Juno’s Microwave Vision Peers beneath Surface of Jupiter’s Volcanic Moon Io

NASA’s Juno spacecraft recently captured data revealing the internal thermal conditions of Jupiter’s moon Io. Known as the most volcanically active body in our solar system, Io undergoes constant gravitational stress that generates significant internal heat. Previously, scientists relied on infrared measurements that provided only a look at the surface skin temperature.

The research team used the Microwave Radiometer instrument on Juno to peer beneath the crust. These findings mark the first time researchers have measured temperatures below the surface of a volcanic moon. The data shows a temperature increase of more than 20 degrees Celsius within the top few meters of the surface.

The microwave observations also provided insights into the composition of the moon’s upper layer. The readings suggest the surface has a low density, similar to volcanic ash or porous pumice rather than solid rock. The study identifies two primary mechanisms for this heat: it is either rising steadily through a conducting crust or escaping through scattered patches of thin crust above lava flows and hot vents.

Dr. Scott Bolton, the principal investigator for the Juno mission, notes that this discovery has implications for understanding volcanoes on Earth. By applying similar microwave sensing techniques to terrestrial volcanoes, researchers can gain a clearer understanding of subsurface heat gradients. This data serves as a bridge for comparing geological processes across different worlds in the solar system.