Volume 16, Number 115
Winter 2006

Cover: An infrared image from NASA’s Spitzer Space Telescope shows hundreds of thousands of stars crowded into the swirling core of our spiral Milky Way galaxy. In visible-light pictures, this region cannot be seen at all because dust lying between earth and the galactic center blocks our view. The vertical span is 890 light-years and the horizontal span is 640 light-years. The plane of the Milky Way runs vertically through the center of the photo.