Hera, launched on October 7, 2024, heads for the binary system of asteroids Didymos. This binary system is made up of two asteroids, dimorphos and Didymos, the first being a smaller asteroid in orbit around the second. The DART (Double Asteroid Redirection Test) probe of NASA was sent in 2022 to test for the first time the deviation of an asteroid by scattering on Dimorphos. The mission was crowned with success, the impact having changed the orbit of Dimorphos.
Hera is expected to arrive in the binary system Didymos at the end of 2026 to carry out a study of Dimorphos after the impact, in order to help scientists understand the effectiveness of asteroid deviation techniques for the defense of planets. But ESA needed to test the probe camera in conditions similar to those expected when it will see Didymos for the first time.
Hera, using its asteroid framing camera, captured Otero, a rare asteroid type A, at a distance of about three million kilometers. Hera’s camera observed the asteroid for three hours, taking photos every six minutes. A period of time created from these images revealed the movement of the asteroid, thus differentiating it from a star.
After observing Otero in May 2025, Hera’s imagery was used two months later. On July 19, she captured Kellyday, who appeared about 40 times less luminous than Oleo. Giacomo Moreso, Flight Dynamics Engineer at the European Center for Spatial Operations (ESOC) from ESA in Darmstadt, Germany, described as “very encouraging” the results of HERA quick response observations proves that it is ready for its mission to Didymos.
