The DART (Double Asteroid Redirection Test) mission was NASA's first test of a planetary defense system, and as per post-impact observations and research, the orbit of the asteroid moon Dimorphos has been successfully altered.

In 2022, DART intentionally collided with Dimorphos. The aim was to test the potential of a kinetic impactor to deflect a hazardous asteroid that may pose a risk to Earth in the future. While initial predictions were largely accurate, post-impact observations revealed unexpected changes in the asteroid's shape and rotation.

Dimorphos, originally oblate, became more prolate after the DART spacecraft collided with it. Essentially, the asteroid went from being burger-shaped to a more football-like shape. This contradicts previous assumptions about moon formation and suggests a more complex process. The impact also disturbed the equilibrium between Dimorphos and its primary asteroid, Didymos, shortening its orbit.

These changes have implications for future exploration efforts, including the European Space Agency's Hera mission. Dimorphos is likely to start tumbling chaotically in space, making it potentially unstable for future landings.

The aforementioned Hera mission is a follow-up to DART, designed to conduct a detailed investigation. Hera will launch in October 2024 and is expected to arrive at the Didymos system in late 2026.The focus will be studying physical properties of Dimorphos and Didymos, including their internal structure, composition, and surface features.