A new study shows that NASA's Double Asteroid Redirection Test (DART) altered the orbit of a whole asteroid system. In September 2022, a spacecraft was deliberately crashed into Dimorphos, a small moonlet circling the asteroid Didymos, using the kinetic impactor technique. The impact cut Dimorphos' orbital period around Didymos by about 33 minutes. It also slightly changed the path of the Didymos–Dimorphos pair around the Sun, demonstrating a practical approach to planetary defence.