Webb maps the mineral signature of planet-shattering collisions.
WHAT HAPPENED: Su and colleagues compiled 12 newly observed extreme debris discs plus follow-up and archival targets, 21 systems in total. Spectra sort them into silica-rich and silica-poor.
WHY IT MATTERS: Planetary embryos are too small to image directly. Their collision debris is now a measurable proxy for impact energy and composition.
WHAT IT COULD BECOME: A clock for the rocky-planet assembly phase, and a test of whether our own Late Heavy Bombardment left a silica-poor infrared flicker.
WHAT IT MEANS FOR YOU: The Moon-forming impact stops being a unique story and becomes a class of events with a measurable rate.