The DART project, the first ever project to change the trajectory of asteroids and redirect them, involved the launch of an unmanned controlled spacecraft to the binary near-Earth asteroid Didymos and a collision with its Dimorph component (Didymos / Dimorphos). And so it happened – on September 26, 2022, the DART spacecraft hit Dimorphos.
At that time, the Hubble Space Telescope took a series of images showing tons of dusty debris from the impact at nearly 21,000 kilometers per hour. Astronomers didn’t know what to expect. They were surprised, delighted and somewhat puzzled by the results. The dust in the photographs emanated from the asteroid in the shape of a cone, then swirled along the orbit of its companion, and then formed a comet-like tail.

The DART experiment also provided new insights into planetary collisions that may have been common in the early solar system.
Source: Li, Jy et al, Ejecta from the DART-produced active asteroid Dimorphos, Nature (2023). DOI: 10.1038/s41586-023-05811-4. www.nature.com/articles/s41586-023-05811-4