DART images reveal asteroids ejecting 'cosmic snowballs' — ejecta dynamics force rethink of planetary‑defense models
NASA's DART mission captured images showing the impacted asteroid ejecting large clumps of material — 'cosmic snowballs' — a phenomenon engineers initially mistook for a camera fault. The observed clumping and trajectories of ejecta alter assumptions about momentum transfer and debris dispersal used in planetary‑defense planning.