Scientific American: Discovered in 2004, the super-Earth 55 Cancri e was thought to be a large rocky world with a thick, hot atmosphere. By mapping thermal changes of the planet's surface using the Spitzer Space Telescope, Brice-Olivier Demory of the University of Cambridge and his colleagues have now found that the planet is likely airless. The scientists discovered that the planet is tidally locked with its parent star, meaning that one side is perpetually covered in sunlight. The data from the telescope showed that the dark side of the planet reached temperatures of 1000 °C and that the lit side was more than twice as hot. If the planet had an atmosphere, winds would distribute the heat more evenly and minimize the temperature difference. However, the hottest spot on the planet is not directly in line with the star, suggesting that something is redistributing the heat. Demory's team believes that the hot spot, which is shifted eastward, is most likely caused by the movement of molten lava circulating heat from the dayside surface toward the nighttime one, where it cools and solidifies.
