When NASA’s DART spacecraft deliberately crashed into the asteroid moonlet Dimorphos, it did more than change the asteroid’s local orbit — it slightly shifted the path of the entire asteroid pair around the Sun. The impact blasted debris into space, doubling the force of the spacecraft’s hit and nudging the system’s solar orbit by a tiny but measurable amount. It marks the first time humans have altered the trajectory of a celestial object around the Sun. The result strengthens the case for using spacecraft impacts as a future planetary defense strategy. Dimorphos and its larger partner Didymos are bound together by gravity. The two asteroids orbit a shared center of mass in what scientists call a binary system. Because they are gravitationally linked, any change to one of them can influence the moti... [5606 chars]