About the cover
Spitzer Space Telescope observations, reported by Laughlin et al. this week, provide a first glimpse of time-varying ‘weather’ on an extrasolar planet. The cover image represents the calculated optical emission from the planet: the blue crescent is scattered starlight, and the colour arises from a combination of Raleigh scattering and absorption by alkali metal ions. The equatorial jet and high-latitude vortices on the night side are glowing with their own intrinsic thermal emission. [Image: D. Kasen.]
