The European Space Agency’s Hera spacecraft has begun close inspections of the asteroid NASA deliberately struck in a planetary defence test four years ago.
ESA announced on Wednesday that Hera is now studying Didymos and its moonlet Dimorphos from 25 to 30 kilometres away. The spacecraft released its first close-up image of the pair on 5 November, taken from 60 kilometres out.
NASA’s DART spacecraft slammed into Dimorphos in September 2022 to test whether a collision could shift an asteroid off course. The impact shortened the moonlet’s orbit around Didymos by about 33 minutes, the first time humans had measurably changed the orbit of another Solar System body.
Hera’s job now is to measure what the impact actually did. The car-sized probe carries 25 science instruments and two shoebox-sized CubeSats, Milani and Juventas, and ESA describes the work as a crash-site investigation. One key measurement is the mass of Dimorphos, which will show how efficiently the impact’s momentum transferred.
Hera will move closer next month, to about 20 kilometres from the asteroids. ESA plans to release detailed images of both asteroids on 25 November. Hera principal investigator Patrick Michel said the first image already shows a side of Didymos that DART’s camera never saw.
Source: Phys.org
