File:HD189733 11.jpg

Astronomers have measured the first-ever infrared spectrum of two planets orbiting distant Sun-like stars. The planet HD 189733b, shown here in an artist's rendering, appears to be missing common molecules like water and methane. Astronomers speculate that these molecules are present but hidden behind a high layer of silicate clouds. Credit: David A. Aguilar (CfA) Source is http://www.cfa.harvard.edu/press/2007/pr200703_images.html. Used with permission, see http://www.cfa.harvard.edu/policies/image_use.html