"Boulders Break Free: Hubble Captures Dimorphos' Escape"
Astronomers using the Hubble Space Telescope have discovered a swarm of boulders drifting away from the asteroid Dimorphos, possibly shaken off when NASA's DART impactor spacecraft intentionally collided with the asteroid. The boulders range in size from 1 m to 6.7 m and are some of the faintest objects ever imaged in the Solar System. This finding opens up new opportunities for studying the aftermath of the impact using ESA's upcoming Hera mission. The boulders are not shattered pieces caused by the impact but were already scattered across the asteroid's surface. The impact is estimated to have shaken off 2% of the boulders, and Hera will determine the actual crater size. Dimorphos may have formed from material shed by the larger asteroid Didymos, making it a rubble pile held together by weak gravity. The origin of the lifted boulders is still unclear, but they could be part of an ejecta plume or shaken loose by a seismic wave from the impact.