Juno uncovers buried heat beneath Io's volcanic crust

NASA’s Juno spacecraft used its Microwave Radiometer to measure heat beneath Io’s surface for the first time, finding temperatures rise sharply within a few feet of the crust (more than 40°F). The findings suggest a thin, porous surface layer and heat moving through Io’s crust that could result from conduction or cooling lava flows, offering new insights into tidal heating that powers Io’s volcanism and potentially informing heat processes on other worlds with buried oceans; future high-resolution observations could distinguish between conduction and lava-driven heating.