NASA's Juno Probe Measures Heat Flowing From Deep Inside Volcanic Moon Io

NASA's Juno spacecraft used its Microwave Radiometer (MWR) during two flybys of Jupiter's volcanic moon Io to measure heat flowing from deep within the moon's interior. The instrument was originally designed to probe Jupiter's atmosphere but has been repurposed during Juno's extended mission. Io is the most volcanically active body in the Solar System.