Winds on tidally-locked planet
Studies of HD 189733b – discovered in 2005 transiting the star HD 189733, which lies some 63 light years from Earth in the constellation Vulpecula – have revealed that the planet has a mass of around 13 per cent greater than Jupiter's, but that it's 180 times closer to its sun than our own gas monster.
That, and the fact that it's tidally locked, mean that temperatures on the permanently sun-facing side hit 1,000°C, and a positively balmy 650°C on the dark side.
That's according to a 2007 observation by NASA's Spitzer Space Telescope, although later work by Swiss astronomers suggested temperatures in the upper atmosphere might reach a scorching 3,000°C.
Whatever the case, it's bloody hot, but the "mild" (as NASA puts it) temperature variation between the planet's lit and unlit sides mean that winds are likely distributing heat around the planet.