ESA's Hera spacecraft captures first close-up of asteroid Didymos after DART impact
The European Space Agency's Hera probe has returned its first detailed image of the Didymos asteroid system, revealing the previously unseen side of the primary body and providing new data on the aftermath of NASA's DART mission.
The European Space Agency's Hera spacecraft has transmitted its first close-up photograph of the Didymos asteroid pair, the target of NASA's 2022 Double Asteroid Redirection Test (DART) mission. The black-and-white image shows the primary asteroid Didymos, about half a mile across, from roughly 37 miles away, with most of its smaller companion Dimorphos, a 500-foot-wide moonlet, hidden in shadow.
The view captures the side of Didymos that DART never observed, displaying boulders, craters, grooves and a ridge that encircles the asteroid’s middle. Mission scientists said the features may include debris ejected by the DART impact, which shortened Dimorphos’s orbital period by 33 minutes, a larger change than anticipated.
"The first thing we said was 'Wow!'" Hera principal investigator Patrick Michel said in a statement, adding that the image feels like looking at a new world. Mission scientist Michael Kueppers noted that some of the observed structures could be material displaced during the collision. Detailed images of both bodies are scheduled for release on Nov. 25.
Hera will continue to map the crash site to determine whether the impact created a deep crater, a shallow dent, or altered the overall shape of Dimorphos. Its companion probe, Juventas, will use radar to probe Dimorphos’s interior, while Hera measures the asteroid’s mass and density to assess its composition and structural integrity. Scientists also aim to confirm whether the impact induced a wobble in Dimorphos’s rotation, as telescope data suggest it may now be tumbling. The mission’s findings are intended to refine the kinetic-impact technique for future planetary-defense efforts.