NASA's Chandra X-Ray Observatory, designed to observe X-rays from high energy regions of the universe, regularly releases images taken using the Advanced CCD Imaging Spectrometer (ACIS). This image shows a pulsar located exactly at the geometric center of the supernova remnant known as G11.2-0.3. The image is accompanied by a table giving the scale, category, coordinates, observation date and...

NOVA's Runaway Universe site is the companion Web site to the television program of the same name, which followed the efforts of two rival teams of astronomers as they search for exploding stars, map out gigantic cosmic patterns of galaxies, and grapple with the ultimate question: What is the fate of the universe? Visitors of the site will find an interactive timeline of the universe, learn what...