This image shows the orientation of the magnetic field in the distant 9io9 galaxy, seen here when the Universe was only 20% of its current age — the furthest ever detection of a galaxy’s magnetic field. Dust grains within 9io9 are somewhat aligned with the galaxy’s magnetic field, and due to this, they emit polarized light, meaning that light waves oscillate along a preferred direction rather than randomly. ALMA detected this polarization signal, from which astronomers could work out the orientation of the magnetic field, shown here as curved lines overlaid on the ALMA image. Credit: ALMA (ESO/NAOJ/NRAO)/J. Geach et...