NASA has recorded the most powerful volcanic eruption outside of Earth on Io, one of Jupiter’s moons. On December 27, 2022, Juno, NASA\u2019s spacecraft, witnessed numerous active volcanoes erupting simultaneously and releasing far more energy than any other eruption recorded in the solar system to date.<\/p>\n
A team of researchers from Italy’s National Institute for Astrophysics<\/a> (INAF) published a paper summarizing the results of their analysis of Juno’s infrared instrument data. It is believed that Io’s volcanism may be connected beneath the surface by a large network of magma reservoirs.<\/p>\n Io currently holds the record for being the most volcanically active body in the solar system, with an estimated 400 active volcanoes. However, this most recent eruption was unprecedented. The eruption covered approximately 40,400 square miles, which is larger than many U.S. states, and released between 140 and 260 terawatts. By comparison, the infamous 1980 Mount St. Helens eruption released around 52 terawatts.<\/p>\n Unprecedented Observations From Juno<\/p>\n \u201cIt is also notable that this eruption occurred simultaneously from multiple active sources; as such, the eruption increased its brightness by over 1,000 times from what would be expected in typical conditions,\u201d said Dr. Alessandro Mura of INAF. The eruption\u2019s evidence suggests that it was a massive eruption<\/a> event occurring at one time and traveling beneath the surface of Io for a distance of hundreds of kilometers.<\/p>\n A massive hotspot \u2014 larger the Earth\u2019s Lake Superior \u2014 can be seen just to the right of Io\u2019s south pole in this annotated image taken by the JIRAM infrared imager aboard NASA\u2019s Juno on Dec. 27, 2024, during the spacecraft\u2019s flyby of the Jovian moon. (CREDIT: NASA\/JPL-Caltech\/SwRI\/ASI\/INAF\/JIRAM <\/p>\n Evidence of the eruption was collected during one of Juno’s closest flybys of Io, when the spacecraft was approximately 46,200 miles above the moon’s surface. The eruption was detected with the Jovian Infrared Auroral Mapper (JIRAM), which was specifically designed to study Jupiter\u2019s atmosphere<\/a> but was also capable of detecting the volcanic thermal energy of Io.<\/p>\n The temperature measurements collected by JIRAM were so intense that parts of the detector became saturated. Despite the saturation, researchers were able to determine the eruption’s temperature and pressure by using additional spectral measurement data and stray light patterns on the JIRAM detector.<\/p>\n Signs Of A Shared Magma System<\/p>\n The main hot spot was approximately 400 kilometers long and remained heated throughout the entire observation period. Previous measurements of the same spot were negligible. Many of the other nearby hot spots erupted at the same time, with some increasing their thermal energy by more than 1,000 times.<\/p>\n There is a significant difference between volcanoes in the same area that erupted and those that did not erupt. This suggests that some volcanoes may share a magma system underground<\/a>, while others have separate magma sources.<\/p>\n The Moon was shaped through the combination of pressure and fire<\/p>\n Why Io Is So Volcanically Active<\/p>\n Io’s intense volcanic activity is due to the effects of Jupiter’s gravitational pull on the moon. Jupiter\u2019s immense gravity creates pressure on Io, causing it to flex like a stress ball. This constant flexing heats the moon\u2019s interior. When heated, the rocks convert into magma, which continues to rise to the surface and cool down.<\/p>\n Images of Io captured in 2024 by the JunoCam imager aboard NASA\u2019s Juno show significant and visible surface changes (indicated by the arrows) near the Jovian moon\u2019s south pole. These changes occurred between the 66th and 68th perijove, or the point during Juno\u2019s orbit when it is closest to Jupiter. (CREDIT: NASA\/JPL-Caltech\/SwRI\/MSSS Image processing by Jason Perry) <\/p>\n The magma system used by scientists to describe Io is referred to as a \u201cheat pipe system.\u201d Magma rises to the surface, erupts, cools, and then sinks again to continue the cycle. This process provides material that keeps Io\u2019s interior extremely hot. The same mechanism could also be responsible for the formation of Io’s massive mountains<\/a>, similar to those found on Earth due to tectonic forces rather than volcanic material buildup.<\/p>\n Prior to this eruption, scientists had not established how magma moves through Io\u2019s crust or whether distant volcanoes share a connection. This eruption has provided an important clue for researchers. Several newly discovered hot spots were detected at distances of 400 kilometres or more from one another, making coincidental eruptions extremely unlikely.<\/p>\n The research team has proposed that a magma network exists beneath Io\u2019s surface, potentially shaped like a sponge filled with molten pockets. A sudden surge of magma or a shift in subterranean compression may have triggered the simultaneous eruption of multiple hot spots.<\/p>\n What\u2019s Next For Io<\/p>\n