A Wider View

On the Cover: Generations of stars glow in this infrared stellar "family tree" image taken by the Spitzer Space Telescope. This wispy, star-forming region, called W5, is about 6,500 light-years away in the constellation Cassiopeia. Here, the oldest stars are the blue dots in the hollow cavities (other blue dots are background and foreground stars not associated with the region). Younger stars line the cavity rims and show as pink at the ends of the pillars at upper right. White indicates star-forming areas, red shows heated dust that pervades the cavities, and green highlights dense clouds. For an expanded view of this image, visit http://www.spitzer.caltech.edu/Media/releases/ssc2008-15/ssc2008-15a.shtml.