NASA Deflects Dimorphos, Cutting Asteroid Orbit by 33 Minutes
Updated
Updated · ScienceBlog.com · Jul 12
NASA Deflects Dimorphos, Cutting Asteroid Orbit by 33 Minutes
3 articles · Updated · ScienceBlog.com · Jul 12
Summary
33 minutes — far above NASA’s 73-second success threshold — were shaved off Dimorphos’ orbit around Didymos after DART struck the moonlet in September 2022.
14,000 mph impact speed let the spacecraft act as a kinetic impactor, while ejecta from the collision added recoil that amplified the deflection beyond a simple direct hit.
2.70 millimeters per second of along-track velocity change and a momentum enhancement factor of 2.2 to 4.9 showed debris played a major role in shifting the asteroid’s motion.
160-meter Dimorphos posed no threat to Earth; NASA chose the binary system so telescopes could measure the orbital change cleanly from Earth.
Hera, the European Space Agency’s follow-up mission, will study the crater, mass and structure of the Didymos-Dimorphos system to refine how future asteroid-deflection missions might work.
DART proved we can deflect asteroids, but is our biggest planetary defense challenge now finding the thousands of hidden threats?
As Hera approaches the DART impact site, what are the chances the 2022 collision created a new, unpredictable debris field in space?
Defending Earth: How DART and Hera Are Shaping the Future of Asteroid Impact Prevention
Overview
The report highlights the progress of ESA's Hera mission, which launched in October 2024 and is set to arrive at the Didymos asteroid system in November 2026. After launch, Hera executed a major engine burn and set its course toward Mars, where it performed a successful flyby in March 2025. This flyby allowed the team to test Hera’s instruments and adjust its trajectory toward Didymos. Following this, the team began imaging faint asteroids to fine-tune the main camera, preparing for Hera’s first glimpse of Didymos. These steps ensure Hera is ready for its crucial planetary defense mission.