NASA’s IXPE satellite may have solved a longstanding astrophysical mystery: how are X-rays produced in the extreme jets of supermassive black holes? By observing the blazar BL Lacertae, IXPE recorded low X-ray polarization versus very high optical polarization—confirming Compton scattering as the likely mechanism. This breakthrough supports the electron-photon interaction theory over proton-based explanations.
