Hera images asteroid pair separately, European Space Agency says

The European Space Agency (ESA) says its Hera spacecraft has returned its first image showing Didymos and its smaller companion, Dimorphos, as separate objects rather than one dot. Universe Today, which carried the agency’s account, put the probe about 1,280 kilometers from the pair.

The observation follows NASA’s deliberate collision of its DART spacecraft with Dimorphos in September 2022 to test whether an impact could deflect an asteroid. That collision changed Dimorphos’s orbital period—the time it takes to travel around Didymos—by 32–33 minutes. Hera launched in October 2024 to investigate the aftermath.

Didymos and Dimorphos form a binary asteroid system: they orbit each other while traveling around the Sun. Their estimated sizes differ substantially.

Closer observations still ahead

The new image distinguishes the targets during Hera’s approach; it does not yet reveal how DART changed Dimorphos’s geology. Hera’s follow-up task is to examine the post-impact surface and investigate the asteroid’s structure.

Hera plans to deploy Milani and Juventas, small satellites called CubeSats, for observations closer to the surface than Hera itself can fly. Milani will study the minerals at the impact site. Juventas will use radar that penetrates the ground to investigate whether Dimorphos’s interior is solid rock or a loose pile of rubble, as researchers have proposed.

Ian Carnelli, ESA’s Hera mission manager and head of its Systems Department, said the spacecraft’s views would sharpen as it approaches. He said ESA would unveil the first detailed images of Dimorphos on 25 November 2026.