
Dimorphos
Didymos I Dimorphos is a minor-planet moon of the near-Earth asteroid 65803 Didymos, with which it forms a binary system. It has a diameter of 170 meters and has been characterised as a low-density rubble pile. Discovered in 2003 at the Ondřejov Observatory, Dimorphos was the target of the Double Asteroid Redirection Test, a NASA space mission that deliberately collided a spacecraft with the moon in September 2022 to alter its orbit around Didymos. The ESA mission Hera is planned to arrive at the Didymos system in 2026 to further study the effects of the collision on the moon.