Figure 8-11 The Spectrum of a Simulated Planet The image on the left is a simulation of what infrared telescopes might see when looking for habitable planets. The white dot at the center is a nearby Sunlike star, and the smaller dots around it are planets orbiting the star. On the right is the simulated infrared spectrum of one of the planets, showing broad absorption lines of water vapor (H2O), ozone (O3), and carbon dioxide (CO2). While all these molecules can be created by nonbiological processes, the presence of life will change the relative amounts of each molecule in the planet’s atmosphere. Thus, the infrared spectrum of such planets will make it possible to identify worlds on which life may have evolved.