A magnetar called SGR 0418+5729 (SGR 0418) has been shown to have the lowest surface magnetic field ever found for this type of neutron star. Magnetars have surface magnetic fields that are usually ten to a thousand times stronger than SGR 0418's. Data from Chandra, XMM-Newton, Swift, and RXTE was used to measure the surface magnetic field. These results have implications for understanding supernova explosions and the number and evolution of magnetars. // X-ray: NASA/CXC/CSIC-IEEC/N.Rea et al; Optical: Isaac Newton Group of Telescopes, La Palma/WHT; Infrared: NASA/JPL-Caltech; Illustration: NASA/CXC/M.Weiss