This Chandra X-ray Observatory image of the supernova remnant Cassiopeia A appears as a brilliant, roughly spherical pink, blue and green shell of glowing material with bright lines or veins sprinkled throughout, all resting on a solid black background. The image is a composite of different X-ray energy levels. The red, green, and blue regions in the image of Cassiopeia A show where the intensity of low, medium, and high-energy X-rays, respectively, is greatest. Pinkish-red material on the left outer edge is enriched in iron, whereas a bright greenish white region on the lower left is enriched in silicon and sulfur. In the blue region on the right edge, low and medium energy X-rays have been filtered out by a cloud of dust and gas in the remnant. At the center of the nebula is a tiny, bright dot, the compact object (a neutron star) left behind after the supernova.