ENVIRONMENT

NASA’s Juno Spacecraft Probes Heat Below Io’s Surface

Juno’s Microwave Radiometer data reveals heat emanating from beneath Jupiter’s moon Io.

30 July 2026 · 05:17 · 1 sources

On July 22, 2026, NASA shared new findings from the Juno spacecraft's Microwave Radiometer (MWR) instrument regarding Jupiter's moon Io. The MWR’s lowest frequency channels, operating at 0.6 and 1.25 gigahertz, have the capability to penetrate the surface, detecting heat rising from beneath Io’s crust to depths of several meters. This data complements infrared measurements, which capture surface temperatures, by providing insights into subsurface thermal activity on Io.

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NASA Environment — NASA’s Juno Peers Beneath Io’s Surface

THE QUESTIONS THIS EVENT LEAVES BEHIND

NASA’s Juno Spacecraft Probes Heat Below Io’s Surface

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What geological processes on Io could cause heat to be detected several meters beneath its surface?

How might the detection of subsurface heat influence our understanding of Io’s volcanic activity?

What are the limitations of using microwave frequencies to probe beneath planetary surfaces?

How could future missions build on Juno’s findings to further investigate Io’s subsurface characteristics?

What impact does subsurface heat detection have on assessments of Io’s potential for hosting transient atmospheres or plumes?