The asteroids Didymos and Dimorphos
The asteroids Didymos and Dimorphos
It is assumed that around 15 percent of asteroids are binary (or triple) asteroid systems. Many of the smaller bodies are so-called ‘rubble pile asteroids’. They originated from asteroids that were completely destroyed by a collision and whose fragments then came together again in a loose gravitational state. Due to the relatively low mass and gravity of the bodies involved, the smaller asteroids orbit their ‘parents’ at a comparatively low speed of less than one metre per second. This opens up the possibility of measurably shifting the orbit of one of these asteroid moons – something that would not be possible with such precision for a single asteroid in a much faster-moving solar orbit. Hera will use this opportunity to find out whether asteroids posing a threat to Earth can be deflected.
