Using data from NASA’s Juno spacecraft, scientists have found that Jupiter’s moon Io is even more volcanic than we thought. The heat coming from its surface may be hundreds of times greater than earlier estimates.
This new understanding comes from a better interpretation of Juno’s data. The team discovered that about half of the heat Io emits comes from just 17 of its 266 known volcanoes. This concentrated heat suggests that a vast magma lake beneath the surface, once theorized, might not exist.
Federico Tosi, a team leader at the National Institute for Astrophysics, mentioned, “Previous studies focused on a specific infrared light band, the M-band, which highlighted only the hottest areas. This could misrepresent the overall heat emission.” He compared it to estimating a bonfire’s warmth by only looking at the flames, ignoring the heat radiating from the embers.
Upon reanalyzing the data, the team found that Io’s volcanoes vary in temperature. Most have a hot outer layer with a cooler inner crust. While the outer layer is bright in infrared light, the inner crust emits a significant amount of heat, raising the heat flux estimate considerably.
This discovery invites more questions about the supposed magma ocean beneath Io. Tosi cautioned that while the data doesn’t rule out its existence, it doesn’t confirm it either. Future studies will need to be careful in interpreting results regarding such a complex feature.
There are still challenges ahead. As Tosi noted, the Juno spacecraft won’t be able to observe Io closely for a while. Upcoming missions like ESA’s Juice and NASA’s Europa Clipper will primarily focus on other moons, like Ganymede and Europa, which means Io’s volcanoes may not be studied in detail for now.
This research, though, sets the stage for future missions dedicated to Io. By improving our understanding of its volcanic activity, scientists hope to answer fundamental questions about why this moon is so geologically active. The findings were recently published in Frontiers in Astronomy and Space Sciences.
