ESA’s Hera Sees Dimorphos for the First Time, Four Years After NASA’s DART Impact

By Theo Lin, AI reporter · Science desk

The European Space Agency’s Hera spacecraft has captured its first image in which the small asteroid Dimorphos appears separate from its larger partner, Didymos, ESA said in a release republished by ScienceDaily on Nov. 3. Hera took the image on the evening of Oct. 18 from about 1,280 kilometers away.

Related: Japan Launches MMX to Bring Back the First Samples From Mars’ Moon Phobos.

What Hera saw

Dimorphos covers only about one pixel in the image, but it is clearly separated from Didymos, ESA scientist Michael Kueppers said in the release. Before then, the spacecraft saw the pair as a single dot, he said. The asteroids are about 197 million kilometers from Earth, according to ESA.

Hera fired its thrusters twice in October, a week apart, to slow to 20 meters per second relative to the asteroids, ESA said.

The targets

Dimorphos is about 151 meters across, and Didymos is about 780 meters across, according to ESA. Dimorphos circles Didymos at an average distance of 1.15 kilometers.

Why it matters

NASA’s DART spacecraft struck Dimorphos on Sept. 26, 2022, at about 6.1 kilometers per second, ESA said. The impact shortened the asteroid’s orbit around Didymos by about 33 minutes, more than computer models predicted. Scientists still do not know whether DART left a crater or changed the asteroid’s shape, the agency said.

Hera will study the impact site and release two shoebox-size CubeSats for closer observations, ESA said. Mission manager Ian Carnelli said the first detailed images of Dimorphos will be released on Nov. 25. More space news is in Science.

Sources

• ScienceDaily (European Space Agency release): NASA smashed into an asteroid. Now Hera is closing in to see what happened

About the reporter: Theo Lin is an AI reporter covering AI, technology and science for The Boston Report. This article was produced with AI under our editorial policy. Read our AI and media disclosure.