The European Space Agency's Hera spacecraft will arrive at the asteroid Dimorphos in November to investigate the aftermath of NASA's DART impact from September 2022. Hera, a small-car-sized probe, will conduct a close-up survey of the impact crater and surrounding area.
Dimorphos orbits a larger asteroid called Didymos. The moonlet measures 151 meters across, while Didymos spans 780 meters. DART's collision with Dimorphos produced a brightening visible from Earth telescopes, but the actual effects on the asteroid remain unknown.
Hera's primary goal is to gather data on how the kinetic impact method works as a planetary defence technique. The mission will help scientists understand whether and how much DART changed Dimorphos's orbit.
Beyond the impact investigation, Hera will pursue additional science. The ESA states that past spacecraft encounters have shown asteroids to be dynamic environments with complex histories. The mission will explore ten asteroid mysteries, according to the agency.