris splits in two: about a third is silica-rich, the fingerprint of high-energy crashes between Mars-sized bodies — the same kind of violence, on the same scale, as the impact that likely formed our own Moon. The rest comes from gentler grazes between Moon-sized objects. Only the youngest stars, under 300 million years old, still show the big, Moon-making kind of crash. Our solar system's violent childhood, replayed across the galaxy.