An international group of scientists from Belgium, the U.S., and Italy have published a new study showing that Jupiter's Io and Ganymede moons are leaving a noticeable set of footprints in the planet's bright aurorae.
While Earth has its own aurora, the aurorae of Jupiter is remarkably different when it comes to how it is created. Because of the planet's strong plasma-driven magnetosphere, charged particles will oftentimes hit the atmosphere of Jupiter, which causes a magnificent light display that in many ways looks very much like our own. Yet, as Phys.org reports, there are no traces of footprints left behind in Earth's aurora that are caused by the moon.
Scientists discovered these footprints after they analyzed data from NASA's Juno space probe, observing that when Io was extremely close to Jupiter, the planet's aurora was left with odd looking squiggles in it. Research showed it to be very much like a Von Kármán vortex, and scientists noted that as Io drifted away from Jupiter, so too did its strange footprint.
Just like the footprint that was discovered with Io, scientists noticed that Ganymede also created the same type of footprint in the aurorae of Jupiter when it was near. However, in the case of this moon, the footprint was discovered to have created two spots, almost as though it had been sliced in half.