Astronomy Picture of the Day

Explanation: Last Wednesday the voyaging Lucy spacecraft encountered its first asteroid, 152830 Dinkinesh, and discovered the inner-main belt asteroid has a moon. From a distance of just over 400 kilometres, Lucy's Long-Range Reconnaissance Imager captured this close-up of the binary system during a flyby at 4.5 kilometre per second or around 10,000 miles per hour. A marvelous world, Dinkinesh itself is small, less than 800 metres (about 0.5 miles) across at its widest. Its satellite is seen from the spacecraft's perspective to emerge from behind the primary asteroid. The asteroid moon is estimated to be only about 220 metres wide.