Using NASA’s Neutron star Interior Composition Explorer (NICER), astronomers have observed the merging of multimillion-degree X-ray spots on the surface of a magnetar called SGR 1830-0645. X-ray spots on the surface of the magnetar SGR 1830-0645. Image credit: Younes et al., doi: 10.3847/2041-8213/ac4700. Magnetars are isolated neutron stars with extremely powerful magnetic fields — up to 10 trillion times more intense than a refrigerator...