As ESA’s Hera mission for planetary defence completes its pre-launch testing, its target asteroids have come into focus as tiny worldlets of their own. A special issue of Nature Communications published this week presents studies of the Didymos asteroid and its Dimorphos moon, based on the roughly five and a half minutes of close-range footage returned by NASA’s DART spacecraft before it impacted the latter body – along with post-impact images from the Italian Space Agency’s LICIACube.
