Didymos is a binary asteroid system located in the near-Earth region of space. It consists of two bodies: a larger primary asteroid named Didymos and a smaller moonlet called Dimorphos. The system is approximately 800 meters in diameter for Didymos and about 160 meters for Dimorphos. NASA's DART mission, launched in 2021, aims to test planetary defense techniques by impacting Dimorphos. The goal is to change the moonlet's orbit around Didymos, demonstrating a method to potentially redirect asteroids that could threaten Earth in the future.