Scientists solve 40-year mystery over Jupiter’s X-ray aurora

A research team co-led by UCL has solved a decades-old mystery as to how Jupiter produces a spectacular burst of X-rays every few minutes. The X-rays are part of Jupiter's aurora - bursts of visible and invisible light that occur when charged particles interact with the planet's atmosphere. A similar phenomenon occurs on Earth, creating the northern lights, but Jupiter's is much more powerful, releasing hundreds of gigawatts of energy, enough to briefly power all of human civilisation*. In a new study, published in Science Advances , researchers combined close-up observations of Jupiter's environment by NASA's satellite Juno, which is currently orbiting the planet, with simultaneous X-ray measurements from the European Space Agency's XMM-Newton observatory (which is in Earth's own orbit). The research team, led by UCL and the Chinese Academy of Sciences, discovered that X-ray flares were triggered by periodic vibrations of Jupiter's magnetic field lines. These vibrations create waves of plasma (ionised gas) that send heavy ion particles "surfing" along magnetic field lines until they smash into the planet's atmosphere, releasing energy in the form of X-rays. Co-lead author Dr William Dunn (UCL Mullard Space Science Laboratory) said: "We have seen Jupiter producing X-ray aurora for four decades, but we didn't know how this happened.