IMAGE: The volcano-laced surface of Jupiter’s moon Io was captured in infrared by the Juno spacecraft’s Jovian Infrared Auroral Mapper (JIRAM) imager as it flew by at a distance of about 80,000 kilometers on July 5, 2022. Brighter spots indicate higher temperatures in this image. CREDIT: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM
Io is incredibly volcanic and is often referred to as the ‘most volcanic body in the solar system’, which may not be true and is still debated, but it sure sounds cool. Or hot. Something neat. No matter the answer to that debate, Io has a lot of volcanos — over 400 of them; however, they are not caused by plate tectonics like volcanos are on Earth. Due to the tidal heating caused by Jupiter as well as the other Galilean moons, Io’s interior stays hot enough to create magma and gets fractures by the constant cooling and heating for that magma to breach the surface. All those eruptions on Io send particles into space, and those particles have caused several different observed phenomena.
Back in 2021, researchers led by George Clark analyzed data from NASA’s Juno spacecraft and found that Io is, in fact, a particle accelerator for Jupiter. All those volcanic particles start out by forming an exceedingly thin atmosphere around the tiny moon; it’s so thin that it’s technically an exosphere and not an atmosphere! From there, the particles interact with charged particles surrounding Jupiter and end up charged themselves and then swept into the powerful magnetic field lines. Basically, an electric circuit is formed between Io and Jupiter, stretching over 400,000 kilometers.