Jupiter's Great Red Spot - a hurricane three times bigger than Earth - is blasting the planet's upper atmosphere with heat, astronomers have found.
Using measurements from an infrared telescope in Hawaii, a UK and US team found evidence for temperatures as high as 1,500C - hundreds of degrees warmer than anywhere else on the planet.
They suggest the hotspot is created by thunderous soundwaves "breaking" in the thin upper reaches of the atmosphere.
The research is published in Nature.
It arguably solves what planetary scientists had dubbed an "energy crisis" for gas giants like Jupiter: temperatures in their upper atmospheres soar much higher than can be explained by solar energy - especially given their vast distances from the Sun.
If the mysterious heat were generated by local sources, like Jupiter's famous storm, then the conundrum would be solved - and these measurements are the first direct evidence of any such activity.
Study co-author Dr Tom Stallard, from the University of Leicester, said this was a major step forward in a "20-30 year odyssey" to try and understand heat flow on Jupiter.
"Ever since Voyager, we've had measurements of the temperature at the top of Jupiter's atmosphere, and it's been hot across the whole globe - from the poles, all the way to the equator," he told foreign media.