University of California
Center for Science Education: Gallery
A gallery of astronomy images which depict galaxies, comets, the moon, planets, nebulae, supernovae as seen in various regions of the electromagnetic spectrum. Each image in the gallery is described. Fascinating!
California Institute of Technology
Ipac: Iras Gallery
This site from IPAC is a series of images of various celestial objects and regions as viewed in infrared light. Each photo is accompanied by a caption.