Hera Reaches the Asteroid DART Struck—Now Scientists Must Measure What Really Changed

November 12, 2026. Europe’s Hera spacecraft is beginning close-range study of the Didymos–Dimorphos asteroid pair, turning NASA’s 2022 DART impact from a successful demonstration into a test of how reliably a future asteroid could be deflected.

What has actually happened?

The Associated Press reported on November 12 that Hera is observing the asteroid system from roughly 25–30 kilometres away, with closer observations planned. The European Space Agency separately documented the spacecraft’s approach in an update published November 5, including images taken during October and the braking manoeuvres that brought the probe into the asteroid system. The two reports describe different stages of the approach and should not be mistaken for simultaneous measurements.

Why the DART result needs a follow-up

In September 2022, NASA deliberately struck Dimorphos, the smaller asteroid orbiting Didymos. The impact shortened Dimorphos’s orbit around its parent by about 33 minutes, according to ESA. That result established that a spacecraft can measurably alter an asteroid’s motion. It did not establish that every asteroid would respond the same way.

Hera is investigating the target’s shape, composition, mass and response to the collision. Those properties influence how momentum is transferred. Without them, a future planetary-defence mission could have difficulty predicting the effect of an impact on a different asteroid.

What comes next

ESA has scheduled the release of detailed asteroid images for November 25. Future close observations and the mission’s CubeSats are intended to refine scientists’ understanding of the DART collision. These are planned investigations, not findings already established.

Bottom line: Hera is not responding to an asteroid currently threatening Earth. It is gathering the measurements needed to make a tested deflection technique more predictable if a hazardous object is discovered in the future.

Featured image: illustrative night-sky photograph by Paul Lichtblau / Unsplash; not an image captured by Hera.