A research team co-led by University College London has solved a decades-old mystery as to how Jupiter steadily produces spectacular bursts of X-rays, reports Phys.org. 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 civilization. In a 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 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 (ionized 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. The auroras occur at Jupiter’s north and south poles, often with clockwork regularity. During this observation, Jupiter was producing bursts of X-rays every 27 minutes. The charged ion particles that hit the atmosphere originate from gas pouring into space from giant volcanoes on Jupiter’s moon, Io. This gas becomes ionized (its atoms are stripped free of electrons) due to collisions in Jupiter’s immediate environment, forming a donut of plasma that encircles the planet. Co-author professor Graziella Branduardi-Raymont said: “X-rays are typically produced by extremely powerful and violent phenomena such as black holes and neutron stars, so it seems strange that mere planets produce them, too. We can never visit black holes, as they are beyond space travel, but Jupiter is on our doorstep. With the arrival of the satellite Juno into Jupiter’s orbit, astronomers now have a fantastic opportunity to study an environment that produces X-rays up close.” The magnetic field vibration may result from interactions with the solar wind or from high-speed plasma flows within Jupiter’s magnetosphere.
https://phys.org/news/2021-07-scientists-year-mystery-jupiter-x-ray.html
