Despite the claims of certain science fiction novels and films, humans cannot see in infrared. As many people know, the primary source of infrared radiation is heat, and the study of infrared astronomy allows scientists to detect radiation emitted from objects throughout the universe. This delightful website (created by NASA and the Infrared Processing and Analysis Center at the California Institute of Technology) provides a wide range of material on this fascinating area of scientific study. Visitors can lean about the discovery of infrared, learn about the technology that is used in such endeavors, and of course, look over dozens of infrared images and video clips. Educators will be glad to learn that there are a number of activities offered here for use in the classroom, including one that will help students learn how to build a photocell detector.