One pixel, two asteroids: Hera can finally see both rocks it travelled so far to meet

For months they were a single point of light. Now Europe's Hera spacecraft, closing in from about 1,280 kilometres away, has separated its two target asteroids in one view for the first time: Didymos, about 780 metres across, and its smaller companion Dimorphos, about 151 metres wide — roughly the height of the Great Pyramid of Giza, and still just one pixel across. Two gentle braking burns, about a week apart, have slowed Hera to around 20 metres per second relative to the pair, easing it toward a careful close-up survey. This is the follow-up act to 2022, when NASA's DART spacecraft deliberately struck Dimorphos and shortened its orbit by about 33 minutes — the first time humanity moved an asteroid. Hera's job is to find out exactly what that hit did: whether it left a crater, how much material flew off, and what the little asteroid is made of, so a one-off experiment can become a method scientists truly understand.