Expanding Plume from DARTs Impact

What happens if you crash a spaceship into an asteroid? In the case of NASA 's DART spaceship and the small asteroid Dimorphos , as happened last week, you get quite a plume . The goal of the planned impact was planetary protection -- to show that the path of an asteroid can be slightly altered , so that, if done right, a big space rock will miss the Earth . The high brightness of the plume, though, was unexpected by many, and what it means remains a topic of research. One possibility is that 170-meter wide Dimorphos is primarily a rubble pile asteroid and the collision dispersed some of the rubble in the pile. The featured time-lapse video covers about 20 minutes and was taken from the Les Makes Observatory on France 's Reunion Island , off the southeast coast of southern Africa. One of many Earth-based observatories following the impact , the initial dot is primarily Dimorphos's larger companion: asteroid Didymos . Most recently, images show that the Didymos - Dimorphos system has developed comet-like tails . DART Impact on Dimorphos: Notable images submitted to APOD