WASHINGTON—In the moments before NASA’s DART spacecraft slammed into the asteroid Dimorphos in a landmark planetary defense test in 2022, it took high-resolution images of this small celestial object and its larger companion Didymos.
These images have enabled scientists to unravel the complicated history of these two rocky bodies located in the vicinity of Earth and gain insight into the formation of what are called binary asteroid systems—a primary asteroid with a secondary moonlet orbiting it.
