European Hera spacecraft begins close inspections of asteroid rammed by NASA

A European spacecraft has begun close-up observations of an asteroid system that was deliberately struck by a NASA probe four years ago. The European Space Agency announced Wednesday that its Hera spacecraft is now operating between 15 and 18 miles (25 to 30 kilometers) from the asteroid Didymos and its moonlet Dimorphos.

In 2022, NASA's Double Asteroid Redirection Test (Dart) spacecraft intentionally crashed into Dimorphos to test whether a kinetic impact could alter the trajectory of a potentially hazardous asteroid. The collision shortened the moonlet's orbit around Didymos and nudged it into a slightly different path around the sun. The impact also sent rubble and boulders flying off, creating a debris trail that extended thousands of miles into space for months.

Hera, which launched in 2024 and is roughly the size of a small car, will move even closer next month, approaching within 12 miles (20 kilometers). ESA officials described the mission as a "crash site investigation." The probe carries 25 scientific instruments and a pair of shoebox-sized Cubesats that will survey Dimorphos in greater detail and attempt to land on it. Scientists note that some debris from the 2022 impact may still be present in the area.

Dimorphos is about 500 feet (151 meters) in diameter, while Didymos measures roughly 2,560 feet (780 meters) across.