Artist’s impression of Jupiter’s GRS heating the upper atmosphere. Researchers from Boston University’s (BU) Center for Space Physics report today in Nature that Jupiter’s Great Red Spot may provide the mysterious source of energy required to heat the planet’s upper atmosphere to the unusually high values observed. Sunlight reaching Earth efficiently heats the terrestrial atmosphere at altitudes well above the surface—even at 400 miles high, for example, where the International Space Station orbits. Jupiter is over five times more distant from the Sun, and yet its upper atmosphere has temperatures, on average, comparable to those found at Earth. The sources of the non-solar energy responsible for this extra heating have remained elusive to scientists studying processes in the outer solar system.