Hera has photographed Didymos and its moon Dimorphos as separate objects for the first time. The smaller asteroid remains barely a pixel across, but the image marks a step in the spacecraft’s approach. Closer measurements are planned to investigate how NASA’s earlier impact changed Dimorphos and shortened its orbit around its larger companion.
The European Space Agency’s Hera spacecraft has distinguished asteroid Didymos and its small moon Dimorphos as separate objects in an image for the first time. The monochrome picture was taken on October 18 and released on October 27. Dimorphos remains barely a pixel across, but it can now be separated from its larger companion after earlier views showed the system as one point.[1], [2]
Hera was approximately 1,280 kilometers from the pair when the camera took the image; the system lay about 197 million kilometers from Earth. Didymos is roughly 780 meters across and Dimorphos about 151 meters. NASA’s DART impactor struck the smaller body in 2022. Debris flew outward and the moon’s orbital period around Didymos shortened by approximately 33 minutes.[1]
The mission is intended to examine how Dimorphos’s mass, composition and internal structure contributed to that deflection. Another question is whether DART excavated a crater or reshaped the body more widely. More detailed imaging is planned for November 25, with two small companion satellites intended to complement the main spacecraft. These investigations remain ahead of Hera: the first resolved image supplies neither the planned mass measurements nor an internal map.[1]
