Astronomy is arguably the oldest science, and has featured strongly throughout the history of Nature — the first quasar, the first exoplanet, the nature of spiral nebulae, to name but a few of the advances reported in its pages. The launch of Nature Astronomy now enables much expanded coverage of the modern discipline: the journal welcomes research across astronomy, astrophysics and planetary science, with the aim of fostering closer interaction between the researchers in each of these areas.